# AD 56-22-02: Wing Attachment Washers

- Type: Airworthiness directive
- Status: Current
- Products: Helio H-391B
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 16 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/985A021222A7C96286256A38005ED2DE.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/56-22-02

## The airworthiness directive

56-22-02 HELIO: Applies to Model H-391B Aircraft, Serial Numbers 003 to 029 Inclusive.

Compliance required within next 100 hours.

Cases have been reported of finding cracked upper wing attachment thrust washers, P/N HS-15. These are special heat-treated washers installed beneath the head of the bolt attaching the top of the front wing spar to the carry-through structure. Accordingly, these washers must be replaced with new improved type procured from the airplane manufacturer.

(Helio Field Service Bulletin No. 13 dated July 18, 1956, covers this same subject and specifies the bolt torque requirements.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 1A8](https://openairdocs.org/tcds/1A8): Helio Alaska Inc.; names 1 of 9 models: H-391B

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 16 (16 by airframe model, 0 by engine model)
- Makers: Helio 16

Models with the most aircraft:

- [Helio H-391B](https://openairdocs.org/model/helio-h-391b): 16 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/56-22-02/models.md
Every aircraft: https://openairdocs.org/ad/56-22-02/aircraft.md

Its text cites no advisory circulars or STCs.

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