miller22
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Single Engine Escape Procedures

Wed Jan 06, 2010 5:03 pm

How common is it that an aircraft would not be able to meet the single-engine climb rate for a given SID?

Consider an example where an aircraft loses an engine on a SID, can't maintain the single-engine climb gradient required on the SID, and can't turn back to the departing airport due to weather. I've heard of escape procedures being developed for just this scenario, but exactly how common are these?

Does anyone have any examples?
 
Mir
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RE: Single Engine Escape Procedures

Wed Jan 06, 2010 5:08 pm

If you can't meet the climb requirements for the SID with an engine out, don't depart. Either take some weight off, wait for lower temperatures, etc. That solves most of the problems right there.

-Mir
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bri2k1
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RE: Single Engine Escape Procedures

Wed Jan 06, 2010 5:23 pm

SIDs do not have to be accepted anyway. If you can't meet the climb gradient for a SID, but you're planning on departing the airport anyway, you should have some idea of where you're going to go. When I'm in IMC, that's always on my mind -- which way to visual conditions in case of ice, mechanical failure, whatever.

Not being able to return to an airport due to weather, but still being safe to depart from it, seems like a narrow slice of circumstances, too. If you can land in 200 and 1/4, but the weather is below that, should you be taking off in the first place?
Position and hold
 
JETPILOT
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RE: Single Engine Escape Procedures

Wed Jan 06, 2010 5:57 pm

Airlines use runway analysis which gave you the maximum operating weight for a given runway at an airport. If you didn't meet the second segment climb requirment or any of that runways requirments then you were not legal to depart that runway. You can also use a runway with a tailwind if you can meet those requirments. You don't always need to takeoff into the wind. In San Jose CR it is not uncommon to see planes after 8 or 9AM start using the runway opposite direction becasue of the increasing daytime heat they can no longer meet the second segment climb gradient with the mountains. The runway in the opposite direction is downslope and has no mountains but usually has a slight tailwind. We can take that if we meet those weight requirments which are often higher.
 
miller22
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RE: Single Engine Escape Procedures

Wed Jan 06, 2010 6:29 pm

I'm thinking more from a planning perspective. How common are escape procedures for an airline's operation into a specific airport. I know I've seen some of them before, but can't remember any specific examples.
 
miller22
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RE: Single Engine Escape Procedures

Wed Jan 06, 2010 6:36 pm



Quoting Bri2k1 (Reply 2):
If you can land in 200 and 1/4, but the weather is below that, should you be taking off in the first place?

This is the idea behind a takeoff alternate, which most definitely exist. This is considering a part 121 operation deciding whether an airline would start service into a city with an escape procedure. I know that it has in the past. I'm just curious if anyone has any examples.
 
DashTrash
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RE: Single Engine Escape Procedures

Wed Jan 06, 2010 9:24 pm

Escape maneuvers are pretty common. At my old job we called them special departure procedures. They were broken down into simple or complex specials. A simple procedure would give you a point at which you commenced a turn, then a flap retract altitude. A complex special may have a couple of turns in it predicated off various fixes. DCA has a complex special. ROA, BTV, IPT, PIT, LGA, ITH, AGS are some airports that had simple specials. We had the procedure listed on the perf data in the release.

The company I work for now uses charted escape procedures at ASE, EGE, TEX, SUN, and a couple of others. They are considered VFR maneuvers and allow lower than standard climb gradients. We still can't use them for IMC departures, and although we may fly it should we lose an engine, they don't give us any relief on the departure minimums.

Without an escape procedure you must be able to maintain a 3.2 climb gradient to a safe altitude in IMC, or 1.6 in VMC. If flying a SID that states a higher climb gradient you must be able to meet that requirement, or you cannot fly the SID.

All second segment climb gradients are single engine.
 
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glen
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RE: Single Engine Escape Procedures

Thu Jan 07, 2010 10:23 am

A lot of SID procedures may not be suitable to follow in case of engine failure due to several reasons:

- SID's are based on gradients from 3.3% up to approx. 9%, while the the aircraft minimum required one-engine-out performance is 2.4%(2-engine aircraft) and 3.0%(4-eng a/c).
- There are different SID's published for one runway
- The aerodrome obstacle chart usually covers a straight climb area, whereas SIDs often turn away from this sector.

The standard engine-out procedure therefore is to climb on RWY track to 1500 ft AAL, then turn back to the aerodrome. Acceleration and clean-up after the turn. Hold over the airport.

At airports where terrain conditions don't allow this procedure specific Engine Failure Climb Out Procedures (EFCOP) are designed to allow a safe climb out in case of engine-failure at V1.
"The horizon of many people is a circle with zero radius which they call their point of view." - Albert Einstein
 
flyinTLow
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RE: Single Engine Escape Procedures

Thu Jan 07, 2010 11:57 am



Quoting Mir (Reply 1):
If you can't meet the climb requirements for the SID with an engine out, don't depart. Either take some weight off, wait for lower temperatures, etc. That solves most of the problems right there.

That's not correct at all.

A lot of SIDs have climb gradients due to many different reasons (not only terrain, but also noise abatement, airspace structure, military shooting areas, etc.). One of the best examples for that is ZRH. Whoever departed out of there on RWY 28 knows what I am talking about. SID for ZRH is a bunch of turns which basically take you back overhead the airport with a teardrop and then continue to whereever you want to go.
The EOSID (that's what you are talking about, Engine Out SID, which is developed for each and every RWY) for RWY 28 (at least with my company) is something like 7.5 DME KLO RT follow R280 KLO and so on.

Thilo
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miller22
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RE: Single Engine Escape Procedures

Fri Jan 08, 2010 10:54 pm

DashTrash,GLEN, and FlyinTLow,

All great information, thanks!

It's my understanding that the escape procedures are carrier and aircraft specific. Is this the case?
 
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glen
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RE: Single Engine Escape Procedures

Sat Jan 09, 2010 6:50 am



Quoting Miller22 (Reply 9):
It's my understanding that the escape procedures are carrier and aircraft specific. Is this the case?

Normally they are not aircraft specific. As all planes require the same climb gradient in the engine-out case (see reply 7) they can use the same engine-failure climb out procedure. As a 4-engine aircraft requires a slightly higher gradient you are save on a procedure which is designed for a 2-engine a/c anyway.
There can be cases where a procedure might be aircraft specific (or only for a group of aircraft). E.g. if there is a speed limit in the procedure for a turn to stay within the protected area.

These procedures can be carrier specific, but there are many companies having them designed and calculated by someone else - therefore many carriers have the same procedures from one supplier.
"The horizon of many people is a circle with zero radius which they call their point of view." - Albert Einstein

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