AD 76-16-01 ACTIVE

76-16-01 AIRESEARCH MANUFACTURING COMPANY OF ARIZONA: Amendment 39-2683. Applies to the following groups of Model TPE331 series engines:

Group A: TPE331-1-101B, S/N 93058 through 93061; TPE331-1-151A, S/N 92249 and 92336 through 92354; TPE331-1-151K, S/N 26001 through 26014; TPE331-1-151G, S/N 91193 through 91198; TPE331- 2-201A, S/N 90218 through 90278, TPE331-3U-303G or TPE331-3UW-303G, S/N 03108, 03109, and 03112 through 03180 and 05031 through 05042; TPE331-3U-307G, S/N 03001 and 03009; TPE331-5-251C, S/N 22006 through 22057; TPE331-5-251K, S/N 06113, 06190 through 06442 and 06444 through 06454; TPE331-6-251M or TPE3310-6-252M, S/N 20144 and 20182 through 20467 and 20469 through 20533; TPE331-6-252B, S/N 27001 and 27002, and any Model TPE331-1, -2, -3, -5, or -6 engines which have been modified in accordance with AiResearch Service Bulletin TPE331-72-0064 dated February 1, 1974 or subsequent revisions.

Group B: TPE331-1-101B, S/N 93062, 93063; TPE331-1-151A, S/N 92355 through 92357; TPE331- 1-151K, S/N 26015 through 26023; TPE331-2-201A, S/N 90279 through 90296; TPE331-3U-303G or TPE331-3UW-303G, S/N 03181 through 03197, 05043 through 05052; TPE-5-251C, S/N 22058 through 22119; TPE331-5-251K, S/N 06443, 06455 through 06556; TPE331-6-251M or TPE331-6-252M, S/N 20534 through 20577.

Group C: TPE331-1-101F, S/N 98017 through 98019; TPE331-1-151K, S/N 91194 and 91195; TPE331-2- 201A, S/N 90297 through 90303; TPE331-3U-303G or TPE331-3UW-303G, S/N 05053 through 05058, S/N 05016, S/N 03001, S/N 03010, S/N 03011, and S/N 03198 through 03205; TPE331-5-251K, S/N 06557 through 06576; TPE331-5-251C, S/N 22120 through 22139, TPE331-5-251M, S/N 28001 through 28005; TPE331-6-251M, S/N 20468, S/N 20017, and S/N 20018; TPE331-6-252B, S/N 27003 and S/N 27004, and any Model TPE331-1, -2, -3, -5, or -6 engines which have been modified in accordance with AiResearch Service Bulletin TPE331-72-0064, dated February 1, 1974, or subsequent revisions.

NOTE: Operators of airplanes incorporating the engines affected by this airworthiness directive are advised to examine the applicability section, Configuration Identification, Table 1, or AiResearch Service Bulletin TPE331-72-0092, Revision 5, dated June 8, 1976, or later FAA-approved revision, to identify the extent of work required by this airworthiness directive which may have been previously performed.

Compliance required as indicated.

To detect and prevent fatigue failures of the high speed pinion (HSP) bearing oil transfer tube, supply tube, and lubricating adapter, and to detect, correct, and prevent loosening of the HSP bearing carrier bolts, accomplish the following:

(a) For engines in Group A, above, within the next 100 hours time in service after December 30, 1974 (the effective date of Amendment 39-2054, AD 74-26-11), unless already accomplished, accomplish the following in accordance with AiResearch Service Bulletin TPE331-72-0092, dated December 9, 1974, or later FAA-approved revision:

(1) Replace the two high speed pinion bearing carrier bolts, P/N MS21279-07, with two bolts, P/N MS9489-07, and lockplate, P/N 3101483-1,

(2) Inspect to insure proper torque on bolt, P/N MS21279-10, securing lube nozzle, P/N 3101209, and

(3) If aluminum lube adapter, P/N 3101210, is not replaced as described in paragraph (d) of this directive, inspect to insure proper torque on bolt, P/N MS21297-07, securing this lube adapter.

(b) For engines in Group A and Group B, above, which incorporate the oil transfer tube, P/N 3101187-1, within the next 100 hours time in service after December 30, 1974, unless already accomplished within the last 100 hours time in service prior to December 30, 1974, and thereafter at intervals not to exceed 200 hours time in service from last inspection, until the modifications of paragraph (c) are accomplished, accomplish the following in accordance with AiResearch Service Bulletin TPE331-72-0092, dated December 9, 1974, or later FAA-approved revision:

(1) Inspect the integral support bracket on oil transfer tube, P/N 3101187-1, for cracks or separation, and

(2) If the oil transfer tube bracket is cracked or separated, before further flight, replace both the oil transfer tube and oil supply tube with new tubes, oil transfer tube, P/N 3101475-1, and oil supply tube, P/N's 3101473-1 or 3101473-2, and associated hardware.

(c) For engines in Group A and Group B, above, which incorporate the oil transfer tube, P/N 3101187-1, before accumulating a total of 1800 hours time in service after December 30, 1974, unless already accomplished, replace the oil transfer tube, P/N 3101187-1, with one of the following serviceable oil transfer tubes in accordance with AiResearch Service Bulletin TPE331-72-0092, Revision 1, dated, January 1, 1975, or later FAA-approved revision:

(1) P/N 3101187-2 which has been heat-treated and reidentified as P/N 3101187-3,
(2) P/N 3101187-3, or
(3) P/N3101475-1

(d) For engines in Group A, Group B, and Group C, above, within the next 200 hours time in service after the effective date of this AD, unless already accomplished, accomplish the following in accordance with AiResearch Service Bulletin TPE331-72-0092, Revision 5, dated June 8, 1976, or later FAA-approved revision:

(1) Replace the aluminum main journal bearing lubricating adapter, P/N's 3101210-1 or 3101210- 2, with a new steel lubricating adapter, P/N's 3101474-1 or 3101474-2, and

(2) If two carrier bolts, P/N MS9489-07, and lockplate, P/N 3101483-1, are not replaced, inspect these carrier bolts manually for any indication of looseness. If loose bolts are found, before further flight install a new lockplate, P/N 3101483-1, and retorque the two carrier bolts, P/N MS9489-07

(e) Equivalent procedures, inspections, modifications, or parts may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region.

(f) Aircraft may be flown to a base for accomplishment of inspections and modifications required by this AD per FAR's 21.197 and 21.199.

This supersedes Amendment 39-2054 (39 F.R. 4439), AD 74-26-11, as amended by Amendments 39-2092 (40 F.R. 6771), 39-2214 (40 F.R. 22126), 39-2254 (40 F.R. 28605), 39-2367 (40 F.R. 42740), and 39-2382 (40 F.R. 48499).

This amendment becomes effective August 6, 1976.