Wheels up landing involving a Cessna 210L, VH-TIJ, Darwin Aerodrome, Northern Territory, on 7 December 1996

Arriving at the destination the landing gear failed to extend when the pilot selected it down.

His attempts to extend it using the manual hand pump were unsuccessful as he was unable to build up enough hydraulic pressure in the system to operate the gear. Hydraulic fluid was then noticed seeping from behind the centre console which he identified as a serious leak from the power pack He was able to replenished the lost hydraulic fluid with spare engine oil carried onboard the aircraft, but this failed to rectify the loss of hydraulic pressure.

After calculating the aircraft's endurance, the pilot decided to return to Darwin where he carried out a wheels up landing.

An inspection revealed that one of the "O" ring seals located at the joint between the landing gear manifold and the power pack was split, causing a hydraulic fluid leak, and loss of hydraulic pressure.

The manifold had been removed the previous day to change the servo-valve, and it is possible the "O" ring was damaged during reinstallation. Several successful gear retraction tests had been carried out after completion of the work, followed by about 9 gear cycles in flight before the leak developed.