Hiller UH-12 B, N38763, 4 August 2012

Hiller UH-12 B, N38763


The pilot carried out hovering practice on the airfield for about 15 minutes before translating away for a visual circuit. Weather conditions were fine, with a surface wind from the south-west at 15 kt and an air temperature of 15°C. Whilst downwind, the pilot noticed a high engine oil temperature and low pressure, which had both been normal during the earlier hovering. He turned towards the grass area to the north of the runway for an immediate landing. As the helicopter lost translational lift, the pilot noticed that main rotor rpm was reducing so he applied power to correct. However, as the rotor rpm did not recover, the pilot lowered the collective control. The helicopter descended in a slight tail-low attitude and the tail struck the ground, causing damage to the airframe and tail rotor assembly. The pilot’s assessment was that the helicopter had lost power, compounded by the fact that the carburettor heat control had not been returned to the ‘cold’ position before the approach and landing.

Download report:

Hiller UH-12 B N38763 04-13.pdf (173.64 kb)

Published 10 December 2014