Originally Posted by
LOMCEVAK
zzuf,
I used the phrase 'accelerated stall' to mean a stall at greater than 1g (as per Def Stan 00-970 and Mil Specs). FAR23 and CS23 use the same phrase to mean a deceleration rate of 3-5 IAS per second - again, apologies for ambiguous phraseology. At 30 deg AoB and 75% MCP the pitch attitude will be high to achieve the deceleration but normal acceleration and IAS will be low. I have flown this test in a high powered piston aircraft under the old CAA Schedule 233 and been about 60 deg nose up with full rudder and almost full aileron, the ASI below its minimum value and still not reached an aerodynamic stall! However, normal acceleration was less that 1 due to the nose up attitude. Remember that it is pitch attitude that determines the deceleration rate, not normal acceleration.
L
Lomcevak,
I had intended to leave the response as a PM, changed my mind due to other responses.
A requirement of FAR 23.203 is deceleration at 3 to 5 kts per second, "with steadily increasing normal acceleration". It seems that you have misinterpreted the FAR and that the tests you have done are not correct.
I typically tried for a stall at about 2g, generally it requires a bit of a work up to hit 2g (with g steadily increasing), 3 - 5 kts per second deceleration, 30 degrees of bank and stall simultaneously.
But, as you mentioned, there will be plenty of low g, low speed, high pitch attitude experiences as you develop a test procedure for a particular aircraft.
Don't forget these are test points to be demonstrated for certification, looks simple, but the workup may be time consuming and involve some exacting aircraft control. Of course after you hit the test point you need to accurately record the aircraft behaviour.
If you have ever flown tests to determine lift and thrust boundaries you will know that your last sentence (above) won't survive much scrutiny.
Cheers