Parts · Engine

Hmu

279 failure reports named the hmu in the last ten years, 653 since 1995, most often on the Boeing 737; the condition most often found was "failed".

Reports by year

Reports by year, as a table

	reports
1995	16
1996	15
1997	16
1998	16
1999	18
2000	10
2001	14
2002	19
2003	22
2004	12
2005	22
2006	22
2007	21
2008	15
2009	20
2010	13
2011	22
2012	20
2013	19
2014	18
2015	24
2016	28
2017	23
2018	34
2019	27
2020	30
2021	29
2022	31
2023	20
2024	16
2025	18
2026	23

Which system the reports file it under last ten years

Engine274Landing gear2Electrical power1Propeller1Airframe structure1

Reports by system, as a table

	reports
Engine	274
Landing gear	2
Electrical power	1
Propeller	1
Airframe structure	1

Models most often reporting it last ten years

Boeing 737183Boeing 76723Bell 40710Airbus A3199Airbus A3209Mcdonnell Douglas MD-116Airbus A3213Boeing 7473Boeing 7773Bombardier BD-100 Challenger 300 and 3503Dehavilland DHC-83Embraer EMB-1203

Models most reported, as a table

	reports
Boeing 737	183
Boeing 767	23
Bell 407	10
Airbus A319	9
Airbus A320	9
Mcdonnell Douglas MD-11	6
Airbus A321	3
Boeing 747	3
Boeing 777	3
Bombardier BD-100 Challenger 300 and 350	3
Dehavilland DHC-8	3
Embraer EMB-120	3

How it failed the condition found, last ten years

failed64faulted54faulty43malfunctioned37leaking21inoperative11defective10unserviceable6slow4unknown4

Conditions found, as a table

	reports
failed	64
faulted	54
faulty	43
malfunctioned	37
leaking	21
inoperative	11
defective	10
unserviceable	6
slow	4
unknown	4

Engines most often reporting it

CFM International CFM56-7B27E 43 CFM International CFM56-7B27 33 CFM International CFM56 series 32 General Electric CF6-80C2B6F 14 CFM International CFM56-7B26/2 10 Allison (Rolls-Royce) 250-C47B 8 CFM International CFM56-7B20 7 CFM International CFM56-7B24/3 7 CFM International CFM56-7B27/B3 6 CFM International CFM56-5B4/3 3

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.