Pilot – June 2018

Tech Log: Rotax 915iS

pilotweb.aero | Pilot June 2018 | 39

While chatting with Siegi I
mentioned my dissatisfaction at
the rather complicated engine start
sequence of the 912iS-engined
EuroFox operated by one of the
clubs where I tow, and he delighted
in showing me a single rotary
switch that he had installed in the
912iS-powered tug he flies at his
local gliding club. It is very clever.
Basically, the second setting (‘Off’
is the first) powers up the EMU
(engine management unit or ECU),
and the third turns on Lane A and
the main fuel pump. Turning the
key to the fourth position selects
Lane B and the aux pump On, and
the main pump and Lane A Off.
Setting the Key to A+B turns on
both lanes and both pumps, turning
it to the final spring-loaded ‘Start’
position energises the starter. It is

brilliant (for example, you cannot

accidentally turn the pumps off

before the Lanes) and brilliantly

simple, especially compared to the

EuroFox I usually fly, which needs a

key to be turned twice, five tumbler

switches moved and a button

pressed to get it going! I expect to

see this switch (made by Kraus &

Naimer, if you’re interested) become

the industry standard for the 912iS

and 915iS.

A better ignition switch