# AD 59-17-06: Pulley Guards

- Type: Airworthiness directive
- Status: Current
- Products: Helio H-391B and H-395 (USAF L-28A or U-10B)
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 32 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/13FC9A3554232FC586256A38005EDDC8.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/59-17-06

## The airworthiness directive

59-17-06 HELIO: Applies to All Model H-391B Aircraft and Model H-395, Serial Number 075 and 502 Through 509 Inclusive.

Compliance required within next 100 hours or by November 1, 1959, whichever occurs first. Install additional pulley guards at three 3-inch stabilator control system pulleys located at:

  (a) The upper left-hand corner of the fuselage truss just aft of the firewall.

  (b) Just forward of the lower left-hand side of the instrument panel.

  (c) Directly under the forward attach point of the vertical stabilizer in the aft portion of the tail cone. (The cable makes a 180 degree turn around this pulley.)

(Helio Service Bulletin No. 20 covers this subject.)

## 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 2 of 9 models: H-395 (USAF L-28A or U-10B), 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: 32 (32 by airframe model, 0 by engine model)
- Makers: Helio 32

Models with the most aircraft:

- [Helio H-391B](https://openairdocs.org/model/helio-h-391b): 16 aircraft (airframe model)
- [Helio H-395](https://openairdocs.org/model/helio-h-395): 16 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/59-17-06/models.md
Every aircraft: https://openairdocs.org/ad/59-17-06/aircraft.md

Its text cites no advisory circulars or STCs.

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