Spitfire IXe Engine Failure

[Dagwoodyt]

At near constant 2-4lb. boost the engine seems to die within ~15 min. I have done QM dogfights of > 30 min. in other aircraft having much less automation. What am I missing here?

[DD_Arthur]

What rpm setting are you running when this happens?

[Dagwoodyt]

That was @3000 rpm. Just tried  reducing rpm of failing engine to 71% and got an ~30 min run time with engine still running upon landing.

Edited August 19, 2019 by Dagwoodyt

[=FEW=fernando11]

"Engine modes:
Max Cruising power (unlimited time): 2650 RPM, boost +7
International power (up to 1 hour): 2850 RPM, boost +12
Emergency Max All Out power (up to 5 minutes): 3000 RPM, boost +18"

 

you were running the engine for longer than allowed at that high RPM...

 

You can find such information, for all planes,  if while playing you press the O key, and go to the specifications tab on the right side while having the full screen map.

 

I think you can also look at the same info on the "setup" screen before starting the mission. Where you Select diferent loadouts and skins/paintjobs for the planes.

 

 

or here:. https://forum.il2sturmovik.com/topic/25993-aircraft-flight-and-technical-specifications-and-operational-details/

 

[Dagwoodyt]

Understood. Thanks!

[kendo]

A related question - what is the recommended / best way to approach managing the Spitfire IX engine - I mean the relation between use of RPM/pitch selector and throttle? Should RPM/pitch selector be kept constant and throttle used to vary actual RPM/MP, or is it necessary to adjust both?

 

Ashamed to say I just haven't got my head around the Spit - constantly blowing engines. Maybe got too fixed on the Russian engine management for too long. But the German engines seem logical and easy too. Just the Spit that embarrasses me.

 

Thanks for any advice.

 

[Jade_Monkey]

You have to manage both. Not too difficult, only two dials to monitor and the technochat of you have it on. 

[JimTM]

Here's a couple of tips:

• Increase RPM before increasing boost
  
  For example, to go from cruise power to international power (2850 RPM, boost +12), increase RPM to 2850 first and then increase boost to +12. You can then leave RPM alone and decrease throttle or increase it back to +12. Or, you can increase RPM to 3000 and then increase boost to +18 for emergency power.
   
• Decrease boost before decreasing RPM
  
  For example, to go from international power to cruise power (2650 RPM, boost +7), decrease boost to +7 first and then decrease RPM to 2650.

 

Edited August 19, 2019 by JimTM

[Dagwoodyt]

The confusing thing is that when airscrew is left full forward (100%), engine will die quickly even if boost is zeroed. Even so, it seems airscrew needs to be @ 100% for takeoff and landing.

[=FEW=fernando11]

58 minutes ago, Dagwoodyt said:

The confusing thing is that when airscrew is left full forward (100%), engine will die quickly even if boost is zeroed. Even so, it seems airscrew needs to be @ 100% for takeoff and landing.

The way the current engine limitations is modeled, if you go over EITHER 2850 RPM OR  boost +12, you are in emergency mode.

The closer yo are to 3000 RPM or +18 the less time you have, up to only 5 min.

If posible avoid going into emergency mode unless you need/want to, and even then try to be a bit less than 100% RPM and throttle unless it's really really necesary...

 

By the way, a new way of modeling engines limitations has been confirmed to be in the works by the Developers.

[Dagwoodyt]

It's cIear that the rpm limitation has to be respected. I am still a bit surprised at how quickly 3k rpm @2-4 lb. boost will kill the IXe engine, but could be accurate. Though not of any great moment, I had imagined that airscrew pitch changes for the IXe might be animated, but not that I can detect.

[=FEW=fernando11]

If you mean the change in the actual angle of the airscrew. It is animated. But on the spit, as many others you Select a RPM setting, and a governor tries to mantain that RPM, you do not select prop pitch directly.

In the 109s and some other aircraft you can directly change prop pitch (on manual mode) and see the airscrew angle change slowly. Also on any plane that has prop feathering option, like the 110s, a20 and I think hs129.

 

 

[Dagwoodyt]

If the IXe's airscrew lever does not change prop pitch, what is its' function?

[RNAS10_Oliver]

25 minutes ago, Dagwoodyt said:

If the IXe's airscrew lever does not change prop pitch, what is its' function?

 

It does change the prop pitch. But just as Fernando already stated you do not choose the pitch you want but instead choose the revolutions per minute that you want and the aircraft has a governor that then changes the airscrews pitch in order to achieve that chosen speed.

 

Quote

But on the spit, as many others you Select a RPM setting, and a governor tries to mantain that RPM, you do not select prop pitch directly.

 

Edited August 20, 2019 by Oliver88

[=FEW=fernando11]

The "airscrew lever" on the spit IX is in fact a RPM selector lever.

 

Well. Off the top of my head:

 

You have 2 diferent types of props. Fixed, and variable pitch.

 

Of the variable pitch, you can have a further 2 types.

Simple Variable Pitch, and Constant Speed props.

On the variable pitch prop. You controll directly the angle of the blades. Say, you set it to 60º and it Will stay at that angle, FIXED until you change it again, so the RPM Will vary with your throttle, and speed changes!

 

The constsnt speed prop (like on the spit), you set it to a desired RPM, and a GOVERNOR usualy on the prop hub will automaticaly change the airscrew angle to achive that desired RPM. Only when the airscrew reaches the mechanical limit of the angle they can have the RPM Will start to change.

Also RPM might "jump" a bit with sudden throttle changes while the automation adjust the angle...

 

Look at this video for further information. Diferent plane. But same type of RPM mamagment 

 

 

AND the earlier link for a mix of Variable Pitch ( on the 109 when using manual prop pitch mode) and "automatic" when using auto RPM mode...

To be More exact. The 109 uses a diferent mode. When in auto. The prop pitch is automaticaly linked to the manifold presure. So at higer MP the engine automaticaly sets a higer RPM. And at lower MP a lower RPM.

[Dagwoodyt]

Helpful, thanks!

[danielprates]

12 hours ago, Dagwoodyt said:

If the IXe's airscrew lever does not change prop pitch, what is its' function?

 

 It does change pitch. But the feedback you monitor is the resulting change in RPM and not the actual pitch.

[RedKestrel]

15 hours ago, =FEW=fernando11 said:

 

 

By the way, a new way of modeling engines limitations has been confirmed to be in the works by the Developers.

Got a link? I don't think I've seen this in any of the dev diaries. Very interesting, it would be great to see detonation modeled and other things, rather than the simplified timers.

[=RvE=Windmills]

29 minutes ago, RedKestrel said:

Got a link? I don't think I've seen this in any of the dev diaries. Very interesting, it would be great to see detonation modeled and other things, rather than the simplified timers.

 

It's more an 'it will happen' at some point rather than an active project iirc, it wasn't a DD but feedback on a thread. Though somebody else can probably dig it up.

[CountZero]

On 8/19/2019 at 8:38 PM, Dagwoodyt said:

At near constant 2-4lb. boost the engine seems to die within ~15 min. I have done QM dogfights of > 30 min. in other aircraft having much less automation. What am I missing here?

Also you can turn on instrument panel in realisam settings, and youll be informed in techchat when time limit expired and its recharged, so you can track better why engine brakes on airplanes with timers, on experet realisam this stil dont work for some od reason.

[=FEW=fernando11]

4 hours ago, =RvE=Windmills said:

 

It's more an 'it will happen' at some point rather than an active project iirc, it wasn't a DD but feedback on a thread. Though somebody else can probably dig it up.

Indeed.

I have been looking for the actual quote. But couldn't find it.

But it was mentioned two ir three times un the last few months