The pilot of the Lancair 320 aircraft planned to fly, with a
passenger, from Archerfield to Rockhampton and return. The aircraft
was refuelled at Rockhampton and after an hour's stopover, they
departed for Archerfield, on climb to the planned cruise altitude
of 5,500 ft above mean sea level. The aircraft left controlled
airspace at 1403 Eastern Standard Time. At 1428 Brisbane Flight
Service received a Mayday transmission from the aircraft. The pilot
indicated that the engine had lost all oil pressure, and that she
intended to land on a road. This was the last recorded transmission
from the aircraft. The crews of searching aircraft did not hear any
transmissions from the missing aircraft's emergency locator
transmitter (ELT). The crew of a search aircraft sighted the
wreckage at 1815.
The pilot held a commercial pilot licence, and a medical
certificate limited to private operations. She had been taught to
fly the aircraft type in July 1994, and up to December 1997 had
gained 104 hours experience on type. The pilot met the 90-day
recency requirement specified in the Civil Aviation Regulations
pertaining to the carriage of passengers. However, with the
exception of a 30-minute flight on 13 December 1997, the only
flying experience gained by the pilot in the last 90-days was the 3
hours flown on the day of the accident. The passenger held a
private pilot licence but was not experienced on the aircraft
type.
The wreckage was located about 380 m south of a dirt road
aligned 080/260 degrees M. The road was new and unusually wide due
to the recently constructed clearway through the coastal forest. it
had a natural surface and was suitable for an emergency landing.
The surface wind at the time of the accident was an easterly at
about 15 kts.
Examination of the accident site revealed that the aircraft
struck the ground at an angle of 45-50 degrees nose-down and banked
approximately 90 degrees left. The left wingtip struck the ground
first. The aircraft then cartwheeled, traversed a windrow of felled
trees, and came to rest inverted, aligned approximately 345 degrees
M, 22 m from the initial impact point. The engine, firewall and
instrument panel had separated from the fuselage in one piece. The
empennage had separated in a whiplash action and had come to rest 8
m beyond the fuselage, also aligned approximately 345 degrees M.
The landing gear was locked in the extended position and the
wingflaps were retracted. A significant quantity of oil had escaped
from the engine during flight, as evidenced by oil along the lower
fuselage. A search of the area where the aircraft was parked at
Rockhampton found a small pool of fresh oil consistent with engine
oil dripping from the engine cowling during the stopover. It could
not be established if oil had been added to the engine at
Rockhampton.
The ELT was mounted in the rear of the fuselage but was
disconnected from its aerial due to impact forces. The unit was
turned off 42 hours after the accident. Later specialist
examination found that the near-new batteries were almost depleted,
indicating that the unit had been operating but not radiating
effectively without its aerial.
The engine was removed to an engineering workshop and dismantled
under the supervision of BASI investigators. Approximately 1 L of
oil was recovered from the engine and there was no sign of seizure
damage to any engine component. Specialist engineering opinion was
that the engine was serviceable before impact. Destruction dynamics
of the wooden-bladed, variable-pitch propeller assembly indicated
that the engine was producing power at impact. During removal of
the engine ancillary components, a high-pressure oil hose was found
to be holed. The braided steel, rubber-lined hose had been resting
on the Number 1 cylinder exhaust pipe and had worn through due to
vibration and heat.
The oil hose had been fitted to replace the engine
manufacturer's stainless steel line between the propeller hub and
the propeller governor at the rear of the engine crankcase.
Replacement of the stainless steel line with a braided steel hose
was authorised by Civil Aviation Safety Authority (CASA)
Airworthiness Directive (AD) AD/LYC/86 Amdt. 1 issued on 12 July
1990. The AD referred to Textron Lycoming Service Instruction 1435,
which specified a Type D, teflon hose with steel
braiding/fire-sleeving, and instructions on clamping/routing. The
item fitted to the aircraft was a Type A, steel-braided, rubber
hose of lower specifications than the Type D hose and was
clamped/routed incorrectly. The aircraft was amateur-built by its
previous owner. The hose had been installed before the aircraft's
initial airworthiness inspection prior to being placed on the
Australian Aircraft Register.
Forty flight-hours before the accident, the engine's cylinders
had been removed/refitted during unscheduled maintenance. The
aircraft had also undergone a periodic inspection at the same
maintenance organisation 19.4 flight hours before the accident.
Although the engine did not show any signs of seizure and some
oil remained, the length of time that the engine may have continued
to operate could not be determined. Bundaberg aerodrome, 72 km from
the accident site, was the nearest suitable aerodrome. Considering
the loss of oil pressure, the pilot's decision to carry out a
precautionary landing on a road in an area devoid of other suitable
landing sites was appropriate. The circumstances of the approach
could not be determined. Although the wingflaps had not been
configured for landing, the disposition of the wreckage was
consistent with a right-base position for landing into wind. The
attitude of the aircraft at impact was consistent with a loss of
control at a height from which recovery was not possible.
Comparison of limitation data contained in the aircraft flight
manual and the flight test results contained in the aircraft files
held by CASA revealed a discrepancy in the documented aerodynamic
stalling speeds. The stall speeds specified in the aircraft flight
manual were lower by 2 kt when compared with the relevant flight
test power-off stalling speeds.
Although not implicated in the accident sequence, two other
discrepancies were found which involved the fitment of an
automotive engine oil filter to the engine, and a right-angle drive
adaptor for the rear mounted propeller governor. Neither was
covered under an Australian Engineering Order or Supplemental Type
Certificate for the Textron Lycoming engine.
During the course of the investigation it was reported that
maintenance by unqualified personnel had been performed on the
propeller system following the last periodic inspection. This could
not be substantiated.
