Operating Manual
UL
POWER
UL
260,
UL
350,
UL
390,
UL
520
M0310: OM 260 - 520A01 Revision No: 04
Date:
2021-11-18
Page:
17
of
23
Attention
: Increase of engine speed is only permitted when oil pressure reading remains below
maximum.
Prior to take-off
Warming up period:
Start warming up period with engine running between 1200 and 1500 rpm, duration depending on
ambient temperature, until:
oil temperature reaches at least 50°C (122°F)
cylinder head temperatures are at least 50°C (122°F)
Attention
: Always check temperatures and pressures are within limits.
Idle speed:
When warm, engine can be set at idle speed.
Note:
Although engine idle speeds of 700 rpm can be obtained, we recommend the ground idle to
be at least 850 rpm for smooth running.
Throttle response:
When ready for take-off, as part of your power checks, do a short full throttle ground test. No
irregularities may occur.
Attention
: Boost pressure must be within range
Fuel pressure must be within range
Note:
Check with aircraft/propeller operating handbook, since engine speed depends on the
propeller used.
Ignition test:
The engine is equipped with double redundant ignition. Switch off one ignition coil at the time and
verify that engine still operates normally on either of ignition coils separately.
Attention
: RPM difference between running with coil 1, with coil 2 or both may not exceed 5%
of nominal RPM
Take-off and cruise
Climbing with the engine at maximum take-off power (
see ‘Table 1 :
P
erformance’ )
is permitted
during a time period of max. 5 minutes.
In cruise, keep the engine power below the maximum continuou
s power settings (see ‘Table 1 :
Performance’) for conti
nuous operation.
Attention
: Observe that all temperatures and pressures remain within limits at all times. If
engine limit values are at/or approaching red line, reduce power and land as soon as
possible if unable to establish flight within acceptable limits.
