AD 71-16-02

Airworthiness directive · Rotex Voltage Sensing Unit · Textron DH.125 Series 1A and DH.125 Series 1A-522

Effective
November 5, 1971
Models
DH.125 Series 1A, DH.125 Series 1A-522
Data sheet
TCDSA3EU
Product
Aircraft · Large airplane
Amendment
39-1329

Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed January 21, 2026.

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The airworthiness directive

71-16-02 HAWKER-SIDDELEY AVIATION, LTD.: Amdt. 39-1251 as amended by Amendment 39-1329. Applies to Hawker-Siddeley Model DH-125 series 1A serial numbers 25013, 25104, 25016, 25018, 25021, 25022, 25026, 25027, 25030, 25031, 25034 through 25039, 25042, 25051 through 25053, 25057, and 25058; and series 1A-522 serial numbers 25017, 25020, 25023, 25029, 25032, 25033, 25043, 25046, 25047, 25060, 25064, 25065, 25066, 25068, 25070, 25073 through 25075, 25078, 25079, 25082 through 25084, 25086 through 25088, 25091, 25093, and 25095 airplanes.

To prevent a hazardous drift in the Rotax voltage sensing unit, within the next 200 hours' time in service after the effective date of this AD, unless already accomplished, incorporate Rotax Modification No. SP.7172 by replacing the transistor T.1 in the Rotax Voltage Sensing Unit Type U.3624 or U.3624/1 with a new transistor in accordance with Hawker Siddeley Aviation, Ltd., 125 Series Aircraft Service Bulletin 24/124 (7355), dated July 9, 1970, or later ARB-approved issue or FAA-approved equivalent.

Amendment 39-1251 became effective August 23, 1971.

This Amendment 39-1329 becomes effective November 5, 1971.

Affected TCDS · 1

The type certificate data sheets for the models this AD names, matched by model and maker.

Registered aircraft

No registered aircraft matched this AD’s modelsForeign aircraft aren’t included, and ADs on propellers and appliances aren’t matched by model.