Parts · Landing gear

Downlock

13 failure reports named the downlock in the last ten years, 86 since 1995, most often on the Boeing 747; the condition most often found was "missing". 10 FAA approvals let 5 companies make a replacement downlock, Aviation Materials Management INC holding the most (3).

Reports by year

Reports by year, as a table

	reports
1995	4
1996	5
1997	4
1998	7
1999	9
2000	5
2001	3
2002	4
2003	6
2004	3
2005	3
2006	3
2007	2
2008	2
2009	3
2010	2
2012	3
2013	2
2014	2
2015	1
2016	1
2018	2
2020	1
2021	1
2022	1
2023	1
2025	4
2026	2

Which system the reports file it under last ten years

Landing gear12Heating, ice protection and utility systems1

Reports by system, as a table

	reports
Landing gear	12
Heating, ice protection and utility systems	1

Models most often reporting it last ten years

Boeing 7472Boeing 7571Boeing 7671Bombardier CL-600 Challenger and CRJ1Cessna 560 Citation V, Ultra, Encore and Excel1Embraer EMB-505 Phenom 3001Embraer ERJ 170 E170 and E1751Embraer ERJ 190 E190 and E1951Piper PA-32 Cherokee Six, Lance and Saratoga1Piper PA-44 Seminole1

Models most reported, as a table

	reports
Boeing 747	2
Boeing 757	1
Boeing 767	1
Bombardier CL-600 Challenger and CRJ	1
Cessna 560 Citation V, Ultra, Encore and Excel	1
Embraer EMB-505 Phenom 300	1
Embraer ERJ 170 E170 and E175	1
Embraer ERJ 190 E190 and E195	1
Piper PA-32 Cherokee Six, Lance and Saratoga	1
Piper PA-44 Seminole	1

How it failed the condition found, last ten years

missing2broken1bypassing1cracked1damaged1disconnected1faulty1intermittent1leaking1out of position1

Conditions found, as a table

	reports
missing	2
broken	1
bypassing	1
cracked	1
damaged	1
disconnected	1
faulty	1
intermittent	1
leaking	1
out of position	1

Approved replacement parts 10 parts manufacturer approvals

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

Aviation Materials Management INC 3Goodrich Landing Gear 2Aviation Materials Management, INC. 2Aviation Materials Management, INC 2Efs Aerospace INC 1

For these models most: Boeing 737 (10).

Maker	Part	Replaces	Fits	Granted	Status
Aviation Materials Management, INC	Downlock 273A2201-1	273A2201-1	Boeing 737-600 Series, 737-700 Series,...	2015-02-12	current
Aviation Materials Management, INC	Downlock Assembly 273A2201-1	273A2201-1	Boeing 737-600 Series, 737-700 Series,...	2015-02-12	current
Aviation Materials Management, INC.	Downlock 273A2201-1	273A2201-1	Boeing 737-600 Series, 737-700 Series,...	2014-09-04	current
Aviation Materials Management, INC.	Downlock Assembly 273A2201-1	273A2201-1	Boeing 737-600 Series, 737-700 Series,...	2014-09-04	current
Aviation Materials Management INC	Downlock Assembly 273A2201-1	273A2201-1	Boeing 737-600 Series, 737-700 Series,...	2013-02-26	current
Aviation Materials Management INC	Downlock Assembly 273A2201-1	273A2201-1	Boeing 737-600 Series, 737-700 Series,...	2010-10-05	current
Aviation Materials Management INC	Downlock 273A2201-1	273A2201-1	Boeing 737-600 Series, 737-700 Series,...	2010-10-05	current
Goodrich Landing Gear	DOWNLOCK ASSEMBLY 273A2201-1	273A2201-1	Boeing 737-600 SERIES, 737-700 SERIES,...	2008-11-24	current
Goodrich Landing Gear	DOWNLOCK ASSEMBLY 273A2201-1	273A2201-1	Boeing 737-600 SERIES, 737-700 SERIES,...	2008-11-24	current
Efs Aerospace INC	DOWNLOCK ASSEMBLY - MLG 273A2201-1	273A2201-1	Boeing 737-600 Series, 737-700 Series,...	2005-08-12	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.