Category: Navion, flap, gear, hydrolic
Applicability: All models
Supersedes: n/a
Compliance: Inspect by May 1, 1959, and at each periodic inspection thereafter.
Procedure: Several
failures of hydraulic actuating cylinders have occurred causing the loss
of the use of the flaps and the landing gear to
collapse. To prevent further difficulties
of this nature, the following items must be accomplished
(1) Inspect the flap and landing
gear actuating cylinders for cracks. If any cracks appear, the cylinder
must be replaced.
(2) Determine, by means of a hydraulic
gage, that the hydraulic system pressure relief valve is adjusted to 1125+25,
-0 p.s.i. Excessive pressures could cause damage to the components of the
system.
(3) Hydraulic fluid restrictors
are required in the nose gear lines, Serial Numbers 1271 and subsequent,
main gear lines, Serial Numbers 1790 and subsequent, and flap lines, all
serial numbers.
(4) Inspect the linkage adjustments
of the landing gear bungee springs and the flap stops and determine that
they have been properly adjusted in accordance with appropriate service
manuals.
Notes: Tusco
Corporation Service Letter No. 79 dated December 23, 1958, covers this
same subject.
AD-59-06-04