Is anyone out there using the Aircraft Performance Group (APG) Airport Obstacle Analysis special departure procedures?
Our company just bought into the program and we are all going through the training now. Any real life experience good or bad? The idea is getting a rough welcome from the pilots at our company and causing a lot of concerns. The idea of switching from the published DP to the special DP in the FMS after losing an engine above V1 in the mountains is what concerns us the most all this while in IMC.
What have your experiences been in particular around mountainous airports?
Any info appreciated.
APG Airport Obstacle Analysis
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hawker driver
- Rank 5
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Re: APG Airport Obstacle Analysis
HD: I don't have experience with APG, but I have used Jeppesen and AeroData for flight planning. Both will offer engine-out procedures that can differ significantly from the published departure. Is the concern workload, and is your op single-pilot or two crew?
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fougapilot
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Re: APG Airport Obstacle Analysis
We use APG for our operation.
When we came on board with APG, I had a long list of questions and had a lengthy phone conversation with APD's performance guru. The only thing I can say is that they know their stuff.
It is true that their numbers are significantly different from what you and I would come up with, but the safety margin (as per FAR/CAR requirements) are still respected.
One thing we tend to forget is that a SID is based on ALL engines being operating. Now a days, most SIDs are designed to meet ATC , navigation and/or noise requirements. A SID might require a significant climb gradient, but it most likely is not be for obstacle clearance. An example comes to mind; Fort of France in Martinique. The SID for the runway that heads over the ocean (with only a few sailboats as obstacle) has a 7%+ climb requirements. When we went there with our CL601, we could not take off with enough fuel to fly home and meet this climb requirement. But the SID required us to do a climbing RH turn and fly directly to a Navaid that sits on top of a hill - hence the steep climb. but should we loose an engine at V1, the last thing in the world I would do is turn towards a hill.
APG has quite a large number of topographic data. If memory serves, they have over 5000 airport with "escape route" in their data base. With this information, they are capable of determine the actual climb requirement to avoid the obstacles. Remember, a SID or Obstacle procedure will never list a climb lower then 3.3% (200'/nm). However, in specific location, a lower gradient can safely provide obstacle avoidance. One thing we also do not know is the real climb gradient required for this specific takeoff. The published information on obstacles clearance procedures assume you will fly over the departing end of the runway with an engine failed, at V2 and at 35ft. Truth be told, rarely will your takeoff be equal to the available runway. Suppose for a second that your t/o distance is 3500' and the runway is 7000' long. You will start your climb with still 3500' of runway in front of your nose. The climb gradient specified in the t/o procedure no longer applies for you are already well above it. So, to maintain the same obstacle clearance, you could have a flatter climb which allows you to t/o heavier.
APG will never tell you the actual climb gradient required to avoid obstacles at a specific airport. If they did, they would go out of business for we could do our own math, give it to all our friends... They will however give you the V speeds, the maximum t/o weight and the reason for the weight limitation (structural, runway length, obstacles...) and if need be an escape procedure. One thing you need to remember is APG will provide you the MAXIMUM t/o weight to clear obstacles. Nobody says by how much you will clear obstacles, but you will clear them.
Hope this helps,
F
When we came on board with APG, I had a long list of questions and had a lengthy phone conversation with APD's performance guru. The only thing I can say is that they know their stuff.
It is true that their numbers are significantly different from what you and I would come up with, but the safety margin (as per FAR/CAR requirements) are still respected.
One thing we tend to forget is that a SID is based on ALL engines being operating. Now a days, most SIDs are designed to meet ATC , navigation and/or noise requirements. A SID might require a significant climb gradient, but it most likely is not be for obstacle clearance. An example comes to mind; Fort of France in Martinique. The SID for the runway that heads over the ocean (with only a few sailboats as obstacle) has a 7%+ climb requirements. When we went there with our CL601, we could not take off with enough fuel to fly home and meet this climb requirement. But the SID required us to do a climbing RH turn and fly directly to a Navaid that sits on top of a hill - hence the steep climb. but should we loose an engine at V1, the last thing in the world I would do is turn towards a hill.
APG has quite a large number of topographic data. If memory serves, they have over 5000 airport with "escape route" in their data base. With this information, they are capable of determine the actual climb requirement to avoid the obstacles. Remember, a SID or Obstacle procedure will never list a climb lower then 3.3% (200'/nm). However, in specific location, a lower gradient can safely provide obstacle avoidance. One thing we also do not know is the real climb gradient required for this specific takeoff. The published information on obstacles clearance procedures assume you will fly over the departing end of the runway with an engine failed, at V2 and at 35ft. Truth be told, rarely will your takeoff be equal to the available runway. Suppose for a second that your t/o distance is 3500' and the runway is 7000' long. You will start your climb with still 3500' of runway in front of your nose. The climb gradient specified in the t/o procedure no longer applies for you are already well above it. So, to maintain the same obstacle clearance, you could have a flatter climb which allows you to t/o heavier.
APG will never tell you the actual climb gradient required to avoid obstacles at a specific airport. If they did, they would go out of business for we could do our own math, give it to all our friends... They will however give you the V speeds, the maximum t/o weight and the reason for the weight limitation (structural, runway length, obstacles...) and if need be an escape procedure. One thing you need to remember is APG will provide you the MAXIMUM t/o weight to clear obstacles. Nobody says by how much you will clear obstacles, but you will clear them.
Hope this helps,
F
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youngtimer
- Rank 2
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- Joined: Fri Aug 03, 2007 4:57 pm
Re: APG Airport Obstacle Analysis
At one of my previous employs, we started looking (not using) APG figures for use in the mountains. Now these were supposed to be tailored to the aircraft for single engine departures, but were not yet certified at the time and may have been early on in the developement of APG's data. Anyways, one of the mountain airport (I can't remember which) single engine departures as per APG was checked out by another pilot very familiar with that area, and it would have flown the aircraft into a building, thus making me very nervous about APG. Again, this was awhile ago and single engine margains of error will be tight but don't go blindly using numbers without looking and making sure they make sense, just like everything else in life.
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hawker driver
- Rank 5
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Re: APG Airport Obstacle Analysis
Thanks for the information,
I just heard from our safety committee and they are supportive of the APG program but want the training to be improved. We are now waiting on management to come back with an improved way of presenting the program and explaining it to the pilots. Until then they will not sign off on it.
I also heard from one of our Legacy pilots who did the confirmation flights with the inspectors watching in the simulator. His opinion was that the margin of error was very small for the escape maneuver when departing Aspen with an engine out.
Seeing as Aspen and Eagle are some of our regular destinations we will be looking into that closer.
What was your training like? Classroom or computer based? How much time was allotted for the APG training?
Our initial ILS PRM training which was computer based was just the FAA video and a quiz. After that we would have to do one in the simulator every year.
I just heard from our safety committee and they are supportive of the APG program but want the training to be improved. We are now waiting on management to come back with an improved way of presenting the program and explaining it to the pilots. Until then they will not sign off on it.
I also heard from one of our Legacy pilots who did the confirmation flights with the inspectors watching in the simulator. His opinion was that the margin of error was very small for the escape maneuver when departing Aspen with an engine out.
Seeing as Aspen and Eagle are some of our regular destinations we will be looking into that closer.
What was your training like? Classroom or computer based? How much time was allotted for the APG training?
Our initial ILS PRM training which was computer based was just the FAA video and a quiz. After that we would have to do one in the simulator every year.
Re: APG Airport Obstacle Analysis
The standard climb gradient as per design criteria(ICAO Pans ops, US terps and CDN TP308) for diverse/route departures is 200ft/NM which incorporates 48ft/nm ROC based on a 40: 1 slope(2.5%) from the DER(departure end of runway). The actual climb gradient is 152ft/nm (6076.1/40) + 48ft/nm = 200ft/nm.
If there is a penetration of the 40:1 slope we still give you the 48ft/nm over the penetration, that’s why you get a C/G in excess of 200ft/nm to a CTA(climb to altitude) to which further application of the increased C/G isn’t required.
I assume – and please correct me if I am wrong – the APG will still give you the 152ft/nm but a much lower ROC, hence the “flatter” C/G which is about all you may get in a engine out situation.
Also the 35ft above the DER is no longer applicable for IAP Diverse Departure here in Canada and same for Terps, Pans Ops, however if APG uses the DER +35ft in their calculations, well all the better for you because the OIS(obstacle identification surface) is now higher by 35 ft.
I have seen some pictures of airports internationally and I ofter wonder about the certification standards, if there are any at all.
If there is a penetration of the 40:1 slope we still give you the 48ft/nm over the penetration, that’s why you get a C/G in excess of 200ft/nm to a CTA(climb to altitude) to which further application of the increased C/G isn’t required.
I assume – and please correct me if I am wrong – the APG will still give you the 152ft/nm but a much lower ROC, hence the “flatter” C/G which is about all you may get in a engine out situation.
Also the 35ft above the DER is no longer applicable for IAP Diverse Departure here in Canada and same for Terps, Pans Ops, however if APG uses the DER +35ft in their calculations, well all the better for you because the OIS(obstacle identification surface) is now higher by 35 ft.
I have seen some pictures of airports internationally and I ofter wonder about the certification standards, if there are any at all.
