On the morning of the accident, the pilot woke at 0530 Central
Summer Time (CSuT) and started duty at 0630. The pilot had
undertaken an Instrument Flight Rules (IFR) Regular Public
Transport (RPT) check flight in a Cessna 402 for 2.3 hours during
the mid-morning on the day of the occurrence. The pilot's
performance during the check flight was considered above average.
The pilot was then tasked by the company for a Visual Flight Rules
(VFR) charter flight in a Cessna 210. Towards the end of this
substantial tour of duty, the pilot entered the Croker Island
circuit for an approach to runway 31 at about 1806. During final
approach, the pilot did not recall any auditory landing gear
warnings, nor did he recall the status of the landing gear
indicator lights. The pilot proceeded to land the aircraft with the
landing gear retracted. This event occurred at approximately 1813
(CSuT). The pilot and five passengers were unharmed and evacuated
the aircraft.
The pilot reported that he was fatigued during the flight and
that the landing gear pump circuit breaker had popped on the final
leg to Croker Island. The pilot recycled the landing gear pump
circuit breaker and realised that the electric motor was still
running. The pilot subsequently elected to pull the circuit breaker
to prevent damage to the electric motor. This procedure was
executed in accordance with the Cessna 210 Information Manual
recommendation that when the hydraulic pump continues to run after
gear cycle completion (up or down), the gear pump circuit breaker
should be pulled out to shut off the hydraulic pump motor, thereby
preventing damage to the pump and motor. The circuit breaker must
be re-engaged prior to landing so that the landing gear can been
extended (sections 3-20 & 7-12 of Cessna 210 Information
Manual). On approach to Croker Island, the pilot selected the
landing gear down but forgot to re-engage the landing gear pump
circuit breaker. Consequently, the wheels did not deploy.
The pilot reported that the aircraft had sustained damage to the
propeller and the underside of the aircraft. An initial engineering
inspection revealed no apparent damage to the engine crankshaft or
other engine components. A maintenance engineer from the company's
contracted maintenance organisation found the landing gear handle
in the fully extended position and the landing gear pump circuit
breaker disengaged.
The pilot had accrued 2286.9 hours of flight time, of which
785.0 hours were on the Cessna 210. The pilot was considered as
above average and very capable by both the chief pilot and the
check-and-training officer. The pilot had flown five aircraft types
in the week preceding the occurrence.
The maintenance release indicated no problems with the landing
gear. The pilot reported that the Cessna 210 was well maintained
and serviceable prior to flight.
The company did not have a documented procedure for the actions
required when the landing gear hydraulic pump continues to run when
the landing gear has been retracted. The Cessna 210 Information
Manual recommends that when the hydraulic pump continues to run
after gear cycle completion (up or down), the gear pump circuit
breaker should be pulled out to shut off the hydraulic pump motor,
thereby preventing damage to the pump and motor. The circuit
breaker must be re-engaged prior to landing so that the landing
gear can been extended (sections 3-20 & 7-12 of Cessna 210
Information Manual). The pilot reported that he was familiar with
this procedure as annotated in the Cessna 210 Information Manual.
The pilot also reported that the landing gear warning systems were
tested and found to be fully functional prior to flight. These
systems include the landing gear intermittent warning tone and gear
indicator lights.
The pilot did not recall hearing any audio warning indicating
that the gear had not extended until the aircraft was on the
ground. In addition, the pilot did not recall the status of the
landing gear indicator lights prior to landing. Finally, the pilot
did not visually confirm the extension of the landing gear.
The pilot reported that he was very tired on the day of the
occurrence and that he had been tired for some time leading up to
the accident. The pilot's work/rest history for the 14 weeks before
the accident was examined using a computerised fatigue algorithm
developed by the Centre for Sleep Research, University of South
Australia. The results indicated that the pilot was probably not
suffering severely from cumulative fatigue on the day of the
accident. On the day of the occurrence, however, the pilot reported
feeling tired and he had been on duty for almost 12 hours before
the accident. Moreover, he had been awake for almost 14 hours
before the accident.
The pilot probably suffered from a transient fatigue related
memory lapse where he forgot to re-engage the landing gear pump
circuit breaker before landing and failed to visually check that
the landing gear was down and locked.