How to control ceiling altitude?

[cjn1042]

Hi.
I'm using Prepar3D with FSXPilot.
When flying using '60ft Pusher Drone', it is possible to fly to an altitude of 3,500m.
It lose control above the altitude.
And similary using F-22, it can fly to 10,000m.
It seems like the maximum altitude is fixed.

So I want to fly more than 10,000m using '60ft Pusher drone'.
Is it possible? And could you tell me how to use it?

Thank you.

[JorgenSA]

This aircraft (drone) is powered by a two-stroke, two-cylinder piston engine, as far as I can see not supercharged.

Given such an engine, a maximum altitude of 3,500 meters seems reasonable.

But 10,000 meters is somewhere in the realm of fantasy. For that you would need a supercharged engine, which would mean 4-stroke and many more cylinders. Something like a Rolls-Royce Merlin 60-series. And that, of course means a totally different aircraft...

Jorgen

[agfreeman]

Is there any particular reason why you want the drone to go above 10km? And to what height exactly? And any reason why you want a drone?

P3D won't allow it to go any higher simply because it's following the laws of physics and what the designer plugged in as the parameters, which would roughly follow the real life aircraft (I say roughly because I can't get a lot of the included aircraft to perform to the maximum performance envelope of the real aircraft).

To me the drone supplied looks like the RQ-1 predator which had a max altitude of around 7.6km. So the model might slightly be off.

As Jorgen said, you'll need a totally different aircraft. There are some freebies out there, including a Global Hawk (flyaway simulation) and you may find the Predator's descendant, the MQ-9 Reaper somewhere. Both have a real life max altitude that exceed 10km (the Global Hawk being higher), but there is the question as to whether time has been taken to model them accurately enough to get that high, trial and error I'm afraid.

Your other options are:
1) Modify the .air file using something like Aircraft Airfile Manager, but you'll need to change a host of things to get it up that high and a good understanding of aerodynamics.

2) Replace the airfile with that of another aircraft that can exceed 10km (I had a Santa's sleigh for FSX once... that used the .air file from a Mirage if I recall correctly...he had no trouble doing his rounds).

However, in both of the last cases the aircraft will not perform or handle 'like it was supposed to', in other words be extremely unrealistic, and you'll probably have to change other things too so you are probably better off looking for a different drone model.

[JorgenSA]

AG,

You raise good points, but notice that the MQ-9 is powered by a turboprop of 900 HP, and the RQ-1, while the engine is piston and 115 HP, is also turbocharged. If you look at the aircraft.cfg file of the 60 ft. drone, you'll see the engine specs.

I would imagine (but don't know positively) that normally-aspirated piston engines have a practical max. ceiling of about 4,000 m, for the same reason that a human should/must wear oxygen at and above that level, namely that the oxygen part-pressure in the air becomes too low.

Jorgen

[agfreeman]

Good point Jorgen, I forgot about those settings.

With some careful flying I have managed to get the drone up to 30,000 ft, 83 KIAS. It took a while but it got there. Could really do with autopilot!