Thanks again guys! Now I have a little problem with three different concepts:
*maximum service ceiling.
*absolute ceiling.
*maximum operating ceiling.
If I m not confused, the first also means an aircraft's density altitude at which its maximum rate of climb is lower or equal to 100 feet per minute.
The absolute celing is the highest altitude at which the aircraft can maintain level flight.
The second one, The absolute celing is the highest altitude at which the aircraft can maintain level flight.
And de maximum operating ceiling is about the problems with pressurisation (the body aircraft can't cope with it)
But if we talk about the Mcrit, Coffin Corner and Speed stall, What is the ceiling limitation? Are we talk about the absolute ceiling too? Sorry but this the point where I get confused!!!