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AD 77-07-08

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Airworthiness directive · Tail Rotor Tension Torsion Bars · FH1100 Manufacturing 1100 and FH-1100

FAA copy· 22 KB
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AboutSource files 1
Effective
August 5, 1977
Models
1100, FH-1100
Data sheet
TCDSH2WE
Registered aircraft
8 matched by model
Product
Aircraft · Rotorcraft
Amendment
39-2992

Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed May 30, 2024.

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The airworthiness directive

77-07-08 FAIRCHILD (HILLER): Amendment 39-2866 as amended by Amendment 39-2992. Applies to Model 1100 and FH-1100 type helicopters certified in all categories.

Compliance required as follows:

To detect improper surface finish in the bolt holes at each end of the tail rotor tension torsion bars, P/N's 24-55106 which could lead to cracking of the bar plates, accomplish the following within the next 25 hours in service after the effective date of this AD unless already accomplished.

Inspect the two tail rotor tension torsion bars, P/N's 24-55106 which have serial numbers prior to 1922 or illegible serial numbers, in accordance with Fairchild FH-1100 Service Bulletin No. SBFH1100-55-2A dated 19 January 1977, Section 2 "Accomplishment Instructions" or equivalent procedure approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

If tension torsion bars are found unacceptable in accordance with the service bulletin or those procedures approved bythe Chief, Engineering and Manufacturing Branch, replace the bar with one that has been inspected and found acceptable in accordance with the service bulletin or an equivalent procedure approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region may adjust the inspection interval specified in this AD.

Amendment 39-2866 became effective April 11, 1977. This Amendment 39-2992 becomes effective August 5, 1977.

Affected TCDS · 1

The type certificate data sheets for the models this AD names, matched by model and maker.

TCDS H2WEAir Space Design and Manufacturing LLCNames all 2 models: 1100 and FH-1100

Registered aircraft · 8

Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.

By aircraft maker
  • Fairchild Hiller8
By year built
19681972

5 with no year recorded

By model

Aircraft

N232FHRoberts Edgar S · Washoe Valley, NVS/N 232N434FHMetro Service Air Inc · Fairbanks, AKBuilt 1968 · S/N 142N5052FDi Pietro Anthony · New Port Richey, FLBuilt 1970 · S/N 198N5071FHiller Aviation Group Inc · Carson City, NVBuilt 1972 · S/N 238N54BLDaumeries Baudouin · Pagosa Springs, COS/N 233N559FBo LLC · Wilmington, DES/N 173N581FHSale Reported · Crown Point, INSale reportedS/N 81N915BLNorthwest Helicopters LLC · Olympia, WAS/N 158

NTSB investigations that cite this AD · 2

Their narratives or probable cause name AD 77-07-08, often to say whether the aircraft complied with it.

NTSB MIA06LA126Accident · No injuriesLimited investigationFinal reportFairchild Hiller FH-1100 · Navarre, FLThe inadequate manufacturing of the plates of the tail rotor tension-torsion bar assembly resulting in fatigue failure.Jun 8, 2006 · N4035G · Substantial damageNTSB MIA96FA168Accident · 2 fatalField investigationFinal reportHiller FH-1100 · Webster, FLinadequate compliance with AD 77-07-08 (and SB FH1100-55-2A) by other maintenance personnel, and subsequent fatigue failure of plates in the tail rotor torsion tension bar. Factors related to the accident were: manufacturing discontinuities…Jun 28, 1996 · N598F · Substantial damage