The pilot of the Mooney M20J aircraft had planned to take one of
his employees from Jandakot to Laverton via Melita Station, where
he intended to deliver a small quantity of equipment. The aircraft
arrived overhead Melita Station at about 1730 Western Standard
Time, approximately 2 hours and 20 minutes after departure. A
station hand reported that the aircraft flew over the upwind
threshold of the airstrip at a low level and heading in a southerly
direction. The aircraft then appeared to fly a downwind leg of a
normal circuit before it banked sharply to the left onto an
apparent final approach. The station hand then saw the aircraft fly
quite close to the ground for about half the length of the
airstrip, before adopting a nose-high attitude. The engine noise
then increased, although it sounded laboured. When the aircraft was
about 100 ft above the ground, he heard the engine noise stop. He
then saw the aircraft pitch nose-down and impact the ground in a
near vertical attitude. The aircraft was destroyed by the impact
and the occupants received fatal injuries. There was no fire.
The aircraft wreckage was located 270 m beyond the northern end
of the airstrip and 20 m to the right of the extended centreline.
The landing gear was extended, and damage evidence indicated that
the propeller was not under power at impact. The flaps were
extended; however, their exact setting at impact could not be
determined.
The fuel boost pump switch was found in the "off" position.
However, it could not be established if the switch was in that
position before the accident. The engine-driven fuel pump was
damaged during the impact and the investigation was unable to
determine if it was functioning correctly prior to the accident. If
the engine-driven fuel pump had failed while the fuel boost pump
switch was turned off, the engine could have failed due to fuel
starvation.
The aircraft was fitted with an emergency locator transmitter
(ELT) certified to US Federal Aviation Administration Technical
Standard Order (TSO)-C91. Although it appeared to be correctly
mounted and connected, The ELT did not activate at the time of the
accident. Its instrument panel mounted switch was selected to "arm"
and the ELT unit's switch was selected to "auto". The investigation
could not determine why the ELT had not operated during the
accident. When tested during the investigation, it operated
normally.
The Melita Station airstrip, with a useable length of
approximately 900 m, was adjacent to the homestead and was aligned
approximately north-south. There was no airstrip lighting at
Melita; however, runway lighting was available at Laverton.
At the time of the accident, the wind was calm and there was no
cloud. The temperature was about 15 degrees Celsius. The
stationhand stated that although it was twilight, he was able to
carry out his tasks without artificial lighting. Airservices
Australia advised that the end of daylight on the day of the
accident was 1733. The aircraft's flight manual indicated that the
aircraft was equipped for night flight.
The pilot held a private pilot licence and a night visual flight
rules rating, and was endorsed on the aircraft type. During his
aviation medical examination, the pilot indicated that he had a
significant family cardiac history. The post-mortem examination
established that one of the pilot's coronary arteries was
approximately 90 per cent blocked.
The aircraft departed Jandakot with both fuel tanks full. Each
tank contained approximately 121 L of useable fuel. Reference to
the aircraft's flight manual indicated that fuel usage for the
flight should have been between 90 L and 100 L. The pilot's
operating handbook (POH) warned that if the selected fuel tank
contained less than 30.3 L of fuel, take-off manoeuvres and
prolonged sideslips may cause a loss of engine power. Had the
engine been drawing fuel from only one tank during the flight from
Jandakot to Melita, there would have been approximately 20 L to 30
L of fuel remaining in that tank on arrival at Melita. The
nose-high pitch attitude that the aircraft was seen to adopt
shortly before the accident might have caused a loss of engine
power had the selected fuel tank contained less than 30.3 L.
Immediately after the impact, fuel was seen flowing from the
aircraft and a strong smell of fuel was evident for some time
afterwards. The aircraft's weight and centre of gravity were
estimated to have been within the prescribed limits at the time of
the accident.
The loss of control during the apparent go-around was consistent
with the engine losing power and the aircraft stalling at a height
from which recovery was not considered to be possible. The POH
warned that the aircraft might lose up to 290 ft of altitude during
a stall at maximum weight.
The investigation was unable to establish the reason for the
engine failure and did not identify any pre-existing aircraft
defects that might have influenced the circumstances of the
accident. The significance of the effects of the pilot's medical
condition could not be determined.