A captains dilemma re engine precautionary in-flight shut down
The minute you shut down an engine you MUST divert and land at 'the nearest suitable airport'.
CAO 20.6 The pilot in command of a multi-engine aircraft in which 1 engine fails or its rotation is stopped, may proceed to an aerodrome of his or her selection instead of the nearest suitable aerodrome if, upon consideration of all relevant factors, he or she deems such action to be safe and operationally acceptable.
An interesting area is if considering EDTO (ETOPS):
CAO 82.0 IFSD, or in-flight shutdown, means an engine:
(a) ceasing to function normally in flight for any reason;
So if non EDTO, it doesn't matter whether you shut the engine down or not, you can go where you like.
EDTO, it doesn't matter whether you shut the engine down or not as it is considered to be the same thing, you then have to go to the nearest suitable.
may proceed to an aerodrome of his or her selection instead of the nearest suitable aerodrome if, upon consideration of all relevant factors, he or she deems such action to be safe and operationally acceptable
Once you decide to bypass the nearest airport that suits your operation, you are entering a legal no-man's-land! You really are gambling on the fact that nothing else will go wrong!
That said, Operators Manuals, Aircraft Manuals and Checklists are often more restrictive in what you should or can do in certain situations, so CAO 20.6 may not be that useful in the circumstance.
Last edited by Capt Fathom; 21st Jul 2011 at 06:40. Reason: grammar
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If there's something wrong with an engine you shut it down, because if things get worse you could end up in front of the Court of Inquiry, which will be a lot worse.
Apart from that if you get to your destination and have to do a go-around, it could get very dire indeed.
Apart from that if you get to your destination and have to do a go-around, it could get very dire indeed.
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Flawless logic and command judgment
With the benefit of hindsight it could be argued the crew might have been tempted to shut down the engine in the air if they had known about 174 first stage turbine blades all curly and twisted. Especially if by sheer bad luck they had a go-around and used the bad engine not knowing what had happened in the guts of the engine. But of course, flawless logic and command judgement meant a go-around was a million to one chance and would never happen
.
So if non EDTO, it doesn't matter whether you shut the engine down or not, you can go where you like.
EDTO, it doesn't matter whether you shut the engine down or not as it is considered to be the same thing, you then have to go to the nearest suitable.
EDTO, it doesn't matter whether you shut the engine down or not as it is considered to be the same thing, you then have to go to the nearest suitable.
I do not agree the CAO implies "go where you like". You'd be a very brave captain to deliberately overfly a suitable aerodrome if there were no operational reasons eg wx, blocked runway or navaid failure for not landing there.
Suitable has a specific meaning in the CAO as we all know. However in a legal sense there are broader issues.
For example "Bloggs, why did you overfly a perfectly good airport, deemed as suitable, to fly further to airport x?"
"Well due to the pathetic coverage of RFFS in this country I considered providing a higher level of safety to my passengers and crew by flying to an airport with RFFS for our arrival and landing on one engine (insert failure)"
For example "Bloggs, why did you overfly a perfectly good airport, deemed as suitable, to fly further to airport x?"
"Well due to the pathetic coverage of RFFS in this country I considered providing a higher level of safety to my passengers and crew by flying to an airport with RFFS for our arrival and landing on one engine (insert failure)"
If the dud engine is running at idle within all limits, I'll take the use of its ancillaries every time. An in flight shut down is often irrevocable within a short time span.
Once on the ground, by all means shut it down.
Once on the ground, by all means shut it down.
However in a legal sense there are broader issues.
Perhaps.
What is this legal leg I would not be able to stand on?
Turn around over MEK head back to ZNE ~ 205 nm plus the turn.
Continue from overhead MEK to PH ~ 340 nm
ZNE no RFFS, poor facilities, PH has RFFS and all that a capital city can offer.
Difference of about 135 nm at say 480 knots ~ 17 minutes difference, probably less with a 180 degree turn over MEK. So about 15 minutes difference.
So NOW you want to throw a second engine failure at me. Okay. How many second engine failures have ever been recorded? Not simultaneous like the Hudson River A320. Not fuel starvation. Separate unrelated engine failures on a twin jet?
At least when "the second donk quit" as you put it. My idling other engine would give me power and hydraulics. To the point of impact anyway.
What is this legal leg I would not be able to stand on?
Turn around over MEK head back to ZNE ~ 205 nm plus the turn.
Continue from overhead MEK to PH ~ 340 nm
ZNE no RFFS, poor facilities, PH has RFFS and all that a capital city can offer.
Difference of about 135 nm at say 480 knots ~ 17 minutes difference, probably less with a 180 degree turn over MEK. So about 15 minutes difference.
So NOW you want to throw a second engine failure at me. Okay. How many second engine failures have ever been recorded? Not simultaneous like the Hudson River A320. Not fuel starvation. Separate unrelated engine failures on a twin jet?
At least when "the second donk quit" as you put it. My idling other engine would give me power and hydraulics. To the point of impact anyway.
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Can't agree with the logic that by keeping a 'sick' engine running you are not obliged to land ASAP (twin engined aircraft). If said engine is not capable of sustaining flight (on it's own) you are essentially single-engine ops, no "ifs or buts". The aircraft will have no redundancy, and is down to one critical system - the opposite good engine. Surely airmanship; a lawyer would have a field day listening to anyone arguing otherwise.
What if said engine runs ok at 1/2 thrust? It gets murky. You've gotta decide the 'sustain flight' conundrum and be certain it'll get no worse.
If you do have a recalcitrant donk, but can keep it running, do so for the other services it provides. However, consider actioning the shutdown checklist - barring fuel control to shutoff - and perform a single engine approach (ie speeds / flap settings) and brief a single engine G/A using only the good engine. By doing this, should the engine misbehave further - particularly during a high-workload time (eg approach) - all you have to do is move the fuel control switch to cut-off. No interruptions to the profile; no changes to the briefing...
Finally, an engine shutdown with all nearby airfields about 'fogged' out, whatever, is considered a 'double failure' (on a non-ETOPS segment) - ie statistically not considered. All bets are now off, and the safer course of action could be an unauthorised autoland versus a 2 hour slog to a suitable airport. It'll be your decision on the day ... too many variables to list.
My thoughts....
What if said engine runs ok at 1/2 thrust? It gets murky. You've gotta decide the 'sustain flight' conundrum and be certain it'll get no worse.
If you do have a recalcitrant donk, but can keep it running, do so for the other services it provides. However, consider actioning the shutdown checklist - barring fuel control to shutoff - and perform a single engine approach (ie speeds / flap settings) and brief a single engine G/A using only the good engine. By doing this, should the engine misbehave further - particularly during a high-workload time (eg approach) - all you have to do is move the fuel control switch to cut-off. No interruptions to the profile; no changes to the briefing...
Finally, an engine shutdown with all nearby airfields about 'fogged' out, whatever, is considered a 'double failure' (on a non-ETOPS segment) - ie statistically not considered. All bets are now off, and the safer course of action could be an unauthorised autoland versus a 2 hour slog to a suitable airport. It'll be your decision on the day ... too many variables to list.
My thoughts....
Last edited by Static in the Attic; 25th Jul 2011 at 05:06. Reason: Corrections
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What is required vs what is reasonable
Icarus,
Some Devil's advocacy:
Do you believe that an engine that has gone bang, physically vibrated and shown excessive TGT but will apparently run OK at idle or somewhere short of normal thrust settings has "failed"?
Does your QRH say for engine failure "Land at nearest suitable airport"?
How would a reasonable person view it, given that it clearly is not capable of normal operation and may be on the verge of further performance degradation or complete failure?
Here is the test you may have to meet, from CASA Draft Part 91:
Overhead MEK, where is the nearest suitable? And in your PER option, consider (4)(l) carefully...
This is nothing new, as it reflects much of CAO 20.6, but it now will have a specific penalty provision as well as potential administrative action against your licence (no double jeopardy!).
Stay Alive,
Some Devil's advocacy:
Do you believe that an engine that has gone bang, physically vibrated and shown excessive TGT but will apparently run OK at idle or somewhere short of normal thrust settings has "failed"?
Does your QRH say for engine failure "Land at nearest suitable airport"?
How would a reasonable person view it, given that it clearly is not capable of normal operation and may be on the verge of further performance degradation or complete failure?
Here is the test you may have to meet, from CASA Draft Part 91:
91.170 In-flight emergencies
...
(2) The pilot in command of a multi-engined aircraft commits an offence if:
Penalty: 50 penalty units.
(3) It is a defence to a prosecution for an offence against subregulation (2) that:
...
(2) The pilot in command of a multi-engined aircraft commits an offence if:
(a) during a flight of the aircraft, an engine fails or its rotation is stopped; and
(b) the pilot does not:
(b) the pilot does not:
(i) fly the aircraft to the nearest aerodrome that is suitable for landing the aircraft; and
(ii) land the aircraft at the aerodrome.
(ii) land the aircraft at the aerodrome.
(3) It is a defence to a prosecution for an offence against subregulation (2) that:
(a) the pilot flew the aircraft to, and landed at, an aerodrome (the alternative aerodrome) that was not the nearest aerodrome suitable for landing the aircraft; and
(b) the pilot believed, having considered the matters mentioned in subregulation (4), that it was safe to fly the aircraft to, and land the aircraft at, the alternative aerodrome; and
(c) the belief was reasonable in the circumstances.
(4) For paragraph (3) (b), the matters are the following:(b) the pilot believed, having considered the matters mentioned in subregulation (4), that it was safe to fly the aircraft to, and land the aircraft at, the alternative aerodrome; and
(c) the belief was reasonable in the circumstances.
(a) the nature of the malfunction that caused the engine to fail, or caused its rotation to stop, and the possible mechanical difficulties that may occur if the flight continued beyond the nearest aerodrome suitable for landing the aircraft;
(b) the availability of the inoperative engine to be used;
(c) the altitude of the aircraft and whether it is able to maintain a safe altitude;
(d) the weight of the aircraft and the amount of usable fuel remaining;
(e) the additional distance to be flown to the alternative aerodrome, taking into account the aircraft’s performance availability should another engine fail;
(f) the relative characteristics of the nearest aerodrome and the alternative aerodrome;
(g) weather conditions on the route to the nearest aerodrome and the alternative aerodrome and at other possible landing places;
(h) air traffic congestion on the route to, and at, the nearest aerodrome and the alternative aerodrome;
(i) the pilot’s familiarity with the nearest aerodrome and the alternative aerodrome;
(j) the type of terrain to be flown over on the route to the nearest aerodrome and the alternative aerodrome;
(k) whether the flight to the nearest aerodrome or the alternative aerodrome will be over water;
(l) whether the flight to the nearest aerodrome or the alternative aerodrome will be over a populous area.
(5) An offence against subregulation (1) or (2) is an offence of strict liability.(b) the availability of the inoperative engine to be used;
(c) the altitude of the aircraft and whether it is able to maintain a safe altitude;
(d) the weight of the aircraft and the amount of usable fuel remaining;
(e) the additional distance to be flown to the alternative aerodrome, taking into account the aircraft’s performance availability should another engine fail;
(f) the relative characteristics of the nearest aerodrome and the alternative aerodrome;
(g) weather conditions on the route to the nearest aerodrome and the alternative aerodrome and at other possible landing places;
(h) air traffic congestion on the route to, and at, the nearest aerodrome and the alternative aerodrome;
(i) the pilot’s familiarity with the nearest aerodrome and the alternative aerodrome;
(j) the type of terrain to be flown over on the route to the nearest aerodrome and the alternative aerodrome;
(k) whether the flight to the nearest aerodrome or the alternative aerodrome will be over water;
(l) whether the flight to the nearest aerodrome or the alternative aerodrome will be over a populous area.
Note For the defence of sudden or extraordinary emergency, see section 10.3 of the Criminal Code.
This is nothing new, as it reflects much of CAO 20.6, but it now will have a specific penalty provision as well as potential administrative action against your licence (no double jeopardy!).
Stay Alive,
