SAIB NM-18-32

FAA Aviation Safety

SPECIAL AIRWORTHINESS

INFORMATION BULLETIN SUBJ: Electrical Power – Direct Current Power Center SAIB: NM-18-32 Date: December 3, 2018 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin advises registered owners and operators of Bombardier, Inc., Model BD-100-1A10 (Challenger 300) airplanes of the potential for malfunctions of the Direct Current Power Center (DCPC) unit.

Background

Operators of Bombardier, Inc., Model BD-100-1A10 (Challenger 300) airplanes reported erratic electrical status indications on the push-button annunciators and the engine instrument and crew alerting system; in some cases, the malfunction of the DCPC, which provides electrical power to the avionics equipment on the airplane, caused momentary loss of electrical power and loss of flight displays. These malfunctions were attributed to the printed circuit board (PCB) inserted in the DCPC.

The PCBs are susceptible to movement within the DCPC as a result of the installation design, and this movement resulted in the loss of communication between the PCB and the DCPC motherboard.

Zodiac Aerospace, which manufactured the applicable DCPCs, issued Service Bulletins 320GC03Y-24-012, 970GC02Y-24-013, and 975GC02Y-24-013, Revision 03, all dated December 15, 2012, to provide procedures for modifying DCPC units manufactured by Zodiac Aerospace.

Bombardier issued Service Bulletin 100-24-23, dated November 26, 2012, and Revision 01, dated March 2, 2015, to provide procedures for reworking the DCPC system; the Bombardier service information also refers to the Zodiac Aerospace Service Bulletins as a secondary source of service information.

On February 26, 2014, we issued Airworthiness Directive 2014-05-23, Amendment 39-13528, which requires modification of the DCPCs to address loss of electrical power, which could result in the loss of flight displays and reduced controllability of the airplane. Although the actions in the referenced service information and the AD have been done, none of these corrective actions have resolved the DCPC PCB issues. Inspections of the modified DCPC units revealed that the modification is ineffective .

We have requested the assistance of Transport Canada Civil Aviation Authority (TCCA) for resolution of the issues identified. TCCA is working with Bombardier to investigate these safety concerns and develop additional modifications that will address the identified unsafe condition (the loss of electrical power and flight displays). Once these modifications are developed, approved, and available, we might consider additional rulemaking.

Recommendations

The FAA recommends that all owners and operators of the affected airplanes incorporate the actions outlined in Bombardier Advisory Wire, AW300-24-0289, dated November 28, 2017.

2 For Further Information Contact

Steven Dzierzynski, Aerospace Engineer, Avionics & Electrical Systems Section, AIR-7H2, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone:

(516) 228-7367; fax: (516) 794-5531; email: steven.dzierzynski@faa.gov.

For Related Service Information Contact

Bombardier, Inc., 400 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; telephone 514- 855-5000; fax 514-855-7401; email ac.yul@aero.bombardier.com; Internet http://www.bombardier.com.