Weird Weather Encounter
07-10-2022, 01:23 PM
#21
Disinterested Third Party
Joined APC: Jun 2012
Posts: 6,026
Weather penetration should never be predicated on the color on the radar screen, alone. It's a given that on a magenta-colored return, penetrating the core into level 5-6 weather is extremely hazardous and shouldn't be done, but the black space beyond that magenta return might be much worse. In that case, the heavy precipitation in the magenta area may be attenuating what lies beyond; simply because it isn't painting yet doesn't mean there's nothing there. The point is that it's important to consider the total, or big picture, which involves situational awareness, use of tilt, gain (where appropriate), and an understanding of weather theory, as well as actual reported and forecast conditions. Frozen precipitation doesn't paint well, but can be extremely hazardous. Precipitation can come from above, or below. Rising air on the upshear, or upwind side of a cell, can be equally hazardous to the descending air in or on the downwind or downshear side of the cell. Weather won't paint in an overhang in many cases, but there may still be hazards there, such as hail. In fact, regarding color, one might see a green return along an overhang, but encounter hail significant enough to shatter radomes, windscreens, or damage or shut down engines.
When looking at a return, look at the winds aloft, both forecast and what you're seeing in real-time as provided by your instrument data (bearing in mind that what you see right now may not be what's going on when you get closer to the cell (especially if the cell lies on a frontal boundary). Mild colors and level 1-2 returns (green), or 3 (yellow) may be indicating downwind of the cell, but may in fact be quite hazardous, despite fairly benign returns.
Look at your range and altitude, and tilt. When there's weather, move that tilt around; see what is above and below. If I'm sitting at 35,000', I might put the bottom of my radar beam at 80 miles; what's seen beyond 80 miles may actually be below me, as I'm looking down through the weather. If it stays a threat inside of 80 miles, especially inside 40, deviation is warranted, but it's well to keep in mind that the the weather is dynamic and over a short time it can change considerably. As noted before, the rising column of air that rolled me, with shaker and pusher, was approximatley 12,000 feet per minute vertical rate. What was below moments ago may. now be above. A few days ago I got video of a cell ahead of us that was below, and grew well above us at 35,000, as we approached. Setting tilt is useful in cruise, but varying tilt not only when working around or approaching weather, but when in cruise, is also not only useful, but important, as is understanding what that tilt is doing and what's being displayed as a result.
Most radars have auto squelch or auto gain settings, as well as variable gain. I see a lot of guys who take their radar off the auto setting (where it should be, most of the time), and play with it, not knowing what they're doing. What your'e seeing when you'e made manual adjustments can't be compared to what you would have seen in auto, and can lead to some bad choices.
Your question is about penetrating green and yellow returns; setting aside that not all radars display or provide the same information, and older radars (monochromatic) don't feature color coding, yellow and green provide a scale of dbz returns (decibels). Where are they in relation to the cell(s)? Are they changing? How do they change as you tilt up or down? Are you in freezing conditions, or are you looking up or down into freezing conditions? Might you be looking at frozen precipitation, which gives a lesser return? If it's got velocity but is frozen, you may be looking at hail or other dangerous precip that may also have high velocity. Alternate the use of turbulence settings, which give some measure of velocity of precipitation; it may also change your perception of what you're seeing. If the yellow and green is wide or narrow, this may also give an important clue as to what it contains; a narrow band of yellow and green next to a red or magenta return might indicate a rapidly changing gradient in moisture content, and provide some clue as to intensity, but simply because that's where the moisture stops (at the edge of the return) doesn't mean that's where the weather or hazards begin or end. Going between two cells can be quite hazardous.
If you're talking about green or yellow returns on their own, not associated with other weather (such as a defined cell), then the yellow may represent the areas of avoidance, but it won't be linear looking up and down. It may move as you tilt, meaning the column of rising or descending air is also tilted, typically with the wind. Remember that wind doesn't blow a cell, but blows through a cell; it's constantly forming and dissipating, even though it looks like a cell defined by the visual appearance of the clouds. Air is blowing through it; wind is blowing through it. Air may be rising or descending on either side; typically it's rising on the upwind, or upshear side of the cell, though not necessarily, and not uncommonly, the air is descending on the downwind side...though again, not necessarily. The yellow return identifying an area with greater moisture content (and energy) may show a base in a different location than upper levels as you adjust your tilt; typically this will lean the same direction as the winds, but bear in mind that wind direction and velocity changes with altitude and other factors. Look for changes in the return with time, especially significant changes in a short period. What looks like a harmless return may not be in a few minutes.
Vertical velocity is cumulative; a parcel of air rising at 1,200 fpm hits a parcel of air rising at 500 fpm, and may shortly be doing 1,700 fpm. The addition or loss of moisture and the increase or release of energy imparts changes in vertical velocity that can cause rapid changes.
Icing should be considered, and viewed as multiple potential threats. Engine icing is different than structural airframe icing, and frozen precipitation another threat; all are considerations when looking at radar returns. Is the return benign because there's nothing there, or because it's frozen, and if it is frozen, it it frozen at higher altitudes, falling? Frozen at lower altitudes, rising? I see a lot of assumptions in the cockpit about icing and the state of precipitation; most notably, that it's too cold to be liquid. No, it's not. Look out the window at that cell at 35,000' and see if it's sharply defined puffiness, or more of a cottony, fluffy look...the latter is usually glaciated (but can still quickly ice an engine under the right circumstances); the former has liquid precip, or should be presumed to have liquid or supercooled precip; it can change state rapidly and that may be deceptive on radar, too. The worst Icing I've encountered on research flights has been around -15C, typically with high moisture contents (around two grams of moisture per cubic centimeter, though you won't be able to tell that with conventional instrumentation). I've seen it build rapidly enough I can see it move, inside fairly mild returns without an actual falling precip..the moisture is in there, and the cloud has a lot of energy, but it's got a mild return...good place for ice, under the right circumstances. Same for flight above cells, or flight in ice crystals at higher altitudes, and those circumstances produce very mild returns.
Look at your circumstance. Do you have a bleed inoperative or an engine shut down? That should temper your thinking regarding what you're seeing, and is all the more reason to be active on the tilt as you explore not just a small cross section of the space ahead of you but above and below it. Get a good picture of what you're seeing; the dimensions and returns will change as you tilt. Make small, incremental changes, give time for a sweep or two, and look closely for changes from one sweep to the next, or over several sweeps.
When looking at a return, look at the winds aloft, both forecast and what you're seeing in real-time as provided by your instrument data (bearing in mind that what you see right now may not be what's going on when you get closer to the cell (especially if the cell lies on a frontal boundary). Mild colors and level 1-2 returns (green), or 3 (yellow) may be indicating downwind of the cell, but may in fact be quite hazardous, despite fairly benign returns.
Look at your range and altitude, and tilt. When there's weather, move that tilt around; see what is above and below. If I'm sitting at 35,000', I might put the bottom of my radar beam at 80 miles; what's seen beyond 80 miles may actually be below me, as I'm looking down through the weather. If it stays a threat inside of 80 miles, especially inside 40, deviation is warranted, but it's well to keep in mind that the the weather is dynamic and over a short time it can change considerably. As noted before, the rising column of air that rolled me, with shaker and pusher, was approximatley 12,000 feet per minute vertical rate. What was below moments ago may. now be above. A few days ago I got video of a cell ahead of us that was below, and grew well above us at 35,000, as we approached. Setting tilt is useful in cruise, but varying tilt not only when working around or approaching weather, but when in cruise, is also not only useful, but important, as is understanding what that tilt is doing and what's being displayed as a result.
Most radars have auto squelch or auto gain settings, as well as variable gain. I see a lot of guys who take their radar off the auto setting (where it should be, most of the time), and play with it, not knowing what they're doing. What your'e seeing when you'e made manual adjustments can't be compared to what you would have seen in auto, and can lead to some bad choices.
Your question is about penetrating green and yellow returns; setting aside that not all radars display or provide the same information, and older radars (monochromatic) don't feature color coding, yellow and green provide a scale of dbz returns (decibels). Where are they in relation to the cell(s)? Are they changing? How do they change as you tilt up or down? Are you in freezing conditions, or are you looking up or down into freezing conditions? Might you be looking at frozen precipitation, which gives a lesser return? If it's got velocity but is frozen, you may be looking at hail or other dangerous precip that may also have high velocity. Alternate the use of turbulence settings, which give some measure of velocity of precipitation; it may also change your perception of what you're seeing. If the yellow and green is wide or narrow, this may also give an important clue as to what it contains; a narrow band of yellow and green next to a red or magenta return might indicate a rapidly changing gradient in moisture content, and provide some clue as to intensity, but simply because that's where the moisture stops (at the edge of the return) doesn't mean that's where the weather or hazards begin or end. Going between two cells can be quite hazardous.
If you're talking about green or yellow returns on their own, not associated with other weather (such as a defined cell), then the yellow may represent the areas of avoidance, but it won't be linear looking up and down. It may move as you tilt, meaning the column of rising or descending air is also tilted, typically with the wind. Remember that wind doesn't blow a cell, but blows through a cell; it's constantly forming and dissipating, even though it looks like a cell defined by the visual appearance of the clouds. Air is blowing through it; wind is blowing through it. Air may be rising or descending on either side; typically it's rising on the upwind, or upshear side of the cell, though not necessarily, and not uncommonly, the air is descending on the downwind side...though again, not necessarily. The yellow return identifying an area with greater moisture content (and energy) may show a base in a different location than upper levels as you adjust your tilt; typically this will lean the same direction as the winds, but bear in mind that wind direction and velocity changes with altitude and other factors. Look for changes in the return with time, especially significant changes in a short period. What looks like a harmless return may not be in a few minutes.
Vertical velocity is cumulative; a parcel of air rising at 1,200 fpm hits a parcel of air rising at 500 fpm, and may shortly be doing 1,700 fpm. The addition or loss of moisture and the increase or release of energy imparts changes in vertical velocity that can cause rapid changes.
Icing should be considered, and viewed as multiple potential threats. Engine icing is different than structural airframe icing, and frozen precipitation another threat; all are considerations when looking at radar returns. Is the return benign because there's nothing there, or because it's frozen, and if it is frozen, it it frozen at higher altitudes, falling? Frozen at lower altitudes, rising? I see a lot of assumptions in the cockpit about icing and the state of precipitation; most notably, that it's too cold to be liquid. No, it's not. Look out the window at that cell at 35,000' and see if it's sharply defined puffiness, or more of a cottony, fluffy look...the latter is usually glaciated (but can still quickly ice an engine under the right circumstances); the former has liquid precip, or should be presumed to have liquid or supercooled precip; it can change state rapidly and that may be deceptive on radar, too. The worst Icing I've encountered on research flights has been around -15C, typically with high moisture contents (around two grams of moisture per cubic centimeter, though you won't be able to tell that with conventional instrumentation). I've seen it build rapidly enough I can see it move, inside fairly mild returns without an actual falling precip..the moisture is in there, and the cloud has a lot of energy, but it's got a mild return...good place for ice, under the right circumstances. Same for flight above cells, or flight in ice crystals at higher altitudes, and those circumstances produce very mild returns.
Look at your circumstance. Do you have a bleed inoperative or an engine shut down? That should temper your thinking regarding what you're seeing, and is all the more reason to be active on the tilt as you explore not just a small cross section of the space ahead of you but above and below it. Get a good picture of what you're seeing; the dimensions and returns will change as you tilt. Make small, incremental changes, give time for a sweep or two, and look closely for changes from one sweep to the next, or over several sweeps.
07-10-2022, 02:50 PM
#22
Gets Weekends Off
Joined APC: May 2014
Posts: 171
Originally Posted by JohnBurke
Weather penetration should never be predicated on the color on the radar screen, alone. It's a given that on a magenta-colored return, penetrating the core into level 5-6 weather is extremely hazardous and shouldn't be done, but the black space beyond that magenta return might be much worse. In that case, the heavy precipitation in the magenta area may be attenuating what lies beyond; simply because it isn't painting yet doesn't mean there's nothing there. The point is that it's important to consider the total, or big picture, which involves situational awareness, use of tilt, gain (where appropriate), and an understanding of weather theory, as well as actual reported and forecast conditions. Frozen precipitation doesn't paint well, but can be extremely hazardous. Precipitation can come from above, or below. Rising air on the upshear, or upwind side of a cell, can be equally hazardous to the descending air in or on the downwind or downshear side of the cell. Weather won't paint in an overhang in many cases, but there may still be hazards there, such as hail. In fact, regarding color, one might see a green return along an overhang, but encounter hail significant enough to shatter radomes, windscreens, or damage or shut down engines.
When looking at a return, look at the winds aloft, both forecast and what you're seeing in real-time as provided by your instrument data (bearing in mind that what you see right now may not be what's going on when you get closer to the cell (especially if the cell lies on a frontal boundary). Mild colors and level 1-2 returns (green), or 3 (yellow) may be indicating downwind of the cell, but may in fact be quite hazardous, despite fairly benign returns.
Look at your range and altitude, and tilt. When there's weather, move that tilt around; see what is above and below. If I'm sitting at 35,000', I might put the bottom of my radar beam at 80 miles; what's seen beyond 80 miles may actually be below me, as I'm looking down through the weather. If it stays a threat inside of 80 miles, especially inside 40, deviation is warranted, but it's well to keep in mind that the the weather is dynamic and over a short time it can change considerably. As noted before, the rising column of air that rolled me, with shaker and pusher, was approximatley 12,000 feet per minute vertical rate. What was below moments ago may. now be above. A few days ago I got video of a cell ahead of us that was below, and grew well above us at 35,000, as we approached. Setting tilt is useful in cruise, but varying tilt not only when working around or approaching weather, but when in cruise, is also not only useful, but important, as is understanding what that tilt is doing and what's being displayed as a result.
Most radars have auto squelch or auto gain settings, as well as variable gain. I see a lot of guys who take their radar off the auto setting (where it should be, most of the time), and play with it, not knowing what they're doing. What your'e seeing when you'e made manual adjustments can't be compared to what you would have seen in auto, and can lead to some bad choices.
Your question is about penetrating green and yellow returns; setting aside that not all radars display or provide the same information, and older radars (monochromatic) don't feature color coding, yellow and green provide a scale of dbz returns (decibels). Where are they in relation to the cell(s)? Are they changing? How do they change as you tilt up or down? Are you in freezing conditions, or are you looking up or down into freezing conditions? Might you be looking at frozen precipitation, which gives a lesser return? If it's got velocity but is frozen, you may be looking at hail or other dangerous precip that may also have high velocity. Alternate the use of turbulence settings, which give some measure of velocity of precipitation; it may also change your perception of what you're seeing. If the yellow and green is wide or narrow, this may also give an important clue as to what it contains; a narrow band of yellow and green next to a red or magenta return might indicate a rapidly changing gradient in moisture content, and provide some clue as to intensity, but simply because that's where the moisture stops (at the edge of the return) doesn't mean that's where the weather or hazards begin or end. Going between two cells can be quite hazardous.
If you're talking about green or yellow returns on their own, not associated with other weather (such as a defined cell), then the yellow may represent the areas of avoidance, but it won't be linear looking up and down. It may move as you tilt, meaning the column of rising or descending air is also tilted, typically with the wind. Remember that wind doesn't blow a cell, but blows through a cell; it's constantly forming and dissipating, even though it looks like a cell defined by the visual appearance of the clouds. Air is blowing through it; wind is blowing through it. Air may be rising or descending on either side; typically it's rising on the upwind, or upshear side of the cell, though not necessarily, and not uncommonly, the air is descending on the downwind side...though again, not necessarily. The yellow return identifying an area with greater moisture content (and energy) may show a base in a different location than upper levels as you adjust your tilt; typically this will lean the same direction as the winds, but bear in mind that wind direction and velocity changes with altitude and other factors. Look for changes in the return with time, especially significant changes in a short period. What looks like a harmless return may not be in a few minutes.
Vertical velocity is cumulative; a parcel of air rising at 1,200 fpm hits a parcel of air rising at 500 fpm, and may shortly be doing 1,700 fpm. The addition or loss of moisture and the increase or release of energy imparts changes in vertical velocity that can cause rapid changes.
Icing should be considered, and viewed as multiple potential threats. Engine icing is different than structural airframe icing, and frozen precipitation another threat; all are considerations when looking at radar returns. Is the return benign because there's nothing there, or because it's frozen, and if it is frozen, it it frozen at higher altitudes, falling? Frozen at lower altitudes, rising? I see a lot of assumptions in the cockpit about icing and the state of precipitation; most notably, that it's too cold to be liquid. No, it's not. Look out the window at that cell at 35,000' and see if it's sharply defined puffiness, or more of a cottony, fluffy look...the latter is usually glaciated (but can still quickly ice an engine under the right circumstances); the former has liquid precip, or should be presumed to have liquid or supercooled precip; it can change state rapidly and that may be deceptive on radar, too. The worst Icing I've encountered on research flights has been around -15C, typically with high moisture contents (around two grams of moisture per cubic centimeter, though you won't be able to tell that with conventional instrumentation). I've seen it build rapidly enough I can see it move, inside fairly mild returns without an actual falling precip..the moisture is in there, and the cloud has a lot of energy, but it's got a mild return...good place for ice, under the right circumstances. Same for flight above cells, or flight in ice crystals at higher altitudes, and those circumstances produce very mild returns.
Look at your circumstance. Do you have a bleed inoperative or an engine shut down? That should temper your thinking regarding what you're seeing, and is all the more reason to be active on the tilt as you explore not just a small cross section of the space ahead of you but above and below it. Get a good picture of what you're seeing; the dimensions and returns will change as you tilt. Make small, incremental changes, give time for a sweep or two, and look closely for changes from one sweep to the next, or over several sweeps.
When looking at a return, look at the winds aloft, both forecast and what you're seeing in real-time as provided by your instrument data (bearing in mind that what you see right now may not be what's going on when you get closer to the cell (especially if the cell lies on a frontal boundary). Mild colors and level 1-2 returns (green), or 3 (yellow) may be indicating downwind of the cell, but may in fact be quite hazardous, despite fairly benign returns.
Look at your range and altitude, and tilt. When there's weather, move that tilt around; see what is above and below. If I'm sitting at 35,000', I might put the bottom of my radar beam at 80 miles; what's seen beyond 80 miles may actually be below me, as I'm looking down through the weather. If it stays a threat inside of 80 miles, especially inside 40, deviation is warranted, but it's well to keep in mind that the the weather is dynamic and over a short time it can change considerably. As noted before, the rising column of air that rolled me, with shaker and pusher, was approximatley 12,000 feet per minute vertical rate. What was below moments ago may. now be above. A few days ago I got video of a cell ahead of us that was below, and grew well above us at 35,000, as we approached. Setting tilt is useful in cruise, but varying tilt not only when working around or approaching weather, but when in cruise, is also not only useful, but important, as is understanding what that tilt is doing and what's being displayed as a result.
Most radars have auto squelch or auto gain settings, as well as variable gain. I see a lot of guys who take their radar off the auto setting (where it should be, most of the time), and play with it, not knowing what they're doing. What your'e seeing when you'e made manual adjustments can't be compared to what you would have seen in auto, and can lead to some bad choices.
Your question is about penetrating green and yellow returns; setting aside that not all radars display or provide the same information, and older radars (monochromatic) don't feature color coding, yellow and green provide a scale of dbz returns (decibels). Where are they in relation to the cell(s)? Are they changing? How do they change as you tilt up or down? Are you in freezing conditions, or are you looking up or down into freezing conditions? Might you be looking at frozen precipitation, which gives a lesser return? If it's got velocity but is frozen, you may be looking at hail or other dangerous precip that may also have high velocity. Alternate the use of turbulence settings, which give some measure of velocity of precipitation; it may also change your perception of what you're seeing. If the yellow and green is wide or narrow, this may also give an important clue as to what it contains; a narrow band of yellow and green next to a red or magenta return might indicate a rapidly changing gradient in moisture content, and provide some clue as to intensity, but simply because that's where the moisture stops (at the edge of the return) doesn't mean that's where the weather or hazards begin or end. Going between two cells can be quite hazardous.
If you're talking about green or yellow returns on their own, not associated with other weather (such as a defined cell), then the yellow may represent the areas of avoidance, but it won't be linear looking up and down. It may move as you tilt, meaning the column of rising or descending air is also tilted, typically with the wind. Remember that wind doesn't blow a cell, but blows through a cell; it's constantly forming and dissipating, even though it looks like a cell defined by the visual appearance of the clouds. Air is blowing through it; wind is blowing through it. Air may be rising or descending on either side; typically it's rising on the upwind, or upshear side of the cell, though not necessarily, and not uncommonly, the air is descending on the downwind side...though again, not necessarily. The yellow return identifying an area with greater moisture content (and energy) may show a base in a different location than upper levels as you adjust your tilt; typically this will lean the same direction as the winds, but bear in mind that wind direction and velocity changes with altitude and other factors. Look for changes in the return with time, especially significant changes in a short period. What looks like a harmless return may not be in a few minutes.
Vertical velocity is cumulative; a parcel of air rising at 1,200 fpm hits a parcel of air rising at 500 fpm, and may shortly be doing 1,700 fpm. The addition or loss of moisture and the increase or release of energy imparts changes in vertical velocity that can cause rapid changes.
Icing should be considered, and viewed as multiple potential threats. Engine icing is different than structural airframe icing, and frozen precipitation another threat; all are considerations when looking at radar returns. Is the return benign because there's nothing there, or because it's frozen, and if it is frozen, it it frozen at higher altitudes, falling? Frozen at lower altitudes, rising? I see a lot of assumptions in the cockpit about icing and the state of precipitation; most notably, that it's too cold to be liquid. No, it's not. Look out the window at that cell at 35,000' and see if it's sharply defined puffiness, or more of a cottony, fluffy look...the latter is usually glaciated (but can still quickly ice an engine under the right circumstances); the former has liquid precip, or should be presumed to have liquid or supercooled precip; it can change state rapidly and that may be deceptive on radar, too. The worst Icing I've encountered on research flights has been around -15C, typically with high moisture contents (around two grams of moisture per cubic centimeter, though you won't be able to tell that with conventional instrumentation). I've seen it build rapidly enough I can see it move, inside fairly mild returns without an actual falling precip..the moisture is in there, and the cloud has a lot of energy, but it's got a mild return...good place for ice, under the right circumstances. Same for flight above cells, or flight in ice crystals at higher altitudes, and those circumstances produce very mild returns.
Look at your circumstance. Do you have a bleed inoperative or an engine shut down? That should temper your thinking regarding what you're seeing, and is all the more reason to be active on the tilt as you explore not just a small cross section of the space ahead of you but above and below it. Get a good picture of what you're seeing; the dimensions and returns will change as you tilt. Make small, incremental changes, give time for a sweep or two, and look closely for changes from one sweep to the next, or over several sweeps.
When you say you set the bottom of your radar beam at 80 miles. Does this mean you put your range at 80 miles and then tilt to paint a small amount of ground clutter at that range? FWIW the radar I use is in the CRJ 700 (I believe the beam width is 7 degrees, but I have no documentation anywhere to confirm that - this is quite a bit wider than that of larger airliners with a 3 degree beam width, I think).
07-10-2022, 07:42 PM
#23
Disinterested Third Party
Joined APC: Jun 2012
Posts: 6,026
The easiest way to set the bottom of your beam at a range is to set the next highest range, so say, 160 miles. The 80 mile arc will be in the middle of the display, or half-way up the display. Tilt your beam down until your see tickles of ground return near the 80 mile line, and you've got the bottom of your beam at eighty miles.
If you think of this like your car headlight, which projects from a single point on your vehicle, looking forward, the light projects out in a cone-shape, pointy end of the cone at the light, extending outward and expanding away from your vehicle. Radar works in a similar fashion, so you may envision your car headlight projecting a beam forward, and the point where it first directly illuminates the ground is the bottom of the headlight beam. Likewise for your radar. From that point, moving forward, or down range, you're looking down to the ground, through anything in the air.
Objects that aren't in the beam must be progressively lower, the closer you get to the bottom of the beam, so if you're set the tilt to paint ground returns at 80 miles, what's beyond it is in the beam, what's just shy of 80 miles can be a little above ground and not get painted, and what's directly under you can be nearly as tall as you are and not get painted ("painted" meaning you see a return on the radar, or in other words, the object is reflective of the radar, and it's in the beam). Beyond the beam, objects from the surface to a much higher altitude, can be detected. Because when you're in cruise, most weather comes from the surface and goes up, starting looking at the ground, upward, is a wise choice. Precip will be falling, storms building upward, etc. It's a good place to detect storms, and the most reflective (wet) parts of the storms will be the lowest parts, like looking for the roots of a tree to know there's a tree above it. You'll paint a lot of the tree, or the storm, as well.
Where this becomes useful is as you move forward, the object that you painted beyond 80 miles, may be tall enough to stay in your beam, or it may have been a shorter object which will eventually not be tall enough to be directly illuminated; it will appear to weaken and then disappear, as you approach it. This suggests weather well below youIf the weather continues to be clear and well defined, and especially if it grows at say, 40 miles, it's time to be thinking about which way you'll be deviating based on surrounding activity, winds, etc...try to go upwind, but try not to go between other cells that are close or building, etc. This is where you have to look at the total picture and begin to form a plan.
I see a lot of radar users who throw their range display out to 320 (or farther) and tilt the radar up, or use a 1 or 0 or -1 setting for tilt (the tilt numbers aren't actually telling you where true zero is...that's something you have to establish on your own). This is false confidence, and while it may illuminate something of marginal use, it's not providing what they may think it is. As distance increases, so does attenuation, such that the information that comes back needs re-interpretation, or it may be deceptive. Zero, incidentally, is a value that assumes the center of the beam at the horizon. On your display, the radar is a two dimensional wedge that lays flat, extending away from your radome, so many degrees left or right, but it also extends up and down, too, and it has a bottom edge and an upper edge, of the cone, and one can envision an imaginary middle of the cone...that's where the tilt number comes in. Despite gyro stabilization and other neat tricks, the nature of radar installation, and aircraft pitch and attitude, and other factors, the true zero of the radar beam usually doesn't coincide with the number you see on your display in the cockpit.
Knowing cone or beam width and angle and distance and finding true zero are elements of making an accurate determination of storm tops and bases...something that's not really taught any more, and which takes some time to go over (and depends on what you're flying and the radar installed, dish or plate size, etc). Mostly we use radar to get the picture of what's out there and go around it, without getting too fancy, and that's generally a good plan. My personal use in cruise over long distances when I'm not examining something specific is to park the beam lower edge at 80, and watch to see what appears...and then begin tilting and scanning and looking, as well as frequently ranging in and out, during the flight. Combined with as much preflight information as you can get, it's another tool for avoidance, rather than penetration, and that should be emphasized. Today pilots are not given adequate training to analyze storms, and I don't think they necessarily should be: our emphasis is rightfully on avoiding storms and convective activity.
Sometimes we find ourselves in places with a lot of activity, and at that point, we are looking to get around or through, even if it's an escape path. In such a case, the single biggest thing we need to understand is attenuation. Your car headlight has only so much light to throw out there. It can get diffused and not go as far, or absorbed, or reflected back, such as driving in fog, or near road signs, or obstacles, and it may not illuminate as far down the road as you might hope. You could see an object in the headlights, and think you've got the big picture, but you really don't, because too much light is being reflected back. You come up on some road construction, and all the reflective signs throw a lot of light back in your face, so much so that you don't see the deer or moose standing just beyond, or in the construction. In radar terms, this is a "radar shadow," where some of the reflective (moist) weather has reflected or absorbed or diffused so much of our radar energy that we don't see what's laying beyond, and it looks clear, or black, on our display. Any time you see a clear area just beyond what you're painting, suspect that there's something you're not seeing in that clear area. If the plan is to squeeze through that gap then zig back on course into that clear area, don't be surprised that you've fallen into a trap and that worse weather lays beyond...hidden by what you were just avoiding. Attenuation.
Another issue that's not discussed much at all is that radar units not are used infrequently. This might be the case with an aircraft that isn't pulled out of the hangar often (corporate airplane, for example), or may be the case with an aircraft equipped with more than one radar unit). Not so true of newer radars, but very true of older radars, the equipment itself, specifically the magnatron, requires frequent use or it looses efficiency; some older radars might require use within a month or might need component replacement. Few seem aware of this today; energizing of those components affects the efficiency and viability of those components, and if they sit for too long, they won't tell you what you think they should be telling you. Older weather radar in particular is very much a use-it-or-lose-it proposition.
Another issue that I've seen has been radome transmissibility; radomes are usually a honeycomb material, which means they're fiberglass layers over an expanded matrix that acts as a filler or stiffener or thickener of the radome, usually shaped like honecomb cells in a beehive. These cells are hollow and if pin holes develop in the radar, the honecomb holds moisture, which is reflective to radar. If you start seeing lobes or lines appear on your radar, or inverse lobes, seen as streaks of color away from the radar beam center, or streaks of dark, these may be signs of moisture in the radome, and should be reported to maintenance; they can hide airborne returns, or reflect high levels of energy back to the radar system; one is deceptive, the other potentially harmful, but requires maintenance. This can occur as a result of deterioration, lightning strikes, physical damage, inadequate repair work, etc, and should be noted when using the radar. Remember, the guys in the hangar don't operate it, and don't see what you see. The only chance to catch such stuff may be when you're using it operationally. Be as detailed as you can in your description.
If you think of this like your car headlight, which projects from a single point on your vehicle, looking forward, the light projects out in a cone-shape, pointy end of the cone at the light, extending outward and expanding away from your vehicle. Radar works in a similar fashion, so you may envision your car headlight projecting a beam forward, and the point where it first directly illuminates the ground is the bottom of the headlight beam. Likewise for your radar. From that point, moving forward, or down range, you're looking down to the ground, through anything in the air.
Objects that aren't in the beam must be progressively lower, the closer you get to the bottom of the beam, so if you're set the tilt to paint ground returns at 80 miles, what's beyond it is in the beam, what's just shy of 80 miles can be a little above ground and not get painted, and what's directly under you can be nearly as tall as you are and not get painted ("painted" meaning you see a return on the radar, or in other words, the object is reflective of the radar, and it's in the beam). Beyond the beam, objects from the surface to a much higher altitude, can be detected. Because when you're in cruise, most weather comes from the surface and goes up, starting looking at the ground, upward, is a wise choice. Precip will be falling, storms building upward, etc. It's a good place to detect storms, and the most reflective (wet) parts of the storms will be the lowest parts, like looking for the roots of a tree to know there's a tree above it. You'll paint a lot of the tree, or the storm, as well.
Where this becomes useful is as you move forward, the object that you painted beyond 80 miles, may be tall enough to stay in your beam, or it may have been a shorter object which will eventually not be tall enough to be directly illuminated; it will appear to weaken and then disappear, as you approach it. This suggests weather well below youIf the weather continues to be clear and well defined, and especially if it grows at say, 40 miles, it's time to be thinking about which way you'll be deviating based on surrounding activity, winds, etc...try to go upwind, but try not to go between other cells that are close or building, etc. This is where you have to look at the total picture and begin to form a plan.
I see a lot of radar users who throw their range display out to 320 (or farther) and tilt the radar up, or use a 1 or 0 or -1 setting for tilt (the tilt numbers aren't actually telling you where true zero is...that's something you have to establish on your own). This is false confidence, and while it may illuminate something of marginal use, it's not providing what they may think it is. As distance increases, so does attenuation, such that the information that comes back needs re-interpretation, or it may be deceptive. Zero, incidentally, is a value that assumes the center of the beam at the horizon. On your display, the radar is a two dimensional wedge that lays flat, extending away from your radome, so many degrees left or right, but it also extends up and down, too, and it has a bottom edge and an upper edge, of the cone, and one can envision an imaginary middle of the cone...that's where the tilt number comes in. Despite gyro stabilization and other neat tricks, the nature of radar installation, and aircraft pitch and attitude, and other factors, the true zero of the radar beam usually doesn't coincide with the number you see on your display in the cockpit.
Knowing cone or beam width and angle and distance and finding true zero are elements of making an accurate determination of storm tops and bases...something that's not really taught any more, and which takes some time to go over (and depends on what you're flying and the radar installed, dish or plate size, etc). Mostly we use radar to get the picture of what's out there and go around it, without getting too fancy, and that's generally a good plan. My personal use in cruise over long distances when I'm not examining something specific is to park the beam lower edge at 80, and watch to see what appears...and then begin tilting and scanning and looking, as well as frequently ranging in and out, during the flight. Combined with as much preflight information as you can get, it's another tool for avoidance, rather than penetration, and that should be emphasized. Today pilots are not given adequate training to analyze storms, and I don't think they necessarily should be: our emphasis is rightfully on avoiding storms and convective activity.
Sometimes we find ourselves in places with a lot of activity, and at that point, we are looking to get around or through, even if it's an escape path. In such a case, the single biggest thing we need to understand is attenuation. Your car headlight has only so much light to throw out there. It can get diffused and not go as far, or absorbed, or reflected back, such as driving in fog, or near road signs, or obstacles, and it may not illuminate as far down the road as you might hope. You could see an object in the headlights, and think you've got the big picture, but you really don't, because too much light is being reflected back. You come up on some road construction, and all the reflective signs throw a lot of light back in your face, so much so that you don't see the deer or moose standing just beyond, or in the construction. In radar terms, this is a "radar shadow," where some of the reflective (moist) weather has reflected or absorbed or diffused so much of our radar energy that we don't see what's laying beyond, and it looks clear, or black, on our display. Any time you see a clear area just beyond what you're painting, suspect that there's something you're not seeing in that clear area. If the plan is to squeeze through that gap then zig back on course into that clear area, don't be surprised that you've fallen into a trap and that worse weather lays beyond...hidden by what you were just avoiding. Attenuation.
Another issue that's not discussed much at all is that radar units not are used infrequently. This might be the case with an aircraft that isn't pulled out of the hangar often (corporate airplane, for example), or may be the case with an aircraft equipped with more than one radar unit). Not so true of newer radars, but very true of older radars, the equipment itself, specifically the magnatron, requires frequent use or it looses efficiency; some older radars might require use within a month or might need component replacement. Few seem aware of this today; energizing of those components affects the efficiency and viability of those components, and if they sit for too long, they won't tell you what you think they should be telling you. Older weather radar in particular is very much a use-it-or-lose-it proposition.
Another issue that I've seen has been radome transmissibility; radomes are usually a honeycomb material, which means they're fiberglass layers over an expanded matrix that acts as a filler or stiffener or thickener of the radome, usually shaped like honecomb cells in a beehive. These cells are hollow and if pin holes develop in the radar, the honecomb holds moisture, which is reflective to radar. If you start seeing lobes or lines appear on your radar, or inverse lobes, seen as streaks of color away from the radar beam center, or streaks of dark, these may be signs of moisture in the radome, and should be reported to maintenance; they can hide airborne returns, or reflect high levels of energy back to the radar system; one is deceptive, the other potentially harmful, but requires maintenance. This can occur as a result of deterioration, lightning strikes, physical damage, inadequate repair work, etc, and should be noted when using the radar. Remember, the guys in the hangar don't operate it, and don't see what you see. The only chance to catch such stuff may be when you're using it operationally. Be as detailed as you can in your description.
07-10-2022, 08:40 PM
#24
Gets Weekends Off
Joined APC: May 2014
Posts: 171
Originally Posted by JohnBurke
The easiest way to set the bottom of your beam at a range is to set the next highest range, so say, 160 miles. The 80 mile arc will be in the middle of the display, or half-way up the display. Tilt your beam down until your see tickles of ground return near the 80 mile line, and you've got the bottom of your beam at eighty miles.
If you think of this like your car headlight, which projects from a single point on your vehicle, looking forward, the light projects out in a cone-shape, pointy end of the cone at the light, extending outward and expanding away from your vehicle. Radar works in a similar fashion, so you may envision your car headlight projecting a beam forward, and the point where it first directly illuminates the ground is the bottom of the headlight beam. Likewise for your radar. From that point, moving forward, or down range, you're looking down to the ground, through anything in the air.
Objects that aren't in the beam must be progressively lower, the closer you get to the bottom of the beam, so if you're set the tilt to paint ground returns at 80 miles, what's beyond it is in the beam, what's just shy of 80 miles can be a little above ground and not get painted, and what's directly under you can be nearly as tall as you are and not get painted ("painted" meaning you see a return on the radar, or in other words, the object is reflective of the radar, and it's in the beam). Beyond the beam, objects from the surface to a much higher altitude, can be detected. Because when you're in cruise, most weather comes from the surface and goes up, starting looking at the ground, upward, is a wise choice. Precip will be falling, storms building upward, etc. It's a good place to detect storms, and the most reflective (wet) parts of the storms will be the lowest parts, like looking for the roots of a tree to know there's a tree above it. You'll paint a lot of the tree, or the storm, as well.
Where this becomes useful is as you move forward, the object that you painted beyond 80 miles, may be tall enough to stay in your beam, or it may have been a shorter object which will eventually not be tall enough to be directly illuminated; it will appear to weaken and then disappear, as you approach it. This suggests weather well below youIf the weather continues to be clear and well defined, and especially if it grows at say, 40 miles, it's time to be thinking about which way you'll be deviating based on surrounding activity, winds, etc...try to go upwind, but try not to go between other cells that are close or building, etc. This is where you have to look at the total picture and begin to form a plan.
I see a lot of radar users who throw their range display out to 320 (or farther) and tilt the radar up, or use a 1 or 0 or -1 setting for tilt (the tilt numbers aren't actually telling you where true zero is...that's something you have to establish on your own). This is false confidence, and while it may illuminate something of marginal use, it's not providing what they may think it is. As distance increases, so does attenuation, such that the information that comes back needs re-interpretation, or it may be deceptive. Zero, incidentally, is a value that assumes the center of the beam at the horizon. On your display, the radar is a two dimensional wedge that lays flat, extending away from your radome, so many degrees left or right, but it also extends up and down, too, and it has a bottom edge and an upper edge, of the cone, and one can envision an imaginary middle of the cone...that's where the tilt number comes in. Despite gyro stabilization and other neat tricks, the nature of radar installation, and aircraft pitch and attitude, and other factors, the true zero of the radar beam usually doesn't coincide with the number you see on your display in the cockpit.
Knowing cone or beam width and angle and distance and finding true zero are elements of making an accurate determination of storm tops and bases...something that's not really taught any more, and which takes some time to go over (and depends on what you're flying and the radar installed, dish or plate size, etc). Mostly we use radar to get the picture of what's out there and go around it, without getting too fancy, and that's generally a good plan. My personal use in cruise over long distances when I'm not examining something specific is to park the beam lower edge at 80, and watch to see what appears...and then begin tilting and scanning and looking, as well as frequently ranging in and out, during the flight. Combined with as much preflight information as you can get, it's another tool for avoidance, rather than penetration, and that should be emphasized. Today pilots are not given adequate training to analyze storms, and I don't think they necessarily should be: our emphasis is rightfully on avoiding storms and convective activity.
Sometimes we find ourselves in places with a lot of activity, and at that point, we are looking to get around or through, even if it's an escape path. In such a case, the single biggest thing we need to understand is attenuation. Your car headlight has only so much light to throw out there. It can get diffused and not go as far, or absorbed, or reflected back, such as driving in fog, or near road signs, or obstacles, and it may not illuminate as far down the road as you might hope. You could see an object in the headlights, and think you've got the big picture, but you really don't, because too much light is being reflected back. You come up on some road construction, and all the reflective signs throw a lot of light back in your face, so much so that you don't see the deer or moose standing just beyond, or in the construction. In radar terms, this is a "radar shadow," where some of the reflective (moist) weather has reflected or absorbed or diffused so much of our radar energy that we don't see what's laying beyond, and it looks clear, or black, on our display. Any time you see a clear area just beyond what you're painting, suspect that there's something you're not seeing in that clear area. If the plan is to squeeze through that gap then zig back on course into that clear area, don't be surprised that you've fallen into a trap and that worse weather lays beyond...hidden by what you were just avoiding. Attenuation.
Another issue that's not discussed much at all is that radar units not are used infrequently. This might be the case with an aircraft that isn't pulled out of the hangar often (corporate airplane, for example), or may be the case with an aircraft equipped with more than one radar unit). Not so true of newer radars, but very true of older radars, the equipment itself, specifically the magnatron, requires frequent use or it looses efficiency; some older radars might require use within a month or might need component replacement. Few seem aware of this today; energizing of those components affects the efficiency and viability of those components, and if they sit for too long, they won't tell you what you think they should be telling you. Older weather radar in particular is very much a use-it-or-lose-it proposition.
Another issue that I've seen has been radome transmissibility; radomes are usually a honeycomb material, which means they're fiberglass layers over an expanded matrix that acts as a filler or stiffener or thickener of the radome, usually shaped like honecomb cells in a beehive. These cells are hollow and if pin holes develop in the radar, the honecomb holds moisture, which is reflective to radar. If you start seeing lobes or lines appear on your radar, or inverse lobes, seen as streaks of color away from the radar beam center, or streaks of dark, these may be signs of moisture in the radome, and should be reported to maintenance; they can hide airborne returns, or reflect high levels of energy back to the radar system; one is deceptive, the other potentially harmful, but requires maintenance. This can occur as a result of deterioration, lightning strikes, physical damage, inadequate repair work, etc, and should be noted when using the radar. Remember, the guys in the hangar don't operate it, and don't see what you see. The only chance to catch such stuff may be when you're using it operationally. Be as detailed as you can in your description.
If you think of this like your car headlight, which projects from a single point on your vehicle, looking forward, the light projects out in a cone-shape, pointy end of the cone at the light, extending outward and expanding away from your vehicle. Radar works in a similar fashion, so you may envision your car headlight projecting a beam forward, and the point where it first directly illuminates the ground is the bottom of the headlight beam. Likewise for your radar. From that point, moving forward, or down range, you're looking down to the ground, through anything in the air.
Objects that aren't in the beam must be progressively lower, the closer you get to the bottom of the beam, so if you're set the tilt to paint ground returns at 80 miles, what's beyond it is in the beam, what's just shy of 80 miles can be a little above ground and not get painted, and what's directly under you can be nearly as tall as you are and not get painted ("painted" meaning you see a return on the radar, or in other words, the object is reflective of the radar, and it's in the beam). Beyond the beam, objects from the surface to a much higher altitude, can be detected. Because when you're in cruise, most weather comes from the surface and goes up, starting looking at the ground, upward, is a wise choice. Precip will be falling, storms building upward, etc. It's a good place to detect storms, and the most reflective (wet) parts of the storms will be the lowest parts, like looking for the roots of a tree to know there's a tree above it. You'll paint a lot of the tree, or the storm, as well.
Where this becomes useful is as you move forward, the object that you painted beyond 80 miles, may be tall enough to stay in your beam, or it may have been a shorter object which will eventually not be tall enough to be directly illuminated; it will appear to weaken and then disappear, as you approach it. This suggests weather well below youIf the weather continues to be clear and well defined, and especially if it grows at say, 40 miles, it's time to be thinking about which way you'll be deviating based on surrounding activity, winds, etc...try to go upwind, but try not to go between other cells that are close or building, etc. This is where you have to look at the total picture and begin to form a plan.
I see a lot of radar users who throw their range display out to 320 (or farther) and tilt the radar up, or use a 1 or 0 or -1 setting for tilt (the tilt numbers aren't actually telling you where true zero is...that's something you have to establish on your own). This is false confidence, and while it may illuminate something of marginal use, it's not providing what they may think it is. As distance increases, so does attenuation, such that the information that comes back needs re-interpretation, or it may be deceptive. Zero, incidentally, is a value that assumes the center of the beam at the horizon. On your display, the radar is a two dimensional wedge that lays flat, extending away from your radome, so many degrees left or right, but it also extends up and down, too, and it has a bottom edge and an upper edge, of the cone, and one can envision an imaginary middle of the cone...that's where the tilt number comes in. Despite gyro stabilization and other neat tricks, the nature of radar installation, and aircraft pitch and attitude, and other factors, the true zero of the radar beam usually doesn't coincide with the number you see on your display in the cockpit.
Knowing cone or beam width and angle and distance and finding true zero are elements of making an accurate determination of storm tops and bases...something that's not really taught any more, and which takes some time to go over (and depends on what you're flying and the radar installed, dish or plate size, etc). Mostly we use radar to get the picture of what's out there and go around it, without getting too fancy, and that's generally a good plan. My personal use in cruise over long distances when I'm not examining something specific is to park the beam lower edge at 80, and watch to see what appears...and then begin tilting and scanning and looking, as well as frequently ranging in and out, during the flight. Combined with as much preflight information as you can get, it's another tool for avoidance, rather than penetration, and that should be emphasized. Today pilots are not given adequate training to analyze storms, and I don't think they necessarily should be: our emphasis is rightfully on avoiding storms and convective activity.
Sometimes we find ourselves in places with a lot of activity, and at that point, we are looking to get around or through, even if it's an escape path. In such a case, the single biggest thing we need to understand is attenuation. Your car headlight has only so much light to throw out there. It can get diffused and not go as far, or absorbed, or reflected back, such as driving in fog, or near road signs, or obstacles, and it may not illuminate as far down the road as you might hope. You could see an object in the headlights, and think you've got the big picture, but you really don't, because too much light is being reflected back. You come up on some road construction, and all the reflective signs throw a lot of light back in your face, so much so that you don't see the deer or moose standing just beyond, or in the construction. In radar terms, this is a "radar shadow," where some of the reflective (moist) weather has reflected or absorbed or diffused so much of our radar energy that we don't see what's laying beyond, and it looks clear, or black, on our display. Any time you see a clear area just beyond what you're painting, suspect that there's something you're not seeing in that clear area. If the plan is to squeeze through that gap then zig back on course into that clear area, don't be surprised that you've fallen into a trap and that worse weather lays beyond...hidden by what you were just avoiding. Attenuation.
Another issue that's not discussed much at all is that radar units not are used infrequently. This might be the case with an aircraft that isn't pulled out of the hangar often (corporate airplane, for example), or may be the case with an aircraft equipped with more than one radar unit). Not so true of newer radars, but very true of older radars, the equipment itself, specifically the magnatron, requires frequent use or it looses efficiency; some older radars might require use within a month or might need component replacement. Few seem aware of this today; energizing of those components affects the efficiency and viability of those components, and if they sit for too long, they won't tell you what you think they should be telling you. Older weather radar in particular is very much a use-it-or-lose-it proposition.
Another issue that I've seen has been radome transmissibility; radomes are usually a honeycomb material, which means they're fiberglass layers over an expanded matrix that acts as a filler or stiffener or thickener of the radome, usually shaped like honecomb cells in a beehive. These cells are hollow and if pin holes develop in the radar, the honecomb holds moisture, which is reflective to radar. If you start seeing lobes or lines appear on your radar, or inverse lobes, seen as streaks of color away from the radar beam center, or streaks of dark, these may be signs of moisture in the radome, and should be reported to maintenance; they can hide airborne returns, or reflect high levels of energy back to the radar system; one is deceptive, the other potentially harmful, but requires maintenance. This can occur as a result of deterioration, lightning strikes, physical damage, inadequate repair work, etc, and should be noted when using the radar. Remember, the guys in the hangar don't operate it, and don't see what you see. The only chance to catch such stuff may be when you're using it operationally. Be as detailed as you can in your description.
Interestingly enough, I'm not sure I've seen one Captain using the technique above of actually painting the ground. They always seem to have the radar tilted above the 0 degree mark, even in cruise. I can't blame them, because like I said, I think our radar training is incredibly underwhelming, if not basically non-existent on tilt technique. That said, it is a bummer because often times there is only one radar control. Some of our aircraft do have separate radar controls, which allows you to control the settings on your own MFD.
Thanks again.
07-15-2022, 09:05 PM
#26
Gets Weekends Off
Joined APC: Apr 2011
Posts: 1,533
Thanks for the refresher course, JohnBurke. I started in the airline world 31 years ago in turboprops, and flew them for years through Tornado Alley, Florida, and the eastern 1/3 of this country (west coast for many years too, but the western US is nothing like what lies east of the Rockies, in terms of thunderstorms). I quickly learned that I wanted to get my hands on as much info as I could, in terms of what it is, how it works, how to use it, and pitfalls to avoid. I read as many narratives on accident reports as I could (you remember Southern 242, I imagine - a great object lesson on how attenuation can lead a crew down a primrose path). I used to practice with the tilt control in each of the different types I flew back then (Saab 340, ATR), finding beam width, beam center, then playing around estimating radar tops from our lowly 15,000 feet or so as I scanned cells around us (usually while in the clear). I actively used to (and still do) look for signs of attenuation when scanning areas of weather, and there were times when we’d be at 15,000 feet or so, out over the gulfstream headed to Nassau from Miami, at night, in continuous pouring rain - with our returns attenuated out beyond about 15-20 miles or so - and about the best we could do was constantly look for areas on the screen that would look like the edge of the rain was moving in toward us somewhat, then move away from that area, fully knowing that in reality, it was greater attenuatio presenting us a possible sucker hole. With nothing but ocean out there, there usually wasn’t enough return even in rough seas to get a useful ground return.
I’ve used the same techniques with the RJ’s, 737’s, and now some of the older Airbuses I occasionally fly. The newer models have that amazing Multi-scan technology, which works so well, so I usually just leave it in Auto and let the electronics present me with a really useful picture. Not always, though. Sometimes the old school in me wants to go back to manual for a few sweeps, working with the tilt and gain.
I’ve used the same techniques with the RJ’s, 737’s, and now some of the older Airbuses I occasionally fly. The newer models have that amazing Multi-scan technology, which works so well, so I usually just leave it in Auto and let the electronics present me with a really useful picture. Not always, though. Sometimes the old school in me wants to go back to manual for a few sweeps, working with the tilt and gain.
07-16-2022, 03:57 AM
#27
Gets Weekends Off
Joined APC: Feb 2008
Posts: 19,273
Originally Posted by 450knotOffice
Thanks for the refresher course, JohnBurke. I started in the airline world 31 years ago in turboprops, and flew them for years through Tornado Alley, Florida, and the eastern 1/3 of this country (west coast for many years too, but the western US is nothing like what lies east of the Rockies, in terms of thunderstorms). I quickly learned that I wanted to get my hands on as much info as I could, in terms of what it is, how it works, how to use it, and pitfalls to avoid. I read as many narratives on accident reports as I could (you remember Southern 242, I imagine - a great object lesson on how attenuation can lead a crew down a primrose path). I used to practice with the tilt control in each of the different types I flew back then (Saab 340, ATR), finding beam width, beam center, then playing around estimating radar tops from our lowly 15,000 feet or so as I scanned cells around us (usually while in the clear). I actively used to (and still do) look for signs of attenuation when scanning areas of weather, and there were times when we’d be at 15,000 feet or so, out over the gulfstream headed to Nassau from Miami, at night, in continuous pouring rain - with our returns attenuated out beyond about 15-20 miles or so - and about the best we could do was constantly look for areas on the screen that would look like the edge of the rain was moving in toward us somewhat, then move away from that area, fully knowing that in reality, it was greater attenuatio presenting us a possible sucker hole. With nothing but ocean out there, there usually wasn’t enough return even in rough seas to get a useful ground return.
I’ve used the same techniques with the RJ’s, 737’s, and now some of the older Airbuses I occasionally fly. The newer models have that amazing Multi-scan technology, which works so well, so I usually just leave it in Auto and let the electronics present me with a really useful picture. Not always, though. Sometimes the old school in me wants to go back to manual for a few sweeps, working with the tilt and gain.
I’ve used the same techniques with the RJ’s, 737’s, and now some of the older Airbuses I occasionally fly. The newer models have that amazing Multi-scan technology, which works so well, so I usually just leave it in Auto and let the electronics present me with a really useful picture. Not always, though. Sometimes the old school in me wants to go back to manual for a few sweeps, working with the tilt and gain.
07-16-2022, 06:59 AM
#28
Gets Weekends Off
Joined APC: Apr 2011
Posts: 1,533
Originally Posted by sailingfun
Autoscan is not even the current best technology. The current state of the art changes tilt constantly and scans for shadow areas as well as turbulence. If you play with the tilt you actually degrade the presentation. The question is will your airline pay to retrofit your fleets. Some will and some won’t.
We also have the much older Airbuses that utilize totally outdated radar technology. I WISH my airline would update those systems, but I doubt they ever will.
Cheers.
07-22-2022, 04:15 AM
#29
Gets Weekends Off
Joined APC: May 2021
Posts: 319
Originally Posted by CH1203
What do you think this was? I was flying around some heavy weather taking off out of Medellin. Night IMC, lightning flashing all over the place. We were on the SID because of all the terrain and had to fly into the green/yellow radar returns. We were getting nonstop St. Elmo’s Fire. Then all of the sudden, our radome lit up like a Christmas tree. A continuous cone shaped plume of purple/pink glowing plasma engulfed the windshield. It literally looked like we were the space shuttle reentering the atmosphere from space. I don’t think it was a lightning strike because there was no evidence of anything on the walk-around and it wasn’t a quick flash... it was a constant almost “blow torch” look. Any ideas?
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