In a discussion with a colleague we realized we had no idea whether manufacturers actually conduct a stall in an aircraft at or near it's certified ceiling. FAR 25 here
eCFR ? Code of Federal Regulations
does not seem to stipulate any altitudes for the stalls to be demonstrated.
A further question came up as to whether compressibility could factor into an aircraft's stall behaviour (I know the TAS will still be slow compared to cruise, however the higher angles of attack near or at a stall can still produce some compressibility effects). Further, perhaps the thin air at such a slow speed, plus any airframe effects could cause a jet engine to flame out.
Anyone in the know?
Hawk