Four Donk Plane with two out
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Four Donk Plane with two out
Hello, all you four engine drivers out there..
Can you please tell me if on your type there is any chance at all of it flying with two engines gone after V1, and if yes, at what weight and with how much runway eaten up?
regards, OORW
Can you please tell me if on your type there is any chance at all of it flying with two engines gone after V1, and if yes, at what weight and with how much runway eaten up?
regards, OORW
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How about explaining the basis of your query so one would know how to answer. Are you a layman, flightsimmer, private pilot or airline pilot? This is a professional section- couldn't you perhaps phrase the question a bit better- you may be offended if the answer comes in the same vein!
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Depends on the aircraft weight and speed. If the aircraft is clean and you have speed, it will fly quiet well. R of C wont be ballistic but you will stay in the air, if you maintain speed.
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The answer to
1) is yes, and BA occasionally practised it in the sim for what that is worth
2) Not a lot
3) No idea
From a 2 engined driver who asked a four-engined (BA) driver. If your question is on issues around the BRU crash I would be certain it would not fly.
1) is yes, and BA occasionally practised it in the sim for what that is worth
2) Not a lot
3) No idea
From a 2 engined driver who asked a four-engined (BA) driver. If your question is on issues around the BRU crash I would be certain it would not fly.
“… is any chance at all of it flying with two engines gone after V1,”
Yes, providing the aircraft is flown at or above Vmca2.
In those aircraft which are allowed to dispatch with an engine inoperative (ferry flight) this is the basis of the take off calculations. The takeoff speeds are chosen so that V2 >= Vmca2.
There may be specific handling procedures when on the runway to accelerate the three good engines to mitigate the effects of Vmcg1, i.e. two engine roll, the third engine accelerated at higher airspeed. Calculations also take into account take off / climb weight, which generally is not a problem for ferrying.
In some aircraft types / situations there may be a small period of risk if an engine fails after V1 but before V2 (Vmca2). At this point probabilities come into the equation e.g. is the failure an asymmetric or symmetric engine, will it occur between V1 and V2. IIRC there are differing certification standards in this area, i.e. some authorities allow the risk, others require V1=V2>Vmca2.
The requirements and resultant probabilities in certification are the bases of not considering a four engine take off with two failing at a critical stage of take off. This is not to say it will not or has not happened, but it is sufficiently remote not to worry about (train) at a critical stage of flight. Where such failures have occurred some crews have been able to mitigate the assumptions of certification e.g. IIRC at BAe146 lost 2.5 engines shortly after rotate (TNT, Rome, Geese??).
Yes, providing the aircraft is flown at or above Vmca2.
In those aircraft which are allowed to dispatch with an engine inoperative (ferry flight) this is the basis of the take off calculations. The takeoff speeds are chosen so that V2 >= Vmca2.
There may be specific handling procedures when on the runway to accelerate the three good engines to mitigate the effects of Vmcg1, i.e. two engine roll, the third engine accelerated at higher airspeed. Calculations also take into account take off / climb weight, which generally is not a problem for ferrying.
In some aircraft types / situations there may be a small period of risk if an engine fails after V1 but before V2 (Vmca2). At this point probabilities come into the equation e.g. is the failure an asymmetric or symmetric engine, will it occur between V1 and V2. IIRC there are differing certification standards in this area, i.e. some authorities allow the risk, others require V1=V2>Vmca2.
The requirements and resultant probabilities in certification are the bases of not considering a four engine take off with two failing at a critical stage of take off. This is not to say it will not or has not happened, but it is sufficiently remote not to worry about (train) at a critical stage of flight. Where such failures have occurred some crews have been able to mitigate the assumptions of certification e.g. IIRC at BAe146 lost 2.5 engines shortly after rotate (TNT, Rome, Geese??).
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Depending on weight (mass for you European folks), altitude, and ambient temperature, it is possible to contine the climb, with two engines failed, on the same side.
Possible with the B707, and B747.
An example.
Circa 1985, location JED, type B747SP.
Max AUW, departing 34L, ambient temperature 28C.
At 200 agl, severe vibs from number two.
Number two throttle retarded, vibs decreased (as would be expected).
Throttle advanced again (bad idea) at 400 agl.
Severe vibs again from number two, then bang.
Number two now finished, and bits from number two migrated to number one.
Number one still producing rated thrust, however the F/E notices that number one fire pull handle red light is eluminated, but no fire bell.
Without saying anything, F/E now acts on his own, and pulls number one fire pull handle.
Resultant configuration: 800 agl, on two engines only (3&4).
Captain (PF) starts slow descent, requests flap retraction on speed schedule, requests immediate fuel dumping.
Clean speed reached at 200 agl, and a very shallow climb established, for a return for landing.
Aircraft landed 34L, without futher incident using reduced flap setting.
As can be seen, a failure of two engines in the immediate climb after takeoff can be accomplished successfully, if flown correctly.
Very doubtful with two engines failed while on the runway...at all but the lowest of weights.
Possible with the B707, and B747.
An example.
Circa 1985, location JED, type B747SP.
Max AUW, departing 34L, ambient temperature 28C.
At 200 agl, severe vibs from number two.
Number two throttle retarded, vibs decreased (as would be expected).
Throttle advanced again (bad idea) at 400 agl.
Severe vibs again from number two, then bang.
Number two now finished, and bits from number two migrated to number one.
Number one still producing rated thrust, however the F/E notices that number one fire pull handle red light is eluminated, but no fire bell.
Without saying anything, F/E now acts on his own, and pulls number one fire pull handle.
Resultant configuration: 800 agl, on two engines only (3&4).
Captain (PF) starts slow descent, requests flap retraction on speed schedule, requests immediate fuel dumping.
Clean speed reached at 200 agl, and a very shallow climb established, for a return for landing.
Aircraft landed 34L, without futher incident using reduced flap setting.
As can be seen, a failure of two engines in the immediate climb after takeoff can be accomplished successfully, if flown correctly.
Very doubtful with two engines failed while on the runway...at all but the lowest of weights.
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B747-200 simulator:-
Wt 280,000kgs X-wind 10 kts, temp +5C Nacelle anticing 'on', sea level airport (no terrain).
No 1 failed at V1 +5kts and No 4 failed at Vr.
Gear up and climb of 200-300fpm to 1000'aal. Level flight clean-up.
B747-400 simulator:-
Wt 380,000kgs, wind calm, temp +28C sea level airport (no terrain).
No 4 failed at V1+5kts and No 3 failed at 800' rad.alt.
Slow descent ( trading alt. for accel.) and flaps retracted at bug speed -5kts. Lowest alt. reached 400' rad.alt. Accelerated to 280 kts to turn into live engines (not possible at Flaps up speed).
In both cases, fuel jettison (2000kgs per min.) not used until after flaps retracted.
For either 747 types, flight following failure of both adjacent engines at between V1 and Vr would probably be impossible - but I stand to be corrected by anyone who has had time in the sim to experiment.
Wt 280,000kgs X-wind 10 kts, temp +5C Nacelle anticing 'on', sea level airport (no terrain).
No 1 failed at V1 +5kts and No 4 failed at Vr.
Gear up and climb of 200-300fpm to 1000'aal. Level flight clean-up.
B747-400 simulator:-
Wt 380,000kgs, wind calm, temp +28C sea level airport (no terrain).
No 4 failed at V1+5kts and No 3 failed at 800' rad.alt.
Slow descent ( trading alt. for accel.) and flaps retracted at bug speed -5kts. Lowest alt. reached 400' rad.alt. Accelerated to 280 kts to turn into live engines (not possible at Flaps up speed).
In both cases, fuel jettison (2000kgs per min.) not used until after flaps retracted.
For either 747 types, flight following failure of both adjacent engines at between V1 and Vr would probably be impossible - but I stand to be corrected by anyone who has had time in the sim to experiment.
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F/E now acts on his own ...
Had a similar incident on the Electra years ago where the F/E pulled the handle (in the blink of an eye and during the landing flare, mind you) when a prop decoupled.
Post flight, we thought that his action showed initiative .. but that it might have been better had he consulted with the pilots prior to doing something which could have had significant consequences.
I presume that a like discussion occurred after your example ?
Had a similar incident on the Electra years ago where the F/E pulled the handle (in the blink of an eye and during the landing flare, mind you) when a prop decoupled.
Post flight, we thought that his action showed initiative .. but that it might have been better had he consulted with the pilots prior to doing something which could have had significant consequences.
I presume that a like discussion occurred after your example ?
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I presume that a like discussion occurred after your example ?
F/E
Immediately terminated, with an exit visa issued within 48 hours.
Captain.
A very experienced guy on B747 and TriStar aircraft, received a company commendation, and three months additional salary.
He retired to Australia two years later (he was a native Australian).
A superb airman and well respected by all who knew him.
F/O
Complained to the B747 fleet manager that he was not kept in the 'loop' with the Captains actions.
Fleet manager read the riot act to this guy, and sent him back to the simulator, with a suggestion that he RTFB on two engines inop scenarios.
The Captain also stated that he thought it was inappropriate to hold 'ground school' for the F/O, while trying to keep the blue side up and avoiding terra firma.
Fleet manager agreed and in addition, sent all local F/O's to the sim for additional engine inop scenarios.
All B747 F/E's...likewise.
The company was very fortunate to have, in command of that particular flight, an experienced Captain who positively knew what he was doing.
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To clarify my original query: im a two engine bus man. Never been anywhere near a quad.
Yes, the question was inspired by the BRU accident, and also by another thread about tri-engines, and how well they will fly after two out.
I am aware that a two engine out on takeoff is not considered for planning. I was only after a general idea and perhaps a few stories
The answers from 411a and point8six are the sort of thing I was hoping for.
Thanks people!
Yes, the question was inspired by the BRU accident, and also by another thread about tri-engines, and how well they will fly after two out.
I am aware that a two engine out on takeoff is not considered for planning. I was only after a general idea and perhaps a few stories
The answers from 411a and point8six are the sort of thing I was hoping for.
Thanks people!
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Will it Fly on 2 Engines?
Have a read of www.dm.af.mil/news/story.asp?id=123075451 for a recounting of a USAF C141 Starlifter going double asymmetric at about 200'AGL after take-off from RAAF Base Richmond in 1977. Their problem was compounded by a fire in the cargo compartment caused by hot turbine blades setting the load on fire.
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Friend of mine was giving a check ride to one of our 'old and bold' Standards guys on the C-130 sim. He said that this guy was so bloody good that having he though he'd try a double EFATO, with both engines on one side, just after rotate. This didn't even cause him to break into a sweat so he failed another one...he still couldn't make him crash - don't think they even publish a Vmca for that one...
Poor old 411A, in all you're stories an experienced Captain always saves the day whilst battling against incompetent F/Os and F/Es. Still it's always a happy ending with the unfortunate individual or individuals being chewed out or sent home. After of course being put right by their more experienced four striped betters......Strange though because so many of the F/Os and F/Es I've flown with have proved to be excellent operators who do much to enhance the safety of the flight. Then again I suppose if you train people well, have high expectations and place trust in them they are less likely to disappoint. Maybe all these companies you work for should try that.....
Poor old 411A, in all you're stories an experienced Captain always saves the day whilst battling against incompetent F/Os and F/Es. Still it's always a happy ending with the unfortunate individual or individuals being chewed out or sent home. After of course being put right by their more experienced four striped betters......Strange though because so many of the F/Os and F/Es I've flown with have proved to be excellent operators who do much to enhance the safety of the flight. Then again I suppose if you train people well, have high expectations and place trust in them they are less likely to disappoint. Maybe all these companies you work for should try that.....
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We used to try 2 engine out on T/O on DC10 simulator. It could be done but just and probably not at high weight.
There was a graph/table? if I remember correctly which plotted the level off altitude against weight - it was sometimes below ground level!
Other DC10 drivers may remember better than me.
On 26 at Gatwick, at high weight, I thought the best course of action was to call finals at Dunsfold!!
There was a graph/table? if I remember correctly which plotted the level off altitude against weight - it was sometimes below ground level!
Other DC10 drivers may remember better than me.
On 26 at Gatwick, at high weight, I thought the best course of action was to call finals at Dunsfold!!
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....in all you're stories an experienced Captain always saves the day whilst battling against incompetent F/Os and F/Es.
That is what the experienced Captain is there for, in my opinion.
He commands the ship, and saves the day when it all goes pear-shapped.
You can train junior guys all day long in the sim for six months, but nothing is a substitute for line flying, done on a regular basis, with an experienced Commander at the helm.
So-called 'new' training methods, including 'enhanced CRM' for the junior guys is positively no substiture for handling experience, when the chips are down, and you are in a dire emergency situation.
You have to positively know the drill, and action accordingly, otherwise one could end up dead as a doornail...along with a whole lot of other folks.
This is not to say, however, that many First Officers aren't up to the task.
Many are, as demonstrated in the same airline when three of four hydraulic systems were disabled in an L1011, and the fourth with slightly more than half of system fluid remaining, with the First Officer flying (only his column active), landed enroute, successfully...just like he was trained to do.
A superb accomplishment.
He was also a senior First Officer, shortly scheduled for command upgrade training...which he completed most successfully.
Last edited by 411A; 5th Jun 2008 at 16:25.
In the distant past I flew a 3-eng ferry flight in a Vanguard, also sim trained for 3-eng ferries on both the B747-200 and A340-300
During these exercises the two engine inop performance is taken into account. Not surprisingly this results in very restricted take-off weights and high V speeds. At the normal weights used on these aircraft it is therefore fairly obvious that only multiple PARTIAL power losses and or sufficient height to trade will make such scenarios flyable.
During these exercises the two engine inop performance is taken into account. Not surprisingly this results in very restricted take-off weights and high V speeds. At the normal weights used on these aircraft it is therefore fairly obvious that only multiple PARTIAL power losses and or sufficient height to trade will make such scenarios flyable.
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Experienced Commanders save the day.
411A, I know you have spent many years on the L1011 and I am sure you are a very experienced Commander. You do, however, seem to believe that it is only the experience of the Captain which saves the day when things go pear shape. In my experience it has often been the F/E who has the most experience on a particular aircraft type and most Captains and First Officers seemed to appreciate that fact. Of course the Captain will in most cases be the one who safely puts the aircraft on the ground. Equally, in most cases, he will have been greatly assisted by his F/O, and his F/E if one is part of the crew.
If you really believe that it is always the Captain who alone is the great saviour then I am pleased that I have never had the pleasure of having to crew with you. Again, in my experience, the best people with whom to fly are those that believe that all the crew are there because they have a part to play in the overall operation and can make a valuable contribution in all circumstances.
Geez, I'm pleased I've got that off my chest, I feel so much better now.
PS. I'm talking about fully trained F/E's with considerable experience as a Ground Engineer before they trained as a F/E, not a pilot placed in the F/E's seat.
If you really believe that it is always the Captain who alone is the great saviour then I am pleased that I have never had the pleasure of having to crew with you. Again, in my experience, the best people with whom to fly are those that believe that all the crew are there because they have a part to play in the overall operation and can make a valuable contribution in all circumstances.
Geez, I'm pleased I've got that off my chest, I feel so much better now.
PS. I'm talking about fully trained F/E's with considerable experience as a Ground Engineer before they trained as a F/E, not a pilot placed in the F/E's seat.
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411A, I know you have spent many years on the L1011 and I am sure you are a very experienced Commander. You do, however, seem to believe that it is only the experience of the Captain which saves the day when things go pear shape.
I'm talking about fully trained F/E's with considerable experience as a Ground Engineer before they trained as a F/E, not a pilot placed in the F/E's seat.
However, when these few F/E's act on their own, and start actioning fire pull handles without good reason, everyone ends up in trouble, make no mistake.
Definitely not a good scenario.
This is precisely why fleet managers have heartburn.
Big time.
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One Man Bands
411A, Surely you do not contend that it is only F/E's who make mistakes. Of course, any F/E who would take it upon himself to "Fire Handle" an engine without (a) being requested to do so, and (b) getting confirmation that he has the applicable "Fire Handle" is out of order. I would suggest that you read the report on the over-run of Bangkok by a Qantas B747-400 to see that it is not only F/E's who screw up. That particular accident was the result of a total lack of planning and lack of communication during the landing and attempted "Go-around" come "Full-stop". There are numerous instances where the PF, whether the Captain or not, has made a mistake which led to the loss of an aircraft and people. Fortunately, we are not robots and are all capable of getting it wrong. To suggest that only the Captain can "save the day" is way out of line, regardless of how many years experience the Captain may have. Believe me, I have flown with some Captains (thankfully very few in number) who give everyone heartburn, not just their fleet manager.