All engine vs single engine departures
10-13-2015, 02:03 PM
#11
Gets Weekends Off
Joined APC: Jul 2008
Position: 747 Captain (Ret,)
Posts: 804
I have mentioned this in this forum before, but please do not assume that a one engine inoperative is the same as a single engine operating. Many aircraft will still have two or three, or possibly even seven left operating after a single engine failure.
Ralph
Ralph
10-13-2015, 03:01 PM
#12
Disinterested Third Party
Joined APC: Jun 2012
Posts: 6,023
There seems to be a lot of confusion on the part of the original poster regarding aircraft performance, certification, and climb segments, as well as procedures.
If you're in a Part 25 turbojet aircraft, there's no grey area or ambiguity regarding climb performance with all engines, or engine out. That's established as a function of certification, and you should be fully aware of the significance of your V2 speed and your segmented minimum climb gradients and published performance.
Assuming an engine failure at or greater than V1, your initial performance is accelerating to V2 and accelerating in that condition until gear retraction. A positive climb gradient is required.
Second segment climb performance begins with gear retraction (assumed at 35') and continues to a minimum of 400' while maintaining V2. Many operators and manufacturers stipulate a minimum 400' before configuration changes. Minimum climb gradient for a 2 engine aircraft with one engine inoperative is 2.4%. Second segment does not necessarily end at 400' AGL; that's the minimum altitude at which second segment may terminate.
Specific aircraft procedures (and company engine-out procedures) may dictate a general cleanup or level off altitude for engine-out performance, or may have a specific value for a specific departure or runway at a specific location, with attendant altitudes particular to that runway. There are many places around the world where it's unsafe to level or begin cleaning up at 400' and one may climb higher while turning to a predetermined heading as part of the engine-out procedure.
The third climb segment begins at 400' minimum, but not necessarily so. It begins upon acceleration from V2 to the minimum flap retraction speed as one cleans up the airplane. Minimum climb gradient is no altitude loss, and some operations level the aircraft for this phase. This phase continues through flap retraction.
Fourth segment climb is after flap retraction, with maximum continuous thrust set, and a climb to 1,500 AGL minimum with a 1.2% climb gradient.
The original poster indicated that an engine-out cleanup or level off altitude that's different from the all-engine(s) level-off altitude is unsafe. One might gather that the original poster is assigned to his first turbojet aircraft and that he may not be familiar with the necessity of understanding and briefing the expected all-engine departure, as well as the engine-out departure procedure. Often the two are not the same.
Know before you go.
If your company has an established procedure to fly, then fly it. If your training facility wants to see you clean up at 400' after flying off with an engine out, then do that. Brief it, and fly it as briefed.
Calculate your performance. Don't guess. It's not arbitrary or a grey area.
Following engine-out procedures is not a "CRM nightmare." Engine-out procedures that differ from an all-engine procedure are not unusual or unsafe. Fly the airplane you've got. If you're departing with all engines and lose one, then you need to be able to transition seamlessly to an engine-out procedure. It should be second nature and that's why you train for losing an engine at or above V1. Know what the aircraft can do, the procedure necessary to make the aircraft do it, then follow that procedure.
If you're in a Part 25 turbojet aircraft, there's no grey area or ambiguity regarding climb performance with all engines, or engine out. That's established as a function of certification, and you should be fully aware of the significance of your V2 speed and your segmented minimum climb gradients and published performance.
Assuming an engine failure at or greater than V1, your initial performance is accelerating to V2 and accelerating in that condition until gear retraction. A positive climb gradient is required.
Second segment climb performance begins with gear retraction (assumed at 35') and continues to a minimum of 400' while maintaining V2. Many operators and manufacturers stipulate a minimum 400' before configuration changes. Minimum climb gradient for a 2 engine aircraft with one engine inoperative is 2.4%. Second segment does not necessarily end at 400' AGL; that's the minimum altitude at which second segment may terminate.
Specific aircraft procedures (and company engine-out procedures) may dictate a general cleanup or level off altitude for engine-out performance, or may have a specific value for a specific departure or runway at a specific location, with attendant altitudes particular to that runway. There are many places around the world where it's unsafe to level or begin cleaning up at 400' and one may climb higher while turning to a predetermined heading as part of the engine-out procedure.
The third climb segment begins at 400' minimum, but not necessarily so. It begins upon acceleration from V2 to the minimum flap retraction speed as one cleans up the airplane. Minimum climb gradient is no altitude loss, and some operations level the aircraft for this phase. This phase continues through flap retraction.
Fourth segment climb is after flap retraction, with maximum continuous thrust set, and a climb to 1,500 AGL minimum with a 1.2% climb gradient.
The original poster indicated that an engine-out cleanup or level off altitude that's different from the all-engine(s) level-off altitude is unsafe. One might gather that the original poster is assigned to his first turbojet aircraft and that he may not be familiar with the necessity of understanding and briefing the expected all-engine departure, as well as the engine-out departure procedure. Often the two are not the same.
Know before you go.
If your company has an established procedure to fly, then fly it. If your training facility wants to see you clean up at 400' after flying off with an engine out, then do that. Brief it, and fly it as briefed.
Calculate your performance. Don't guess. It's not arbitrary or a grey area.
Following engine-out procedures is not a "CRM nightmare." Engine-out procedures that differ from an all-engine procedure are not unusual or unsafe. Fly the airplane you've got. If you're departing with all engines and lose one, then you need to be able to transition seamlessly to an engine-out procedure. It should be second nature and that's why you train for losing an engine at or above V1. Know what the aircraft can do, the procedure necessary to make the aircraft do it, then follow that procedure.
10-13-2015, 03:56 PM
#13
Gets Weekends Off
Thread Starter
Joined APC: Feb 2010
Posts: 2,278
Originally Posted by JohnBurke
The original poster indicated that an engine-out cleanup or level off altitude that's different from the all-engine(s) level-off altitude is unsafe. One might gather that the original poster is assigned to his first turbojet aircraft and that he may not be familiar with the necessity of understanding and briefing the expected all-engine departure, as well as the engine-out departure procedure. Often the two are not the same.
I understand the certification requirements and I do not have a question about those. My issue is my company uses a third party performance calculator that allows us to depart runways at a much heavier weight than the aircraft manufacturer performance charts. Do do that, it specifies a level off altitude (acceleration/flap retraction altitude) for every runway. This altitude is usually 1,000-2,000 ft AGL. My company's normal procedures are to retract the flaps at 400 ft AGL. My issue is what happens if the engine fails at 401 ft AGL yet my engine failure path is assuming I will continue the second segment climb to 1,200 ft AGL. At previous employers always adjusted our normal flap retraction altitude to match our engine out flap retraction altitude. Right now if we lost an engine at 401 ft AGL out of Aspen, I would not feel very comfortable trying to fly the engine out procedure for that runway knowing it counted on me having 15 degrees of flaps for another 2,200 feet.
And in the future, it would be nice if you dropped your condescending tone. You often have good things to add to the conversation, but the way you say it often makes you sound like an arrogant jerk.
10-13-2015, 04:47 PM
#14
Disinterested Third Party
Joined APC: Jun 2012
Posts: 6,023
Originally Posted by 2StgTurbine
Sorry, but this is no where close to my first jet aircraft. This is my first time working for a company that does not have a dedicated training department however.
I understand the certification requirements and I do not have a question about those. My issue is my company uses a third party performance calculator that allows us to depart runways at a much heavier weight than the aircraft manufacturer performance charts. Do do that, it specifies a level off altitude (acceleration/flap retraction altitude) for every runway. This altitude is usually 1,000-2,000 ft AGL. My company's normal procedures are to retract the flaps at 400 ft AGL. My issue is what happens if the engine fails at 401 ft AGL yet my engine failure path is assuming I will continue the second segment climb to 1,200 ft AGL. At previous employers always adjusted our normal flap retraction altitude to match our engine out flap retraction altitude. Right now if we lost an engine at 401 ft AGL out of Aspen, I would not feel very comfortable trying to fly the engine out procedure for that runway knowing it counted on me having 15 degrees of flaps for another 2,200 feet.
I understand the certification requirements and I do not have a question about those. My issue is my company uses a third party performance calculator that allows us to depart runways at a much heavier weight than the aircraft manufacturer performance charts. Do do that, it specifies a level off altitude (acceleration/flap retraction altitude) for every runway. This altitude is usually 1,000-2,000 ft AGL. My company's normal procedures are to retract the flaps at 400 ft AGL. My issue is what happens if the engine fails at 401 ft AGL yet my engine failure path is assuming I will continue the second segment climb to 1,200 ft AGL. At previous employers always adjusted our normal flap retraction altitude to match our engine out flap retraction altitude. Right now if we lost an engine at 401 ft AGL out of Aspen, I would not feel very comfortable trying to fly the engine out procedure for that runway knowing it counted on me having 15 degrees of flaps for another 2,200 feet.
Are you saying that you're using performance data that's not in accordance with Part 25, or that doesn't meet aircraft type certificate certification data?
Are you saying that your company has runway analysis which specifies altitudes for a particular runway for the cleanup, but requires you to disregard that analysis and clean up at 400' regardless? That appears to be what you've said. How do you justify disregarding the data established for the runway analysis?
If your company's standard 2 engine procedure is to retract flaps at 400', but you have a procedure which requires you to climb to a different altitude following an engine failure prior to cleaning up, then follow your engine-out procedure exactly as you've briefed.
If you have an engine failure at 401' after you are accelerating from V2 to Vf to initiate flap retraction, then there shouldn't be any question as to what you must do. If you're flying clean, then you have a minimum speed to maintain. If you're not yet clean but accelerating, you've got an engine-out procedure to perform, and you'll continue on that procedure until you've achieved the minimum height specified with your runway analysis, as briefed.
The runway analysis for an engine-out procedure assumes an engine at V1, gear retraction at 35,' and so on. This builds a lower climb gradient into the equation by continuing the takeoff through Vr, accelerating to V2, and climbing out at V2 at the minimum climb gradient. If instead, you've experienced an engine failure later in the takeoff (your 401' example), then you've already experienced a much higher climb gradient owing to your normal all-engine takeoff and climb to that point. Regardless of where the failure occurs, you'll follow your engine-out procedure, and if you're flying clean at that point, clearly you wont' need to clean up and you clearly won't be dirtying up and slowing to V2. You've got a minimum speed to maintain.
Don't get caught in the trap of doing something stupid because it's "procedure." If the company tells you to clean up at 400 and you are unable due to terrain, then rock supercedes "procedure" and you either outclimb the terrain, or it outclimbs you. Aspen is a place where you should know your options and contingencies beyond simply reciting the numbers. Look at all the data. Look at the obstacle departure procedure. Know the MSA. Know the local weather patterns. Aspen is a place where you can see reasonable weather at the field, but find out not long after takeoff that a wall of snow is coming up the canyon from the left.
If you don't want to clean up at 400' and you know that you'll be better off keeping that climb going to a minimum altitude on all engines, then do that. You'll have a much better climb gradient on all engines, and will get to that minimum altitude quicker, and can get cleaned up there. It's your butt on the line and it's not the chief pilot who will paddle you with a ruler, but a pine tree that will get shoved through the back of your head. Make sure you really do have the performance.
When at FSI or Simuflite, fly the procedure the way they want it flown. Have a talk with them if you will, but do what's needed to complete your training evolution. Remember that in the field, what really counts isn't pleasing a check airman in a simulator, but actually outclimbing the rock. If you need to hold onto flaps and V2 a little longer, far better that than accelerating into a hillside at Vf as you bring up the flaps.
Right?
10-13-2015, 09:00 PM
#15
Gets Weekends Off
Thread Starter
Joined APC: Feb 2010
Posts: 2,278
I am going to assume that I am misinterpreting your tone, but we seem to be in agreement on nearly everything. My company developed their SOPs based on the aircraft manufacturer performance data, but uses APG for dispatch purposes which requires a different takeoff profile than the certification standards. The aircraft manufacturer designs their profiles to meet certification standards and APG designs their profiles to clear the terrain. As a result, there is a discrepancy, and before I take it up with the chain of command, I wanted to make sure I wasn't missing something.
[QUOTE=JohnBurke;1991849If you have an engine failure at 401' after you are accelerating from V2 to Vf to initiate flap retraction, then there shouldn't be any question as to what you must do. If you're flying clean, then you have a minimum speed to maintain. If you're not yet clean but accelerating, you've got an engine-out procedure to perform, and you'll continue on that procedure until you've achieved the minimum height specified with your runway analysis, as briefed.[/QUOTE]
This is contrary to the information I have received from APG. Although my actual experience in the aircraft and extrapolation from the AFM has taught me that your assumption that an engine failure at 401 ft AGL puts me ahead of the game, APG has told me that their specific engine out procedures are designed to cover the aircraft from V1 to the indicated level off altitude assuming we are using their specific profile (leaving the flaps at takeoff until level off altitude). APG only has performance data for an engine failure at V1; not V1+1 KIAS or at 4001 ft AGL, so as a result, the treat any engine failure below their indicated level off altitude as an engine failure at V1.
To me it seems my company purchased AGP in order to provide greater dispatch flexibility, but have never thought about how AGP climb profiles differ from the standard certification climb profile. This is not that strange as a previous airline I worked for did the same thing with AeroData. After a few years of using 400 ft as the flap retraction altitude, the training department finally realized we should leave the flaps at takeoff until the altitude specified indicated by AeroData.
I was simply turning to this professional pilot community to determine if there was an explanation that would justify my company's SOPs of following the certification climb profile despite using third party performance data that assumes we are following an alternate climb profile.
[QUOTE=JohnBurke;1991849If you have an engine failure at 401' after you are accelerating from V2 to Vf to initiate flap retraction, then there shouldn't be any question as to what you must do. If you're flying clean, then you have a minimum speed to maintain. If you're not yet clean but accelerating, you've got an engine-out procedure to perform, and you'll continue on that procedure until you've achieved the minimum height specified with your runway analysis, as briefed.[/QUOTE]
This is contrary to the information I have received from APG. Although my actual experience in the aircraft and extrapolation from the AFM has taught me that your assumption that an engine failure at 401 ft AGL puts me ahead of the game, APG has told me that their specific engine out procedures are designed to cover the aircraft from V1 to the indicated level off altitude assuming we are using their specific profile (leaving the flaps at takeoff until level off altitude). APG only has performance data for an engine failure at V1; not V1+1 KIAS or at 4001 ft AGL, so as a result, the treat any engine failure below their indicated level off altitude as an engine failure at V1.
To me it seems my company purchased AGP in order to provide greater dispatch flexibility, but have never thought about how AGP climb profiles differ from the standard certification climb profile. This is not that strange as a previous airline I worked for did the same thing with AeroData. After a few years of using 400 ft as the flap retraction altitude, the training department finally realized we should leave the flaps at takeoff until the altitude specified indicated by AeroData.
I was simply turning to this professional pilot community to determine if there was an explanation that would justify my company's SOPs of following the certification climb profile despite using third party performance data that assumes we are following an alternate climb profile.
10-14-2015, 02:24 AM
#16
Disinterested Third Party
Joined APC: Jun 2012
Posts: 6,023
Certification standards do nothing more than set a minimum level of performance, in this case with an engine out in a worse-case scenario during takeoff. The earlier in the takeoff the engine fails, the longer the takeoff, the longer the takeoff and climb distance, and as a result, the lower the overall climb gradient shall be for the first segment (and depending on the time of failure or phase of the takeoff, and departure), subsequent segments where a failure may occur).
APG is a Aircraft Performance Group, which provides runway analysis for a given runway on a given day under given conditions. A runway analysis takes into account not just temperature, runway length, and weight, but also obstacles in the departure path, for a specific aircraft performance model. A runway analysis isn't about wringing extra performance or bang-for-the-buck out of an airplane. It's about safety.
It's a good idea to know before you take off that while at JFK on a given day you could use diverse climb criteria for the departure (200'/nm) for the climb, today at XXX airport you need something else. You view the chart and determine what the required climb gradient is, and then determine if you can make that climb gradient at this temperature and weight. In a departure procedure, there may be multiple points in the departure that require a certain climb; can you make them all? Can you make them with an engine-out? That's where the runway analysis comes in.
The runway analysis is telling you that you need to do something other than standard in the event of an engine failure or power loss, and here's what you do. You can view it as a gimmick the company is using to enable them to legally operate at that field, or you can view it as the lifesaving piece of equipment and tool that it is, and incorporate it into your briefing and fly it as briefed, to save your life.
Yes, on a given day with no obstacles, you could fly the minimum certification profile for departure, and there's nothing to hit. Today, not so. Today, as you brief for takeoff, with an engine failure, there's no configuration change until 1750', at which time you will turn left heading 180, level the aircraft, clean up to Vf, and then continue your climb to 10,000. Etc. Today your terrain and obstacles require it. Today isn't a departure without obstacles. Today, if you want to live you'll take advantage of the runway analysis which has been prepared for your departure, and fly it.
Note that even diverse departure criteria for an area departure from a given runway assumes a climb to 400' before turning on course and climbing at a rate of 200'/nm enroute. If a runway as diverse climb criteria, you can do that; takeoff, turn any direction, and climb at the minimum gradient. If it doesn't, then you'll need a departure procedure, obstacle departure, or runway analysis to allow you to know what climb is required. Note that you've got to be able to do this with all engines, or with an engine-out; even if you lose an engine, the obstacles are still there, and must still be cleared. Unless your company has been issued a special engine-out procedure (the proverbial "pink pages" from Jepp), then you will make a determination if you can do it using the runway analysis provided. The runway analysis says "yes, you can do it, but you'll need to do it this way." If you choose not to do it that way, then no, you can't do it.
The alternative, if you don't want to take advantage of a detailed obstacle analysis for your departure, is to get out a sectional and chart and plotter and do all the math in determining exactly what distances to what obstacles in the departure you can make with an engine out, and what climb gradients you'll have at what point. I've seen many departure analysis which tell me I'm fine until obstacle #15 in the departure procedure that I'm requesting, and then I'm in trouble. To do the calculations to that point, assuming I had a way of getting that data at all, would have been arduous and taken a very long time. I had the data quickly, in the cockpit, before engine start, thanks to an obstacle analysis program. Because that program is approved and has all the data necessary to safely fly out, I need to adhere to it. Likewise, if the program tells me that I can't fly the procedure, even though I think I can...I can't. Legally, it's my butt.
A few years ago I was called to the company office to defend an airman, as his union representative. He made a departure in Afghanistan, which contains some very tall rocks. He had made a departure from the same runway the night previous, under nearly identical conditions, with a nearly identical load. When all of his trip data was placed in an envelope at the end of the trip and sealed up for the company, he figured it was done. As it turned out, he was not.
The trip data is occasionally reviewed, and spot checked. It's kept for a certain period of time, and the company would pick packets at random (or not, depending on one's sinister views) for inspection. In this case, they opened his trip packet, and reviewed his takeoff and landing data. It turned out that he couldn't accept the runway assignment. It was a last minute assignment while taxiing, departing opposite direction, and though the crew had already completed all their planning and briefing for the former runway, they felt confident based on the previous night's flying that they'd be fine. As it turned out, there was one obstacle in the departure procedure that they accepted which made it a no-go. All-engines, no problem. The obstacle analysis determined that with an engine-out, however, based on the departure they selected, there would be a problem. It was a technical issue that had to do with the input into the program; had they selected it as a VFR departure rather than an IFR departure in the obstacle analysis, the program would have let them go. They'd run it all previously the night before, and off they went. When the company ran the numbers from the comfort of a stateside office, they caught the error, and we all ended up in a review board, and I ended up in negotiations with the Chief Pilot in order for the captain to keep his job.
He did, but it was close.
Take the obstacle analysis seriously. Run the numbers yourself on some of the departures to see if they fly, and run them using a different profile to see if they don't.
Today, we will continue the climb to 1250' before cleaning up, as indicated in our departure obstacle analysis. Liberal, Kansas, we woiuldn't need to do that. Newark, not a problem. Here, today, tonight, this runway, this weight, this temperature, this departure, we do. We'll leave takeoff flaps set until 1250', then clean up, because we have a professional obstacle analysis that tells us that if we dont', and we lose an engine, we will lack the climb gradient performance to meet the obstacle clearance requirements for the selected departure procedure.
A number of years ago, I flew for a fractional operator. There was a small hill at one end of a runway, and there was a numbers-oriented individual in the company who took the time to calculate that with an engine-out on the runway at V1, we'd strike the hill XX feet below the top. We couldn't climb over the hill. The solution was simple, really. Go around the hill. Left, right, didn't matter. Go around the hill. Visually, it could be done. Not on instruments, however. A low visibility day, or low ceiling, or both, one couldn't maneuver around the hill, and shouldn't. The obstacle analysis for the hill was different under visual conditions, and under instrument conditions.
You'll note that some departure procedures specify a minimum visibility on departure, for the same reason.
Some departures have a lot of potential obstacles. Aspen, as you've noted, is one of them. A glance at the SARDD3 obstacle departure identifies a requirement of 460'/nm to 14,000,' along with departure minimums of 400' and 1 mile. (Why the ceiling and visiblity requirement? The procedure requires greater than standard/diverse climb criteria, and so places the ceiling in 100' increments above the controlling obstacle on the initial departure, and requires a minimum visibility of a mile)
You could climb to 400' and initiate your clean-up, but you'd still have to maintain 460'/nm in order to do it, while doing it. You can't put the climb gradient on hold while you do it. Obstacles and terrain don't give you a pass or tell you to take your time while they wait. They're still there, and the laws of physics still apply. If you can clean up at 400' and still make the grade, have a ball, but you have a very useful tool in your obstacle analysis which is telling you to change your cleanup altitude for that departure from that runway on that day in that aircraft, to a different number. Ignore it at your peril.
Standard operating procedure means doing something the same way under standard conditions. If you have a runway analysis or obstacle analysis which is telling you that the departure requires something else, then you don't ignore it simply to follow "SOP." Operating conditions are no longer standard. Now you need to do something else.
Going back to the SARDD3, the takeoff obstacle notes include:
Rwy 33: Multiple trees beginning 35' from DER, 386' right of centerline, up to 100' AGL/7722' MSL. Multiple trees, bushes and terrain beginning 4' from DER, 400' left of centerline, up to 100' AGL/7821' MSL. Multiple trees, bushes, and terrain beginning 2484' from DER, 752' left of centerline, up to 100' AGL/8179' MSL.
Do you want to whip out the aircraft flight manual and calculate your departure based on those obstacles, individually, overlay them into the departure procedure, compare them to the obstacle departure as well as your other procedures, make a comparative analysis against your aircraft performance on all engines and with an engine-out, compare that to the standard procedure of cleaning up at 400', and then make a decision? Or would you rather have that all done for you and presented as an obstacle analysis with the data already tied off with a pretty pink ribbon? I'd rather have the full analysis, and use that valuable tool to my advantage in planning my departure, do that I know I can make the grade in the event of an engine failure at any point.
I understand what you're saying. You're conflicted between what seems to be an inflexible and possibly unwise company standard procedure of cleaning up at 400,' on each takeoff, and the question of keeping yourself configured to a higher altitude in the event an obstacle analysis says otherwise. You don't have a training department, but use an outside vendor such as Simuflite or FSI. You're conflicted between being told to clean up at 400,' and following the guidance from the obstacle analysis which is telling you that you need to climb higher before cleaning up. I get it.
First, the obstacle analysis is a safety tool, and it's also got some legal teeth. Ignore it at your peril. If anything happens and you're asked why you had the data and ignored it, you'll be spinning in the wind, music stopped, no available chairs.
Second FSI or simuflite don't have your company's analysis data. That's an analysis service paid for by your company, so there's going to be a certain disconnect between the boilerplate standard that the training vendor will provide, and what your company is doing, unless the company chooses to incorporate their data into the vendor's program.
Third, when you use an obstacle analysis and you're given something that's not standard, then standard operating procedure (eg, clean up at 400') no longer applies. You have non standard conditions; adapt accordingly.
Fourth, design certification criteria is not a hard 400' altitude. 400' is the MINIMUM altitude for flap retraction insofar as the climb gradient schedule is assigned. It can be higher, and that's not something that the manufacturer could know at the time of certification. The question for the manufacturer is strictly one of aircraft performance to meet a MINIMUM generic certification standard. What's actually required in the field, when rocks and hills and trees and a spinning Julie Andrews in a blue gingham skirt intervene, will determine what's actually required of the flight crew in order to stay alive. That's where your obstacle analysis comes in, and that analysis tells you how far from "SOP" you must deviate in order to remain safe and alive.
If SOP says clean up at 400' and considers an engine failure at V1, the obstacle analysis differs by considering an engine failure at any point from V1 thereafter until you've cleared the obstacles, and tells you that you had better keep the climb going to XXX altitude, if you want to live. Remember Arnold the Terminator, "Come with me if you want to live?" That's the obstacle analysis. Ignore it at your risk.
On a given day, we might normally clean up at 400' or a thousand feet, or whatever the company procedure might be, but today we will be cleaning up at a different altitude, thanks to the benefit of the obstacle analysis which not only tells us that we can safely depart, but how to do it. Thanks Arnold, next time Julie.
APG is a Aircraft Performance Group, which provides runway analysis for a given runway on a given day under given conditions. A runway analysis takes into account not just temperature, runway length, and weight, but also obstacles in the departure path, for a specific aircraft performance model. A runway analysis isn't about wringing extra performance or bang-for-the-buck out of an airplane. It's about safety.
It's a good idea to know before you take off that while at JFK on a given day you could use diverse climb criteria for the departure (200'/nm) for the climb, today at XXX airport you need something else. You view the chart and determine what the required climb gradient is, and then determine if you can make that climb gradient at this temperature and weight. In a departure procedure, there may be multiple points in the departure that require a certain climb; can you make them all? Can you make them with an engine-out? That's where the runway analysis comes in.
The runway analysis is telling you that you need to do something other than standard in the event of an engine failure or power loss, and here's what you do. You can view it as a gimmick the company is using to enable them to legally operate at that field, or you can view it as the lifesaving piece of equipment and tool that it is, and incorporate it into your briefing and fly it as briefed, to save your life.
Yes, on a given day with no obstacles, you could fly the minimum certification profile for departure, and there's nothing to hit. Today, not so. Today, as you brief for takeoff, with an engine failure, there's no configuration change until 1750', at which time you will turn left heading 180, level the aircraft, clean up to Vf, and then continue your climb to 10,000. Etc. Today your terrain and obstacles require it. Today isn't a departure without obstacles. Today, if you want to live you'll take advantage of the runway analysis which has been prepared for your departure, and fly it.
Note that even diverse departure criteria for an area departure from a given runway assumes a climb to 400' before turning on course and climbing at a rate of 200'/nm enroute. If a runway as diverse climb criteria, you can do that; takeoff, turn any direction, and climb at the minimum gradient. If it doesn't, then you'll need a departure procedure, obstacle departure, or runway analysis to allow you to know what climb is required. Note that you've got to be able to do this with all engines, or with an engine-out; even if you lose an engine, the obstacles are still there, and must still be cleared. Unless your company has been issued a special engine-out procedure (the proverbial "pink pages" from Jepp), then you will make a determination if you can do it using the runway analysis provided. The runway analysis says "yes, you can do it, but you'll need to do it this way." If you choose not to do it that way, then no, you can't do it.
The alternative, if you don't want to take advantage of a detailed obstacle analysis for your departure, is to get out a sectional and chart and plotter and do all the math in determining exactly what distances to what obstacles in the departure you can make with an engine out, and what climb gradients you'll have at what point. I've seen many departure analysis which tell me I'm fine until obstacle #15 in the departure procedure that I'm requesting, and then I'm in trouble. To do the calculations to that point, assuming I had a way of getting that data at all, would have been arduous and taken a very long time. I had the data quickly, in the cockpit, before engine start, thanks to an obstacle analysis program. Because that program is approved and has all the data necessary to safely fly out, I need to adhere to it. Likewise, if the program tells me that I can't fly the procedure, even though I think I can...I can't. Legally, it's my butt.
A few years ago I was called to the company office to defend an airman, as his union representative. He made a departure in Afghanistan, which contains some very tall rocks. He had made a departure from the same runway the night previous, under nearly identical conditions, with a nearly identical load. When all of his trip data was placed in an envelope at the end of the trip and sealed up for the company, he figured it was done. As it turned out, he was not.
The trip data is occasionally reviewed, and spot checked. It's kept for a certain period of time, and the company would pick packets at random (or not, depending on one's sinister views) for inspection. In this case, they opened his trip packet, and reviewed his takeoff and landing data. It turned out that he couldn't accept the runway assignment. It was a last minute assignment while taxiing, departing opposite direction, and though the crew had already completed all their planning and briefing for the former runway, they felt confident based on the previous night's flying that they'd be fine. As it turned out, there was one obstacle in the departure procedure that they accepted which made it a no-go. All-engines, no problem. The obstacle analysis determined that with an engine-out, however, based on the departure they selected, there would be a problem. It was a technical issue that had to do with the input into the program; had they selected it as a VFR departure rather than an IFR departure in the obstacle analysis, the program would have let them go. They'd run it all previously the night before, and off they went. When the company ran the numbers from the comfort of a stateside office, they caught the error, and we all ended up in a review board, and I ended up in negotiations with the Chief Pilot in order for the captain to keep his job.
He did, but it was close.
Take the obstacle analysis seriously. Run the numbers yourself on some of the departures to see if they fly, and run them using a different profile to see if they don't.
Today, we will continue the climb to 1250' before cleaning up, as indicated in our departure obstacle analysis. Liberal, Kansas, we woiuldn't need to do that. Newark, not a problem. Here, today, tonight, this runway, this weight, this temperature, this departure, we do. We'll leave takeoff flaps set until 1250', then clean up, because we have a professional obstacle analysis that tells us that if we dont', and we lose an engine, we will lack the climb gradient performance to meet the obstacle clearance requirements for the selected departure procedure.
A number of years ago, I flew for a fractional operator. There was a small hill at one end of a runway, and there was a numbers-oriented individual in the company who took the time to calculate that with an engine-out on the runway at V1, we'd strike the hill XX feet below the top. We couldn't climb over the hill. The solution was simple, really. Go around the hill. Left, right, didn't matter. Go around the hill. Visually, it could be done. Not on instruments, however. A low visibility day, or low ceiling, or both, one couldn't maneuver around the hill, and shouldn't. The obstacle analysis for the hill was different under visual conditions, and under instrument conditions.
You'll note that some departure procedures specify a minimum visibility on departure, for the same reason.
Some departures have a lot of potential obstacles. Aspen, as you've noted, is one of them. A glance at the SARDD3 obstacle departure identifies a requirement of 460'/nm to 14,000,' along with departure minimums of 400' and 1 mile. (Why the ceiling and visiblity requirement? The procedure requires greater than standard/diverse climb criteria, and so places the ceiling in 100' increments above the controlling obstacle on the initial departure, and requires a minimum visibility of a mile)
You could climb to 400' and initiate your clean-up, but you'd still have to maintain 460'/nm in order to do it, while doing it. You can't put the climb gradient on hold while you do it. Obstacles and terrain don't give you a pass or tell you to take your time while they wait. They're still there, and the laws of physics still apply. If you can clean up at 400' and still make the grade, have a ball, but you have a very useful tool in your obstacle analysis which is telling you to change your cleanup altitude for that departure from that runway on that day in that aircraft, to a different number. Ignore it at your peril.
Standard operating procedure means doing something the same way under standard conditions. If you have a runway analysis or obstacle analysis which is telling you that the departure requires something else, then you don't ignore it simply to follow "SOP." Operating conditions are no longer standard. Now you need to do something else.
Going back to the SARDD3, the takeoff obstacle notes include:
Rwy 33: Multiple trees beginning 35' from DER, 386' right of centerline, up to 100' AGL/7722' MSL. Multiple trees, bushes and terrain beginning 4' from DER, 400' left of centerline, up to 100' AGL/7821' MSL. Multiple trees, bushes, and terrain beginning 2484' from DER, 752' left of centerline, up to 100' AGL/8179' MSL.
Do you want to whip out the aircraft flight manual and calculate your departure based on those obstacles, individually, overlay them into the departure procedure, compare them to the obstacle departure as well as your other procedures, make a comparative analysis against your aircraft performance on all engines and with an engine-out, compare that to the standard procedure of cleaning up at 400', and then make a decision? Or would you rather have that all done for you and presented as an obstacle analysis with the data already tied off with a pretty pink ribbon? I'd rather have the full analysis, and use that valuable tool to my advantage in planning my departure, do that I know I can make the grade in the event of an engine failure at any point.
I understand what you're saying. You're conflicted between what seems to be an inflexible and possibly unwise company standard procedure of cleaning up at 400,' on each takeoff, and the question of keeping yourself configured to a higher altitude in the event an obstacle analysis says otherwise. You don't have a training department, but use an outside vendor such as Simuflite or FSI. You're conflicted between being told to clean up at 400,' and following the guidance from the obstacle analysis which is telling you that you need to climb higher before cleaning up. I get it.
First, the obstacle analysis is a safety tool, and it's also got some legal teeth. Ignore it at your peril. If anything happens and you're asked why you had the data and ignored it, you'll be spinning in the wind, music stopped, no available chairs.
Second FSI or simuflite don't have your company's analysis data. That's an analysis service paid for by your company, so there's going to be a certain disconnect between the boilerplate standard that the training vendor will provide, and what your company is doing, unless the company chooses to incorporate their data into the vendor's program.
Third, when you use an obstacle analysis and you're given something that's not standard, then standard operating procedure (eg, clean up at 400') no longer applies. You have non standard conditions; adapt accordingly.
Fourth, design certification criteria is not a hard 400' altitude. 400' is the MINIMUM altitude for flap retraction insofar as the climb gradient schedule is assigned. It can be higher, and that's not something that the manufacturer could know at the time of certification. The question for the manufacturer is strictly one of aircraft performance to meet a MINIMUM generic certification standard. What's actually required in the field, when rocks and hills and trees and a spinning Julie Andrews in a blue gingham skirt intervene, will determine what's actually required of the flight crew in order to stay alive. That's where your obstacle analysis comes in, and that analysis tells you how far from "SOP" you must deviate in order to remain safe and alive.
If SOP says clean up at 400' and considers an engine failure at V1, the obstacle analysis differs by considering an engine failure at any point from V1 thereafter until you've cleared the obstacles, and tells you that you had better keep the climb going to XXX altitude, if you want to live. Remember Arnold the Terminator, "Come with me if you want to live?" That's the obstacle analysis. Ignore it at your risk.
On a given day, we might normally clean up at 400' or a thousand feet, or whatever the company procedure might be, but today we will be cleaning up at a different altitude, thanks to the benefit of the obstacle analysis which not only tells us that we can safely depart, but how to do it. Thanks Arnold, next time Julie.
10-14-2015, 03:51 AM
#17
Gets Weekends Off
Joined APC: Oct 2008
Position: JAFO- First Observer
Posts: 997
To the OP, check out AIM 5-2-8, which explains Obstacle Departures (ODP's). It is a common misconception that air carrier crews must comply with the IFR Departures, Including ODP's, that have a published climb gradient, and be able to make that climb gradient with the loss of an engine. SIDs and ODP's assume that ALL engines are operating. There is no regulatory requirement to "make" the published climb gradient on one engine.
However, 14 CFR Part 121 and 135 regulations Require that the air carrier have "contingency" or "extraction plans" in the event of an engine failure and the published (TERPs) SID or ODP cannot be flown safely. This is where Airport Analysis and special "tailored" engine out departure procedures come into play. APG, Aero Data etc are some of the companies that develop such procedures. Note that for Corporate (Part 91) operations, engine out extraction plans are not required by regulation. However, Most corporate flight departments realize the benefits of using airport analysis and voluntarily use the services of APG or Aero Data as part of their SMS/SRM.
FAA, in concert with NBAA, has produced some great videos on the subject. If you go to the NBAA web site and do a search, you will find great information which Mirrors what I have outlined here.
Hope this helps.
However, 14 CFR Part 121 and 135 regulations Require that the air carrier have "contingency" or "extraction plans" in the event of an engine failure and the published (TERPs) SID or ODP cannot be flown safely. This is where Airport Analysis and special "tailored" engine out departure procedures come into play. APG, Aero Data etc are some of the companies that develop such procedures. Note that for Corporate (Part 91) operations, engine out extraction plans are not required by regulation. However, Most corporate flight departments realize the benefits of using airport analysis and voluntarily use the services of APG or Aero Data as part of their SMS/SRM.
FAA, in concert with NBAA, has produced some great videos on the subject. If you go to the NBAA web site and do a search, you will find great information which Mirrors what I have outlined here.
Hope this helps.
Last edited by PerfInit; 10-14-2015 at 03:52 AM. Reason: Spelling error
10-14-2015, 11:16 AM
#18
Gets Weekends Off
Thread Starter
Joined APC: Feb 2010
Posts: 2,278
Thanks for bringing that up PerfInit. I actually had a class where the majority of experienced pilots had been limiting their takeoff weight at certain airports because they thought they had to meet the departure procedure climb gradients even after an engine failure.
Again, I am not disputing anything you have said, nor is it news. My issue was trying to justify my company's SOP of cleaning up at 400 ft AGL. I do include any engine failure paths in my briefings, but when every APG runway analysis I have seen calls for a flap retraction altitude much higher than 400 ft AGL, the solution is not as simply as modifying the flap retraction altitude to meet APG, because that means we be modifying the SOP 100% of the time. It will require retraining of both the pilots, sim instructors, and training centers. All of our procedures and checklists have been built off the assumption that at 400 ft, the flaps are always retracted, and changing that can introduce new threats.
One example is on this aircraft, you cannot exceed 200 KIAS with the flaps down. Since we are used to accelerating to 250 KIAS after takeoff or sometimes level off as low as 1,500 ft AGL on departure, moving our flap retraction altitude to what APG says can cause flap over speeding issues. And I am not going to get into the implications this has on the stabilizer of the Citation Excel.
So again, if you review my original post, I wanted to know if there was a way we could keep using the 400 ft acceleration height SOP while using APG for dispatch to prevent having to invest so much time and energy into creating new SOPs that satisfy the APG runway analysis. As I thought at the beginning, there does not appear to be a way to do that, and new SOPs are required.
Originally Posted by JohnBurke
If SOP says clean up at 400' and considers an engine failure at V1, the obstacle analysis differs by considering an engine failure at any point from V1 thereafter until you've cleared the obstacles, and tells you that you had better keep the climb going to XXX altitude, if you want to live. Remember Arnold the Terminator, "Come with me if you want to live?" That's the obstacle analysis. Ignore it at your risk.
One example is on this aircraft, you cannot exceed 200 KIAS with the flaps down. Since we are used to accelerating to 250 KIAS after takeoff or sometimes level off as low as 1,500 ft AGL on departure, moving our flap retraction altitude to what APG says can cause flap over speeding issues. And I am not going to get into the implications this has on the stabilizer of the Citation Excel.
So again, if you review my original post, I wanted to know if there was a way we could keep using the 400 ft acceleration height SOP while using APG for dispatch to prevent having to invest so much time and energy into creating new SOPs that satisfy the APG runway analysis. As I thought at the beginning, there does not appear to be a way to do that, and new SOPs are required.
10-14-2015, 02:32 PM
#19
Disinterested Third Party
Joined APC: Jun 2012
Posts: 6,023
Originally Posted by 2StgTurbine
I actually had a class where the majority of experienced pilots had been limiting their takeoff weight at certain airports because they thought they had to meet the departure procedure climb gradients even after an engine failure.
Originally Posted by 2StgTurbine
I do include any engine failure paths in my briefings, but when every APG runway analysis I have seen calls for a flap retraction altitude much higher than 400 ft AGL, the solution is not as simply as modifying the flap retraction altitude to meet APG, because that means we be modifying the SOP 100% of the time. It will require retraining of both the pilots, sim instructors, and training centers.
Originally Posted by 2StgTurbine
So again, if you review my original post, I wanted to know if there was a way we could keep using the 400 ft acceleration height SOP while using APG for dispatch to prevent having to invest so much time and energy into creating new SOPs that satisfy the APG runway analysis.
Originally Posted by 2StgTurbine
One example is on this aircraft, you cannot exceed 200 KIAS with the flaps down. Since we are used to accelerating to 250 KIAS after takeoff or sometimes level off as low as 1,500 ft AGL on departure, moving our flap retraction altitude to what APG says can cause flap over speeding issues. And I am not going to get into the implications this has on the stabilizer of the Citation Excel.
After the wreck, in the next life, just explain it to the passengers this way: "Well, we were used to doing it the other way, and none of us were smart enough to account for obstacles on the departure. Therefore, we just kept doing it the only way we knew how, and well, you're all dead. Sorry."
I'm sure they'd buy that for a dollar.
10-14-2015, 03:32 PM
#20
Gets Weekends Off
Thread Starter
Joined APC: Feb 2010
Posts: 2,278
Originally Posted by JohnBurke
Perhaps that's because the experienced ones are smart enough to not want to run into a mountain side during an engine failure on departure.
Originally Posted by JohnBurke
Sure, you can keep ignorning the data that's bought and provided to keep you alive. You can run the numbers and determine that you can make it on two engines, and just go, and guess at whether you'll make it after an engine falure. By all means, have a ball.
Originally Posted by JohnBurke
All of which is entirely irrelevant if you maintain V2 until your clean up altitude as provided by APG.
I don't know what you deal is, but somehow you think I am some idiot who does not understand certification standards, aircraft performance charts, or runway analysis programs. I actually teach this stuff and have written manuals on implementing procedures to address this.
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