The U.S. aircraft register, updated daily
Parts · Airframe structure

Counterweight

16 failure reports named the counterweight in the last ten years, 81 since 1995, most often on the Boeing 737; the condition most often found was "corroded". 45 FAA approvals let 16 companies make a replacement counterweight, Ontic Engineering & Manufacturing INC holding the most (17).

Reports by year

0369121995200120072012202112025
Reports by year, as a table
reports
19953
19965
19982
19992
200012
20016
20026
20035
20044
20051
20072
20083
20092
20101
20116
20121
20132
20142
20191
20203
20212
20224
20232
20243
20251

Which system the reports file it under last ten years

Airframe structure15Flight controls1
Reports by system, as a table
reports
Airframe structure15
Flight controls1

Models most often reporting it last ten years

Boeing 73712Cessna 680 Citation Sovereign and Latitude2Mcdonnell Douglas MD-111
Models most reported, as a table
reports
Boeing 73712
Cessna 680 Citation Sovereign and Latitude2
Mcdonnell Douglas MD-111

How it failed the condition found, last ten years

corroded13out of adjust2worn1
Conditions found, as a table
reports
corroded13
out of adjust2
worn1

Engines most often reporting it

Lycoming AEIO-360 series 1

Approved replacement parts 45 parts manufacturer approvals

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

Ontic Engineering & Manufacturing INC 17Wencor West INC 3Wencor LLC (Formerly Dixie Aerospace LLC) 3Rsw Products INC 3Aar Pma Products 3Tmt Research Development INC 2Source Manufacturing INC 2Fliegen Works INC 2Electro-Methods INC 2Diagnostic Solutions International, LLC 2Safran Power USA LLC 1Jet Avion Corporation A Heico Aerospace Company 1Core Parts LLC 1Aerocraft, INC. 1Able Engineering and Component Services, INC. 1Able Aerospace Services, INC. 1

For these models most: Md Helicopters Inc 500 (1), Md Helicopters Inc 369 (1), Hughes Helicopters Inc HUGHES 369 (1), Airbus A321 (1), Airbus A320 (1), Airbus A319 (1), Agusta Spa A109 (1).

MakerPartReplacesFitsGrantedStatus
Source Manufacturing INCCounterweight 659330CL2TMT659330CL2Erickson... (T73-P-1) JFTD12A-4A, (T73-P-700) JFTD12A-5A2026-04-10current
Source Manufacturing INCCounterweight 659330CL1TMT659330CL1Erickson... (T73-P-1) JFTD12A-4A, (T73-P-700) JFTD12A-5A2026-04-10current
Diagnostic Solutions International, LLCCounterweight T/R Phase P/UTarget 17333Modification ArticleLeonardo S.p.A. Model A109E2025-03-03current
Core Parts LLCCounterweight 3012252CP3012252Pratt & Whitney Canada Corp. PT6A-6, PT6A-6A, PT6A-6B2022-10-12current
Diagnostic Solutions International, LLCCounterweight T/R Phase P/U Target 1733317333Leonardo Helicopters A109E2020-04-21current
Safran Power USA LLCCounterweight Assembly - Matched Set S17089501708950Airbus SAS A318 Model -111, A318 Model -112,...2020-02-05current
Ontic Engineering & Manufacturing INCCounterweight 3032829CL53032829CL5Pratt & Whitney Canada JT15D-5, -5A, -5B2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3018015CL13018015CL1Pratt & Whitney Canada JT15D-1, -1A, -1B2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3032828CSL53032828CL5Pratt & Whitney Canada JT15D-5, -5A, -5B2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3018015CL23018015CL2Pratt & Whitney Canada JT15D-1, -1A, -1B2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3032829CL43032829CL4Pratt & Whitney Canada JT15D-5, -5A, -5B2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3040465CL13040465CL1Pratt & Whitney Canada JT15D-5D2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3040406CLD3040406CLDPratt & Whitney Canada JT15D-5D2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3032828CL33032828CL3Pratt & Whitney Canada JT15D-5, -5A, -5B2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3040465CL53040465CL5Pratt & Whitney Canada JT15D-5D2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3032828CL43032828CL4Pratt & Whitney Canada JT15D-5, -5A, -5B2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3040406CLC3040406CLCPratt & Whitney Canada JT15D-5D2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3040406CLF3040406CLFPratt & Whitney Canada JT15D-5D2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3041590CL213041590CL21Pratt & Whitney Canada JT15D-5D2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3018015CL43018015CL4Pratt & Whitney Canada JT15D-1, -1A, -1B2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3040406CLE3040406CLEPratt & Whitney Canada JT15D-5D2017-03-30current
Ontic Engineering & Manufacturing INCCounterweight 3040465CL23040465CL2Pratt & Whitney Canada JT15D-5D2017-03-30current
Able Engineering and Component Services, INC.Counterweight 659328AA659328Erickson Incorporated (T73-P-1), JFTD12A-4A, (T73-P-700)2017-02-01current active
Able Aerospace Services, INC.Counterweight 659328AA659328ERICKSON INCORPORATED (T73-P-1) JFTD12A-4A, (T73-P-700) JFTD12A-5A2017-02-01current active
Aerocraft, INC.Counterweight Kit ARC-500-2-1Modification PartMDHI Hughes) (369D, 369E, 369FF2016-09-05current
Ontic Engineering & Manufacturing INCCounterweight 3018015CL63018015CL6Pratt & Whitney Canada JT15D-1, TJ15D-1A, JT15D-1B2015-06-25current
Tmt Research Development INCCounterweight 659330CL2TMT659330CL2Pratt & Whitney JFTD12A-4A, JFTD12A-5A2013-03-14current
Tmt Research Development INCCounterweight 659330CL1TMT659330CL1Pratt & Whitney JFTD12A-4A, JFTD12A-5A2013-03-14current
Wencor LLC (Formerly Dixie Aerospace LLC)Counterweight 1B7537CL2AARPratt & Whitney 1B7537CL2Pratt & Whitney PW2037, PW2037(M), PW20402011-06-20current
Wencor LLC (Formerly Dixie Aerospace LLC)Counterweight 1B7537CL1AARPratt & Whitney 1B7537CL1Pratt & Whitney PW2037, PW2037(M), PW20402011-06-20current
Wencor LLC (Formerly Dixie Aerospace LLC)Counterweight 1B7537CL3AARPratt & Whitney 1B7537CL3Pratt & Whitney PW2037, PW2037(M), PW20402011-06-20current
Fliegen Works INCCounterweight, Lead, Elevator, Right AAI129-131Modification PartViking Air Limited Bombardier) (de-Havilland) (DHC-3 (Otter)2010-06-08current
Aar Pma ProductsCounterweight 1B7537CL3AAR1B7537CL3Pratt & Whitney PW2037, PW2037(M), PW20402008-11-20current
Aar Pma ProductsCounterweight 1B7537CL1AAR1B7537CL1Pratt & Whitney PW2037, PW2037(M), PW20402008-11-20current
Aar Pma ProductsCounterweight 1B7537CL2AAR1B7537CL2Pratt & Whitney PW2037, PW2037(M), PW20402008-11-20current
Fliegen Works INCCounterweight AAI129-131American Aeromotives AAI129-131Bombardier, Inc. DHC-32003-08-10current
Jet Avion Corporation A Heico Aerospace CompanyCounterweight JA584944CL1-CL6Pratt & Whitney 584944 CL1-CL6Pratt & Whitney JT8D -15A, -17A, -17AR1999-03-18current
Rsw Products INCCounterweight C.P. 22012-2Hamilton Standard Propeller 51431Hamilton Standard Division 2D30, 3D401997-06-30current
Rsw Products INCCounterweight C.P. 22012-1Hamilton Standard Propeller 51431Hamilton Standard Division 2D30, 3D401997-06-30current
Rsw Products INCCounterweight C.P. 22013-1Hamilton Standard Propeller 51432Hamilton Standard Division 12D401997-06-30current
Wencor West INCCounterweight 0.110 x 0.250 x 0.137 534492CL2WEPratt & Whitney 534492CL2Pratt & Whitney JT8D-15A, -17A, -17AR1996-11-13current
Wencor West INCCounterweight 0.110 x 0.250 x 0.137 534492CL3WEPratt & Whitney 534492CL3Pratt & Whitney JT8D-15A, -17A, -17AR1996-11-13current
Wencor West INCCounterweight 0.110 x 0.250 x 0.137 534492CL1WEPratt & Whitney 534492CL1Pratt & Whitney JT8D-15A, -17A, -17AR1996-11-13current
Electro-Methods INCCounterweight EM393513-Pratt & Whitney JT3D, D-3, D-3B1976-08-04current
Electro-Methods INCCounterweight EM426836 N/C dated 1-3-75426836, Rev. D, dated 10-22-70Pratt & Whitney JT3D-1, D-3, D-381975-08-26current

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.