than simple inspections there will be no routine
maintenance of the engine itself. The major
maintenance interval of the engine is based on the
proven safe life of the critical engine components,
the turbine and the compressor.
This is determined
by the number of start-shutdown cycles (and not
factors such as total engine running time or with
any extended interval for operating at reduced EGT).
The initial TBO (Time Between Overhaul) will be set
at 500 cycles, typically enough for 4-5 years use.
M&D Flugzeugbau plan to progressively extend this
TBO as in-service experience increases.
As the TBO approaches, the owner-operator will
advise Jonker Sailplanes / M&D Flugzeugbau. A
replacement engine will be supplied and the existing
engine returned to M&D Flugzeugbau. The engines will
be exchanged according to the Maintenance Manual
procedure. The returned engine will be stripped and
the turbine and compressor replaced, together with
the main bearings.
Other items will be inspected and
replaced on condition. This overhaul will
‘zero-life’ the engine, i.e. it can be considered as
The cost of the overhaul will be the cost of a new
turbine, a new compressor and new main bearings,
plus items replaced on condition, installation
labour and shipping. This cost has yet to be
determined but is expected to be no more than the
equivalent for traditional internal combustion
Routine maintenance of the sustainer installation
such as lubrication and cleaning may be performed by
the owner-operator. Minor services should be
performed by a JS-approved Aircraft Maintenance
Organisation at the times as specified in the JS1
Revelation Maintenance Manual.