PRIMUSr 880 Digital Weather Radar System
Some vertical gyroscopes have provisions for deactivating the roll- erection torque motor (whenever the airplane banks more than approximately 6_) to reduce the effect of lateral acceleration during turns. To some extent, stabilization error is displayed in the radar image after any speed change and/or turn condition. If the stabilization system seems to be in error because the radar begins ground mapping on one side and not the other, or because it appears that the tilt adjustment has slipped, verify that aircraft has been in nonturning, constant- speed flight long enough to allow the gyroscope to erect on true earth gravity.
When dynamic and acceleration errors are taken into account, maintaining accuracy of 1/2 of 1_ or less is not always possible. Adjust the antenna tilt by visually observing the ground return. Then, slowly tilt the antenna upward until terrain clutter no longer enters the display, except at the extreme edges. If ground display is observed on one side but not on the other, the stabilization system is somewhat in error, but it is probably impossible to adjust it more accurately.
Pitch and Roll Trim Adjustments
The PRIMUSâ 880 is delivered from the Honeywell factory or repair facility adjusted for correct pitch and roll stabilization and should be ready for use. However, due to the tolerances of some vertical reference sources, you may elect to make a final adjustment whenever the radar or vertical reference is replaced on the aircraft, or if stabilization problems are observed in flight.
The four trim adjustments and their effects are summarized in table 5- 4.
A28- 1146- 102- 00 | Radar Facts |
|
