Rally Pilot Operating Handbook
Copyright 2008, Rally Aircraft
Revision 4.1
50
7.16 PRIOR TO TAKE-OFF
Warm-up:
Most of the warm-up will have been conducted during taxi, an additional warm-up
before takeoff should be restricted to the checklist procedure. Since the engine is
cowled for efficient in-flight cooling, precaution should be taken to avoid overheat-
ing on the ground.
Warming up period:
Start warming up period at 2000 rpm for approx. 2 minutes, continue at 2500 rpm,
duration depending on ambient temperature, until oil temperature reaches 50° C
(120° F).
•
Check temperatures and pressures.
•
Throttle response:
Short full throttle ground test (consult Aircraft Operator's Manual
since engine speed depends on the propeller used).
ATTENTION
: After a full-load ground test, allow a short cooling run to prevent va-
pour formation in the cylinder head.
7.15 IGNITION CHECK
Prior to flights, verification of proper alternator and voltage regulator operation is
essential. Such verification can be made by loading the electrical system momen-
tarily (3 to 5 seconds) with the landing light or by operating the wing flaps during
the engine run-up (3000 rpm). In all the cases, the voltmeter will remain within a
needle width of its initial position if the alternator and voltage regulator are operat-
ing properly.
Ignition check:
•
Check the two ignition circuits at
4000 rpm
•
Speed drop with only one ignition circuit must not exceed
300
rpm
•
120 rpm
max. difference of speed by use of either circuit, A or B.
NOTE:
The propeller speed depends on the actual reduction ratio.
7.17 TAKEOFF
Power check:
It is important to check full-throttle engine operation early in the takeoff run. Any
sign of rough engine operation or sluggish engine acceleration is good cause for
discontinuing the takeoff. If this occurs, you are justified in making a thorough full-
throttle static run-up before another takeoff is attempted. In the takeoff run the
engine should run smoothly and turn approximately 5400 to 5600 rpm. Full throt-
tle run-ups over gravel are especially harmful to propeller tips; when takeoff must
be made over a gravel surface, it is very important that the throttle be advanced
slowly. This allows the airplane to start rolling before high rpm is developed, and
the gravel will be blow back of the propeller rather than pulled into it. When un-
avoidable small dents appear in the propeller blades, they should be immediately
