Category: navion, wing, fuslage
Applicability: All models
Supersedes: n/a
Compliance: As soon as practicable but not later than October 15, 1954
Procedure: Inspection of a number of Navions has revealed an undesirable condition in which there is relative motion between the wing and fuselage at the wing to-fuselage attachment necessitating installation of additional shear carrying attachment angles between the fuselage and wing. This condition is most prevalent in, but not limited to, older Navions and can be readily detected when the wing root fillets have been removed and a sharp fore and aft shaking force is applied to the wing tip. If loose, the applied force can be made to develop a motion of the wing mass which is opposite to the motion of the fuselage mass, and the looseness will be definitely seen and felt. It is therefore necessary that all Navions be inspected for this condition . In case the wings and fuselage seem to move as a unit mass and feel "solid" to the person applying the force, the corrective action outlined below may be delayed until the next annual inspection of the airplane. If a loose condition is evident, immediate corrective action as indicated in items 1 and 2 is necessary.
1. Determine whether there is any looseness due to elongated holes at the six bolt locations (two outboard and two inboard forward wing attachment bolts and two aft wing attachment bolts). If no elongated holes are found, the corrective action in item 2 should be accomplished. If elongated holes are evident proceed as follows (including item 2):
(a) Ream each of the four forward wing attachment bolt
hales (AN 5 inboard and AN 6 outboard) to receive the next larger size
bolts. Remove and replace only one bolt at a time and torque to 140 inch-pounds.
(If the next larger size bolts had already been installed
previously for other reasons, the rework in accordance
with this directive should be brought to the attention of the local FAA
Agent for detail consideration.
(b) Remove the two AN 5-65A aft attachment bolts, tube spacers, washers and units and install two 4 1/2-inch long 0.064 24ST alclad doubler strips to each end of the bottom inside flange of frame 142.57. Rivet each strip to the frame with four 5/32-diameter rivets and drill and ream to 0.3125-diameter to match the existing 5/16- diameter bolt hole in each frame. The two tube spacers must be shortened to fit within the channel and the two AN 5-65A bolts should be installed and torqued to 140 inch- pounds.
2. Install the following wing-to-fuselage chordwise shear attachment.
(a) An 0.064 24S-T4 alclad angle should be fabricated
to conform to the wing contour and attached to the lower longeron, inboard
flange
(both sides of airplanes). This angle should extend from
the wing front spar reference plane to approximately 1 inch aft of the
wing
center spar reference plane (approximately 22 1/2 inches
long). Attachment to the upper longeron should be made with eight AN 3
bolts.
Attachment to the wing skin should be with fifteen 5/32
rivets (may be blind). Caution should be used in drilling through the wing
skin
to avoid injuring the fuel tank.
(b) Flange of angle attaching to wing skin may be cut
to conform to existing holes in wing skin for tubing which may pass through
this
area.
Notes: Ryan Navion Field Service Bulletin No. 21 covers this same subject.
AD-54-18-01