The pilot, who was of slight build, was tasked with conducting a
regular public transport flight, with 6 passengers, from Gunnedah
to Sydney (Kingsford Smith) airport. The aircraft, an Embraer
EMB-820-C (licence built Piper PA31 Chieftain), had a valid
maintenance release with no significant outstanding entries.
Pre-flight preparation was normal and unrushed and an on-time
departure was accomplished. The weather for the departure was fine
with light wind.
Before initiating takeoff from runway 11, the pilot, who was
appropriately licensed, endorsed and base checked to fly the
EMB-820-C aircraft, carried out engine run-ups and pre-takeoff
checks. The pre-takeoff checks included selecting 15 degrees of
flap and setting the elevator trim. The pilot's normal trim setting
procedure was to wind the trim wheel all the way to the forward
limit and then wind it back 5 to 6 complete turns. Consultation
with industry pilots experienced on the aircraft type revealed that
3 to 4 turns was common. They indicated that pilots of lesser
physical stature have found the aircraft type is easier to rotate
with the elevator trim set to a nose-up position for takeoff,
however that would result in more re-trimming of the aircraft once
airborne and during flap retraction. Low-wing aircraft have a
tendency to pitch up slightly during flap retraction. Additionally,
as an aircraft climbs out of ground effect, changed downwash over
the tailplane produces a further pitch-up tendency.
The pilot reported that the take-off run and rotation appeared
normal, however, as the flaps were retracted the elevator load
increased. The pilot was only able to preserve a safe climb
attitude by using both hands to maintain forward pressure on the
control column. The pilot did not use the electric trim in normal
day-to-day operations and did not consider using it to relieve the
elevator load on that occasion. Believing the problem was either
elevator trim or aircraft centre of gravity related, the pilot
requested the passengers seated at the rear to move toward the
front of the aircraft in order to lighten the load on the controls.
A male passenger positioned himself in the unoccupied right control
seat and, as the control forces were still high, the pilot
requested that the passenger momentarily apply forward pressure on
the control column. The pilot then took one hand from the controls
to manually trim the aircraft and reduce the power.
The aircraft continued to Sydney without further incident and
showed no abnormal handling characteristics on the subsequent
sectors. A comprehensive inspection of the aircraft did not reveal
any discrepancies with the elevator trim system and a review of the
aircraft logbooks indicated no recent reported problems or
disturbance of the trim system for rectification work. It was
calculated that, at takeoff, the aircraft weight was 39 Kg below
the maximum takeoff weight and the centre of gravity was slightly
forward of the mid-point between the forward and aft limits.
Prior to the incident flight the pilot had positioned the
aircraft to Gunnedah from Coonabarabran. The aircraft, which had no
passengers or freight, was landed with full flap and in that
configuration would have required almost full-back (nose-up) trim.
Although not included in the after-landing checks of the operator's
approved Piper Aircraft Corporation paper checklist, it was normal
practise for most pilots to re-set the trim when clear of the
runway. The Pilot's Operating Handbook expanded checklist
recommended that course of action. The expanded checklist was used
for training and as a supplement to normal and abnormal checklists.
It was not meant to be referred to in flight.
