Figure 9-15. Typical Aircraft Preheater
Leaks. Check for leaks in the fuel
system. Look for gas on top of the tank.
Tires. Check for cuts and proper
Maintenance. Consult the applicable
maintenance manual for preventive and scheduled
Towbar. A towbar, show in figure 9-16, is used
for ground movement of aircraft. It can be attached to
gear struts, axles, and helicopter skids. A towbar has
two round or rectangular tubes which are joined at one
end by a steel pivot plate and lunette eye. The lunette
eye attaches to the tow vehicle. The other ends of the
tubes contain the aircraft attachment fittings and wheels
with solid rubber tires for towing the towbar when empty.
Purpose. The towbar is designed to aid in
ground handling of aircraft by providing a link between
the aircraft and a tow vehicle. There are two basic
classes of towbars: the universal and the special. The
universal towbar will accommodate several different
models of aircraft. The special towbar is designed for
use with only one model of aircraft.
Principles of operation. The towbar is
attached to the aircraft by hooks which fit towing rings
on the aircraft or by pins which fit in landing gear axle
holes. The hooks are held in place in the towing rings
by spring-loaded locking pins. The axle pins are held in
the towbar by quick-release pins.
Safety practices and procedures. The
following special precautions should be observed when
using a towbar:
· Take extreme care when putting the lunette
assembly in the pintle hook to avoid pinched
· Be sure the correct towbar is being used.
· Do not use a towbar that is defective.