Engine Failure on Takeoff! Flight Path?

[Slick]

Muttley, don't be scared me old mate, nobody wants to hurt you.

Nobody really appears to know what route to follow once your engine fails.

Sure they do, name an airport an airplane and lets see what happens ! (europe and a twin fan might be a good place to start)


Best Rgds

Can't work this quote thing.

[ 21 July 2001: Message edited by: Slick ]

[Max Angle]

Chimbu chuckles,

Thanks for the view from another side of the biz. I think this thread shows that some at least, on the airline side of life are more than willing to question and if needed, modify our company procedures to produce what we think is a safe operation. One poster said that we were "scaring" him, but at least we are keen and interested enough to be having the debate at all. Most of our colleagues, I suspect, have not given it a second thought. I for one am very happy to have this kind of discussion and hopefully I will learn from it and take something onboard that will help me one day. Roll on PPruNE!

[ 21 July 2001: Message edited by: Max Angle ]

[BOAC]

Mutt, I too hope you enjoyed your units!

To state that Boeing just 'build aircraft' is to denigrate a large part of the service they provide. Boeing do provide an analysis of take-off performance for any runway if you pay and there is performance info. available to enable any operator to check each SID route for terrain clearance and work out emergency turns/EOSIDs if required.

I say again, know how your ops dept calculate this, and follow the procedures unless you have a VERY good reason for not doing so. The thought of people 'spearing off' straight ahead because it seemed like a good idea at the time fills me with fear too.

The really difficult ones are where you have NO published performance data or SIDs and there that=airmanship.

[Stan Woolley]

BOAC

OK see my post above, I believe you fly 737's, can yours climb at 8% single engine at 50 tons,Flap5?I ask again what would you do?

[Capn Laptop]

Last Sector Power, You want to hope that they DO fly straight ahead if there is no published escape procedure.

When calculating takeoff weight charts, it is necessary to assess all the obstacles within the takeoff flight path.

As there may be many SIDS, all turning in different directions, it is normal practice to look at the straight ahead flight path, and if that becomes uneconomic because of terrain, then design a turn.

Turns are a pain because you need to assess radaii of turn at different speed/flap configurations, where straight ahead procedures are not speed dependent.

So - in the event of a failure on the runway, follow the escape procedure or if there isn't one, go straight ahead!

PS for all aeroplanes the analysis needs to be done up to the LSA/MSA not 1500 ft,

12nm is nowhere near enough to get to 1500 ft if the aircraft is performing at NETT. ie 1.6% for a twin.

A twin performing at nett (which is all you are guaranteed!) will climb at 97 ft per nm. A 4 engine aircraft climbing at nett will climb 121 ft per nm.

So for a twin to reach 1500 ft (assuming that the terrain underneath is not rising) it will consume 15.5 track miles.

I look out to 30 nm when I run an analysis, using type A's, topos etc



[ 22 July 2001: Message edited by: Capn Laptop ]

[safety_worker]

Capn Laptop - Hear! Hear!
I couldn't agree with you more.
The perf dept must consider a range of speeds (different fleets), obstacles (determine a corridor width), state the bank angles(15deg/20deg depending on the height and position), etc, etc,. This is important to creating a 'Standard' for the 'Company' (helps cross fleet training safety).
What we must do is to spread this knowledge to all pilots. The last thing one needs is to get into the cockpit and have to explain it all, during the preflight briefing, to a colleague who doesn't 'know it'. So get the company's performance department and the fleets rattled to issue the 'knowhow and the procedures' to fly the departure on an engine failure (doesn't matter how many engined aircraft it is - it should be a standard for the company).
Speaking to ATC in the middle east, all they want to hear, if you are NOT flying their departure instructions, is a 'MAYDAY' or a 'PAN PAN PAN'. It will put them on their toes and they follow a checklist. Here the traffic is not too bad most of the time, except at dusk. Wonder what the European(LHR,CDG,FRA,etc,)/American (Chicago, DFW, LAX etc) ATCs .....think...or...do!
Chimbu Chuckles? Wonder what they think/do in the Far East?.... and Africa?
I wonder if the checklist for ATC is the same the world over, or do they, too, have different opinions as this thread (well we are now enlightened)?
We need to spread this subject with all pilots/concerned personnel, in our companies. We might fly with them one day, OR we might fly with them one day...(in the back!!! )

[Crossunder]

To reply to the original question; which flight path would I follow?
Well, I would follow the fligh path that would ensure obstacle clearance (you know, the one you are supposed to calculate before take-off...). You are not allowed to take off unless:
a) You are able to follow the SID (after an engine failure at Vef)
b) You (your Company) have made a contingency (emergency) procedure which ensures obstacle clearance.
It is as simple as that! And as for the Class A climb gradient requirements; they have nothing to do with obstacle clearance, they shall merely ensure a minimum of manoeuvring capability during climbout. You guys must distinguish between certification and real-life operations.
And as for that fly straight ahead bull****; what the h*** is that? If you do not have an approved engine failure procedure at hand, then why the hell are you taking off in the first place??? Flying IMC below the MSA without following published procedures is irresponsible and I hope I will never have to fly with any of you "straight-ahead"-guys!

[safety_worker]

Crossunder - the engine failure 'on takeoff' could be out of an airport on an island, Male, Maldives. Straight ahead would be ok, no obstacles.
Straight ahead, is okay, provided obstacles are studied within the are as dictated by norms laid down for obstacle clearances/establishing an emergency turn.
What are your company's 'rules/norms' for calculating obstacle clearances regarding an 'engine failure on a twin'?
Bob ... wouldn't happen to be Lt. Col. Hammond?

[Crossunder]

Regarding the island departure; of course the straight ahead procedure could be used, but then this would have to be stated on the plate / in the company's SOP. What I am trying to say is that it isn't up to the pilot right there and then to decide what to do in the event of an engine failure, it must be carefully calculated beforehand in the form of an approved / published procedure.

Where I fly, the pilots don't have to think about it bacause the Flight Support department have issued engine failure procedures (plates) for every AD we use. We just study these before taking off...

[safety_worker]

Crossunder - 'xackerley! That's the way it should be. Every pilot should know the safest course at all times - situational awareness you say? (not only in this situation - call it mission planning for the whole flight)
Do all airlines/operators have this Engine Failure Porcedure for the airfield before their pilots step into a cockpit?
Regulations say (imply by covering their rears) we should!
No 'one' policy for different airlines out of the same airport exists. But as long as it's safe, and taught, and briefed,.....and exists, that's my concern w.r.t. thread.
I feel much better with the thoughts this thread has provoked. Still.....

[Mr Benn]

Have just read through 4 pages of this thread.
Surely it is not as confusing as you are all making it?
Personally I would say this.

We are talking about an early engine failure case here.

*If my company has a published Emeregency Turn procedure, I will follow it.
*If it does not I will do what I briefed.
*What I brief depends on the airport and what surrounds it, terrain wise.
*If I have an engine failure I am going to declare a mayday and can therefore go where I like. I will however tell ATC so they can move others out of my way.
* I will remain responsible for terrain clearance.
*In an emergency, noise abatement procedures can be ignored.
*If I was planning on going straight ahead then that is what I would brief. If there was any terrain ahead then I would brief that.
Surely everyone does that?

You look at the plate, you see what is around, you work out what you are going to do in an engine failure case and you brief it?

Why the confusion? Some people posting here sound like they only brief "straight ahead" or "emergency turn" procedures.

Surely good airmanship means you would say more than just "I will fly straight ahead"?

I would normally brief something like
"if we have an engine failure I will climb straight ahead to MSA (state), then I will ask for radar vectors back to the airport for an ILS (or whatever) approach. If we have more time or we require more time I will fly to XXX navaid and take up the hold".

What is so confusing? Its an emergency, we do what we need to and what we want to to ensure the aircraft remains safe. And we brief it in advance to avoid any confusion.

Or am I missing the point here?

[Speedbird252]

Mr Benn calls it correct me thinks.

There are bound to be variations to this, but it must surely be close to the norm, noise and terrain permitting?

[NorthernSky]

Now, I've put the sunglasses on which means (a) I'm confident of what I'm about to say, though with the caveat that it applies to UK CAA/JAA operators and the requirements placed thereon, and (b) if you disagree, your glaring red faces won't upset me too much.....

First, may I say I'm astounded at the lack of knowledge and awareness displayed relating to this issue. Nothing personal, but Crossunder's post above illustrates my point very clearly.

In general terms, an aircraft commander must know he can make a flight safely. It is only in those terms that Crossunder's comments make sense. However, the regulatory authorities are responsible, again in very general terms, for creating the information environment, and they have not seen fit to provide or require sufficient data to make other than an extremely cursory analysis of the terrain around airports.

First FACT: If there is no emergency turn, then the NTOFP takes you safely straight ahead off the runway to 1500ft and 25nm. In those 25nm you will normally plan to make MSA, and achieve this. Perf A guarantees that the Nett aircraft will be safe.

Second FACT: No aircraft performance data (that I have seen or worked with) analyses SIDs for terrain. Why should they? SIDs are written to get an aircraft from one place to another expeditously, in a manner which suits local ATC requirements, and minimises noise nuisance. SIDs are not of interest to most performance planners, and many seem to pay no heed to them at all. Indeed, one performance provider often says 'Follow the SID' for engine failure in cases where the SID takes you sraight towards the mountains (the performance provider's name is hard to spell, and the airfields involved are coastal Mediterranean). If you doubt this, ask yourself what you would do if you arrive at work and there is a temporary change to a SID - and your performance data does not reflect this change, or when (almost everyday) your departure instructions are to deviate from the SID track and fly a heading. Can you not, then take off, if you cannot fly the precious SID?

The reason for the lack of terrain analysis in SIDs is that (i) the terrain information is not available other than in some instances at great cost and in a format which makes manipulation difficult and (ii) by the time you start to throw in turn performance, raw data navigational accuracy, wind effects, and so on, the calculations become too difficult and vague to be of value, and thus would often be very limiting.

So, that is the performance-related case for following the EOSID or emergency turn (basically the same thing only different), or going straight ahead where no other procedure exists. Of course, as commander, you may do what you like, but if you clang into the hill, you'll carry the can.....

Now, why shouldn't you follow the SID? Well, first, we have seen that there's no assurance of terrain separation. Second, some SIDs involve turns very soon after take-off. Even in an acceptably modern aircraft, engaging the autopilots and executing ENG OUT in the FMC will leave you with drills to do and high workload while you monitor what the aircraft does. In the small Seattle product, do you want to be flying a forty degree turn manually at five hundred feet after take off with an engine on fire and failing while trying to carry out the appropriate drills and keep an eye on your colleague? I don't believe that's a sensible option.

Finally, there is some confusion in relation to ICAO document 8168 and what it says on this issue. Without my copy to hand, I recall that this document says you should follow the 'departure route' following a malfunction. This does NOT mean the 'Standard Instrument Departure', but relates to the route you plan to fly.

From the ATC point of view, once you have said 'Pan' or 'Mayday', you tell the controller what you're doing and he'll help you as much as he can. Here, we meet the issue of airspace, and again I cannot see the logic in, for example, deciding to follow a SID which takes you towards very busy airspace, in the event of a problem. So, brief staright ahead until at a safe altitude (not necessarily MSA; the radar controller will have a much, much lower, safe vectoring altitude which he can tell you about).

Remember the KISS principle: Keep It Simple and Safe.

I do believe, however, that this thread should be compulsory reading for performance departments and Chief Pilots. It illustrates how many are operating in the dark......

[mutt]

NothernSky,

Very interesting post, can i just ask you where you intend to find the obstacle data which covers up to 25 nms from the end of the runway?


Mutt.

[safety_worker]

Nothernsky - illuminating. Precisely the reason I started this thread, so colleagues/fellow aviators could become safer.
Mutt - I am not sure, but here are a variety of places - Appch Plates, State/Airport authorities, topographical charts, Jepp's database? Municipalities around the airport, etc.
Basically, if one really wants, go out there and find out the best you can. If you believe you have, create the EOSID/ET. If you come across a newly erected obstacle, revise the EOSID immediately and NOTAM it.

[john_tullamarine]

safety_worker,

I disagree quite strongly.

Either you address the whole takeoff .. or why bother worrying about any of it ? And the task need not be terribly difficult. We don't want to have a multiplicity of departures. All that is needed is for the ops eng guys to check if the normal path is ok with a failure anywhere along it. If not, then ALL takeoffs can be routed via the V1 OEI escape path.

It is most definitely inappropriate to assign this task to the pilot on the day .. he doesn't have the data and never has the time.

Max Angle,

The Type A data is fine, but of limited use ...

(a) it doesn't go far enough ... 1500 ft can be 40-plus miles out for a twin..
(b) many operators schedule turning flight paths for the very reason that the Type A path is too commercially restrictive because of the rocky bits ...

The 35 foot clearance is above the NFP so the expected clearance to the aircraft's GFP will be substantially in excess of this, and increasing, once you are on your way ...

Again, I would commend people to question their ops eng support people to find out what is and is not included in the specific runway analyses. And this can vary quite significantly from one organisation to another ..

Chimbu chuckles,

For most runways, there will be a multiplicity of potential escape paths.. the task of the ops engineer is to find that which gives the maximum RTOW while keeping the procedure itself reasonably reasonable for the poor guy trying to fly it. Of course, for some runways, there will, indeed, only be the one usable escape.

NorthernSky

I am afraid, dear colleague, that some of your views are the stuff of wishful thinking and fairytales...

For many runways, it is totally unreasonable to expect the pilots to have any reasonable way of addressing the NFP clearance requirements... it is the job of the ops engineers (or backroom pilots who know the ropes) who have the performance data .. and should have the best likelihood of sourcing obstacle data .. and it is this latter task which is the hard bit .. doing the sums is, by comparison, child's play.... (sorry, Mutt, monkey's play)

Where do you get the obstacle data ..? .. from wherever you can.. including throwing a theodolite over the shoulder and going bush if necessary .. the advent of satellite imagery data becoming commercially available makes the task a lot, lot easier .....


Guys and gals .... from the viewpoint of an old (conservative) performance (amongst other strange interests) engineer, airline pilot, and instructor pilot ... the underlying attitudes, wishful thinking, and unfortunate ignorance displayed in this thread is quite terrifyingly alarming.

The task is not easy in most cases .... but, please .... quiz your ops eng support people so that you KNOW what the story is .. then work out where you are intending to go after the concrete bit ends .... it is NOT a case of just going straight ahead .. or following this SID or that ... or any other far fetched idea .... if you don't know .. then you are playing Russian roulette with your aeroplane .....

.. and the simplest trick to give you a reasonable chance if you are not ABSOLUTELY sure that the terrain is benign, and you know that your ops eng people haven't looked at it ? ..... decline the SID and follow the V1 escape procedure for ALL departures, setting course once you are above the sector minima. This might be the stuff of ruffling feathers ... but the alternative is the old ostrich head in the sand approach .....

[NorthernSky]

John,

I enjoy the majority of your posts here, and am glad that you aren't afraid to put forward your views.

However, I think you missed the thrust of my post above.

Regarding pilot responsibility. I was saying, in rather more words, that because there is so little data available, and so little of it is accessible to pilots, an effective analysis is very difficult. We make a 'best guess' at each take-off as to the preferable way out of trouble, the same way we make many other professional judgements.

Regrettably, these matters cannot be as precise as you seem to suggest they should, that this is so is addressed within macro risk asessment.

Moreover, you echo my remarks about the paucity of terrain data. Some of it may be commercially available, but not all. That is why in the majority of cases the NTOFP which goes straight ahead is safe!!!

I object most strongly to airlines whose training departments blithely say 'follow the SID' when their performance is sourced from providers who clearly have not and cannot know whether the SID is terrain safe, but do know that going straight ahead is safe. Worst, I have a feeling that some of this is macho clap-trap driven by the belief that climbing straight ahead when you're in trouble is simply too easy.

Yes, some of the sums post-theodolite-trek may be simple enough, but they are still likely to result in low RTOWs, lower than those assuming a sraight-ahead climb or a simple emergency turn. It's also worth wondering why an airline would want to spend a fortune on assessing lots of terrain around lots of airports when the staright ahead/emergency turn data is already available...?

So, 'dear colleague', I think we are singing from the same hymn-sheet.

I'm glad I had those sunglasses on!

[safety_worker]

The purpose of this thread was to make pilots aware that:-
1. Their Flight Ops Support may 'not' have calculated their takeoff performance correctly. Ask them, satisfy your curiosity, make yourself safer, by knowing/making them know!
2. The SID, in an engine failure situation, 'may' not guarantee obstacle clearance/be the safest route (they don't HAVE to fly it) and ATC doesn't mind us deviating from it (just tell them)
3. Have a safety route out, no matter where you are in the SID.
I have colleagues who are sceptics about EOSIDs/ETs when a SID is issued by ATC, and I am sure all contributors to this thread has made a lot out there think, fly safer.
Their concern is that ATC would get 'upset' in a busy area like LHR, FRA, if we deviate from the SID.
LOL (no laughing matter)- Fly Safe, Engine failure call a mayday, fly safe the way it's stated (straight ahead, EOSID/ET, etc.) the way it was briefed.

Do all Airbus pilots know what their EOSIDs are in their FMGS? Check with your concerned depts!
Ta all.

[ 24 July 2001: Message edited by: safety_worker ]

[Capn Laptop]

There is obviously much confusion about this topic.

1. Pilots are NOT able to make assessments regarding obstacle clearance on the day - unless you are flying out over the water, the pilot does not have all the required data to hand (PS I am a Pilot)

2. If there is a runway specific RTOW chart, it should have been produced from obstacle data that looks out as far as is required to reach the LSA/MSA.

3. If there is a Runway specific RTOW chart, the weight that it produces is ONLY valid if you follow the flight path that was used to assess the obstacles, AND accelerate at the Acceleration Height nominated on the RTOW chart.

4. If someone has gone to the trouble of producing a RTOW chart, they will first look at a straight ahead flight path (cause it is easier) and if that doesn't produce an economically reasonable uplift, they will look for a turning procedure.

5. It is normal practice to NOT annotate the RTOW chart with a procedure UNLESS it is has turn - so if there is no specific instruction on tracking, assume straight ahead.

6. If you don't follow the flight path described (either straight ahead or curved as appropriate) you may as well not have bothered looking at the RTOW chart - cause the numbers are MEANINGLESS!

7. If you choose to ignore the acceleration height on the RTOW chart, and decide to extend the 2nd segment, you may as well not have bothered looking at the chart either - cause you have gone outside the conditions used to produce the weights on the chart. - and don't think that because there is terrain higher than the acceleration height in the extended flight path, that it hasn't been considered, you will probably find that the RTOW programme wants to accelerate the aircraft early, clean up, and then clear the obstacle in a clean configuration - mostly for 5 min eng limit considerations....

There endeth the lesson..

PS, We spend heaps and heaps of hours pouring over type A's, topo's etc, designing procedures, identifying obstacles etc, and whilst I can't speak for others, I go to great lengths to ensure that the RTOW charts and associated procedures I publish for the crews in ther airlines that I have worked, are safe, and easy to fly.

[NorthernSky]

Laptop,

I agree with almost everything you say, but would be interested to know what your evidence is for point (2)?

To my mind, by the way, RTOW charts deal with runway limits as well as with obstacle problems, so checking them is still valid even if you intend to deviate from the chosen route (this would normally be done approaching MSA on all engines, having decided it's safe to route direct to somewhere assuming terrain will be cleared even with a malfunction. Purists will note, correctly, that this is a grey area.