Why autopilot above 24000?
 

I been told by some friends who fly corporate aircraft that it seems to be a wide rule that autopilot must be used above 24000 (scheduled air service too), this came up around discussion of the Citation X. Is this due to the X be unstable above that altitude in thin air? The speed? Because ww2 fighters flew above that by hand with no problems at almost 500 mph? Any insights? thanks!

If I remember correctly, and someone please correct me if I'm wrong.... but it's an RVSM requirement. Doesn't mean you can't hand fly it past FL240, just that you need an operable AP on board. I usually hand fly up to cruise (usually FL350-FL370), and have noticed no appreciable decrease in stability- at least not in the ERJ.

Hmmm, I was under the impression that he auto-pilot had to be used when entering RVSM airspace

From Appendix 4 of 91-RVSM:

An automatic altitude-control system should be operative and engaged during level cruise, except when circumstances such as the need to retrim the aircraft or turbulence require disengagement. In any event, adherence to cruise altitude should be done by reference to one of the two primary altimeters

For more information on DRVSM than you could ever possibly want, cruise on over to http://www.faa.gov/about/office_org/.../enroute/rvsm/

As far as your friends' use of autopilot, that requirement may be specific to the Citation X or to their SOP. Many aircraft have altitude limitations with an inop yaw damper, and the need for George to be flying may be something similar.

autopilot must be on when entering RVSM airspace FL290 to FL 410

handflying isn't allowed..that would be a FAR bust

The autopilot must be on when IN CRUISE in RVSM airspace. There's nothing that prohibits your from handflying climbs and descents, or manually leveling out.

i know, i'm just saying in general..when in RVSM you're going to have the AP on. Thanks for the correction though.

Sure thing- in the end it all comes down to the verbage and technicalities... just wanted to clarify. :)

I try to have it on before the RadAlt hits 610 :D