Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
AIR-21-15 R1
September 16, 2021
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin advises owners and
operators of 328 Support Services GmbH Model 328-100 and -300
airplanes; Learjet, Inc., Model 45 airplanes; Yaborã
Indústria Aeronáutica S.A. Model EMB-135ER, EMB-135LR,
EMB-135BJ (Legacy 600), EMB-135KE, EMB-135BJ (Legacy 650), EMB-135KL,
EMB-145, -145ER, -145MR, -145LR, -145XR, -145MP, and -145EP airplanes;
Textron Aviation Inc. Model 500 550 S550 552 560 and 560XL airplanes,
Model 501 and 551 airplanes, Model 650 airplanes, and Model Hawker 800
(including variant U-125A), 800XP, and 1000 airplanes; Bombardier,
Inc., Model CL-600-1A11 (600); CL-600-2A12 (601), and CL-600-2B16
(601-3A and 601-3R) airplanes; Bombardier, Inc., Model BD-700-1A10 and
BD-700-1A11 airplanes; Viking Air Limited Model CL-215-6B11 (CL-415
Variant) airplanes; and Textron Aviation, Inc., Model 750 airplanes;
having a Honeywell Primus II Radio System with Radio Management Unit
(RMU) 855 installed, of the potential for inadvertent disabling of the
Automatic Dependent Surveillance – Broadcast (ADS-B) Out function. This
SAIB is being revised to remove certain airplanes from the
applicability.
At this time, the airworthiness 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
The FAA received reports in January and February 2020 of ADS-B Out
compliant aircraft on which ADS-B Out transmissions were not operating.
The cause of this was due to certain avionics power up sequences
involving the RMU-855. The crew could be unaware of this issue unless
informed of it by Air Traffic Control (ATC). Honeywell has identified
different airplanes with this equipment, totaling approximately 2,750
affected airplanes. This condition results in failure to comply with 14
CFR 91.225 and 14 CFR 91.227 when ADS-B Out is disabled and the
aircraft operates in the airspace defined in 14 CFR 91.225.
Honeywell Service Bulletin 7013270-34-0024, dated December 19, 2019,
and Honeywell Service Information Letter D201507000061, Revision 4,
dated April 6, 2021, have been issued to provide procedures for
ensuring power up sequencing in the integrated radio system, and
accomplishing a software update at authorized repair stations.
Recommendations
The FAA recommends that all owners and operators of the airplanes
identified above incorporate the actions outlined in the referenced
service information at the earliest opportunity.
For Further Information Contact
Charles Toliver, Aerospace Engineer, Systems and Equipment Section, Los
Angeles ACO Branch, 3960 Paramount Blvd , Lakewood, CA 90712-4137,
telephone: 562-627-5367; e-mail Charles.Toliver@faa.gov.