PRIMUS
r
1000 Integrated Avionics System
A28--1146--112--00
9-3
Troubleshooting
Commonly Used Terms
Frequently, phrases or terms used in pilot writeups are not clearly
understood by all persons concerned. Table 9--1 lists some of the most
common terms and their definitions.
Term
Definition
Autopilot Active Controls continually move in still air with small
command errors.
Autopilot Loose Autopilot does not null command bars
satisfactorily in most modes.
Porpoising
Low frequency oscillation in the pitch axis,
typically 10--second period or longer.
Pumping
The control wheel moves back and forth, usually
with a low frequency, and typically a 1-- to
10--second period.
Stick Bump
Controls give a quick moderate movement,
usually with virtually no aircraft movement,
mostly associated with autopilot engagement or
during mode changes.
Stick Buzz
With autopilot engaged, a high frequency, small
movement of control wheel can be felt without
aircraft movement.
Definitions of Terms
Table 9--1