On 2 July 2005 at about 0920 Eastern Standard Time, the pilot of
a Piper PA-32RT-300 aircraft registered VH-SEQ conducted pre-flight
checks for a local scenic flight from Townsville Airport, Qld. The
pilot then boarded the five passengers and conducted a safety
briefing. The passengers were provided with intercom headsets.
The pilot obtained a clearance from the aerodrome controller
(ADC) and commenced the takeoff. During the take-off roll the pilot
noticed an object go past the windscreen. He rejected the takeoff
and returned to the apron where he shut down the engine and
disembarked the passengers.
The pilot found that the engine cowling bungs1 had not been removed during the pre-flight
inspection. He removed pieces of the bung material from the cowl
openings. The pilot and passengers again boarded the aircraft and
departed for the scenic flight.
While over the city the pilot twice attempted unsuccessfully to
contact the ADC by radio for approach instructions. The pilot
reported that he then noticed that the ammeter did not indicate a
positive battery charge rate. Realising that the electrical system
had failed, he contacted the ADC by mobile telephone and obtained
approach and landing instructions. A passenger later stated that
the headsets had operated intermittently during the flight and
stopped functioning prior to the landing.
The pilot selected the aircraft's landing gear down while on the
downwind leg of the circuit for runway 07. The gear position lights
did not illuminate and he was unable to confirm that the
electro-hydraulic powered landing gear had locked in the down
position. The pilot stated that he twice applied the emergency
landing gear extension checklist procedure. The landing gear
emergency extension checklist required a number of actions to be
completed. These included a fish-tailing or yawing manoeuvre to
ensure that the main landing gear had locked in the down
position.
The pilot then attempted to contact the ADC, but the mobile
telephone had failed due to low battery charge. While on final
approach the pilot received a green light from the ADC confirming
the landing clearance. The pilot stated that he did not advise the
passengers of the potential problem with the landing gear.
The pilot reported that he was aware the landing gear could
collapse and said he had taken extra care to ease the aircraft
gently onto the runway. The right main landing gear collapsed
during the landing roll and the aircraft then veered to the right
and departed the runway surface. The left main and nose landing
gears then collapsed. The pilot and five passengers vacated the
aircraft without assistance. There were no reported injuries to
either the passengers or the pilot.
The subsequent inspection found that a large part of the leather
casing of one engine cowling bung had jammed between the starter
ring gear and starter motor and dislodged the alternator drive
belt. The pilot reported that the cowling bungs were partially
obscured by the 2-bladed propeller and were not fitted with
streamers. The colour of the bungs was similar to that of the
engine cylinder heads. The passengers reported that the pilot said
he had overlooked removing the bungs during the pre-flight
inspection as he was distracted at the time.
Due to the damage to the landing gear and the aircraft
structure, the investigation was unable to establish detailed
reasons for the right main landing gear collapse.
Figure 1: The dislodged alternator belt and fluff from
the bungs
ATSB COMMENT
The circumstances of this accident demonstrate the need for
thorough pre-flight inspections. Once the pilot became aware that
the cowling bungs were damaged, the need for a comprehensive
inspection prior to further flight should have been apparent.
The loss of power to the electrical system occurred when the
battery discharged after the alternator drive belt was
dislodged.
The lack of colour contrast probably contributed to the pilot
not seeing the engine cowling bungs during the pre-flight
inspection. The common practice of using brightly coloured bung
covers with attached streamers would have helped to ensure that the
pilot recognised their presence.
Although the pilot assessed that the risk of landing gear
collapse was remote, he should have provided a specific emergency
briefing to the passengers.