82-05-01 R2 EMPRESA BRASILEIRA DE AERONAUTICA S/A (EMBRAER): Amendment 39-4325 as amended by Amendment 39-4455 is further amended by Amendment 39- 4747. Applies to Models EMB-110P1 and EMB-11OP2 airplanes, certificated in any category.
COMPLIANCE: Required as indicated, unless already accomplished:
To prevent failure of wing flap actuators, accomplish the following:
A) Within the next 50 hours time-in-service after March 1, 1982, and thereafter at intervals not to exceed 1500 landings or 12 months time-in-service, whichever occurs first.
1. Prepare the wing flap actuators for inspection by extending the flaps to the fully-extended position.
CAUTION
Make sure that the Battery Switch is "Off" and that flaps are not inadvertently operated while the
flap actuators are being serviced.
2. Disconnect each wing flap from the actuator lug by removing the cotter pin, nut, washer and attaching bolt.
CAUTION
When removing the attaching bolt, provide a support for flap to prevent its rotation and possible
damage.
3. Remove the safety wire and four retaining screws from the outer cover of the actuator.
4. Slide the inner and outer covers toward the reduction gearbox to expose the threaded shaft. Clean the shaft in accordance with good aircraft practices.
5. While manually retracting and extending the threaded shaft, determine:
a. General condition of the shaft.
b. Movement of the shaft while turning it by hand - must be free and smooth.
c. Longitudinal motion of the shaft in the ballscrew/nut assembly - play must be practically undetectable by handling manually.
d. That the transverse motion of the ballscrew/nut assembly, measured at the rod end of the shaft, does not exceed .20 inch (5 mm), when the shaft is fully extended, near the middle of the course, and retracted.
e. General condition of the ballscrew/nut, its attachment to the main carrier tube, the fastening of the ball-return tube and the general condition of its clamp in the D2246-3 and D2246-4 actuators, and safety of the ball-return cover in the D2246-5, D2246-6, D2246-31 and D2246-41 actuators. For access, it is necessary to remove the plastic strip EEMCO P/N A12139 from the primary cover (if the plastic strip is not damaged during removal, it may be reused).
(i) With the jackscrew extended, move both covers to the rod end, leaving the ball nut completely exposed.
(ii) Remove all dirt and grease from the ball nuts.
(iii) Check the ball-return tube fastening clamp for general condition and proper safety by attempting to move it longitudinally and rotationally. Also check the general condition and safety of the ball-return tube and for security of the ballscrew. Any indication of looseness of the ball-return tube fastening clamp or the ball-return tube is cause for replacement of the actuator.
(iv) Reinstall the plastic strip P/N A12139.6. Inspect for damage and wear of sealing rings in the inner and outer actuator covers, used to protect the ballscrew and threaded shaft from moisture and dirt.
7. If any of the items inspected in Sections 5 and 6 above are not satisfactory, repair or overhaul the actuator in accordance with EEMCO Service Bulletin 27-53- 02, or replace, as necessary.
8. Lubricate the actuator and reduction gearbox:
a. Remove the safety wire and upper screw where the actuator joins reduction gearbox.
b. Manually extend the jackscrew to the mechanical stop.
c. Inject MIL-G-23827 grease into the gearbox through the screw hole to fill the gearbox and main actuator tube.
d. Temporarily install the gearbox upper screw.
e. Manually retract the jackscrew until fresh grease appears between the ball nut and jackscrew.
f. Remove the gearbox upper screw again to remove the excess grease by continuing to manually retract the jackscrew to the mechanical stop.g. Install the upper screw in the gearbox; safety screw with lockwire.
h. Clean the main actuator tube exterior by removing all grease to prevent dust deposits.
i. Lubricate the extended jackscrew by brush-daubing it with MIL- G-23827 grease.
9. Slide the outer cover aft to the proper position on the rod end cap.
10. Install the four retaining screws and safety wire.
11. Reconnect the flap to the actuator lug by installing attaching bolt, washer, nut and cotter pin. Adjust the wing flap control system to assure that the flap actuator does not contact the mechanical stop before the actuating motor stops rotating. The motor stop should be contacted, at a minimum distance of 1/4 turn, before the actuator contacts its mechanical stop for actuators P/N D2246-3, D2246-4, D2246-31, and D2246-41. The minimum distance for P/N D2246-5 and D2246-6 actuators is 1/2 turn. Damage to the mechanism may result if these distances are not maintained.
12. Check for proper operation and rigging of the wing flaps and flap position indication according to EMBRAER Technical Manual T.O. 1C95-2-5. Check and, if necessary, adjust the flap asymmetry detection system.
B) On or before September 30, 1982, replace the flap actuators P/N 2246-3 and D2246-4 with actuators P/N 2246-5 and D2246-6 or P/N D2246-31 and D2246-41, respectively, and continue to comply with paragraph A) of this AD.
C) Upon request by the operator, an FAA Maintenance Inspector, subject to the approval of the Atlanta Aircraft Certification Office, may adjust the inspection compliance times to an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator.
D) Any equivalent method of compliance with this AD must be approved by the Manager, Atlanta Aircraft Certification Office, FAA, 3400 Norman Berry Drive, East Point, Georgia 30320; telephone (404) 763-7428.
EMBRAER Service Bulletin No. 110-27-043, Revision 02, dated July 13, 1983, covers the subject matter of this AD.
This AD supersedes AD 79-24-03 R1, Amendment 39-3974 which, in turn, revised AD 79-24-03, Amendment 39-3616.
Amendment 39-4325 became effective March 1, 1982.
Amendment 39-4455 became effective on August 24, 1982.
This Amendment 39-4747 becomes effective on October 26, 1983.