# AD 77-14-04: Electrical Power

- Type: Airworthiness directive
- Status: Current
- Products: de Havilland Aircraft Co., Ltd., The D.H. 104 Dove Series 1A, D.H. 104 Dove Series 2A, D.H. 104 Dove Series 5A, D.H. 104 Dove Series 5BA, D.H. 104 Dove Series 6A, D.H. 104 Dove Series 6BA, D.H. 104 Dove Series 7A, D.H. 104 Dove Series 7AXC, D.H. 104 Dove Series 8A, D.H. 104 Dove Series 8AXC, D.H.114 Heron Series 2A, D.H.114 Heron Series 2DA and 1 more
- Effective: August 5, 1977
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane, Small/large airplane
- Amendment: 39-2952
- Registered aircraft: 4 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/73E00A29DA3416F7862569AB004B74E7.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/77-14-04

## The airworthiness directive

77-14-04 HAWKER SIDDELEY AVIATION, LTD.: Amendment 39-2952. Applies to DH-104 "Dove" and DH-114 "Heron" airplanes.

Compliance is required within the next 500 hours time in service after the effective date of this AD unless already accomplished.

To prevent the possibility that a loss of generated electrical power would be undetected by the flight crew, accomplish the following:

  (a) Alter the electrical system to incorporate a bus bar low voltage sensing unit, a bus bar low voltage warning light, and an essential service switch, designed and installed in accordance with paragraphs 5 and 6 of Hawker Siddeley Aviation, Ltd., Technical News Sheet, Series: Heron (114), No. N. 6., Issue 3 (for DH-114 "Heron") and CT104, No. 227, Issue 3 (for DH-104 "Dove"), both dated July 3, 1972, as amended to November 20, 1972, or FAA-approved equivalent of either.

  (b) Amend the "Normal and Emergency Procedures", Part B, of the "Operating Procedures" section, Section II, of the applicable Airplane Flight Manual by adding the electrical system operation information contained in paragraphs 7 and 8 and Figure 1 of the applicable Technical News Sheet, referred to in paragraph (a) of this AD, or an FAA-approved equivalent.

  (c) Check the condition of the electrical distribution and generator system in accordance with paragraph 6 of the applicable Technical News Sheet, referred to in paragraph (a) of this AD, or an FAA-approved equivalent, and repair, as necessary. The checks required by this paragraph may be performed by persons authorized to perform preventive maintenance under FAR 43.

This amendment becomes effective August 5, 1977.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-807](https://openairdocs.org/tcds/A-807): Acro Aeronautical Services Ltd; names 10 of 10 models: D.H. 104 Dove Series 8A, D.H. 104 Dove Series 7A, D.H. 104 Dove Series 1A, D.H. 104 Dove Series 5A, D.H. 104 Dove Series 7AXC, D.H. 104 Dove Series 8AXC, D.H. 104 Dove Series 2A, D.H. 104 Dove Series 5BA…
- [TCDS A-816](https://openairdocs.org/tcds/A-816): Acro Aeronautical Services Ltd; names 3 of 3 models: D.H.114 Heron Series 2DA, D.H.114 Heron Series 2A, D.H.114 Heron Series 2X

## 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: 4 (4 by airframe model, 0 by engine model)
- Makers: Dehavilland 4

Models with the most aircraft:

- [Dehavilland DH104 DOVE 6A](https://openairdocs.org/model/dehavilland-dh104-dove-6a): 3 aircraft (airframe model)
- [Dehavilland DH 114 HERON 2X](https://openairdocs.org/model/dehavilland-dh-114-heron-2x): 1 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/77-14-04/models.md
Every aircraft: https://openairdocs.org/ad/77-14-04/aircraft.md

Its text cites no advisory circulars or STCs.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.