Techniques for max altitude?

[DarkFire]

Having done so in the Flanker several times, I tried seeing what maximum altitude I could reach in the Eagle. The technique I used was this:

 

1. Take off under military thrust. Full internal fuel + 3 tanks.

 

2. Climb to 40,000 feet and then hit zone 5.

 

3. Drop the tanks when they limited maximum speed.

 

4. Accelerate to Vmax (~2.6M)

 

5. Perform a 3.5-4G pull up in to a ~80 degree zoom climb.

 

6. Wait until Vv=0.

 

This netted me a shade under 116,400 feet MSL. I've taken the Su-27 to 118,170 before, and I'm pretty sure that the Eagle should be able to climb higher. Is there anything I should be doing differently?

F-15C Max Altitude Test ACMI.zip

[SinusoidDelta]

I'm not able to watch the track right now but that sounds like a reasonable zoom climb technique. You don't really need 3 bags or any really if you perform the climb properly. I usually pull 4G only to a ~55 degree climb angle. I've had the F-15 to just over 122 kft (no proof).

[Sweep]

Sinus, in the post 1.5 FM?

 

I guess I really suck as a vEagle driver...Only able to reach ~85k on a good day.

 

:lol:

[DarkFire]

Sinus, in the post 1.5 FM?

 

I guess I really suck as a Eagle driver...Only able to reach ~85k on a good day.

 

:lol:

 

Bear in mind that the altitude shown in the cockpit will not be your actual altitude, even if you calibrate for QFE prior to take off. The track I attached above for example - my HUD altitude was a shade under 98,500 feet but Tacview and the F2 view (which agree with each other) reported a much higher altitude as listed. Given the area in which I hit max altitude this can;t be explained by the difference between MLS and AGL. This issue seems to be consistent across all the aircraft I've flown in DCS. Not sure why it happens, whether it's realistic or a bug...

[DarkFire]

I'm not able to watch the track right now but that sounds like a reasonable zoom climb technique. You don't really need 3 bags or any really if you perform the climb properly. I usually pull 4G only to a ~55 degree climb angle. I've had the F-15 to just over 122 kft (no proof).

 

Impressive! I'll give it a try without the bags...

[GGTharos]

Just as reference, about the only time you should need/want 3 bags is if you're crossing the ocean ... even then two bags might do better. The two wing tanks collectively have slightly less drag than the belly tank, so if you're putting all three on you have approximately double the drag of either the belly tank or the two wing tanks.

 

Having done so in the Flanker several times, I tried seeing what maximum altitude I could reach in the Eagle. The technique I used was this:

 

1. Take off under military thrust. Full internal fuel + 3 tanks.

[Sweep]

That would be an interesting thing to test....

 

Not that I'd really like to fly for 6 hours, but..........

 

:lol:

[DarkFire]

Just as reference, about the only time you should need/want 3 bags is if you're crossing the ocean ... even then two bags might do better. The two wing tanks collectively have slightly less drag than the belly tank, so if you're putting all three on you have approximately double the drag of either the belly tank or the two wing tanks.

 

Interesting, I didn't know that. Though carrying all 3 tanks I was obviously speed limited, in reality I take it neither the belly nor the wing tanks are supersonic rated? I would imagine that the tanks also have some pretty low max-G ratings in reality.

 

I might give this another go with just the wing tanks, and then with none to see if it makes a difference.

[Svend_Dellepude]

From the F-15A manual:

660 Knots or 1.5M, whichever is less.

Empty tanks are authorized to 800 Knots or 1.8M above 20.000 feet.

Max positive G load seems to be between +4 - +7.33 depending on weight.

I'm sure GG will correct this if I'm wrong.

[GGTharos]

G limit goes up with the C but the idea is that tank limits are BAL per -1.