# AD 53-21-01: Wing Rear Spar Attachment Bolt

- Type: Airworthiness directive
- Status: Current
- Products: Viking Air DHC-2 Mk.I, DHC-2 Mk.II and DHC-2 Mk.III
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 140 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B451A3152FDBB52A86256A34006B7480.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/53-21-01

## The airworthiness directive

53-21-01 de HAVILLAND: Applies to All Model DHC-2 (Beaver) Aircraft.

Compliance required as indicated.

Several cases have been reported where mechanics in the field upon assembling DHC-2 wings to fuselage have installed extra washers, packing, etc., to the rear spar wing bolt in order to take out any end play. It should be pointed out that a clearance is purposely provided in this fitting as the rear wing attachment is not designed to take drag loads.

All Beaver aircraft should be inspected as soon as possible but not later than December 1, 1953, to see that no washers, bushings, etc., have been installed in this fitting and if found they should be removed immediately.

In assembling the wing to fuselage, the front spar must be attached and then the rear wing bolt should be installed. It is quite normal that the rear spar wing fitting should not touch either inboard side of the fuselage fitting, but in most cases the wing fitting is almost against the forward side. The gaps in the fittings front and rear should not be packed with washers or spacers.

The FAA concurs in this mandatory action by the Canadian Department of Transport.

(de Havilland Technical News Sheet, Series B, No. 67, dated August 31, 1953, available from de Havilland Aircraft of Canada, Ltd., Toronto, Ontario, Canada, covers this same subject.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-806](https://openairdocs.org/tcds/A-806): De Havilland Aircraft of Canada Limited; names 3 of 3 models: DHC-2 Mk.II, DHC-2 Mk.III, DHC-2 Mk.I

## 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: 140 (140 by airframe model, 0 by engine model)
- Makers: Dehavilland 135, Dehavilland Acft Of Canada 3, Dehavilland-Shawano 2

Models with the most aircraft:

- [Dehavilland DHC-2 MK. I(L20A)](https://openairdocs.org/model/dehavilland-dhc-2-mk-i-l20a): 91 aircraft (airframe model)
- [Dehavilland DHC 2 MK III](https://openairdocs.org/model/dehavilland-dhc-2-mk-iii): 24 aircraft (airframe model)
- [Dehavilland DHC-2 MK.I](https://openairdocs.org/model/dehavilland-dhc-2-mk-i): 20 aircraft (airframe model)
- [Dehavilland Acft Of Canada DHC-2 MK I](https://openairdocs.org/model/dehavilland-acft-of-canada-dhc-2-mk-i): 3 aircraft (airframe model)
- [Dehavilland-Shawano DHC-2 MK.I](https://openairdocs.org/model/dehavilland-shawano-dhc-2-mk-i): 2 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/53-21-01/models.md
Every aircraft: https://openairdocs.org/ad/53-21-01/aircraft.md

Its text cites no advisory circulars or STCs.

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