Hey guys!

So my problem is that both engines set on fire about 5 seconds into takeoff

There is also a red warning light that goes off during the failed takeoff

I have read and watched closley the pmdg turbo startup procedures, but it still does not help

thanks

Start locks not removed...

You have to remove the start locks.

After engines are stable, slowly decrease throttle (F2) until about halfway, then return to idle.

 

FS2Crew gives an audible indication the locks are removed....I'm not sure if the default JS41 installation comes with a warning or sound to let you know.

 

Btw...this is covered in this guide - http://forum.avsim.net/topic/261431-js41-startup-guide/ which is also stickied at the top of this forum.

I tend to think you did not bring your conditon levers to "Flight". I do not think forgeting the locks will burn the engine because most likely you will not get to the runway with them locked :))))))))

Yes you can taxi with the locks on.

If condition levers aren't in flight all that will happen is you will never get airborne due to lack of rpm.

 

His issue is the start locks.

I agree with Frank, it's the condition levers.

 

The start locks keep the props in the fine position (to allow the starter motors to turn the engine with enough speed to allow startup, feathered position would cause too much drag and the starter motors will not be able to turn the engines fast enough). The condition levers control the rpm, not the start locks, but due to the fine position, the engine can not generate thrust or torque (the prop blades cut through the air at a low angle of attack meaning low "backwards lift" or thrust, and low drag on the blades, meaning low torque).

 

Now, since the engine controls dont allow the rpm to go more than what the condition levers are set at (generally) and the torque generated by the engine is low, the total power generated by the engine is low (power=torque x rotational speed) and therefore the heat put into the engine, and resulting EGT are also low. The position of the start locks can therefore not cause and overheated engine, it just means you are not going anywhere since the prop blades cant be "turned back" to a courser setting to allow the thrust to increase.

 

On a turbine engine, especially turboprops, the speed of the engine has a large part to play in the amount of air that goes into it. As per the manuals: more air means more mass flow to be heated, meaning lower temps overall. Less air, conversely, means more temperature.

 

If you read the manuals, you will learn that, unlike the free turbine turbine turbo-props (think King Air) the engine speed and prop speed on the J41 engines are directly related, since they are geared together. On the free turbine engines, you can change the prop speed with the rpm lever without bothering the other shaft (I believe it's called the high-pressure shaft) too much (there are two seperate shafts, google it for pics). Not so on the geared turbines, where engine speed and prop speed are directly related. Therefore, if you change the prop speed using the condition levers, you are changing the engine speed as well.

 

Lowering the props speed, therefore, means you increase the metals temps in the engine as there is less air to be heated by almost the same amount of fuel. Trying to take off, i.e. giving full power, at low rpm, means that you put too much heat into the engine for too little air and the engine melts, or catches fire.

 

In my opinion it's the condition lever. Move them to the "flight" (full forward) position before you start the take-off run.

 

Also, do not jam the power levers all the way forward. The engine is capable of producing more power than what the metal can handle in terms of temperature. General practice is to move the condition levers forward to around 80% and then inch the levers forward slowly until you reach you desired torque for take-off, or 100%, or you reach the egt limit. So during your take-off run, keep a close eye on the engine guages. Remember that turbine engines dont respond as quickly as piston engines, and turbo-props are slower than turbofans as well, so you must set the power carefully. Be ready to pull back on the power if you overcook it, but best practice is to do it slowly and never exceed the egt limits. Remember, any additional thermal stress on the engines mean you run a greater risk of unwanted trouble later on, and your maintenance bill will increase. To the casual simmer, this is obviously not a problem, you just want the kite in the air without a tail of fire. However, looking at the long-term wellness of the plane will aid you in keeping it happy in the short term as well, if I may be a little philosophical.

 

Alternatively, you can swith the engine fires off in the config manager (run it as admin otherwise it may not save your changes), but to me, the is no sense in paying for this quality of an add-on if you are not going to learn to fly it properly.

 

Last word, read the tutorial, and fly the tutorial flight. It is not as daunting as it may seem, and it will add greatly to your enjoyment of this lovely airie. In my opinion it is better than the NGX to fly, as it keeps you on your toes, for example: our current discussion.

 

Hope this helps.

 

Carl Kohrs

Sorry I had things backwards.

You can taxi to the runway without removing the start locks, but if you apply full power with condition levers in taxi mode, you melt the engine parts.

 

Been a while since I've melted the J41 engines so I tend to forget what failure is cause by what.

So my problem is that both engines set on fire about 5 seconds into takeoff. There is also a red warning light that goes off during the failed takeoff

 

You need to do the tutorial flight, if you're not understanding this issue you're not understanding the aircraft. You will struggle with the J41 unless you do the tutorial and/or read the manual.

 

You have started the engines correctly, by the sounds of it. However, you need to advance the conditions lever to flight to increase engine/prop rpm before takeoff (I think the command is CTRL F4 or SHIFT F4). You will know when you have done this because you will see the engine RPM increasing and the sound pitch of the engines will increase too.

(I think the command is CTRL F4 or SHIFT F4)

 

CTRL + F4 is it.

After starting:

 

Gust locks disengage.

Remove startlocks (FO callout)

Condition Levers Flight (FO callout)

 

You should be fine to start now. Only 100% thrust can not be achieved in hot weather, because max EGT will be met and overridden.

Try following my checklist (see recent post "J41 New Checklist and Comments") in this forum. Whatever you're doing wrong (it could be one of several things), if you follow this checklist you'll get into the air without turning the plane into a fireball. And if you do mess things up, there's even a section for handling engine fires in the air.

 

Al.

Folks,

does a real video exist of melting the engines?

Ahh, well, that's too destructive, eh?

New in the forum, am flying jets at the moment, so will get props too, so paying attentions too