Fire Protection

FAA Aviation Safety SPECIAL AIRWORTHINESS INFORMATION BULLETIN SUBJ: Fire Protection SAIB: NM-20-02 Date: March 11, 2020 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin advises registered owners and operators of The Boeing Company Model 737-8 and -9 airplanes of a potential concern with the red shipping cap on the inlet port of the electronic equipment (E/E) bay smoke detectors.

At this time, the concern is not an unsafe condition that would warrant airworthiness directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR) part 39.

Background

A line check of certain airplanes revealed that the red shipping cap on the inlet port of the E/E cooling supply smoke detectors having part number (P/N) 2156-756A, was not removed during production. Each smoke detector has two ports where air enters into one port and exits out the other. The exhaust smoke detector has both ports connected to the exhaust ducting, and the supply smoke detector has the outlet port connected to the exhaust ducting, while the inlet port is open to the environment. The number of affected airplanes delivered to operators is unknown.

The Boeing Company issued Service Letter 737-SL-26-069-A, dated September 27, 2019, to provide instructions to operators for gaining access to the E/E cooling supply smoke detector in the E/E compartment to remove the red protective cap. The information in this service letter does not change any procedures in Boeing 737MAX Aircraft Maintenance Manual 26-19-01 (Equipment Supply Smoke Detector – Removal/Installation).

Recommendations

The FAA recommends that all owners and operators of the affected airplanes incorporate the actions outlined in the referenced service letter at the earliest opportunity.

For Further Information Contact Brandon Lucero, Aerospace Engineer, Cabin Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3569; email: [email protected].

For Related Service Information Contact

Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; telephone 562-797-1717; Internet https://www.myboeingfleet.com.