UK INVESTIGATORS are virtually certain, that control difficulties played no part in the crash of an Air Algerie Boeing 737-200 on approach to Coventry Airport.

They have found no evidence of rudder-control malfunction in the 21 December 1994, accident and believe that the aircraft's impact with an electricity pylon produced wing damage, which caused it to invert before it struck the ground (Flight International, 4-10 January).

Rudder-control difficulties have been previously reported on 737s and remain a suspected possible cause of two unexplained accidents in the USA.

In an interim report, the UK's Air Accidents Investigation Branch confirms that the aircraft was being flown on a surveillance-radar approach (SRA) because it could not tune into Coventry's instrument-landing system. The co-pilot's altimeter, says the report, was found with the correct QFE altimeter setting - 29.92in Hg (1013mB) - for the approach.

Coventry air traffic control (ATC) passed the crew an obstacle-clearance limit of 650ft (200m) QFE and advised that the SRA to runway 23 would terminate at 3.7km (2nm) from touchdown. Runway visual range was given as 1,100m.

ATC had passed height guidance at 0.5nm intervals. The wing impact with the 86ft pylon was 72ft above ground level at a distance of 2km from touchdown. The aircraft rolled left, and its wingtip hit the roofs of houses "as it passed through the vertical".

Source: Flight International