# AD 76-01-04: Longitudinal Porpoising

- Type: Airworthiness directive
- Status: Current
- Products: Boeing DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-32F (C-9A), DC-9-32F (C-9B), DC-9-33F, DC-9-34, DC-9-34F and DC-9-51
- Effective: January 15, 1976
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-2489
- Registered aircraft: 7 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/8041EC88B77D3CEB862569C900746669.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/76-01-04

## The airworthiness directive

76-01-04 MCDONNELL DOUGLAS: Amendment 39-2489. Applies to Model DC-9-30 and -50 Series Airplanes Fuselage Numbers 757, 763, 780 through 795, 797 and 798, certificated in all categories.

Compliance required within the next 50 hours' time in service or 5 days whichever comes first after the effective date of this AD, unless already accomplished.

To prevent manually induced longitudinal proposing aggravated by the elevator boost system accomplish the following:

Remove the hydraulic bleed stop assembly, P/N 4934616-1, per Douglas Alert Service Bulletin A27-176, dated December 13, 1975, or later FAA-approved revisions, or an equivalent procedure approved by the Chief, Aircraft Engineering Division, FAA Western Region.

This amendment becomes effective on January 15, 1976.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A6WE](https://openairdocs.org/tcds/A6WE): The Boeing Company; names 7 of 25 models: DC-9-34F, DC-9-33F, DC-9-51, DC-9-31, DC-9-32F, DC-9-32 (VC-9C), DC-9-34

## 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: 7 (7 by airframe model, 0 by engine model)
- Makers: Mcdonnell Douglas 5, Douglas 2

Models with the most aircraft:

- [Mcdonnell Douglas DC-9-33F](https://openairdocs.org/model/mcdonnell-douglas-dc-9-33f): 3 aircraft (airframe model)
- [Douglas DC-9-32F](https://openairdocs.org/model/douglas-dc-9-32f): 1 aircraft (airframe model)
- [Mcdonnell Douglas DC-9-32](https://openairdocs.org/model/mcdonnell-douglas-dc-9-32): 1 aircraft (airframe model)
- [Mcdonnell Douglas DC-9-32F](https://openairdocs.org/model/mcdonnell-douglas-dc-9-32f): 1 aircraft (airframe model)
- [Douglas DC-9-33F](https://openairdocs.org/model/douglas-dc-9-33f): 1 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/76-01-04/models.md
Every aircraft: https://openairdocs.org/ad/76-01-04/aircraft.md

Its text cites no advisory circulars or STCs.

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