AD 90-12-01

90-12-01 EMBRAER: Amendment 39-6740. Final Rule of priority letter. Docket No. 90-CE-31-AD. Applicability: Models EMB-110P1 and EMB-110P2 (all serial numbers) airplanes equipped with the 10 degree dihedral stabilizer (as original equipment or as an added modification per EMBRAER Service Bulletin 110-55-022), certificated in any category.

Compliance: Required as indicated in the body of the AD, unless already accomplished.

To prevent failure of the inboard elevator mass balance arms and possible extreme vibration or flutter, resulting in possible loss of the airplane, accomplish the following:

(a) Within the next 10 hours time-in-service (TIS) after the effective date of this AD, dye-penetrant inspect for cracks the areas of the elevator balance weight arms indicated in EMBRAER Alert Service Bulletin 110-027-A088, dated May 10, 1990, and visually inspect for cracks the remaining areas of the arms using a 10x glass for both elevator balance weight arms (Part Number (P/N) 110-3012-01-01 (left) or 110-3012-01-07 (left), and 110-3012-01-06 (right) or 110-3012-01-12 (right)).

(1) If any cracks are found, prior to further flight replace the cracked elevator balance weight arm with a modified arm (P/N 110-3012-01-13 (left) or 110-3012-01-14 (right)) or with an original arm (P/N 110-3012-01-01, 110-3012-01-06, 110-3012-01-07, or 110- 3012-01-12, as applicable) that has been shown to be free from cracks using a visual inspection with a 10x glass.

(2) If no cracks are found, thereafter at intervals not to exceed 25 hours TIS, visually reinspect, using a 10x glass, the entire elevator balance weight arms for cracks.

(3) The above repetitive inspections may be discontinued when the airplane is modified by the installation of modified balance weight arms (P/N 110-3012-01-13 (left) and 110-3012-01-14 (right)).

(b) If not accomplished per paragraph (a) of this AD, within the next 1000 hours TIS after the effective date of this AD, replace both elevator balance weight arms, (P/N 110-3012-01-01 (left) or 110-3012-01-07 (left), and 110-3012-01-06 (right) or 110-3012- 01-12 (right)), with modified arms (P/N 110-3012-01-13 (left) and 110-3012-01-14 (right), as applicable).

(c) Airplanes may be flown in accordance with FAR 21.197 to a location where this AD may be accomplished.

(d) An alternate method of compliance or adjustment of the initial or repetitive compliance times which provides an equivalent level of safety may be approved by the Manager, Atlanta Aircraft Certification Office, 1669 Phoenix Parkway, Suite 210C, Atlanta, Georgia 30349.

NOTE: The request should be forwarded through an FAA Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta Aircraft Certification Office.

This amendment (39-6740, AD 90-12-01) becomes effective on October 15, 1990, as to all persons except those persons to whom it was made immediately effective by priority letter AD 90-12-01, issued June 1, 1990, which contained this amendment.