# AD 87-26-03: Weather Radar Receiver Transmitters

- Type: Airworthiness directive
- Status: Current
- Products: Boeing 737-100 Series, 737-200 Series, 737-200C Series, 737-300 Series, 737-400 Series, 737-500 Series, 737-600 Series, 737-700 Series and 737-800 Series
- Effective: February 1, 1988
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-5803
- Registered aircraft: 823 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/3416BF38512B280B8625695900728E70.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/87-26-03

## The airworthiness directive

87-26-03 BOEING: Amendment 39-5803. Applies to Model 737 series airplanes, specified in Boeing Service Bulletin 737-34A1208, Revision 1, dated May 14, 1987, certificated in any category. Compliance required within the next year after the effective date of this AD, unless previously accomplished.

To minimize the possibility of misleading localizer deviation indication to the flight crew caused by electromagnetic interference, accomplish the following:

A. Replace the existing weather radar receiver-transmitters with modified receiver- transmitters; install 10 db attenuators in line with the localizer coaxial cables; if Bendix VHF navigation receivers are installed, replace with modified receivers; and, for Model 737-300 airplanes equipped with electronic flight instrument system (EFIS), modify specific wire bundles and their routing, in accordance with Boeing Service Bulletin 737-34A1208, Revision 1, dated May 14, 1987, or later FAA-approved revision.

B. An alternatemeans of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of the modification required by this AD.

All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to the Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124-2207. These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington.

This amendment becomes effective February 1, 1988.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A16WE](https://openairdocs.org/tcds/A16WE): The Boeing Company; names 9 of 17 models: 737-500 Series, 737-100 Series, 737-200C Series, 737-800 Series, 737-300 Series, 737-200 Series, 737-700 Series, 737-400 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: 823 (823 by airframe model, 0 by engine model)
- Makers: Boeing 823

Models with the most aircraft:

- [Boeing 737-823](https://openairdocs.org/model/boeing-737-823): 278 aircraft (airframe model)
- [Boeing 737-800](https://openairdocs.org/model/boeing-737-800): 139 aircraft (airframe model)
- [Boeing 737-824](https://openairdocs.org/model/boeing-737-824): 135 aircraft (airframe model)
- [Boeing 737-832](https://openairdocs.org/model/boeing-737-832): 73 aircraft (airframe model)
- [Boeing 737-890](https://openairdocs.org/model/boeing-737-890): 60 aircraft (airframe model)
- [Boeing 737-724](https://openairdocs.org/model/boeing-737-724): 36 aircraft (airframe model)
- [Boeing 737-790](https://openairdocs.org/model/boeing-737-790): 14 aircraft (airframe model)
- [Boeing 737-752](https://openairdocs.org/model/boeing-737-752): 13 aircraft (airframe model)
- [Boeing 737-400](https://openairdocs.org/model/boeing-737-400): 8 aircraft (airframe model)
- [Boeing 737-852](https://openairdocs.org/model/boeing-737-852): 7 aircraft (airframe model)
- [Boeing 737-500](https://openairdocs.org/model/boeing-737-500): 6 aircraft (airframe model)
- [Boeing 737-436](https://openairdocs.org/model/boeing-737-436): 6 aircraft (airframe model)
- [Boeing 737-700](https://openairdocs.org/model/boeing-737-700): 5 aircraft (airframe model)
- [Boeing 737-300](https://openairdocs.org/model/boeing-737-300): 4 aircraft (airframe model)
- [Boeing 737-883](https://openairdocs.org/model/boeing-737-883): 4 aircraft (airframe model)
- [Boeing 737-205](https://openairdocs.org/model/boeing-737-205): 3 aircraft (airframe model)
- [Boeing 737-490](https://openairdocs.org/model/boeing-737-490): 3 aircraft (airframe model)
- [Boeing 737-484](https://openairdocs.org/model/boeing-737-484): 3 aircraft (airframe model)
- [Boeing 737-732](https://openairdocs.org/model/boeing-737-732): 3 aircraft (airframe model)
- [Boeing 737-524](https://openairdocs.org/model/boeing-737-524): 3 aircraft (airframe model)

All 40 models: https://openairdocs.org/ad/87-26-03/models.md
Every aircraft: https://openairdocs.org/ad/87-26-03/aircraft.md

Its text cites no advisory circulars or STCs.

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