Yak 18T, Руководство по летной эксплуатации

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Yak 18T Flight Operations Manual
Page 29 of 82
Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations
Manuals and has not been approved by the Yakovlev Design Bureau or any other authority.
The system is good, but is not cheap (US$1,000), as well as taking a day and a half to
install, and the slight possibility arising of starting with the oil still switched off.
Manifold
drains
The next obvious way of combating the problem is a system whereby pipes are attached in
the three lower manifold drain plugs, which then either go to individual drains or, more
commonly, collect together into one larger pipe, and then into a fuel-drain type tap, which is
opened after flight - oil slowly trickles through it, and before flight it is shut. This is an
excellent system, although most of the systems I have seen incorporate small-bore pipes,
which certainly would not allow oil in sufficient quantities to pass through when cold. There
is also the need to shut the drain tap before the next flight.
Vedeneyev
System
Vedeneyev are of course the original designers of the engine, and they have developed an
ingenious, and fully automatic system whereby, after shutdown, oil drains from the three
lower intake tubes into a container fitted to the bottom of the engine, which, on start up, is
sucked slowly into the supercharger, and then into the cylinders and burnt. This system has
the advantage of being totally automatic, as well as providing extra lubrication around the
engine during the critical start-up period. Prototypes of it are now flying successfully, and it
is hoped that the system can be offered on a commercial basis within a few months. Again
however it is not a simple modification and the existing oil sump, i.e. the large green part of
the engine you see projecting from between the lower cylinders, needs to be removed and
machined.
5.6. Conclusion
Check that the engine was previously run for at least 30 seconds at 60% before being
shutting down. Turn the engine thoroughly through before every start and notice any oil
coming out of the exhausts – even if you have only left the aircraft for half an hour (being
aware of the engine temperature before turning is important to avoid it starting by itself).
Drain the intake tubes if you have left the aircraft for more than a day, or fit one of the
systems above which will drain them for you. If you have failed to start the engine after the
second attempt and engine priming was conducted, then pull through the propeller to remove
any excess fuel from the cylinders.