TCAS - efficient or not
09-15-2016, 04:34 AM
#1
New Hire
Thread Starter
Joined APC: Sep 2016
Posts: 1
TCAS - efficient or not
Dear Captains,
I am going to be flying from Brisbane to Los Angeles (13 hours straight) in a day or so.
I have a lot of paranoid thoughts about what could go wrong and researching online seems to be making it worse! I am having headaches and chest pain before even boarding this flight!
Questions:
1. A TCAS system only seems to work when the approaching plane has *at least* a transponder emitting data. What if somebody switched off the transponder on that plane, how would my plane avoid colliding into it? Why don't planes have Radar on it, which brings me to my next question.
2. We are flying over the Pacific ocean, most of this area is not covered by ground Radar.. right?
3. What if something goes wrong with the plane, we are flying over a wide ocean, where would we land. I have been reading about diversion airports / ETOPS between my destination.. I can't find concrete info about how many of these spots are located in our way and how easy/soon can a plane reach it! Are they even functional airports?
4. My plane is a Qantas 747-400, but I read this model is old. Is there any such thing as "primary Radar" device on it?
5. Also, I read that few years ago an incident of water leakage caused an electric outage in ALL of the planes systems! If such an event occurs, how far can this plane glide and can it actually land on water or is that just a best case scenario!
6. Do all planes ping the satellites? Can the pinging be switched off like a Transponder?
7. Pilots can't see through clouds, will we be flying above the clouds for the most part? Does it help that it's during the day?
8. Is there less traffic on my route?
Worried,
I am going to be flying from Brisbane to Los Angeles (13 hours straight) in a day or so.
I have a lot of paranoid thoughts about what could go wrong and researching online seems to be making it worse! I am having headaches and chest pain before even boarding this flight!
Questions:
1. A TCAS system only seems to work when the approaching plane has *at least* a transponder emitting data. What if somebody switched off the transponder on that plane, how would my plane avoid colliding into it? Why don't planes have Radar on it, which brings me to my next question.
2. We are flying over the Pacific ocean, most of this area is not covered by ground Radar.. right?
3. What if something goes wrong with the plane, we are flying over a wide ocean, where would we land. I have been reading about diversion airports / ETOPS between my destination.. I can't find concrete info about how many of these spots are located in our way and how easy/soon can a plane reach it! Are they even functional airports?
4. My plane is a Qantas 747-400, but I read this model is old. Is there any such thing as "primary Radar" device on it?
5. Also, I read that few years ago an incident of water leakage caused an electric outage in ALL of the planes systems! If such an event occurs, how far can this plane glide and can it actually land on water or is that just a best case scenario!
6. Do all planes ping the satellites? Can the pinging be switched off like a Transponder?
7. Pilots can't see through clouds, will we be flying above the clouds for the most part? Does it help that it's during the day?
8. Is there less traffic on my route?
Worried,
09-15-2016, 06:19 AM
#3
Moderate Moderator
Joined APC: Mar 2008
Position: Curator at Static Display
Posts: 5,681
As perfinit said: Relax!
Yes, TCAS is "efficient," even outside of primary radar coverage.
There are other means to establish position of oceanic aircraft. Generally, aircraft at the same altitude will not be within 60 or 30 miles of each other.
You can "What if???" this to death. In 2015, 560 people died in airline accidents, and two of those were deliberate (bomb; suicide).
Meanwhile: 1.24 MILLION people die worldwide EACH YEAR in auto accidents. 24,000 people die worldwide from lightning.
17.3 million people die each year from heart attacks.
You should probably worry more about your drive to and from the airport, the food you eat on the plane, and spending time on the beach in California under a "little rain cloud" than about your flight getting there.
Relax.
Yes, TCAS is "efficient," even outside of primary radar coverage.
There are other means to establish position of oceanic aircraft. Generally, aircraft at the same altitude will not be within 60 or 30 miles of each other.
You can "What if???" this to death. In 2015, 560 people died in airline accidents, and two of those were deliberate (bomb; suicide).
Meanwhile: 1.24 MILLION people die worldwide EACH YEAR in auto accidents. 24,000 people die worldwide from lightning.
17.3 million people die each year from heart attacks.
You should probably worry more about your drive to and from the airport, the food you eat on the plane, and spending time on the beach in California under a "little rain cloud" than about your flight getting there.
Relax.
09-15-2016, 06:24 AM
#5
Banned
Joined APC: Sep 2016
Posts: 375
09-15-2016, 07:07 AM
#6
Prime Minister/Moderator
Joined APC: Jan 2006
Position: Engines Turn Or People Swim
Posts: 39,277
Regarding commercial airliners...
1. TCAS is a backup. Primary collision avoidance is based on flight planning, then secondary radar, then primary raday, then pilot visual observation (see-and-avoid). If all that fails, then TCAS is the last of many layers of defense.
2. Planes have radar to detect weather, not other planes. Only fighters have radar which can detect (and of course target and attack) other planes. Practically speaking it's hard to install a radar which can see all around the plane, and a radar which can only look in front is of limited use in collision avoidance.
3. ETOPS routes have diversion airports planned within the allowed ETOPS range. Some of these airports (ex. midway island) are manned and maintained only to meet ETOPS requirements, and have no scheduled arrivals. A plane which experiences an engine failure should have no problem reaching a suitable diversion field on the remaining engine (or engines). Loss of all engines is exceeding rare, I can think of two in recent memory (Sully and LHR) and everybody survived.
4. A 747-200 is "old". That's actually what the president of the US flies on. A 747-400 is relatively young as airliners go, or perhaps middle-aged. But Qantas has about the best safety record in airline history, so I'm sure their planes are very well maintained.
Primary (and secondary) radar is used by Air Traffic Control (ATC) to detect aircraft, it is large and heavy and thus not carried on aircraft (secondary radar requires the airplane to emit a transponder code, which all commercial aircraft do, as well as all aircraft allowed to fly near commercial aircraft).
5. A commercial airliner's engines will operate without any electrical power from the plane. Some (including mine) require no electricity at all, all pumps for fuel, oil, and hydraulics are mechanically driven off of the engines. My plane can be flown and landed with no electrical power at all (despite having four generators and two batteries). The ones which have electrical controls and engine accessories have built-in power sources and backups which do not rely on the airplane's power grid. There are many layers of redundancy, and it would be statistically near-impossible for all of them to fail.
6. No. The larger ones designed for over-water ops probably all communicate with satellites. Smaller planes may use land-based radio systems for automated reporting (mine does this, no need for expensive satellite gear since we don't go far from land).
7. Airliners are not affected by clouds or night. We operate under Instrument Flight Rules anyway, so we don't actually need to see outside except to land and takeoff and even then you only need to see a few hundred feet. If we can see out, it's more of a bonus. The plane you're flying will actually have CAT-IIIc autoland, so it can land itself in zero visibility. If visibility or ceilings are low ATC will increase spacing between airport arrivals, which causes delays but not safety issues.
8. The route you're on is utterly deserted. There would be more traffic flying a spaceship to mars.
Have a drink, relax, and enjoy the flight. Qantas has been doing this for a long time and they're really good at it.
1. TCAS is a backup. Primary collision avoidance is based on flight planning, then secondary radar, then primary raday, then pilot visual observation (see-and-avoid). If all that fails, then TCAS is the last of many layers of defense.
2. Planes have radar to detect weather, not other planes. Only fighters have radar which can detect (and of course target and attack) other planes. Practically speaking it's hard to install a radar which can see all around the plane, and a radar which can only look in front is of limited use in collision avoidance.
3. ETOPS routes have diversion airports planned within the allowed ETOPS range. Some of these airports (ex. midway island) are manned and maintained only to meet ETOPS requirements, and have no scheduled arrivals. A plane which experiences an engine failure should have no problem reaching a suitable diversion field on the remaining engine (or engines). Loss of all engines is exceeding rare, I can think of two in recent memory (Sully and LHR) and everybody survived.
4. A 747-200 is "old". That's actually what the president of the US flies on. A 747-400 is relatively young as airliners go, or perhaps middle-aged. But Qantas has about the best safety record in airline history, so I'm sure their planes are very well maintained.
Primary (and secondary) radar is used by Air Traffic Control (ATC) to detect aircraft, it is large and heavy and thus not carried on aircraft (secondary radar requires the airplane to emit a transponder code, which all commercial aircraft do, as well as all aircraft allowed to fly near commercial aircraft).
5. A commercial airliner's engines will operate without any electrical power from the plane. Some (including mine) require no electricity at all, all pumps for fuel, oil, and hydraulics are mechanically driven off of the engines. My plane can be flown and landed with no electrical power at all (despite having four generators and two batteries). The ones which have electrical controls and engine accessories have built-in power sources and backups which do not rely on the airplane's power grid. There are many layers of redundancy, and it would be statistically near-impossible for all of them to fail.
6. No. The larger ones designed for over-water ops probably all communicate with satellites. Smaller planes may use land-based radio systems for automated reporting (mine does this, no need for expensive satellite gear since we don't go far from land).
7. Airliners are not affected by clouds or night. We operate under Instrument Flight Rules anyway, so we don't actually need to see outside except to land and takeoff and even then you only need to see a few hundred feet. If we can see out, it's more of a bonus. The plane you're flying will actually have CAT-IIIc autoland, so it can land itself in zero visibility. If visibility or ceilings are low ATC will increase spacing between airport arrivals, which causes delays but not safety issues.
8. The route you're on is utterly deserted. There would be more traffic flying a spaceship to mars.
Have a drink, relax, and enjoy the flight. Qantas has been doing this for a long time and they're really good at it.
09-15-2016, 08:26 AM
#7
Gets Weekends Off
Joined APC: Jun 2008
Posts: 273
Originally Posted by Lily88
Dear Captains,
I am going to be flying from Brisbane to Los Angeles (13 hours straight) in a day or so.
I have a lot of paranoid thoughts about what could go wrong and researching online seems to be making it worse! I am having headaches and chest pain before even boarding this flight!
Questions:
1. A TCAS system only seems to work when the approaching plane has *at least* a transponder emitting data. What if somebody switched off the transponder on that plane, how would my plane avoid colliding into it? Why don't planes have Radar on it, which brings me to my next question.
2. We are flying over the Pacific ocean, most of this area is not covered by ground Radar.. right?
3. What if something goes wrong with the plane, we are flying over a wide ocean, where would we land. I have been reading about diversion airports / ETOPS between my destination.. I can't find concrete info about how many of these spots are located in our way and how easy/soon can a plane reach it! Are they even functional airports?
4. My plane is a Qantas 747-400, but I read this model is old. Is there any such thing as "primary Radar" device on it?
5. Also, I read that few years ago an incident of water leakage caused an electric outage in ALL of the planes systems! If such an event occurs, how far can this plane glide and can it actually land on water or is that just a best case scenario!
6. Do all planes ping the satellites? Can the pinging be switched off like a Transponder?
7. Pilots can't see through clouds, will we be flying above the clouds for the most part? Does it help that it's during the day?
8. Is there less traffic on my route?
Worried,
I am going to be flying from Brisbane to Los Angeles (13 hours straight) in a day or so.
I have a lot of paranoid thoughts about what could go wrong and researching online seems to be making it worse! I am having headaches and chest pain before even boarding this flight!
Questions:
1. A TCAS system only seems to work when the approaching plane has *at least* a transponder emitting data. What if somebody switched off the transponder on that plane, how would my plane avoid colliding into it? Why don't planes have Radar on it, which brings me to my next question.
2. We are flying over the Pacific ocean, most of this area is not covered by ground Radar.. right?
3. What if something goes wrong with the plane, we are flying over a wide ocean, where would we land. I have been reading about diversion airports / ETOPS between my destination.. I can't find concrete info about how many of these spots are located in our way and how easy/soon can a plane reach it! Are they even functional airports?
4. My plane is a Qantas 747-400, but I read this model is old. Is there any such thing as "primary Radar" device on it?
5. Also, I read that few years ago an incident of water leakage caused an electric outage in ALL of the planes systems! If such an event occurs, how far can this plane glide and can it actually land on water or is that just a best case scenario!
6. Do all planes ping the satellites? Can the pinging be switched off like a Transponder?
7. Pilots can't see through clouds, will we be flying above the clouds for the most part? Does it help that it's during the day?
8. Is there less traffic on my route?
Worried,
I'd love to treat you with kid gloves and give you all the technical reasons why you shouldn't worry but the fact is you're not a pilot and never will be. It's time wasted.
Your pilots are trained better than your dads cardiologist and the equipment you're flying on is maintained better than any vehicle you've ever touched.
Playing these mind games only makes it worse, my wife does this all the time. I tell her the same thing, stop worrying and acting foolish.
09-15-2016, 11:08 AM
#8
Gets Weekends Off
Joined APC: Sep 2013
Position: On the hotel shuttle
Posts: 5,813
Originally Posted by Lily88
Dear Captains,
I am going to be flying from Brisbane to Los Angeles (13 hours straight) in a day or so.
I have a lot of paranoid thoughts about what could go wrong and researching online seems to be making it worse! I am having headaches and chest pain before even boarding this flight!
Questions:
1. A TCAS system only seems to work when the approaching plane has *at least* a transponder emitting data. What if somebody switched off the transponder on that plane, how would my plane avoid colliding into it? Why don't planes have Radar on it, which brings me to my next question.
2. We are flying over the Pacific ocean, most of this area is not covered by ground Radar.. right?
3. What if something goes wrong with the plane, we are flying over a wide ocean, where would we land. I have been reading about diversion airports / ETOPS between my destination.. I can't find concrete info about how many of these spots are located in our way and how easy/soon can a plane reach it! Are they even functional airports?
4. My plane is a Qantas 747-400, but I read this model is old. Is there any such thing as "primary Radar" device on it?
5. Also, I read that few years ago an incident of water leakage caused an electric outage in ALL of the planes systems! If such an event occurs, how far can this plane glide and can it actually land on water or is that just a best case scenario!
6. Do all planes ping the satellites? Can the pinging be switched off like a Transponder?
7. Pilots can't see through clouds, will we be flying above the clouds for the most part? Does it help that it's during the day?
8. Is there less traffic on my route?
Worried,
I am going to be flying from Brisbane to Los Angeles (13 hours straight) in a day or so.
I have a lot of paranoid thoughts about what could go wrong and researching online seems to be making it worse! I am having headaches and chest pain before even boarding this flight!
Questions:
1. A TCAS system only seems to work when the approaching plane has *at least* a transponder emitting data. What if somebody switched off the transponder on that plane, how would my plane avoid colliding into it? Why don't planes have Radar on it, which brings me to my next question.
2. We are flying over the Pacific ocean, most of this area is not covered by ground Radar.. right?
3. What if something goes wrong with the plane, we are flying over a wide ocean, where would we land. I have been reading about diversion airports / ETOPS between my destination.. I can't find concrete info about how many of these spots are located in our way and how easy/soon can a plane reach it! Are they even functional airports?
4. My plane is a Qantas 747-400, but I read this model is old. Is there any such thing as "primary Radar" device on it?
5. Also, I read that few years ago an incident of water leakage caused an electric outage in ALL of the planes systems! If such an event occurs, how far can this plane glide and can it actually land on water or is that just a best case scenario!
6. Do all planes ping the satellites? Can the pinging be switched off like a Transponder?
7. Pilots can't see through clouds, will we be flying above the clouds for the most part? Does it help that it's during the day?
8. Is there less traffic on my route?
Worried,
I strongly recommend printing this out and reading it religiously when you feel anxious...
http://www.economist.com/blogs/gulli.../01/air-safety
And if you don't believe in the harsh truth buried in the root of those statistics, all I can recommend is to drink ... heavily.
09-15-2016, 03:42 PM
#9
Gets Weekends Off
Joined APC: Jun 2014
Posts: 924
What some of the others have said is probably helpful, but here are just a couple more thoughts.
Fear of flying (or any other fear) is often rooted in a fear of the unknown or unfamiliar. It sounds like flying is a fairly unfamiliar experience for you. So it's natural that you would be a bit nervous about it! Remember that the crews, controllers, and other professionals you encounter are operating in their familiar element. This is what they are trained to do, and frankly they do it very very well. The statistics other posters have mentioned are proof of that.
You're not alone; a significant percentage of the flying public has a fear, or at least nervousness, about flying. When you board and are trying to rub the cool sweat off your palms, the guy two or three rows in front of you is probably doing exactly the same thing.
The best way to overcome your fear is not to over-analyze the things that could go wrong, but to focus on what will go right! Spend your time planning your trip and enjoying it. That's the reason you're boarding this flight anyway. Make sure you have materials to take your mind off your anxiety during the flight (books, movies, music, pillows, etc.). If you have anxiety about other things and have conquered it, use those same techniques here.
Sometimes, the only way to fully conquer or develop coping mechanisms for an unnecessary fear is to face it and live your life despite it. Kudos to you for going on this trip despite your concerns. Enjoy your journey.
Fear of flying (or any other fear) is often rooted in a fear of the unknown or unfamiliar. It sounds like flying is a fairly unfamiliar experience for you. So it's natural that you would be a bit nervous about it! Remember that the crews, controllers, and other professionals you encounter are operating in their familiar element. This is what they are trained to do, and frankly they do it very very well. The statistics other posters have mentioned are proof of that.
You're not alone; a significant percentage of the flying public has a fear, or at least nervousness, about flying. When you board and are trying to rub the cool sweat off your palms, the guy two or three rows in front of you is probably doing exactly the same thing.
The best way to overcome your fear is not to over-analyze the things that could go wrong, but to focus on what will go right! Spend your time planning your trip and enjoying it. That's the reason you're boarding this flight anyway. Make sure you have materials to take your mind off your anxiety during the flight (books, movies, music, pillows, etc.). If you have anxiety about other things and have conquered it, use those same techniques here.
Sometimes, the only way to fully conquer or develop coping mechanisms for an unnecessary fear is to face it and live your life despite it. Kudos to you for going on this trip despite your concerns. Enjoy your journey.
09-15-2016, 07:56 PM
#10
Disinterested Third Party
Joined APC: Jun 2012
Posts: 6,023
Originally Posted by Lily88
1. A TCAS system only seems to work when the approaching plane has *at least* a transponder emitting data. What if somebody switched off the transponder on that plane, how would my plane avoid colliding into it? Why don't planes have Radar on it, which brings me to my next question.
Your aircraft has TCAS availability, which responds to other aircraft transponders. If another aircraft does not have a transponder operating, then TCAS on an oceanic route will be of no use in avoiding a collision with the non-transponder equipped aircraft.
All aircraft on your routing will be equipped with a transponder. The vast majority of those aircraft, and all aircraft operating at the altitudes where you'll be riding, are equipped with two transponders.
You'll be flying designated routing over the ocean, and with it known altitudes which are designed to avoid other aircraft.
Originally Posted by Lily88
2. We are flying over the Pacific ocean, most of this area is not covered by ground Radar.. right?
Originally Posted by Lily88
3. What if something goes wrong with the plane, we are flying over a wide ocean, where would we land. I have been reading about diversion airports / ETOPS between my destination.. I can't find concrete info about how many of these spots are located in our way and how easy/soon can a plane reach it! Are they even functional airports?
Originally Posted by Lily88
4. My plane is a Qantas 747-400, but I read this model is old. Is there any such thing as "primary Radar" device on it?
There's no such thing as "primary" radar on an airplane. You may be thinking of radar returns seen by a controller, but it's irrelevant for most of your route. The pilots have no radar that "sees" other aircraft. Weather radar is used for viewing precipitation aloft, and can be used for "seeing" islands on the surface during a long oceanic flight.
Originally Posted by Lily88
\
5. Also, I read that few years ago an incident of water leakage caused an electric outage in ALL of the planes systems! If such an event occurs, how far can this plane glide and can it actually land on water or is that just a best case scenario!
5. Also, I read that few years ago an incident of water leakage caused an electric outage in ALL of the planes systems! If such an event occurs, how far can this plane glide and can it actually land on water or is that just a best case scenario!
The case you're thinking off involved a liquid spill into the lower compartment below the galley, and was a shorting of a main electrical bus, or place that connects various electrical systems.
The 747 has the capability to separate the electrical system into multiple parts to isolate a problem. While it's possible to have a complete electrical loss (I've experienced it in the 747), procedures are available in the cockpit to restore power, divide the systems, and isolate a problem. You shouldn't be concerned about electrical problems in flight as a safety issue on your trip. Not only are electrical problems very rare, but almost anything electrical that could happen on your flight is more of an inconvenience that is handled with a checklist in the cockpit.
Originally Posted by Lily88
6. Do all planes ping the satellites? Can the pinging be switched off like a Transponder?
On your flight, the aircraft has very long range radios that can talk across the ocean (HF radios), and other communication capability that includes long distance data links, as well as sat phones.
It sounds like you're worried about a situation such as MH 370, supposedly disappearing over the ocean. It sounds like you're thinking about the media circus mythology about the aircraft shutting off communications, suicidal captains, and a stealthy disappearance over a remote ocean. Bear in mind that everything you've heard about that on the news is pure conjecture and guesswork, and there's nothing to support any of it. It's sensationalism to sell advertising, and little more.
Also bear in mind that you're flying one of the most respected airlines in the world. You should have no concerns at all about hopping a Qantas flight. I don't worry about it in the least, and as a pilot and person who prefers to continue breathing, I take my travel seriously (as you do, too). Qantas is good to go.
Originally Posted by Lily88
7. Pilots can't see through clouds, will we be flying above the clouds for the most part? Does it help that it's during the day?
Throughout much of your flight you will likely be above most clouds, and flights divert to go around storms. There may be times when your flight will pass through clouds, or be flying at night; this presents no safety concern whatsoever.
Originally Posted by Lily88
8. Is there less traffic on my route?
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