A passenger who claimed to be a co-pilot of another aircraft
type reported verbally that, on approach to land, this aircraft had
suffered buffet and wing drop which he felt was due to a stall. He
was asked to submit a report but none has been received. The person
further reported that he travels in the rear of similar aircraft
frequently and that on this occasion the nose attitude was high on
final approach. Wing drop of the left wing was associated with the
buffet and there were storms in the area during the descent.
The captain was interviewed by telephone and the interviewer was
asked to speak slowly to allow him to understand the questions.
During the arrival the aircraft was vectored by Air Traffic
Control. Heavy icing was encountered during the descent and speed
brakes were used. On the approach to land there was 21 to 23 knot
crosswind from the left. He was unable to remember the minimum
indicated airspeed during the approach. The co-pilot was flying
the
aircraft at the time and a company instructor was on the flight
deck as well. The captain is also a check captain on the type.
Analysis of this approach, and four other approaches to Brisbane
held on the aircraft flight data recorder, was conducted. The
indicated airspeed on this approach varied between 135 and 145
knots between 1500 feet and landing. The rate of descent for the
same period was constant at about 700 feet per minute. Buffet was
experienced between 1200 and 400 feet, during which time the
airspeed varied between 135 and 141 knots. After passing 400
feet the heading altered to the right slightly, indicating that
the left crosswind had reduced and the pilot was correcting to
maintain the aircraft on the runway centreline. This approach was
the most stable of the five approaches analysed and the airspeed
was well above the stall speed on all approaches.