Monday, September 6, 1999 Published at 10:51 GMT 11:51 UK
FAA acts over Cessna safety concerns
Cessna 404: One of the most popular light aircraft
The American Federal Aviation Administration was aware of safety worries over the exhaust system on Cessna planes like the one which crashed near Glasgow killing eight people, it has emerged.
A proposal for an Air Worthiness Directive has been issued by the FAA, but a full regulation will not be issued until there has been period of consultation.
Directives are issued to aircraft operators and give guidance on maintaining particular parts of the plane or making modifications in the interests of safety.
It was initially thought a directive relating to Cessnas, like the one which crashed on Friday, had been issued.
'Working with the FAA'
A Cessna spokeswoman said: "They have issued it as a proposal which will allow users to comment on it and they will take that into account before issuing a full regulation."
She said Cessna was not trying to move the process forward as a result of the crash.
"We are working very closely with the FAA but there is nothing to attribute the accident to the exhaust so there is no reason to move the process any quicker."
The proposed AWD relates to the exhaust system on Cessna twin-engined turbocharged planes.
Possible engine failure
Concerns about the exhaust are thought to have first been raised by the US-based Cessna Pilots Association in 1997.
The CPA warned the FAA there was a possibility of rupturing, cracking or corrosion of an exhaust component on the plane.
The Association claimed a failure there could lead to gasses passing through fuel lines and burning through the engine mounting which could result in possible failure of the front wing spar or engine failure.
In 29 months, 29 people had died in 12 crashes involving turbocharged twin-engined Cessnas where an exhaust system problem was known or suspected, claimed the CPA.
Since Friday's crash there have been claims the plane's starboard engine failed after take-off.
There has also been some speculation that a propeller may have fallen off after the pilot radioed air traffic controllers at Glasgow for clearance to turn back for an emergency landing just two minutes after take-off.
A spokesman for the Air Accident Investigation Branch said the inquiry into the crash would examine the exhaust system.
"The investigation will cover everything that could be a factor," he said.
But Kieron Daly, editor of the Internet service of Air Transport Intelligence, said the majority of accidents involving the Cessna make were the result of pilot error.
The plane's operator, Edinburgh Air Charter Ltd, denied it had received any directive but said it was aware of concerns about exhaust systems and had carried out stringent checks before the crash as a matter of routine.