Aviation consultants warned of a "serious or fatal accident" risk, leading to the grounding of the Garda Air Support Unit's (ASU) fixed-wing spotter aircraft, it emerged yesterday.
The consultants' report, part of a safety audit on the Air Corps whose pilots fly the Garda aircraft, led to the withdrawal earlier this year of the Defender 4000 aircraft, in service since September 1997.
The audit also recommended the runway at Baldonnel Aerodrome be upgraded as a matter of urgency as it was breaking apart. It noted the Air Corps recommended this work in 1993.
The safety audit was ordered by the Minister for Defence, Mr Smith, after the death of four crew members during a helicopter rescue operation in Waterford in July 1999.
The report is complimentary of the Air Corps' safety record and found it "well organised with an effective and well functioning chain of command". Air Corps pilots and technicians compared very well against the highest international standards.
However, it found a "longstanding problem" in relations between the Garda and Air Corps over the operation of the ASU. This could be a potential safety problem, it warned.
The report found that the Garda ASU's Defender 4000 aircraft would become highly unstable if one of its two engines failed, especially during takeoff. The aircraft "demonstrates extremely poor characteristics during single-engine operations", the report said. If airspeed fell because of a failure "the aircraft will uncontrollably enter into inverted flight from which recovery is not very likely, and probably impossible".
The three American consultants drew attention to a series of problems with the aircraft, including leakage of water and the failure of a rear sliding door.
The partial opening of the rear door during flights was a significant cause of concern.
It stated: "Crew members also tell us that the aircraft's rear sliding door partially opens during flight. Since the outside air entering the aircraft may be well below freezing, crew members have been known to depart their seats to place blankets or other objects in the opening to prevent cabin heat loss. In doing this, the crew member is at great risk of falling out of the aircraft should the door open." The consultants made 16 recommendations for urgent work on the aircraft.