Cessna 152 1979, Pilot Operating Handbook

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CESSNA SECTION 4
MODEL 152 NORMAL PROCEDURES
1 July 1978 4- 13
The carburetor heat control knob should be pushed full in during all ground operations unless
heat is absolutely necessary. When the knob is pulled out to the heat position, air entering the
engine is not filtered.
Taxiing over loose gravel or cinders should be done at low engine speed to avoid abrasion and
stone damage to the propeller tips.
The nose wheel is designed to automatically center straight ahead when the nose strut is fully
extended. In the event the nose strut is overinflated and the airplane is loaded to a rearward
center of gravity position, it may be necessary to partially compress the strut to permit steering.
This can be accomplished prior to taxiing by depressing the airplane nose (by hand) or during
taxi by sharply applying brakes.
BEFORE TAKEOFF
WARM-UP
Most of the warm-up will have been conducted during taxi, and additional warm-up before
takeoff should be restricted to the checklist procedures. Since the engine is closely cowled for
efficient in-flight cooling, precautions should be taken to avoid overheating on the ground.
MAGNETO CHECK
The magneto check should be made at 1700 RPM as follows. Move ignition switch first to R
position and note RPM. Next move switch back to BOTH to clear the other set of plugs. Then
move switch to the L position, note RPM and return the switch to the BOTH position. RPM
drop should not exceed 125 RPM on either magneto or show greater than 50 RPM differential
between magnetos. If there is a doubt concerning operation of the ignition system, RPM
checks at higher engine speeds will usually confirm whether a deficiency exists.
An absence of RPM drop may be an indication of faulty grounding of one side of the ignition
system or should be cause for suspicion that the magneto timing is set in advance of the
setting specified.
ALTERNATOR CHECK
Prior to flights where verification of proper alternator and alternator control unit operation is
essential (such as night or instrument flights), a positive verification can be made by loading
the electrical system momentarily (3 to 5 seconds) with the landing light, or by operating the
wing flaps during the engine runup (1700 RPM). The ammeter will remain within a needle
width of its initial position if the alternator and alternator control unit are operating properly.