Below is an excerpt from the CASA briefing newletter e-mailed out on Wednesday the 25th August.
"Cessna 441 Conquest aircraft have been given a new lease of life that can extend operations up to 40,000 hours in flying time. This follows the issue by CASA of a supplemental type certificate for a life extension program for Conquests. Until now these aircraft had a life limit of 22,500 flying hours due to a decision by Cessna in 2007 not to develop a maintenance program for the aircraft type beyond 22,500 hours. Any Conquests in Australia that reached 22,500 hours had to be grounded, with a handful of aircraft affected.
Cessna took the decision not to support a maintenance program because of the substantial work needed to replace components and modify and reinforce the structure of the aircraft.
In 2008 Australian aerospace engineering company TAE Group decided to develop a life extension program to take the Conquest up to 40,000 hours. In conjunction with aeronautical design company Aeronautical Engineers Australia, a detailed engineering analysis of the aircraft and its components was undertaken. The result was the development of a program of major modifications to be made to Conquests when they reach 22,500 hours. The program includes replacing major structural elements such as fuselage frames, reinforcement of other components and external straps to spread loads and provide redundant load paths. There is also a new, rigorous maintenance program which has been developed using modern damage tolerance philosophies. CASA has been closely involved in the development of the Conquest life extension program to ensure the aircraft will be safe to 40,000 hours and there will be compliance with the type certification. The supplemental type certificate for the Cessna 441 life extension program was issued this month."