Page 25 - Volume 10 Number 10

Hence, one way to check the accuracy of the pitch indicator wheel in the cockpit is to set it at zero and then to manually lift the elevators into a neutral position and verify trailing edge alignment. But if you are quite short or if the tail is hanging out over some drainage ditch at the airport, this can become impos- sible to do. Only with a helper in the cockpit who could pull the control wheel back halfway, could the visual check be accomplished. Recognizing that we may be alone with no cockpit helper, the FAA devised a fool-proof method that covers all the conditions, even when the tail is unreachable. You know what it is: Those funny- looking stripes on the elevator tab pushrods and on the bottom of the horizontal stabilizer.
Knowing that the trailing edges will not align, due to the anti- servo action of the tab, when the elevators are in the at-rest, down position, the stripes are applied so that they do indeed align when in that down position.
And, wow, have I seen some weird stripes through the years! I think some stripe-painters didn’t get copied on the memo and did not realize what was to be accomplished here! The stripes should be red with triangles painted on the stabilizers and a single red band painted on the pushrod (see photo on oppostie page). When an apex of the triangle points to the leading edge of the band, the trim should be at zero.
Now for the T-tails. Since the tabs here have no anti-servo nor servo action, the alignment between the elevator and the tab does not change as the elevator travels up and down. So no painted stripes are needed nor desired. Instead, the pilot merely leaves the trim wheel in the cockpit at zero and visually confirms that the trailing edges of tab and elevator are in side-by-side alignment.
OCTOBER 2016
KING AIR MAGAZINE • 23