how do i get to 25000 ft?

Hi there,

Been flying the p51, and it's going fairly well. One question so far. How do I go high? I mean 25000 ft and above.

Doing mission 7 in the campaign.

The engine starts stuttering and that gets solved by pulling back on the throttle. But then there's not enough energy to get higher.

Whats the correct procedure for this?

Increase your RPM's and ensure your 2-stage turbo has engaged.

It's easy to get up to 40k.

But what if RPM is maxed out? i.e. lever all the way forward.

Then RPM is maxed out and there's most definately something wrong.

Is the amber jewel light next to the supercharger control switch burning? If not, check if the supercharger control switch is set to "AUTO" (maybe you switched it to "LOW" by accident).

Did you check your RPM lever as well? Pull it back to decrease the RPM.

Not the fuel, engine keeps running. Last time the supercharger was active, and the same thing happened. Can't remember if supercharger kicked in this time.

The plane just sort of doesn't have enough energy to gain altitude. So speed goes down, and it starts losing altitude. So max so far has been around 22000 feet for me.

Had no issues getting up to 29,000 the other night. Set 2700 RPM, 46" mercury, and make sure your carburetor controls are full forward. Cooler switches should be on automatic. Keep the speed up and climb gradually. The P-51 only does 3200 fpm at sea level, and that falls off rapidly as altitude increases. I could do about 1000 fpm at 29K.

Remember also that when the blower hits critical altitude somewhere around 19,000 (depending on air temperature, etc), you will need to make a power adjustment to maintain 46" mercury. You'll also have to increase throttle from time to time to maintain pressure. It's okay to max the throttle out if that's what it takes to get 46", but don't go over that figure.

Any higher RPM and manifold pressure will kill your engine over the course of a few minutes (which is why it started stuttering), initially robbing you of some power, then the ability to fly altogether. Check the right cockpit wall for the engine limitations panel. Treat that (Packard) Merlin right and it'll do what you want.

Any higher RPM and manifold pressure will kill your engine over the course of a few minutes (which is why it started stuttering), initially robbing you of some power, then the ability to fly altogether. Check the right cockpit wall for the engine limitations panel. Treat that (Packard) Merlin right and it'll do what you want.

Engine damage due to overboost/overload is not included yet, must be something else.

I'm suspecting that you are not keeping the optimal climb speed of 170MPH IAS. Also keep in mind that it takes a long time to get up really high.

Edit: One last thing, currently if the air temperature in the mission is set to something very low, the engine will start to stall out at quite low altitude. Make sure you are somewhere around +5 to +20°C

climb speed is 170 mph. Don't know if that applies to 25k. Will try now in the windy takeoff cam-pain (!) mission.. Rudder is killing me..

Just some data on how it looks from my end.

I can easily get to 20000-23000 ft. There the engine started stuttering, which I correct(ed) by lowering manifold pressure with RPM maxed out.

Above 20000 it gains altitude fairly slowly, just above the 0 mark. But still gaining. A couple of thousand of feet more, with just a slight positive in the variometer, the speed just keeps dropping. So after a while the variometer goes under zero and the plane starts falling again.

That's about as exact as I can be.

What are the critical numbers I need to look out for? 170 mph speed, 46" mercury and what else? Check that the turbo kicks in, red light and all, yes. That's sort of how I've done it, except that it won't keep 170 mph.

Clearly I'm doing something wrong, just can't figure out what.

Thanks, I'll give that a try. What's the physics behind this?

Yes, cold start, not cheat start.

From what you've posted (several times), it's pretty clear that the trouble is with your engine. The things that apply, most of which has been mentioned already:

Mission conditions: Spring 15*C and Sunny, Ramp Start

RPM: 2700

MP: 46"

Magnetos: Both

Fuel Boost: On

Carb Levers: Full forward

Coolers: Automatic (up) with black covers closed

Fuel Shutoff: On

Fuel tank: Something with enough gas in it (check all 3 onboard tanks)

Blower: Automatic

Mixture: Run (the middle position)

Throttle: As needed

There may be issues associated with air induction. Keep your speed up to ensure there is enough ram air coming to the engine. When I climbed through the 20k range, I kept 200-230 mph indicated and rode that most of the way up to 29k.

The second supercharger stage kicks in somewhere around 19000 feet, which is about the time your stutters start. Try maintaining 46" mercury and riding through the stutters. Don't reduce power below 46" just to make them go away.

Other than that, make sure to turn off random system failures...

Thanks, I'll give that a try. What's the physics behind this?

 

Yes, cold start, not cheat start.

I was going to try to explain it myself, but here's something with more detail:

http://www.innovatemotorsports.com/resources/rich.php

I had the same problem flying that mission just an hour or so ago. Engine power wasn't settling, even when I reduced manifold pressure. Then I realised that I still had the mixture set to emergency rich - setting it to the middle position fixed the engine problem immediately. So I'd definitely agree with everyone else recommending that action.

Fun mission though, almost had a disaster when flying the landing circuit at the destination airport. Engine ran out of gas at just the wrong time. Got it hooked up to the next tank just in time :music_whistling:

The community comes to the rescue once again :)

Will give it a shot again tonight!