Parts · Heating, ice protection and utility systems

Warning System

2,397 failure reports named the warning system in the last ten years, 6,456 since 1996, most often on the Boeing 737; the condition most often found was "false activation". 1 FAA approvals let 1 company make a replacement warning system, Honeywell International US LLC holding the most (1).

Reports by year

Reports by year, as a table

	reports
1996	2
1997	2
1998	14
1999	19
2000	240
2001	283
2002	296
2003	139
2004	106
2005	118
2006	554
2007	180
2008	206
2009	246
2010	254
2011	382
2012	186
2013	152
2014	327
2015	353
2016	307
2017	176
2018	736
2019	829
2020	305
2021	7
2022	8
2023	2
2024	11
2025	9
2026	7

Which system the reports file it under last ten years

Heating, ice protection and utility systems931Engine347Instruments and avionics230Flight controls223Landing gear183Airframe structure174Emergency equipment128Fuel system94Electrical power72Cabin, seats and restraints10

Reports by system, as a table

	reports
Heating, ice protection and utility systems	931
Engine	347
Instruments and avionics	230
Flight controls	223
Landing gear	183
Airframe structure	174
Emergency equipment	128
Fuel system	94
Electrical power	72
Cabin, seats and restraints	10

Models most often reporting it last ten years

Boeing 737704Boeing 767649Bombardier CL-600 Challenger and CRJ234Airbus A321148Embraer EMB-145 ERJ 14595Airbus A33071Airbus A32069Boeing 75768Embraer ERJ 170 E170 and E17540Airbus A30039Mcdonnell Douglas MD-1136Airbus A31927

Models most reported, as a table

	reports
Boeing 737	704
Boeing 767	649
Bombardier CL-600 Challenger and CRJ	234
Airbus A321	148
Embraer EMB-145 ERJ 145	95
Airbus A330	71
Airbus A320	69
Boeing 757	68
Embraer ERJ 170 E170 and E175	40
Airbus A300	39
Mcdonnell Douglas MD-11	36
Airbus A319	27

How it failed the condition found, last ten years

false activation1,974activated313malfunctioned27false indication26intermittent18inoperative7unknown5defective4failed4faulty4

Conditions found, as a table

	reports
false activation	1,974
activated	313
malfunctioned	27
false indication	26
intermittent	18
inoperative	7
unknown	5
defective	4
failed	4
faulty	4

Engines most often reporting it

CFM International LEAP-1A33 19CFM International CFM56-7B27 5CFM International CFM56-7B27E 3CFM International CFM56 series 3General Electric CFM56 series 3General Electric CT7-9B 3International Aero Engines V2527-A5 3International Aero Engines V2533-A5 3Lycoming O-360-J2A 3CFM International CFM56-5B4/3 2

Approved replacement parts 1 parts manufacturer approvals

A parts manufacturer approval (PMA) lets a company other than the aircraft's maker make a warning system and sell it as an approved part for the models named. These are the companies holding such approvals for a warning system:

Honeywell International US LLC 1

For these models most: Boeing 737 (1).

Maker	Part	Replaces	Fits	Granted	Status
Honeywell International US LLC	WARNING SYSTEM SWITCHING UNIT 960-2169	MODIFICATION PART	Boeing 737-200	2001-06-24	current

Sources: the FAA's service difficulty reports since 1995 (a report is a part that failed and was fixed, as filed by an airline, repair station or owner; the count shows reporting as much as reliability) and the parts manufacturer approvals in the FAA's Dynamic Regulatory System. The part name is the reporters' and the approval holders' own words, reduced to the first plain words so that spellings meet.