Incident Piaggio Aero P.166 VH-MMP,
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ASN Wikibase Occurrence # 213710
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Date:Tuesday 2 March 1971
Type:Silhouette image of generic P66P model; specific model in this crash may look slightly different    
Piaggio Aero P.166
Registration: VH-MMP
Fatalities:Fatalities: 0 / Occupants: 2
Aircraft damage: Substantial
Location:Essendon Airport, Melbourne, VIC -   Australia
Phase: Landing
Departure airport:YPAD
Destination airport:YMEN
Investigating agency: BASI
Confidence Rating: Accident investigation report completed and information captured
It had been pointed out to the pilot, by another pilot on a previous flight, that the undercarriage retraction cycle was slow and he resolved to have this checked on the approaching 100 hourly inspection. The purpose of this flight was to position the aircraft for this inspection. After a normal flight from Adelaide the pilot selected undercarriage "Down" on a practice ILS approach to Essendon and noticed that cockpit indications for the port undercarriage continued to show "Up". He advised the Tower of the problem and on a subsequent pass over the Tower, ground observers confirmed that the port wheel was still retracted. Since he had plenty of fuel on board, the pilot spent about an hour attempting to lower the undercarriage, using the normal and emergency lowering methods. All systems operated normally, except for the port gear, which remained retracted. Acting upon instructions from engineers on the ground, the passenger removed a panel from the hydraulic system and tapped the port gear jack with the rubber end of a crash axe, but to no avail. The pilot decided to make a wheels up landing on the grass parallel to runway 08, and outside the northern boundary of the flight strip. Although the aircraft landed smoothly the under side of the fuselage was considerably damaged. Subsequent examination of the port undercarriage jack showed that the piston 'O' ring was badly chipped, but the reason for this could not be established. A fragment from the chipped 'O' ring had blocked the orifice of the jack brake valve, preventing operation'of the jack to lower the port gear. The unit containing the defective 'O' ring was required to be overhauled at periods not in excess of 4 years, but examination of the aircraft servicing records showed that it had not been overhauled since 14.2.1967.

Accident investigation:
Investigating agency: BASI
Report number: 
Status: Investigation completed
Download report: Final report


Revision history:

28-Jul-2018 10:49 Pineapple Added
07-Jun-2022 21:04 Ron Averes Updated [Location]

Corrections or additions? ... Edit this accident description

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