Ramon Lopez/WASHINGTON DC

THE US AIR FORCE says that the 3 April Boeing CT-43A flight to Dubrovnik, Croatia, which crashed killing US Commerce Secretary Ronald Brown and 34 others, took place in breach of orders.

The airport's, approach procedure had not been approved by the US Department of Defense, says the USAF's Accident Investigation Board report.

Commanders at the CT-43A's base, the 86th Airlift Wing at Ramstein, Germany, may consequently be subject to courts-martial, according to the USAF.

Flight-planning is criticised because the aircraft's crew failed to appreciate that the non-directional-beacon (NDB) approach demanded the presence of two automatic direction finders (ADF), but the aircraft was fitted with only one. The CT-43A (the military Boeing 737-200) hit high ground during the approach (Flight International, 10-16 April, P8). The board says that the crew rushed the approach, extended the aircraft's landing gear and flaps late, and were flying 80kt (150km/h) above final-approach speed some 9û left of the correct track.

The investigators, however, also blame an "improperly designed" instrument approach procedure; Croatian aviation authorities dispute this. The US National Transportation Safety Board, which took part in the inquiry, claims that if the approach had been designed with standard vertical obstacle clearance limits, the aircraft would not have hit the ground.

Source: Flight International