# AD 90-17-01: Carburetor Air Box Latches

- Type: Airworthiness directive
- Status: Current
- Products: Robinson Helicopter R22, R22 ALPHA, R22 BETA and R22 MARINER
- Effective: September 10, 1990
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-6687
- Docket: 89-ASW-58
- Registered aircraft: 817 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/90252211C2947DC786256A4D0061F976.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/90-17-01

## The airworthiness directive

90-17-01 ROBINSON HELICOPTER COMPANY (RHC): Amendment 39-6687. Docket No. 89-ASW-58.

Applicability: All Model R22 series helicopters, certified in any category, equipped with carburetor air box latches.

Compliance: Required within the next 25 hours' time in service after the effective date of this AD, unless already accomplished.

To prevent carburetor air box latches from coming loose in flight, which could result in power loss in critical maneuvers close to the ground, accomplish the following:

  (a) Remove the three carburetor air box latches and replace with four bolts in accordance with the following:

  (1) Open the air box and remove the filter element.

  (2) Remove the air box from the helicopter.

  (3) Drill out the four rivets in the cover holding 0.25 inch diameter spacers and enlarge the holes to 0.191 inch diameter. Discard the spacers.

  (4) Close the cover, and using the holes in the cover as guides, drill four matching holes through the upper box in line with the holes in the cover.

  (5) Open the air box and drill out all the rivets holding the latches to the cover. Discard the latches and angles. Clean the drilling chips from the box.

  (6) Reinstall the air box to the helicopter.

  (7) Install the filter element and secure the cover using four AN3-35A bolts, AN960-10L washers, AN970-3 washers, and NAS679A3 nuts.

NOTE: Refer to Figure 1 for accomplishing the instructions required by paragraph (a).

  (b) An alternate method of compliance or adjustment of the compliance time, which provides an equivalent level of safety, may be used if approved by the Manager, Los Angeles Aircraft Certification Office, ANM-100L, FAA, Northwest Mountain Region, 3229 E. Spring Street, Long Beach, California 90806-2425.

NOTE: Robinson Helicopter Company Service Bulletin Number 61, dated July 28, 1989, pertains to this AD.

This amendment (39-6687, AD 90-17-01) becomes effective on September 10, 1990.

SB 61

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS H10WE](https://openairdocs.org/tcds/H10WE): Robinson Helicopter Company; names 4 of 4 models: R22, R22 MARINER, R22 ALPHA, R22 BETA

## 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: 817 (817 by airframe model, 0 by engine model)
- Makers: Robinson Helicopter 817

Models with the most aircraft:

- [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta): 634 aircraft (airframe model)
- [Robinson Helicopter R22](https://openairdocs.org/model/robinson-helicopter-r22): 131 aircraft (airframe model)
- [Robinson Helicopter R22 MARINER](https://openairdocs.org/model/robinson-helicopter-r22-mariner): 34 aircraft (airframe model)
- [Robinson Helicopter R22 ALPHA](https://openairdocs.org/model/robinson-helicopter-r22-alpha): 16 aircraft (airframe model)
- [Robinson Helicopter R22 BETA II](https://openairdocs.org/model/robinson-helicopter-r22-beta-ii): 2 aircraft (airframe model)

All 6 models: https://openairdocs.org/ad/90-17-01/models.md
Every aircraft: https://openairdocs.org/ad/90-17-01/aircraft.md

Its text cites no advisory circulars or STCs.

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