AD 78-02-03

78-02-03 PIPER: Amendment 39-3128. Applies to PA-23-250 airplanes with Serial Nos. as shown below certificated in all categories.

To prevent possible hazards in flight associated with weakening of the stabilator, accomplish the following unless previously accomplished:

(a) The following Serial Nos. pertain to S.B. 540 dated January 4, 1977:

(1) Serial Nos. 27-7654001 thru 27-7754057 Within the next 10 hours in service after the effective date of this AD, inspect both stabilator tip tube and weight assemblies for cracks in accordance with the inspection procedures of 1. and 2. under "Instructions" on the sketch/instructions page of S.B. 540, or equivalent procedures.

(i) If cracks are present alter both tube and weight assemblies as indicated in 2. under "Instructions" on the first page of S.B. 540 or equivalent procedures, prior to further flight.

(ii) If cracks are not present alter both tube and weight assemblies within the next 100 hours in service as indicated in 4. under "Instructions" on the first page S.B. 540, or by equivalent procedures.

(iii) For altered parts, the inspection procedures of (a)(1) must be repeated within the next 100 hours in service and thereafter at intervals not to exceed 100 hours in service from the last inspection. If cracks are present replace all cracked parts with new or equivalent parts before further flight.

(2) Serial Nos. 27-7754058 and up

Within the next 100 hours in service after the effective date of this AD and every 100 hours thereafter, inspect both stabilator tip tube and weight assemblies for cracks in accordance with inspection procedures of 1. and 2. under "Instructions" on the sketch/instructions page S.B. 540 or equivalent procedures. If cracks are present replace all cracked parts with new or equivalent parts before further flight.

(b) The following Serial Nos. pertain to Service Bulletin 547 dated March 1, 1977:

(1) Serial Nos. 27-7654001 thru 27-7754054

Within the next 50 hours in service after the effective date of this AD, inspect both stabilator tip ribs for missing rivets and missing tube and weight assembly attachment screws and if necessary alter in accordance with S.B. 547 or equivalent procedures.

(c) The following Serial Nos. pertain to Service Bulletin 569 dated August 24, 1977:

(1) Serial Nos. 27-7654001 thru 27-7754127, 27-7754130, 27-7754131, 27-7754133 thru 27-7754136, 27-7754138 thru 27-7754144

To prevent abnormal stabilator tab horn bushing wear, within the next 50 hours in service after the effective date of this AD replace the right and left stabilator tab forward inboard rib/horn assemblies in installing Piper Kit 761 143 or equivalent Kit.

(d) The following Serial Nos. pertain to Service Letter 807A dated September 8, 1977:

(1) Serial Nos. 27-7654001 thru 27-7754041 equipped with stabilators Piper Part Number 15658-2, 15658-3, 15658-22 or 15658-23.

Within thenext 50 hours in service after the effective date of this AD, reinforce the mounting of the stabilator tube and weight assemblies by installing additional nose- ribs by means of Piper Kit 761 141 or equivalent Kit.

(e) Refer to paragraph 4-65 in the Piper PA-23-250 "Aztec" Service Manual and balance the stabilator when the alterations in paragraphs (a), (c) or (d) of this AD are incorporated.

(f) Upon submission of substantiating data through an FAA Maintenance Inspector, the compliance times specified in this AD may be increased by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

(g) The affected airplanes may be flown in accordance with FAR 21.197 to a location where the AD compliance procedures can be accomplished.

(h) Equivalent procedures and parts must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

This amendment is effective January 26, 1978.