# AD 53-21-02: Horizontal Stabilizer Strut

- Type: Airworthiness directive
- Status: Current
- Products: Grumman American G-21A (Army OA-9, Navy JRF-1, -2, -3, -4, -5, and -6B)
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 34 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/34D931B2C4E3356D86256A38005B4445.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/53-21-02

## The airworthiness directive

53-21-02 GRUMMAN: Applies to All Model G-21A (Converted OA-9, JRF-1 Through JRF-5 and JRF-6B) Aircraft.

Compliance required as indicated.

1. Inspect the threaded portion of the horizontal stabilizer strut lower adjustable end fitting P/N 12561-3, by a magnetic particle inspection method, as soon as practicable, but not later than November 15, 1953, and at 1,000-hour intervals thereafter. Replace fitting if crack is found.

2. Replace these fittings every 3,200 hours. If 3,200 hours is reached before the first inspection, fittings may be used for 50 hours after this inspection provided no cracks are found.

(Grumman Aircraft Engineering Corp. Customer Bulletin G-21A No. 3, dated March 20, 1953, covers this same subject.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS TC 654](https://openairdocs.org/tcds/TC%20654): Frakes Aviation; names 1 of 2 models: G-21A (Army OA-9; Navy JRF-1; -2; -3; -4; -5; and -6B)

## 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: 34 (34 by airframe model, 0 by engine model)
- Makers: Grumman 34

Models with the most aircraft:

- [Grumman G-21A](https://openairdocs.org/model/grumman-g-21a): 34 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/53-21-02/models.md
Every aircraft: https://openairdocs.org/ad/53-21-02/aircraft.md

Its text cites no advisory circulars or STCs.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.