Climb Performance and Escape Routes
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Climb Performance and Escape Routes
Has anyone figured out an easy way of proving satisfactory climb performance will be available after takeoff?
The ERSA Runway Distances Supplement data apparently doesn't meet the "surveyed area" requirements. It only goes out to 600m.
If you're taking off from, say, a non-towered airport on a dark and stormy night, how do you prove that you'll be able to maintain terrain separation whilst climbing the aircraft to MSA/LSALT?
I'm told that operators are required to use the services of a surveying organisation to design an "escape route". These routes then have to be regularly re-asessed and amended.
Since many airports throughout Australia have been issued with GNSS RNAV approaches, this surveying must have already been done, and must also be regularly re-asessed (presumably by AirServices). Just a thought - why haven't SIDs been published by AirServices for these airports?
It'd be pretty simple to use. Blast off, and if an engine fails, follow the SID. If not, set course and you're on your merry way.
If SIDs were available, it'd take a lot of stress from situation of losing a donk after take-off, whether you're in a Duchess or a bizjet. You'd know the best path to follow, and what climb gradient would be required to stay out of the trees. Better still, have them in the 'ol GPS database, and you've then got a CDI to follow.
Thoughts?
The ERSA Runway Distances Supplement data apparently doesn't meet the "surveyed area" requirements. It only goes out to 600m.
If you're taking off from, say, a non-towered airport on a dark and stormy night, how do you prove that you'll be able to maintain terrain separation whilst climbing the aircraft to MSA/LSALT?
I'm told that operators are required to use the services of a surveying organisation to design an "escape route". These routes then have to be regularly re-asessed and amended.
Since many airports throughout Australia have been issued with GNSS RNAV approaches, this surveying must have already been done, and must also be regularly re-asessed (presumably by AirServices). Just a thought - why haven't SIDs been published by AirServices for these airports?
It'd be pretty simple to use. Blast off, and if an engine fails, follow the SID. If not, set course and you're on your merry way.
If SIDs were available, it'd take a lot of stress from situation of losing a donk after take-off, whether you're in a Duchess or a bizjet. You'd know the best path to follow, and what climb gradient would be required to stay out of the trees. Better still, have them in the 'ol GPS database, and you've then got a CDI to follow.
Thoughts?
goneferrying,
The only problem with your idea is that SIDs do not guarentee minimun terain clearence single engine!
Operators of high-capacity aircraft have to have single engine procedures and "escape route" even at airfields with SIDs. You will note many SIDs havve minimun climb gradients published on them. The designer of the SID has no way of knowing whether your aircraft can meet those gradients. It is up to the operator to ensure the aircraft can, or have an alternate procedure if it can't.
The only problem with your idea is that SIDs do not guarentee minimun terain clearence single engine!
Operators of high-capacity aircraft have to have single engine procedures and "escape route" even at airfields with SIDs. You will note many SIDs havve minimun climb gradients published on them. The designer of the SID has no way of knowing whether your aircraft can meet those gradients. It is up to the operator to ensure the aircraft can, or have an alternate procedure if it can't.
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Hi Wiz,
Surely if the SIDs state the climb performance requirement (the required gradient), then pilots would simply need to confirm that their aircraft can do better than that.
Eg: SID says you need 3.3%. AFM says aircraft will do 12% with both running, or 4.2% with one stopped. No dramas.
Am I missing something?
When I say "SIDs", I guess I'm talking more about a simple surveyed path to follow that has a known climb gradient requirement. I wasn't thinking so much about the SIDs at major airports that are designed more for directing traffic flow.
It just strikes me as bizarre that there's a surveyed, known-gradient GNSS RNAV at so many airports, but no surveyed, known-gradient departure. Seems to me that this could be fixed by AirServices (or whoever) by drawing a few lines on existing survey data, and publishing it as a SID or whatever. GNSS NP"D" maybe? ;-)
Surely if the SIDs state the climb performance requirement (the required gradient), then pilots would simply need to confirm that their aircraft can do better than that.
Eg: SID says you need 3.3%. AFM says aircraft will do 12% with both running, or 4.2% with one stopped. No dramas.
Am I missing something?
When I say "SIDs", I guess I'm talking more about a simple surveyed path to follow that has a known climb gradient requirement. I wasn't thinking so much about the SIDs at major airports that are designed more for directing traffic flow.
It just strikes me as bizarre that there's a surveyed, known-gradient GNSS RNAV at so many airports, but no surveyed, known-gradient departure. Seems to me that this could be fixed by AirServices (or whoever) by drawing a few lines on existing survey data, and publishing it as a SID or whatever. GNSS NP"D" maybe? ;-)
Last edited by goneferrying; 3rd Feb 2006 at 18:03.
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4.2% on one is highly unlikely in the duchess or ANY piston twin that I know of. Most of em struggle to do the 1% required as it is! 
Like your ideas goneferrying, but have a look at some of the climb performance problems associated with Canberra or Cairns for example.
Like your ideas goneferrying, but have a look at some of the climb performance problems associated with Canberra or Cairns for example.
Moderator
(a) CASA would have the (GA) pilot do his own analysis .. generally difficult to impracticable depending on the runway concerned.
(b) the minimum survey length depends on the runway classification per ERSA.
(c) a couple of phone calls usually is all it takes to find out if much data exists and who has/controls it (starting point is the airport owner .. often the local council) .. it may or may not take dollars to get the information ... depends on the folks involved. Unless there is a mandated obligation on service providers to do so I don't think that you will see gratuitous information in published data due to the potential for liability.
(d) SID is fine for GA if the weight is constrained for OEI situation .. but that, in general, means that you are taking off with not much on board .. suggest one pays some consideration to areas of interest in terms of splays ...
(e) not quite as simple an exercise, though, as you are suggesting
(f) simple gradient doesn't cut it as one still needs to allow for acceleration profiles (for larger aircraft)
However, this is an important topic and hopefully the thread will generate a bunch of discussion ...
(b) the minimum survey length depends on the runway classification per ERSA.
(c) a couple of phone calls usually is all it takes to find out if much data exists and who has/controls it (starting point is the airport owner .. often the local council) .. it may or may not take dollars to get the information ... depends on the folks involved. Unless there is a mandated obligation on service providers to do so I don't think that you will see gratuitous information in published data due to the potential for liability.
(d) SID is fine for GA if the weight is constrained for OEI situation .. but that, in general, means that you are taking off with not much on board .. suggest one pays some consideration to areas of interest in terms of splays ...
(e) not quite as simple an exercise, though, as you are suggesting
(f) simple gradient doesn't cut it as one still needs to allow for acceleration profiles (for larger aircraft)
However, this is an important topic and hopefully the thread will generate a bunch of discussion ...
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The aircraft I fly will not climb at minimum gradient with OEI. I do not have access to surveyed obstacle clearance charts. I do however have an excellent knowledge of the areas surrounding the airfields I use.
For example, for my home airfield, following an EF in IMC after take-off, I would ... follow the SID to about 7DME or so, turn left off the SID, commence the approach from overhead the airfield. All this regardless of altitude, as long as it's above normal circuit altitude.
I know that the above is not very professional (quantitatively calculated, risk-assessed, demonstrably proven to be safe). I have written it to hear criticisms, and more importantly, how the average joe bloggs without an Operations Department and a Planning Department can do things better.
Looking forward to more posts,
O8
For example, for my home airfield, following an EF in IMC after take-off, I would ... follow the SID to about 7DME or so, turn left off the SID, commence the approach from overhead the airfield. All this regardless of altitude, as long as it's above normal circuit altitude.
I know that the above is not very professional (quantitatively calculated, risk-assessed, demonstrably proven to be safe). I have written it to hear criticisms, and more importantly, how the average joe bloggs without an Operations Department and a Planning Department can do things better.
Looking forward to more posts,
O8
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Oktas8
Good on you for raising the subject again in an enquiring and proactive manner.
Fact is; your GA aircraft =<5700kg right up to the turboprop Conquest and Kingair are not required by certification to demonstrate other than a +ve (=+50fpm) EFATO rate of climb and the ability to maintain level flight (have +50fpm climb available for turbulence) with one engine inop and the propeller feathered etc. at 5,000ft.
That they may have in excess of that in the EFATO case is more a result of the installed HP being required for some other purpose, say runway length, higher and faster considerations. Its a complex design issue balancing it all out economically and efficiently within the boundaries of the market competition, weight limit and the laws of physics.
As the sage john-t points out the only way you can "emulate" or achieve the gradients around which the paltes are designed is to understand the gradient requirements in the first place for ALL phases of flight and aircraft configuration and go to the manufacturers books and work it out.
It's in there, but as john-t points out it is not very encouraging at all.
The manufacturers are careful to point out that "continued flight" in the EFATO take off case is "the least desirable" option available to the pilot during that period before you reach an altitude that will give you obstacle clearance and an opportunity to finish cleaning up the aircraft and establishing stable flight and even some climb.
SIDS unless you have seriously reduced the TOW in most types are not an option.
IMHO you are in full scale emergency mode and an immediate return to the airport WHEN IT IS POSSIBLE after climb to an appropriate height and configuration, which will allow a stable circuit turns without loss of height and airspeed or if that is not possible using the available engine to extend your options forward to find the least worst alighting area.
Get the books out, and work the exercise step by step, metre by metre plotting distance, altitude and gradient with an engine failure after TO below 50ft and zero ROC in turns at MTOW for say ISA+10 and see where you get to for a return to the runway or the completion of a SID. NOTE somewhere in the book usually under the Engine Imop climb charts the manufacturer will have the -ve ROC numbers for windmilling prop, gear and flap. Add em up for the EFATO at takeoff and the number is quite impressive and shows where that "blazing" 1000+fpm all engine ROC goes all so quickly.
Then work out from what height you need to intitate a 1 engine inop go round.
Thats usually whats gets em
and whether you can make the escape profile.
For a C421, engine windmilling -400fpm, gear down -350fpm, flaps15 -200fpm, flaps45 -800fpm. and thats got a bit of grunt too.
Then work it out backwards to the permissible TOW.
It's a fun
exercise and may put a whole new light on the way you have perceived EFATO matters thus far.
It's a requirement anyway. There are many pilots who didn't and they and there passengers paid the ultimate price.
=>5,700kg airline types have it already worked out as it is part of the certification requirement, its there in the manual and takes moments to apply.
Good on you for raising the subject again in an enquiring and proactive manner.
Fact is; your GA aircraft =<5700kg right up to the turboprop Conquest and Kingair are not required by certification to demonstrate other than a +ve (=+50fpm) EFATO rate of climb and the ability to maintain level flight (have +50fpm climb available for turbulence) with one engine inop and the propeller feathered etc. at 5,000ft.
That they may have in excess of that in the EFATO case is more a result of the installed HP being required for some other purpose, say runway length, higher and faster considerations. Its a complex design issue balancing it all out economically and efficiently within the boundaries of the market competition, weight limit and the laws of physics.
As the sage john-t points out the only way you can "emulate" or achieve the gradients around which the paltes are designed is to understand the gradient requirements in the first place for ALL phases of flight and aircraft configuration and go to the manufacturers books and work it out.
It's in there, but as john-t points out it is not very encouraging at all.
The manufacturers are careful to point out that "continued flight" in the EFATO take off case is "the least desirable" option available to the pilot during that period before you reach an altitude that will give you obstacle clearance and an opportunity to finish cleaning up the aircraft and establishing stable flight and even some climb.
SIDS unless you have seriously reduced the TOW in most types are not an option.
IMHO you are in full scale emergency mode and an immediate return to the airport WHEN IT IS POSSIBLE after climb to an appropriate height and configuration, which will allow a stable circuit turns without loss of height and airspeed or if that is not possible using the available engine to extend your options forward to find the least worst alighting area.
Get the books out, and work the exercise step by step, metre by metre plotting distance, altitude and gradient with an engine failure after TO below 50ft and zero ROC in turns at MTOW for say ISA+10 and see where you get to for a return to the runway or the completion of a SID. NOTE somewhere in the book usually under the Engine Imop climb charts the manufacturer will have the -ve ROC numbers for windmilling prop, gear and flap. Add em up for the EFATO at takeoff and the number is quite impressive and shows where that "blazing" 1000+fpm all engine ROC goes all so quickly.
Then work out from what height you need to intitate a 1 engine inop go round.
Thats usually whats gets em and whether you can make the escape profile. For a C421, engine windmilling -400fpm, gear down -350fpm, flaps15 -200fpm, flaps45 -800fpm. and thats got a bit of grunt too.
Then work it out backwards to the permissible TOW.
It's a fun
exercise and may put a whole new light on the way you have perceived EFATO matters thus far.It's a requirement anyway. There are many pilots who didn't and they and there passengers paid the ultimate price.
=>5,700kg airline types have it already worked out as it is part of the certification requirement, its there in the manual and takes moments to apply.
Moderator
... which is why my renewal briefs were always along the line of "touch anything below 200 feet and we land straight ahead ....." ... got better things to do than kill myself needlessly ...
one of the pleasures I have missed in life is not having had the opportunity of flying with you.
Silly Old Git
Going in from Blighty we made it to 18000' by over Lake Geneva John , then a big dirty dive on Turino.
Coming out we went home via Lyon (14000')I think. It would have taken a fortnight to climb up the Geneva route.
Man the ice there in summer , never want to see that again !
Ahhhh the Whistling Wheelbarrow.
Coming out we went home via Lyon (14000')I think. It would have taken a fortnight to climb up the Geneva route.
Man the ice there in summer , never want to see that again !
Ahhhh the Whistling Wheelbarrow.
