# AD 70-10-04: Accumulator Assemblies

- Type: Airworthiness directive
- Status: Current
- Products: Boeing 707-100 Long Body, 707-100B Long Body, 707-100B Short Body, 707-200, 707-300 Series, 707-300B Series, 707-300C Series, 707-400 Series, 720 Series, 720B Series, 737-100 Series, 737-200 Series and 2 more
- Effective: May 16, 1970
- Superseded by: Nothing supersedes this AD
- Product type: Appliance
- Amendment: 39-988
- Registered aircraft: 16 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9C29F7E9F5B0A8D686256A33006FE124.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/70-10-04

## The airworthiness directive

70-10-04 SPRAGUE ENGINEERING: Amdt. 39-988. Applies to all civil aircraft certificated in all categories including, but not limited to the Boeing Models 707/720/737 aircraft and Convair Model 22 aircraft with the Sprague Engineering Accumulator Assemblies, P/N A-200-25 and A-200-50 installed.

Compliance required within the next 3000 hours time in service after the effective date of this AD, unless already accomplished.

To prevent hydraulic accumulator end cap failure due to cyclic fatigue and subsequent explosive hazard to personnel, structure and surrounding equipment, as well as loss of hydraulic system fluid and pressure, accomplish the following:

Replace the aluminum end caps on Sprague Accumulator Assemblies, P/N A-200-25 and -50, with steel end caps, Sprague P/N 60257-2 (oil end cap) and P/N 60257-3 (air end cap), in accordance with the instructions of Sprague Engineering Modification Bulletin No. 2, dated March 28, 1969, or later FAA approved revisions and Sprague Overhaul Instructions with Parts Breakdown, Accumulator Assembly, A-200 Series, dated September, 1967, or an equivalent installation and replacement approved by the Chief, Aircraft Engineering Division, FAA Western Region.

This amendment becomes effective May 16, 1970.

## Affected data sheets (4) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 4A21](https://openairdocs.org/tcds/4A21): The Boeing Company; names 4 of 4 models: 707-100B Short Body, 707-200, 707-100 Long Body, 707-100B Long Body
- [TCDS 4A26](https://openairdocs.org/tcds/4A26): The Boeing Company; names 4 of 4 models: 707-300B Series, 707-400 Series, 707-300 Series, 707-300C Series
- [TCDS A16WE](https://openairdocs.org/tcds/A16WE): The Boeing Company; names 3 of 17 models: 737-100 Series, 737-200C Series, 737-200 Series
- [TCDS 4A28](https://openairdocs.org/tcds/4A28): The Boeing Company; names 2 of 2 models: 720B Series, 720 Series

## 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: 16 (16 by airframe model, 0 by engine model)
- Makers: Boeing 16

Models with the most aircraft:

- [Boeing 737-205](https://openairdocs.org/model/boeing-737-205): 3 aircraft (airframe model)
- [Boeing 707-338C](https://openairdocs.org/model/boeing-707-338c): 2 aircraft (airframe model)
- [Boeing 707-368C](https://openairdocs.org/model/boeing-707-368c): 1 aircraft (airframe model)
- [Boeing 707-321B](https://openairdocs.org/model/boeing-707-321b): 1 aircraft (airframe model)
- [Boeing 707-323B](https://openairdocs.org/model/boeing-707-323b): 1 aircraft (airframe model)
- [Boeing 707-351B](https://openairdocs.org/model/boeing-707-351b): 1 aircraft (airframe model)
- [Boeing 737-200](https://openairdocs.org/model/boeing-737-200): 1 aircraft (airframe model)
- [Boeing 737-201](https://openairdocs.org/model/boeing-737-201): 1 aircraft (airframe model)
- [Boeing 737-210C](https://openairdocs.org/model/boeing-737-210c): 1 aircraft (airframe model)
- [Boeing 737-242C](https://openairdocs.org/model/boeing-737-242c): 1 aircraft (airframe model)
- [Boeing 737-290C](https://openairdocs.org/model/boeing-737-290c): 1 aircraft (airframe model)
- [Boeing 737-209](https://openairdocs.org/model/boeing-737-209): 1 aircraft (airframe model)
- [Boeing 737-275C](https://openairdocs.org/model/boeing-737-275c): 1 aircraft (airframe model)

All 13 models: https://openairdocs.org/ad/70-10-04/models.md
Every aircraft: https://openairdocs.org/ad/70-10-04/aircraft.md

Its text cites no advisory circulars or STCs.

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