| The problems facing engine manufacturers with increased workload on new generation engines are not the only reason for the emergence of gliders around the world. Engine shops are currently having difficulty meeting demand, particularly in Asia, and this is sure to be the case for a few more years still.
The Asia-Pacific region now accounts for some 8400 aircraft in service, equalling the North American fleet for the first time. However, the repairs for these aircraft are slightly different, with Asia having more Airbus and Boeing narrow-body aircraft (63%) and much fewer regional jets.
The vast majority of engine overhauls therefore relate to the CFM56-5/7 (A320/737NG) and the V2500 (A320), which alone account for nearly 9850 engines installed in the region. China is far and away the country which is most affected, with 6 times more engines than all the other countries in the region together.
As Jonathan Berger, Managing Director of Alton Aviation Consultancy, explained during Aero-Engines Asia-Pacific in Singapore, one of the reasons for this relative engine shops saturation is the progress made on the engines themselves, where engines such as the CFM56-5/7B or V2500 are considered almost "too" reliable given their extensive durability (time-on-wing), with shop visits governed by Life-limited parts (LLP) and not by performance deterioration issues (EGT).
This brings with it worldwide, and in Asia in particular, a significant (and highly anticipated) wave of shop visits, whereas until now engine shops had mostly been operating under capacity. This means that it is not rare to see maintenance service centers building up large numbers of jet engines to be processed, leading to longer TATs or even grounded aircraft.
Obviously, this is combined with unscheduled maintenance inspections for the latest generation engines which are experiencing teething issues. The technical problems encountered on the PW1100Gs, the LEAPs and certain Trent 1000s are a matter of public record and also reduce the slots available in especially hard-pressed engine shops.
But Jonathan Berger also emphasised the difficulties engine manufacturers are having in producing enough spare parts for certain programmes (such as turbine blades). In addition, the reduction in the number of aircraft retired from service in Asia over the last two years has also had an impact on recycled parts. Finally, the number of spares available from the few engine leasing companies cannot keep up with demand.
He feels that all of these elements should see wider adoption of PMAs (Parts Manufacturer Approval) even if there are still major sticking points in Asia, because of both tradition and by the contract clauses applied by the lessors in the region.