Old Acro has probably missed the point in using the flight tests following the Essendon PN68 disaster in 1978 as these tests were supposed to prove that the Pilot did it! The report came out a week or so before the inquest, however the Coroner chose to believe the Pilot over the Departments theory that the Pilot had unknowningly applied nose down trim.
The reality is that the “Department” actually had previously failed to comply with their own requirements for the certification of the Autopilot/Trim system by not obtaining copies of the flight test results as their own Regulations stated! In fact the only authoritative flight test available was not carried out until 17/2/1989 after another PN68 had a trim runaway at Moorabbin!
The department's report also failed to report that the aeroplane actually had a trim setting other than as certified! Even so, FAR 23-143c states that the maximum force required to overcome a trim runaway is 75 lbs. So I can personally testify that the Department has a history of issuing accident reports that try to cover up their own shortcomings
The reality is that the “Department” actually had previously failed to comply with their own requirements for the certification of the Autopilot/Trim system by not obtaining copies of the flight test results as their own Regulations stated! In fact the only authoritative flight test available was not carried out until 17/2/1989 after another PN68 had a trim runaway at Moorabbin!
The department's report also failed to report that the aeroplane actually had a trim setting other than as certified! Even so, FAR 23-143c states that the maximum force required to overcome a trim runaway is 75 lbs. So I can personally testify that the Department has a history of issuing accident reports that try to cover up their own shortcomings