Conquests Conquered?

The first Conquest II was developed concurrently with the 404 Titan piston twin, but features two Garrett TPE331 turboprops and is pressurised.

First delivered in 1977, 370 Conquests were built until production ended in 1986, with many still in service around the world.

Although an older aircraft, the Conquest had enjoyed something of a renaissance among some operators such as Jetcraft and Skippers Aviation. With the resources boom increasing demand for both contract and ad hoc charter flying to remote locations, the Conquest’s flexibility and performance became more valued and more of the type have been added to their fleets in recent years.

The groundings of the aircraft came about after the Civil Aviation Safety Authority issued an airworthiness directive on August 24 which immediately affected aircraft with more than 22,500 hours on the airframe.

The impetus for this came from a life limit imposed on the Conquest by Cessna as part of the Supplemental Inspection Document (SID) maintenance program the manufacturer had been working on for supporting the ageing aircraft type.

The Conquest SID was a direct result of an earlier inspection program developed by Cessna for the 402/402C series at the request of the US Federal Aviation Administration in 2005. This was issued in order to address airworthiness issues and bring the 1970s and ’80s built aircraft into line with modern standards for similar aircraft.

After the 402 SID program was established and a life limit on the type introduced, Cessna made the decision to extend the SID inspection and maintenance program to all other pre-1980s twins, including the Conquest.

According to Cessna spokesman Doug Oliver, the manufacturer had been in contact with operators and had made them aware up to 12 months before issuing its warning that it would impose a ‘limit of validity’ on the Conquest. While not a definite life limit, the limit of validity meant that an additional program of maintenance would be required to ensure the integrity of the airframe after this time.

The 22,500 hour limit was imposed after Cessna became aware of possible cracking in the airframe during fatigue testing. This cracking was also confirmed by reports from Conquest operators.

“Cracks appeared in the same locations at about the same airframe time on the airframe cyclic test,” says Oliver.

As a result, Cessna issued the SID for the Conquest with its limit of validity on August 14. Importantly, the manufacturer withdrew all support for aircraft which had reached the limit, effectively washing its hands of those aircraft.

CASA also received the SID on August 14. According to CASA spokesman Peter Gibson, the authority considered its options at the time and chose to move ahead with an airworthiness directive to ground all aircraft which had passed the limit for up to one year. The AD was issued on August 24 and became effective at midnight on August 25.

Gibson explains that safety was the major reason for the regulator’s quick action to ground the aircraft. “We felt that it was a safety issue and so took the action we did without waiting for a long consultation period,” he says.

Cessna says that it is not aware of any other Conquests in the world which have reached the life limit, and so is not surprised that other airworthiness authorities such as the US Federal Aviation Administration have not followed CASA’s lead by issuing a similar AD.

According to Cessna, theFAA, Transport Canada and the European Aviation Safety Authority are still considering whether to enforce the limit by issuing an airworthiness directive.

In the USA, the SID and attached airframe limit are mandatory for Part 135 operators.

However, it will only be a recommended action for private flyers unless the FAA chooses to issue its own AD to ground the aircraft.

At the time the airworthiness directive was issued, there were only six aircraft affected. One of these was with Mount Gambier based O’Connor Airlines. The airline’s Conquest was one of the few operational aircraft in its fleet. This effectively left the airline unable to serve the Adelaide-Whyalla route which the Conquest was utilised for.

As it was the only one of the airline’s Conquests which was operational at the time, it hit the company hard and was one of the reasons the airline entered administration in December last year.

Still harder hit was Jetcraft, which had five aircraft grounded by the AD. A number of these aircraft were away from home base when the company was notified of the AD, which forced it to seek special dispensation from CASA to return these aircraft to its Brisbane base.

The groundings also had a major financial impact and Jetcraft joined O’Connors in administration only a few weeks later.

Although the life limit seems to have effectively ended the lifetime of the Conquest, the door has been left open for another company to develop a remedial maintenance program to extend the life of the Conquest fleet.

Gibson says that this is one of the reasons that the AD is currently only temporary.

But at the time of writing, no third party has approached the regulator about a modification program to extend the life of the aircraft.

Any fix though could be expensive, given that only six aircraft have currently been affected by the grounding order and other Conquests are unlikely to hit the life limit in the short term.

“Cessna has not decided to develop a new inspection or modification program for the Conquest, as the inspections and repairs required would have most likely exceeded the value of the aircraft,” says Oliver.

Cessna, it must be said, has little reason to ensure that the aircraft flies after its life limit is reached. Supporting older aircraft will cost the manufacturer more, particularly if a new maintenance or modification system has to be developed and certified. It also leaves it open to lawsuits should there be an accident resulting from airframe fatigue.

If a solution to the fatigue cracking problem is not found and the current temporary grounding becomes permanent, it begs the question of what happens when the rest of the fleet does eventually hit the 22,500 hour mark.

It seems that replacing the Conquest will not be an easy task. There has been little development in the twin engine, nine-seat aircraft segment since production of the Conquest ended in 1986.

Those which have emerged – such as the Vulcanair A-viatior – are likely to be too expensive for many smaller operators.

One of the possible solutions for Australian operators could come from a derivative of the Conquest – the French built Reims F406 Caravan II. The Caravan is essentially an unpressurised version of the Conquest airframe with Pratt & Whitney PT6A engines instead of the Garrett turboprops.

But the Reims Caravan does have some major disadvantages. It has less range and is also slower than the Conquest. This would make it harder to complete some of the missions which the Conquest has made its own over its years of service in Australia.

A strong candidate for replacing the Conquest could be used Cessna C208 Caravans.

The Caravan, while not a twin, does have good operating economics and is able to carry a similar passenger load to the Conquest over a similar range profile.

However, even used Caravan’s are not cheap, it too isn’t pressurised, it’s slower than the Conquest, and there may be some lingering concerns from some Australian operators about flying single engine aircraft.

More likely is that current operators will look to equip with used Beech King Airs or lower timed Conquests. With the Australian dollar currently high against the greenback, importing these aircraft from the United States could be a viable medium term solution.

Although it remains to be seen if a longer term fix to the Conquest’s problems can be found, it is clear that if a solution has not been found by August this year that the life of the workhorse may come to an end, with regional Australia set to suffer as a result.