DiscoWings

My Feedback: (76)

For the people that have twin turbine jets, have you ever lost 1 turbine in the air? How did the jet fly with just 1 turbine? Was it landable?

I'm setting up a twin F-18 soon and my thinking was the twin would be better than Y-PIPE for reasons mainly because the Y-pipe splits the airflow and in case 1 turbine fails the other can still land the plane (albeit it would be working harder)

Would be nice to hear from folks that are more experienced with this type of setup.

dubd

It really depends on the airframe and power used. The F-18 has it's engines close together, so as long as each turbine has decent power you will likely not notice much difference in flying characteristics if you lost an engine. An A-10 for instance will likely have more issue at slower speeds since the engines are further apart.

David Searles

My Feedback: (49)

With an aircraft like the F-18, with turbines right next to each other, the difference is pretty much restricted to power issues. Ie you'll have to fly at higher power settings than with both turbines running. It will be easier to get "behind the curve" on final for landing. Directional issues will be minor.

The A-10 is a different matter. Much depends on where you are when you lose the one turbine. If it's during the takeoff roll, abort the takeoff at all costs! If you've already established climbing flight, you shouldn't have too much of a problem continuing thru the circuit and landing safely with just some rudder input to counteract the offset thrust.

I have owned and flown F-4, F-15, F-18, BVM Rafale & A-10 twins and have flown and landed all except the Rafale with one turbine running.

David S

CraigG

My Feedback: (40)

DubD and David are both correct. Losing one engine is normally only critical during takeoff and go-around when speed is low and power is high. Correcting promptly with opposite rudder will keep the jet controllable until a safe flying speed is achieved, just like with full-scale. No problems both times I lost an engine on takeoff with my A-10 using that procedure. It's not quite so critical with the F-18's closer spaced engines but still worthwhile to fly it properly.

There is an excellent and informative article on this topic on the JPO website: http://www.jetpilots.org/

Look under "Members", then "Contrails on-line". The article is in the Spring 2010 issue starting on page 9.

Craig

Mariosff

A good idea is to use a rudder gyro to compencate for any thrust asymmetry

highhorse

My Feedback: (2)

Consider adding a yaw gyro?

jseppanen

Confirming the above No trouble with one engine out with this one, 2 x 16kg turbines in this video. NO engine out in this video but had once one engine out - flies very well, no problem flying several minutes... F-15 must be one of the easiest planes with only one engine?
http://www.youtube.com/watch?v=zjCBf...3&feature=plcp

rhklenke

My Feedback: (24)

There is information around somewhere of a guy who did an F-18 with a single engine on one side only - no bi-pipe. I don't recall if he tried to angle it a bit to help with the asymmetrical thrust, but the engine and thrust tube were definitely off to one side - not in the middle like a Eurosport. I think the reports were that it flew fine...

Bob

i3dm

My Feedback: (51)

Yep, i saw an F4 like this in Germany with my own eyes - flew perfectly well.

FenderBean

what about the F-14 and f-15? the F-15 turbines a close together but the F-14 has some distance between the two. I have wondered this myself and now have a vested interest in knowing

CraigG

My Feedback: (40)

Read this article and it should answer your questions:

JPO website: http://www.jetpilots.org/

Look under "Members", then "Contrails on-line". Multi-turbine article is in the Spring 2010 issue starting on page 9.

mr_matt

My Feedback: (10)

I don't have direct knowledge of an f14 but I helped with a maiden of a large su27 back in 1999 or 2000. On downwind for landing, it lost a turbine at very low speed, and as the pilot powered up on the remaining turbine the plane started to yaw and it ended up hitting the ground with full power and full corrective rudder put in. I think this is called "Vmca" in full scale but I don't know for sure. In other words a speed too low to safely loose one motor.

Ends up you don't have enough speed to generate enough corrective yaw force as the good turbine starts generating the adverse yaw when spooling up fast.

S_Ellzey

Lost one of the two engines on Sam Snyder's Avro Vulcan once. Even turning into the dead engine I did not have any trouble making a good landing. That was a ~60 pound model on two P120s that are space some what further apart than most.

sleepless.ch

Don't worry: it's not witchcraft. The only reason for twin engineof full scale aircraft is the safety in case of a dead stick of one engine. In case of a flame out from one engine fly, go around and landing is sometimea little different butnot realy problematic. The most failure is to lose one's nerve.
Forexercice to fly with one engine, program with a switch one turbineto idle. If you accelerate the Jet, only one enginespeed up. The other one stay on idle. You will see,there is no bad surprise.
It must be pointed out thattransmitters don't have warning systems in case of dead stick. Aflame out of one engine is not allways to hear directly (Last of april i lost my grey Su 27, because i flew on the stall range and detectedthe flame outto late).
By the way: i have twin engine experience since 1993 and many flights (SU 27, F-4 Phantom and F-14 Tomcat).

oistein

My Feedback: (1)

twin turbine modern jets should be ok, if it a me262 or gloster meteor it's a different story. then you might want reduce throttle quickly and just land straight away anywhere you can.

highhorse

My Feedback: (2)

Again, would a yaw gyro not be prudent and beneficial for twins? True enough that at too slow a speed with engines too far apart and too mucch power applied to the good engine there might still note enough rudder authority to hand the asymmetric thrust, but a gyro would sure help in any scenario, would it not?

su27flanker

sad to hear su27's are my fav jet love em

whats your fav to fly between the f4, f14 and su27? do they all fly differant?

sleepless.ch

All Airplanes ar a breeze to fly.

SU 27 is a waltz, the twin engine BVM Phantomisa rocket and needs experience to see the flight attitude.
The Tomcat is a mix of both. Wings forward is the Tomcat a gentle cat - like a Flanker. Wings back, it's a ****ing missile.

My favor is the f-14 Tomcat.The F-14 isin the truest sense of the wordafighter Jet(eachflight is afight).
:-)

By the way: the grey Su 27 flew since 1995 with 3 different generation of turbines. The first turbines are JPX 240 Propangas turbines (5 jears sucessfull in use). Twin engine with gas turbines was a big challenge because the gasflow work only with tankpressure and not with a pump. In case of flameout from one engine the gasof the dead stick engineflow unburnt in the fuselage and the secound turbine provide the heat. The solution was a magnetic valve wich operated the gas cock in case of emergency. And 10 jears AMT Mercury with airstart. The last two jears are two IQ Hammer in mission. The wight/power rate was amazing. For one of the first twin turbines RC Jet are 17 Jears in duty not bad economy



[quote]ORIGINAL: su27flanker

sad to hear su27's are my fav jet love em

whats your fav to fly between the f4, f14 and su27? do they all fly differant?

[quote]

David Gladwin

Its avery dangerous thing to say all airplanes are a breeze to fly, it very much depends on the design of the machine. Centerline thrust and big fins on machines like the Su 27 and Mig 29, fine, widely spaced engines, eg Meteor and Canberra with small fins and rudders are a very different kettle of fish. The RAF lost 854 Meteors many during asymmetric practice, Canberra not quite as bad but still a handful on one engine.

Here's what happens to a fullsize Canberra which loses an engine during an overshoot with speed below VMCA (140 knots)

http://www.liveleak.com/view?i=391_1252689169

Notice he has flaps and gear down (worst case scenario) and does not immediately get the nose down meaning speed would have quickly bled off further reducing rudder effectiveness. Too low to eject.

Guess any model Canberra which suffered a single engine failure would suffer a similar fate.

regards,

David.

Frank Sopwith

When flying the Meteor this is indeed my only concern: loosing an engine,
For a plane with the centerlines of the turbinus so far apart I guess the only way is cut the throttle and land asap?

Frank

kevinthoele

My Feedback: (1)

I have landed the Yellow Twin with twin turbines on one engine. No problems. The biggest issue is not letting it get slow as you wont catch up with one engine.

su27flanker

sounds like you have experienced alot of the many changes in model turbines over the years, did you have any more photos of the old flanker that we can drool over


[quote]ORIGINAL: sleepless.ch

All Airplanes ar a breeze to fly.

SU 27 is a waltz, the twin engine BVM Phantomisa rocket and needs experience to see the flight attitude.
The Tomcat is a mix of both. Wings forward is the Tomcat a gentle cat - like a Flanker. Wings back, it's a ****ing missile.

My favor is the f-14 Tomcat.The F-14 isin the truest sense of the wordafighter Jet(eachflight is afight).
:-)

By the way: the grey Su 27 flew since 1995 with 3 different generation of turbines. The first turbines are JPX 240 Propangas turbines (5 jears sucessfull in use). Twin engine with gas turbines was a big challenge because the gasflow work only with tankpressure and not with a pump. In case of flameout from one engine the gasof the dead stick engineflow unburnt in the fuselage and the secound turbine provide the heat. The solution was a magnetic valve wich operated the gas cock in case of emergency. And 10 jears AMT Mercury with airstart. The last two jears are two IQ Hammer in mission. The wight/power rate was amazing. For one of the first twin turbines RC Jet are 17 Jears in duty not bad economy



[quote]ORIGINAL: su27flanker

sad to hear su27's are my fav jet love em

whats your fav to fly between the f4, f14 and su27? do they all fly differant?

dubd

Discowings, did you ever fly the Ultra Lightning?

David Searles

My Feedback: (49)

Frank,

Your best chance would be to immediately kill the live turbine and turn the jet into a glider. With turbines that far apart & your rudder becoming less and less effective as your speed decreases, any thrust at all in the live turbine is apt to make the jet uncontrollable.

David S

David Gladwin

I entirely agree with David S. I have long considered a model Canberra but shied away from it because of my experience with the real Canberra (and Meteor) as shown above. I believe a model of either would be uncontrollable on one engine. (I would be VERY happy to be proven wrong) A symmetrical unpowered glider has vastly a better chance of survival. However, the fuel system I had in mind was to cross wire the fuel solenoid valves so that if one engine fails it immediately shuts down the other. Contrary to what Craig says in his excellent Contrails article you DONT need to get a Jetcat ECU modified, you simply use SEQUENCE for starting. Individual engine start is achieved by a fuel line bypassing the solenoid valve for the first engine in which is mounted a Festo tap. Once both engines are running , and both fuel solenoids are signalled "open" you close the tap. In fact you need only one bypass line to get the first engine started (the other valve will be signalled "open" by the first ECU).

Frank, I wish you every success with the Meteor, a fine and most original model, (although I did spot another Dutch Meteor at a LMA meeting but did not see it fly) perhaps we could meet up at Jetpower.

Regards,

David.

PS On the real Canberra, if you lost an engine after unstick and before SE safety speed of 140 knots plus, the drill WAS to close the other throttle and land straight ahead into the barrier if any. Safest option. Try and fight it, your chances of survival were slim to nil. Meteor was, I believe, the same.