# AD 78-02-04: Pitot Heads

- Type: Airworthiness directive
- Status: Current
- Products: Textron BH.125 Series 600A and HS.125 Series 600A
- Effective: February 6, 1978
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-3130
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/51A600EFA89F8A68862569A50072579E.0001
- DRS record last changed: January 21, 2026
- Page: https://openairdocs.org/ad/78-02-04

## The airworthiness directive

78-02-04 HAWKER SIDDELEY AVIATION, LIMITED: Amendment 39-3130. Applies to Model BH/HS 125-600A airplanes certificated in all categories.

Compliance is required as indicated, unless already accomplished.

To prevent possible loss of airspeed reference to both the pilot and co-pilot due to failure of the heating elements of both pitot heads, within 10 hours time in service after the effective date of this AD, remove the Avimomini pitot heads (L/H and R/H) and replace with Rosemount Model 853 JA pitot heads in accordance with the section entitled "Accomplishment Instructions" and the associated installation drawing, both included in Hawker Siddeley Aviation, Limited Service Bulletin 34-129(2436), Revision 1, dated June 21, 1977, or an FAA-approved equivalent.

This amendment becomes effective February 6, 1978.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A3EU](https://openairdocs.org/tcds/A3EU): Textron Aviation Inc.; names 2 of 50 models: HS.125 Series 600A, BH.125 Series 600A

## Registered aircraft it may apply to (OpenAirDocs)

No registered aircraft matched the models it names.

Its text cites no advisory circulars or STCs.

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