G550 Single engine take off
 

NOT EFTO but a secured right engine, and a full take off run and take off.

I have seen it demonstrated in the sim, and the nose wheel did not deviate fron the CL.

Was it ever "demonstrated" under flight test.

Has any one done it for real.

It is nice to know, if in the real world one needs to go, then one goes....
Interesting to know the "improvement" in fuel burn, etc, etc.

HFR

I do not believe reading the above.
Am I dreamimg, or am I too drunk...?
Or is it my alzheimer starting again...?
xxx
:ugh:
Happy contrails and rolling on the floor
How about moving this to Jet Blast -

My simple advice, dont even think about it.
Next time you are in the sim, you try and see the results for yourself.
It might help if you were to brush up on the basics of aerodymic. In prticular see what are the definitons of VMCG and VMCA.
A one engine out T/O on a 4 enigne airplane is possible. Even then the pilots have to be specially trained for the task and lots of restrictions apply.
Be safe.

Many years ago an ex colleage of mine, (ex RAF fighter jock, (different breed)), told me how it was a boys challenge in the force to get airbourne single engine in a Meteor! "Many tried, all died!"
'Not sure how much truth there was in the story but it was enough for me to understand just one of a twinjet's limitations!

I did a single engine take off in a B767-300 simulator years ago and it worked quite well but there's no way I'd try it in a real aeroplane unless I was being shot at.

Regards,
BH.

Done it 3 times in sim
 

in G550 sim, and each time perfectly controlled, and on the centre line, only used perhaps 10% more runway.

Please do knock it till you have tried it.

BH thats exaxtly what he was asking, as well as has anit actually been done.

When you do your EFTO in the sim, below V1, ignore SOP and continue, and provided you delay your Rotate, keep the aircraft on the centre line, the EFTO in the air is perefectly controllable.

A sim trick that I suggest to trainees, who are aprehensive, and try to rotate very early, and very agressive.



glf

Agreed
 

When well briefed, this is an 'illuminating' exercise to do in the sim - and very nicely reinforces the reasons to delay rotation until under directional control.

Of course you wouldn't try it in the real aircraft.....

I believe it was tried for real at Prestwick a few years ago in a Jetstream, just for laughs. They crashed and died!

I assume that all these sim cases are being conducted with operational NWS on a dry runway ...?

Sims are great but...
 

Here's my two cents...

The sim gets most of it's aero modelling data from flight test, specifically it gets it's data for manoeuvers that are carried out inside the envelope. When you start going outside the established boudaries the sim is extrapolating. So to say you've seen something demonstrated in the sim and the nose wheel never deviated from the centerline is fine, but how far was the model extrapolating in that scenario? I've looped and rolled the Challenger sim, strangely enough beyond +30 degrees of pitch it behaves remarkably similar to a Cessna 150 aerobat - why, because beyond 30 degrees you're outside of the realm of flight test collected data.

I think we're also getting into that grey area between "should" and "can."

Airplanes "can" (i.e. are physically capable) of significantly more than their performance limits would indicate. That margin is there to allow for things to go wrong (e.g. NWS failing at just the wrong moment). But when in the fantasy world of the sim, those grey spaces can be explored.

Should they be? Dunno. At one level there is a chance to learn something. On the other hand, it could lead to false confidence.

I was just reading about Pinnacle 3701 this morning. That's an adventure that may well have simulated just fine but when the complexities of real world engines and thermal expansion got into it, the result was tragedy. Or Darwin Award, you choose.

As for me, I'd love the chance to sit in a sim and push the aircraft into those non-SOP places just to know.

I cannot find the page reference, but I recall D.P. Davies in the standard reference, "Handling the Big Jets", called that a "circus trick". Indeed, it is just that! BelArgUSA, a few too many caipirinhas in late summer Florionopolis?

GF

in Cit 2 sim
 

It was possible int he Citation 2 sim, but with some clever use of power/accelerate/retard/etc, etc.

So the G550 was easier.

Is there any proof of the data points actually used.?

is there any SAV guys who have more valuable input.?

glf

Just-nick

Sorry but you still won't "know" anything. The results you get going outside of the simulation limits may well have no connection to what would really happen. The models may extrapolate in a linear direction but the aircraft response could be very non-linear, or reverse direction. An aircraft is required to be directionally stable at Mmo but it is acceptable to be mildly directionally unstable at higher speeds. I suspect this is not modeled in the simulator so if you were to go and do rudder inputs above Mmo you may well "know" an incorrect result.

There is a famous accident report the NTSB did a few years back on a small bizjet that attempted to get airborne with only one engine going. They were going to try a starter assisted start on the other once airborne. Makes amusing reading and I'll try to find the link.

Bob Hoover
 

Seemed to manage this OK.

Howard Hughes managed it.

The Cessna 337 did it very often too (CLT).

Still Albatross, I think I remember it too.

windy

True enough, Hoser90B. I suppose I was thinking of "know" in a casual and non-literal sense. That sort of extrapolation into the unknowns was exactly what I was getting at when talking about Pinnacle 3701. They ended up in a bad situation made worse by the "core lock" that the engines suffered -- something that the sim probably wouldn't have modeled.

Tried and failed a few times to get a RAAF Gooney Bird off on one. This was after having established that the equivalent of a feathered prop when airborne was roughly 15 inches of boost at 2000 rpm.

Started each attempt with one idling as above and almost down wind. Some reasonable wind was mandatory. Full rudder then allowed for a slow increase in power on the 'live' engine whilst allowing a gradual turn into wind. All of this on the grass. Failures followed as one commenced to sense that a wind speed of over 30 kts was essential.

Finally made it airborne with about 35 Kts of wind much to the relief of Bil Simmonds in the right seat and the SATCO.

Then there was the time I started a take off in a Beverley with an outer electric prop in reverse due to a broken slip ring brush housing.. Didn't take long to abort.

Windmill taxi starts of an engine on early model Hercules C-130s were an interesting challenge.

As long as you observe your VMCG and V1 why should it not work?
Most tricycle-gear aircraft will have enough low speed control to stay on the runway until the rudder begins to bite - you may need to feather the power in - but the only real hazard, that aside, is running out of tarmac, and in a modern high powered machine I doubt that would happen on any but shorter runways. It would be one hell of a trick in a DC3, for sure.

If just one engine will get you off airborne and climbing safely from a V1 cut then why on earth would it not get you from threshold to V1? The answer is it would. So, keep directional control and runway length permitting...

There is a world of difference though, as said above, between "would", "should" and "could".

The early Aero Commander did it well: (con-pilot take note)

The dynamic Vmc would not come into play -- and if thrust were modulated carefully so as to maintain directional control then it is possible or at a heavier weight then the static Vmc would matter---but the TO field length requirement due to the reduced thrust [from having to worry about Vmc] (and you would have to be light-see above and below) if not you'd blow the fuse plugs at tire speed limits---

DP. Davies mentions that this feat was tried in a few twins as a 'circus trick' so try it in the sim but you have to be deft about it,...as an operational technique:\

single engine TO's are best for F-16's:}


PA

3Reds,perhaps you`d better re- read what you have written when you are sober !!

Because < V1 you will be Vmcg limited. By definition you would have to progressivly apply power up to V1 when you may go to max and expect some deviation. Modulate the power in line with the NWS / rudder authority chart. The field length requirements would be huge, I'd recommend proverse wind, fwd cg and let it be a day that I'm not planning on flying...

I'd also recommend amending the take off brief to state "in the event of an engine failure before or after V1, stopping would be grand" :yuk:

Surely you would only blow the fuse plugs if you decided to abort at high speed above the "normal" brake energy limitss. This would be no different to any other day. Hopefully the only abort you would attempt is from 15kts as you taxi off chocks and realise what a bad idea it really is..!

Whilst it may be possible, technically, it's one of those "so why would you want to do that?" questions!

Typhoid I was jnot even dreaming of stopping:eek: forget about the brakes,...I mean If you are light Vmc will have to be crossed at "reduced thrust" --so in that case acceleration to a rotation speed ----will be field length limited

However if you are slightly heavier as to avoid a Vmc situation then although full thust can be had quicker---- the acceration to Vr may be so that you would have no choice but to exceed the tire speed limits whcih also melts the fusible plugs

Note:--- there's really no valid 'vee speeds' for this scenario as this is sooooo far off of any certifaction scheme that all performance figures and assumption are effectively invalidated,...and these speed regress to beings just advisory,...like V2----think about it:)

PA

When you go into a simulator, ( at least at FSI) the certification data used are displayed in the form or the airframe s/n that was used for these said data.
Data collected are the one's available out of the flight testing envellope basically for a transport aircraft ( Vd to Vmca and -1g o 2,5g), the aerodynamics return feelings are then fine tuned in the sim by people who flew he aircraft for real. ( exemption to this rule are FBW aircrafts where the modulation of feedback is done with other means, but still requires a 'check flight')
As a consequence, if the data do not include an all engine out at FL490, what you will get is a pure mathematical extrapolation of the aerodynamic law, nothing else.
As for an engine out take off from brake release, it is obviously doable if the runway is long enough, Vmcg has nothing to do in here ( cf definition of it , the critical engine is made suddenly inoperative, the other(s) one at take off power and you have to parrallel the track using only aerodynamics ( no nswsteering) ). So smoothly adding power should do the trick.

The above mentionned experience of a C550 pilot trying to windmill start an engine on the runway, is all together another story.

You can experience whatever you want in the sim, but if it is not in the AFM, it is BullS_h_i_t.

PS. If you have spare time in the sim, practice all engines go around, and noie abatment procedures :)

Agree entirely with the sentiment that if it's outside the dataset it may be rubbish (though there's a difference between extrapolation and interpolation, obviously) but re the bolded part, I'd doubt many sims have data out at VD.

JAR-STD-1A and the equivalent FAA and ICAO sim QTG (Qualification Test Guide) standards define the test data required for a qualified device. You might be surprised at how little there is required (although a good sim builder will use more than the min).

And not all tuning is done appropriately - in at least one case I know of, the sim was tuned to someone's perception of how the aircraft 'should be', unfortunately not taking into account the actual data showing how it really is.

The sims I know, have data up to Vd, especially if the design has 'interesting characteristic beyond Mmo ( neutral pitch at best lol). Might not be all manufacturers...

Without wishing to stir up a hornets-nest of disapproval, I have done a single-engine take-off in a B.747-400 simulator. Empty (ZFW c. 180T), 10T fuel, Doha RWY 34, (15,000ft) ISA still air. I think I used F.10, although I can't really remember.

Numbers 1, 2 and 4 were shut down. The thrust on No.3 was gingerly increased. It took about 1/3rd of the runway to get above 80kts, due to directional problems. Eventually, about 1/2 to 2/3rd down the runway, I was able to apply full thrust and got airborne just before the end.

I climbed at about 300ft/min to 1500ft and landed at Bahrain.

What does this prove? Nothing really, except it was a lot of fun and increased my already high level of respect for the 747.

Now I'm going to give you all the benefit of the doubt and assume that my readers are intelligent enough to know that I'm not advocating anything similar in the real world. I won't reply to any 'What were you thinking of?' style replies. So there.:bored:

Still Albatross, I think that was a Sabreliner somewhere in the US.

We tried it in the old C550 in Le Bourget some 10 years ago and we could get airborne without really big problems.

First of all, I am NOT a qualified pilot, though I have done a lot of flying ( I'm an aerial photographer, first for BAe now freelance ) - often used as an unofficial autopilot, sometimes given a go for more exciting flying.

I used to work mainly with Test Pilots of the highest calibre ( by calibre I mean standard, I can only think of one who should have been shot out of a gun ) - I'm damn sure you'd be sent out with a kick if you suggested taking off a twin / multi on one engine.

They'd happily do it on a sim', probably without drawing breath, but in real life losing an engine ( ie one was rather counting on more ) is an emergency, usually resulting in the aircraft staying on the ground, even if beyond the runway - at the airfield I worked on in earlier days, Dunsfold, there were raisable barriers at each end.

This came about partly because the main A281 Guildford - Horsham road runs along the Eastern end of the runway.

In the 1970's an HS125 was taking off, piloted by John Cunningham.
It suffered a multi bird strike, snuffing both engines, and was pancacked into the next field; all occupants walked away, very sadly it turned out that another pilot's wife along with several children had parked to watch the aircraft - all were killed.

As for single engine take-offs, it's deliberately putting oneself in an emergency situation ! I can't help thinking of the early days of Gnat / Hawk training, when the instructor would deliberately shut down the engine on finals, " Ha, let's see how you cope with that one ! "

Strangely enough, if the student didn't cope perfectly, they crashed.

After a while it emerged there might be a flaw in the training policy...

Purely in the name of pprune research just done it in the sim for the 680, 70% N1, NWS until the rudder worked the power to T/O, F15 got off in 6000ft comfortably.

The NWS is the key turned it into a non event - very straightforward

And if you did that deliberately in real life, and even survived,
you'd be called a...........

Of that I am aware hence the........


:ugh: :ugh: :ok:

I heard a story once that as part of the F15 programme they had done a single engine take-off for some reason. Any one able to confirm or deny this?

Like little boys and girls why can't we just play sometimes:}


Oooh Pooh:{

In the 60s, Northrop used to advertise the F-5 Tiger as capable of ferry engine-out for several hundred miles.

In the sim when said Instructor was talking me through the technique, we were playing.......... The scene was set....I was the moustached hero airplane repossesor :cool: , tasked herocially with the recovery of some fine bizjet by a banking corporation from some tinpot dictator who had decreed that both ignitors be removed and taken from one of the engines. My trusty FO (who'd already had the incap tap on the shoulder) had been........"left at home for this one" as it was far too dangerous........

Of course I managed to get it off just as the sand and gravel runway dipped into the ocean in true "A-Team" fashion, the instructor was tapping his pen against the back of my seat to simulate the small arms fire......

And then the noise of the motion coming off and the health and safety beeping of the gantry coming down sort of spoiled the moment :yuk:

;)

Right im off to find the wifes mascara to see what I look like with a moustache......

Are you sure about that? Closing the throttle to simulate an engine failure yes, but shutting down the engine on a single-jet I doubt.

Yes,

It was really done in training, throttling back rather than shutting off completely the Hawk adour ( sorry, I should have been clearer ); as you know, with the spool-up time of jets, this still led to a few nasty accidents.

I understood this was a snag to overcome ( not particular to the Hawk ) when the U.S. Navy took on the T-45 Goshawk version, and the Red Arrows + company demonstrator G-Hawk ZA101 have modified throttles for faster mid-range response, probably the T-45 too, but there are a lot better qualified people here to comment than myself.

Back in the days of the early jets there was one occasion when they deliberately flew a FH-1 Phantom (not the big F-4, but a much lighter early Navy straightwing jet) on one engine only. Might have been its first flight IIRC.

Hopefully someone else has more complete recall of this incident which will save me raking through my extensive reference collection for the details.

It was at Edwards or China Lake I think. Reason? They were so keen to fly it they just couldn't wait for the other engine to arrive!

:ooh: