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Unfortunate crash video of a new DeHavilland Mosquito Twin

Old 06-18-2009, 07:50 PM
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cappaj1
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Default Unfortunate crash video of a new DeHavilland Mosquito Twin

I was videotaping a friend who was flying his DeHavilland Mosquito Twin with two 46AX engines, retracts, etc. for his third flight, and one of the engines cut out while he was a good distance away and he lost it at the end of the video.
I was wondering, if anyone has an idea what were the chances of recovery at the point in the video where it starts to go down, flying with a single engine?
http://www.youtube.com/watch?v=4ROcBQG9x3o
Old 06-18-2009, 08:09 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

looks like he turned into the dead engine which is a big no no w/  twins, stalled it out intstead of letting it glide (notice how he tries to keep climbing)
what he should have done was turn the other way (kill other engine maybe, if close to runway), let it glide to the runway, some twins can fly one one engine, that one may have been able to or at least glide for a while. although you will have to keep on the rudder

Old 06-18-2009, 09:01 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

Sad to watch.

As Jimmy has said above, nose down and power cut may have saved that beauty.
Old 06-18-2009, 09:02 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin


ORIGINAL: cappaj1
I was wondering, if anyone has an idea what were the chances of recovery at the point in the video where it starts to go down, flying with a single engine?
After losing the right engine, heclimbed a bitand decayed airspeed... not good. He then allowed it to sustainyaw to the dead engine while holding the nose up.

You'llhave your hands full maintaining flightwith one engine out... Full or near full power is a must for the remaining engine while counteracting the resulting yaw.

Ihate to see that happen, it was a nice plane too.
Old 06-18-2009, 09:12 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

Wow, thats a great video. That is a pretty fast twin. I flew a twin back in the 1990's and was very lucky, flying it for 11 years. Even a dumby like me can learn a few things about twins in that much time. I did pass the point where the plane in the video starts down twice during my twin career. The plane can be recovered by cutting the other engine to an idle. You will hear people talk about Vmc or the minimum controllable airspeed as if it is the line of death. But actually, its just the minimum speed you can control the airplane provided one engine is running wide open. It turns out that you can control the airplane at a much lower speed than Vmc provide that good engine is not running wide open. Then there is the issue of having enough altitide to dive down, gain speed while reducing throttle and illiminating the asymmetrical thrust. You need some room do to this, but not hundreds and hundreds of feet. It actually takes less room than you might think. I can't really tell if he had that much room in the video because its difficult to tell how high he was when it tipped over.

As for the myth that you can't turn toward the dead engine, that simpley isn't true. My twin would only turn toward the dead engineif the good engine was runnng wide open. I would then need to reduce power to leveloff again and then re-apply fullpower. I could turn toward the good engine by reducing power first. Thenwhen its time to level off there is no need to reduce power. But either wayyou turn, you will need to manage the throttle.

In this crash, he did not turn toward the dead engine. Hewas trying to turn toward the good engine. The airplane didn't want todo it even though it was already banked toward the good engine. The result was that he climbed and climbed and slowed and slowed until he dropped below Vmc, then theasymmetrical thrust took over. At that point it tipped from a left back to a right bank and also stalled. The camera then lost the airplane.

I have had time to look at the video several times. In real life it all happens very quickly. Often its difficult to tell which engine has died. Your hands seem to just naturally compensate for the asymmetrical thrust and before you know what ishappening your sticks are in the corners and you still don't know which enginehas died. Its very confusing. And it takes a few times to get it right. I was just plain dumb lucky to have a forgiving airplane that let me have a few tries at it, (a few hundred tries at it).The first time generally is themost brutal and more often than not crashes the airplane. And it appears that this Mosquito was a hotter and less forgiving airplane than my airplane. So the outcome could have gone just as badly forme. Hot twins are very unforgiving things. The tiniest error snowballs rapidly.

What are the chances of recovery ? It depends how high it was when it snapped.My airplanerecovered from a one turn spin as low as100 feet. With the Mosquito being a hotter airplane, it could take twice that amount of room.
Old 06-18-2009, 09:28 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin


ORIGINAL: PilotFighter
That is a pretty fast twin.

The camera then lost the airplane.

What are the chances of recovery ? It depends how high it was when it snapped.My airplanerecovered from a one turn spin as low as100 feet. With the Mosquito being a hotter airplane, it could take twice that amount of room.
If you look at the last pass by the trees before he flies off into the horizon for the last time, you can tell he was zipping along pretty good. I'm guessing he was going 70mph or so, and he wasn't even close to wide open with the plane. At that speed, and with the distance away he was, considering he wasn't that high, I think it'd be difficult for even the best pilots to recover. But I am new at this myself and don't know anything about twins, so I appreciate your insight.

Also, there isn't much more after the plane disappears from view, as there were literally only a couple seconds before it disappeared behind the trees. I had one more second of video before I stopped the camera which I chose not to put in the video as there were some choice words by both myself and the flyer right after it went down that are clearly on the tape. I really felt bad for this guy as it was really a nice airplane and he obviously put alot of time and money into it and was really enjoying flying it.

Old 06-18-2009, 10:20 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

Did it appear to anyone else like it was tail heavy? It seemed to fall out of the sky backwards when it stalled.

Was this his first twin? I haven't flown any, but it just seemed like he was not prepared for the possibility of an engine loss at all.
Old 06-18-2009, 10:21 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin



Hey cappaj1,

I did get the feeling he was pretty low. But also real fast. So I couldn't tell how high he climbed at the end before stalling. He slowed down to nothing at the end. I don't know why, but many people tend to do that. They climb and climb and get real slow. I guess its natural to try and get high when something is wrong. But with twins the answer is to get "fast". Like I said, things happen so fast, it isn't fair to second guess a pilot.

Those tappered wings are killers.

Old 06-18-2009, 11:16 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

All I could hear was some music?
Old 06-18-2009, 11:49 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

I watched the vid a few more times to see how high he was . I think he probably was too low to recover after the stall.

Another thing I noticed was that he was trying to turn toward the good engine and the plane was fighting him. Then he seems to just add more and more up elevator until it stalled. Then bam, it breaks right on him. I think this is a case where people prefer left turns more than right turns. His inclination seems to turn left even though the answer is to turn right. I can certainly understand that. I've gotten myself it tight spots for the very same reason.
Old 06-19-2009, 12:12 AM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

Using this clip as any kind of forensic crash analysis tool when out the door when you added that music. Also to be honest music usually involks the wrath from multi enthusiast' since the engine sound is part and parcel of multi flying and most Rc multi flyers want to hear it.

Pilotfighter has given you the most reasoned answers so far and a lot of myths were stated earlier in this thread for instance here is a link to a conventional twin doing a single engine takeoff and with turns and rolls into the dead engine and of course the landing. Not to say that the subject airplane is capable of the same Some are not.

http://video.google.com/videoplay?do...06427302&hl=en


John
Old 06-19-2009, 01:29 AM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

I've scratch built a DH Dragon Rapide and a SR-71. The DH Dragon is like a powered glider and while running with 1 engine lit I just knife edge fly around til the 2nd engine quits, then glide home. The SR-71 is a higher powered model with not very much built in yaw stability or rudder command. This plane can go into un-recoverable spins even with just 1 engine at idle. The sure-fire fail-safe for this is being able to kill both engines and then glide home.
Old 06-19-2009, 05:48 AM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

I agree he turned into the dead engine......never ever turn into the dead engine.......there was a crash in 1976 at MCAS Cherry Point NC......tunring into a dead engine where the prop was hung on the 36 deg pitch locks.......
Also with twins one engine will be master one will be slave.......you want the weak engine to be the master......that way you're always tunning the strong engine to the weaker one...not the other way around....the reason I brought that up is he seemed to have yaw problems the whole flight including taxi out......
Good looking airplane ,,,,sorry this happened
Old 06-19-2009, 08:02 AM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

Hi!
He did not chop the throttle fast enough and at the same time using left rudder and aileron to dive toward the field.
Instead he climbed and let the speed dvindle.
No good!

But the main fault he did was to not check his engines setting prior to take off.
Old 06-19-2009, 10:15 AM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

What condition is the plane in?  is it repairable or is it totally shot?

Just wondering
Old 06-19-2009, 11:56 AM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

It was beyond repair. The fuselage was in splinters in several places as were parts of both wings. It landed pretty much at the same speed as last seen in the video, nose down into some hard ground. Vince plans on getting a new ARF and transferring everything that survived over though. It's one of his three favorite planes, besides his Spitfire and Mustang.

ORIGINAL: Minnreefer

What condition is the plane in? is it repairable or is it totally shot?

Just wondering
Old 06-19-2009, 03:36 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

Simple, he stalled it.  *sigh*  I've seen that happen far too many times (done it once or twice myself).  Whenever you lose power, keep that nose DOWN to maintain airspeed.  Try to make it back to the field of course, but if you can't do NOT try to stretch it with the elevator.  This never works (see stall).  Maintain a good glide and deal with what you get.  Chances are, even if you don't make it back to the field the landing in the rough will be as gentle as it is possible to be, thus preventing severe damage.
Old 06-19-2009, 05:24 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin


ORIGINAL: PilotFighter

Another thing I noticed was that he was trying to turn toward the good engine and the plane was fighting him.
To me, it appeared the pilot is trying to make a left turn w/o using rudder.

Which enginedid you determine failed?
Old 06-19-2009, 05:31 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin


ORIGINAL: FILE IFR


ORIGINAL: PilotFighter

Another thing I noticed was that he was trying to turn toward the good engine and the plane was fighting him.
To me, it appeared the pilot is trying to make a left turn w/o using rudder.

Which enginedid you determine failed?
I'm not sure - I'll check with Vince - but he did say he found that the low speed needle valve on the engine that went out was open way farther than the engine that kept running. Which means that it was drawing more fuel. Ultimately running out of gas.

Old 06-19-2009, 05:52 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin


ORIGINAL: cappaj1


I'm not sure - I'll check with Vince - but he did say he found that the low speed needle valve on the engine that went out was open way farther than the engine that kept running. Which means that it was drawing more fuel. Ultimately running out of gas.
That MAY be a way to determine the failed engine, but I wouldn't bet too much on it.

If the spinners/props are still attached to the engine/ nacelles... Compairson ofscrapes and 'wipes' on the spinner will tell you the good engine wasfunctioning until impact, broken or whole props can tell a story too (most of the time).

...Anyway, Is he planning on repairs or replacement? That was a nice plane.
Old 06-19-2009, 05:55 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

Well, even though he filled them before taking off, upon recovering the plane, one tank had almost a half tank and the other was completely empty so I'd say that's the engine that cut out.
Old 06-19-2009, 05:58 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

Ahh, An empty left or right tank saves some investigating.


Still hurts though.
Old 06-19-2009, 06:43 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

based on the video :
The right engine failed. The left was still running. He was trying to turn towards the left. He banked left. But the plane climbed rather than turned. ( perhaps too much aileron input and not ennough rudder input) It got slower and slower. Finally it stalled. Or possibly he just tried something, anything that was different. That does go through your mind. I am getting too far away. I am getting too slow. Its as good as gone so try something, anything else. So he might have reversed to the right instead of simply relaxing the "left turn" inputs.The key here is to just let off a little, don't actually put in "right" inputs. And like you said, hold as much "down" as needed to keep the speed up.Its alot to learn in 3 seconds.
Old 06-19-2009, 08:24 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

GYROS saved my twin!!!!!!!!!!!!!!
I have a 62" OV-10 bronco with twin Saito 40's that I've been flying for 3 years now. This is actually the second one - let me explain. I first bought this plane as an arf (Rich Uravich) 52" bronco which I outfitted with the saito. On the 20th or so flight I lost an engine and it yawed quite violently. Needless to to say it crashed in an uncontrollable spiral. I purchased another bronco but this time it was a kit. When I built the new kit, I realized that if I installed a Gyro in the rudder that it may help in the event of a failed engine. Sure enough!!!! Around the 30th or so flight, I lost an engine. THis time though, instead of a hard yaw, the gyro dampened the plane and it gave me enough time to realize which engine failed. While I was not able to fly it all the way in to the LZ, I was able to sit her down easily enough avoiding damage.
Since then I have lost an engine 2 more times - All the with the same results... The rudder Gyro gave me the time I needed to fly it in without a death spiral.

I have two twins now and I'm a firm believer in Tail Gyros. Not only do they prevent a hard yaw during engine loss, the gyro also helps with crosswinds etc.

BTW, The gyro I use is the JR G500A Airplane gyro.

P.S.,one more thing! The gyro makes a twin fly like it's on rails!!!!!!
Old 06-19-2009, 11:26 PM
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Default RE: Unfortunate crash video of a new DeHavilland Mosquito Twin

The problem is, in my opinion, mostly one of recognition of the engine failure and having a prepared mental plan on tap for that problem. Also,
any discussion of this situation is airplane dependent, that is to say some twins are very forgiving, most are not.

This can be really tough when you're not in the cockpit......and sometimes tough even when you're in a full scale twin.

I have limited experience with engine-out flying on a RC twin......but did survive. My protocol was to not take the airplane too far away from me so
that I could better recognize an eng failure.....expecially if I were going to idle the engines. Never idle the engines except at an altitude
where you can make a constant descent to the pattern and then to the runway. For obvious reasons avoid the temptation for a lot of low-level flying.
Always be expecting an engine failure......look for it....listen for it....plan on it.

If you have a friend with you brief him/her on your protocol and tell him to help you listen/look for an eng failure and then to prompt you by
literally yelling at you "1/2 throttle max, nose not above level attitude, no steep turns, put the gear down, you look high, etc......". In other words
a good copilot could help you save the airplane.

When you in fact recognize an engine failure you must impose two things (again, my opinion): 1- Reduce the good engine to 1/2 throttle and do not at
any time use more than that.....if it means landing off-field then do it and try to mimimize the damage. 2- Put the airplane in AT LEAST a level flt
attitude (to the natural horizon) and do not pitch above that attitude.......again this may force you to an off-field landing if you are too far away and/or
too low.

Now for the remainder of the flight consider that you are flying a powerless glider and the remaining engine at half-throttle will be like extending spoilers when you're
certain you have the field made and are slighly high. When you are certain you have the runway made and are slightly high or fast or both, then reduce the good engine to idle and do not touch that throttle again. Make the best of the result landing even if you're off the side or off the end.

Unless you are very experienced at this and your airplane is very forgiving, any thought of a go-around is preposterous.

Don't forget the gear.

My last comment: If you are going to built a beautiful and valuable twin, first built a simple and ugly twin, one that you can wipe out
without wiping out a part of your "self". Practice a lot with it and if you don't have any engine failure then make them happen by filling
one tank 1/2 and the other 1/4, then go fly until one quits. Work on recognition then immediately 1/2 throttle and nose level and now
your flying a glider then when you get lined up on final reduce to idle and land. When you can do that consistently maybe you'll
have a better chance saving that next beautiful airplane.

My 2 cents.....Larry Church

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