Author Topic: 262 and high speed buffet at altitude (Read 310 times)

LLv34_Camouflage · « **on:** November 01, 2002, 05:44:20 AM »

Hi guys,

I was flying a 262 yesterday at 28Kft and noticed that the high speed buffet shake started at around 400 mph IAS. The red (TAS?) needle was around 580 mph. To my understanding, the 262 should not buffet anywhere near 400 IAS. 580 IAS on the other hand would sound ok. This seems to work fine at lower altitudes.

Is there a bug in the 262 modelling, where the buffet at high altitudes starts at TAS instead of IAS? Or am I just poorly educated?

Thanks,

Camo

Innominate · « **Reply #1 on:** November 01, 2002, 06:04:49 AM »

The buffeting is based on mach number, not IAS or TAS. That high up, the speed of sound is much lower, so you'll compress sooner.

Wmaker · « **Reply #2 on:** November 01, 2002, 08:49:33 AM »

AFAIK Innominate is correct. In my experience at lower altitudes 262 starts to buffet near 700mph IAS (670mph or so) which is close to the speed of sound and thus 262's critical mach number.

670mph is 299,45 m/s which is about 32 m/s slower than the speed of sound in standart sea level air pressure.

Pretty well modelled if you ask me.

gripen · « **Reply #3 on:** November 01, 2002, 01:04:12 PM »

Normally the critical mach number is given at 1g conditions, under higher g load buffeting starts at lower mach number.

gripen

LLv34_Camouflage · « **Reply #4 on:** November 04, 2002, 05:12:34 AM »

Thanks for the explanation, guys!

Camo

frank3 · « **Reply #5 on:** November 04, 2002, 07:29:12 AM »

I really dont know anything about the Me-262, I never fly it.
better fly a P47