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the overhaul of these units, whlch occasaonally requlred toe 1nstallatlon and boring of new lmers, dlffered from the 1nitial build—up m that the plug Jets renamed metalled durlng the flushlng. During the Board's :aneetlgatlcn, Vertol changed 1ts procedures to requre msertlon of plastlc plugs 1n all 011 passages
during any 11.ner borlng operatlon, and the removal of plug gets at overhaul prior to flushing.
Responslblllty for FAA eurVelllance of the manufacturmg operations at Torte-1 15 Vested in the Engines-rang and Manufacturlng Distrlct Office (EPIDO) #115. The Supervisng Inspector of ELM-DO #LLS testified that men of has office spent 625 man hours at Vertol 1n fiscal 1963. However, none of these men had ever witnessed the bormg, flushing, or 1nspectlon procedures for aft transnaesmns or m boxes be— cause " . . . the frequency was so low . . . .f' The Prlnclpal FAA A11- Carrler Maintenance InSpeotor a351gned to New York Ali-ways testlfled that melts to Vertol by representatlves of the Arc Garner Dlstrict Office (A030) #31; averaged approxi— mately two per month. He stated, " . . . The primary purpose, of course, 15 for mlfunctlon lovestlgatlon of . . . any problems that have been 1ncurred 1n semce to the transmissions or any component that 15 returned to Vertol for analysis." He also :Lndlcated that he had an opportunlty to observe and evaluate the Vertol overhaul procedure. While th1s overlap of survelllance actiuty was characterlced by both mspeotors as a coordmated effort, there was no comunication between the AGDO and EMDO when machine shav1ngs were found 111 aft transmssaon assembly SfN TA 940, the one Subsequently 1nvolved 1n the acoldent.
Aft tI'ELanlSSILOIl number S/N TA 9-10 had been bullt by York Gears, Ltd. , and mated to mix box S/N TA 11-11. This combination was thtallEd in N 66TSD which, on May 3., 1962, was the flrst Vertol lDT-II dellvered to New York Alrways. At this time these components had a total time (TT) of 123139 and a time 511106 over-— haul (T30) of 5h:3h. They were removed on M y 28, and became the first of two exhibits for the lSOwhour sample overhaulinjtij Follomng thls overhaul the assambly was returned to servace untll July 27, 1962, when a sprag clutch fallure occurred. The necessary repalrs were effected and this unit continued 111 operatlon untll September 1.2, 1962, when 11; ‘oecame an exhlblt for the EGO—haur sample overhaul. At this time a notation was made, H. . . @2111 Shaft P/N 1071320674, s/w TEA—102; Splines distorted and max box end endenced metal pack-up . . . . Nothing was noted that would have prevented further operatlon. . . .” The assembly was then operated until December 8 when 1t was removed because of gear difflcfltlee :In the 1111?: box. At thls tlme aft transmssion S/N TA 9-10 was given a "oonvernence" overhaul. Mm box S/N T15. 11—11 was retired from alrcraft semce. Mix box SIN § 11—102 was built up, bored, flushed, inspected, and load run tested by Vertol.1__3; During this test of this assembly, metal snavmgs were found an the SUIIIEé/a sanguine portion of which Was taped it: the Vertol transmssmn overhaul logbook._ Mi}: has: S/N A llalOE was then mated with aft transmissmn SEN TA 9—10 to form a new agateth-
10f The lSOnh-our sample overhaul was part of the FAA system of 1ncrea51ng eve; haul Etervals.
11/ Hereafter TT hated refers to aft transmission S/N TA 9-10 portion of the assemEIy only. TT for max box S/N A 11—102 comoides wlth the T30 of the assembly.
12/ The transmssmn overhaul logbooks kept by Vertol contaln the records of
mltlal assembly, and all disassemblies, reassemblles, repalrs, over-hauls and load run tests.
