The U.S. aircraft register, updated daily
Parts

Extension Spring

No failure report names the extension spring. 10 FAA approvals let 6 companies make a replacement extension spring, Precision Coil Spring CO holding the most (4).

Approved replacement parts 10 parts manufacturer approvals

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

Precision Coil Spring CO 4Aviation Materials Management INC 2Machen INC 1Gemini Engineering 1Aviation Materials Management, INC. 1Aviation Materials Management, INC 1

For these models most: Boeing 737 (5), Boeing 727 (5), Mcdonnell Douglas MD-11 (2), Mcdonnell Douglas DC-10 (2), Piper PA-60 Aerostar (1), Mcdonnell Douglas DC-9 (1), Boeing 707 (1).

MakerPartReplacesFitsGrantedStatus
Aviation Materials Management, INCExtension Spring 6-661896-66189Boeing 727-200 Series, 727-200F...2015-02-12current
Aviation Materials Management, INC.Extension Spring 6-661896-66189Boeing 727-200 Series, 727-200F...2014-09-04current
Aviation Materials Management INCExtension Spring 6-661896-66189Boeing 727-200 Series, 727-200F...2013-02-27current
Gemini EngineeringEXTENSION SPRING 6-661896-66189Boeing 707-100 LB, 707-100B LB, 707-100B SB2009-06-03current
Aviation Materials Management INCExtension Spring 6-661896-66189Boeing 727-200 Series, 727-200F...2006-08-24current
Machen INCExtension Spring 980231-001Piper 980231-001Aerostar Aircraft PA-60-600, -601, -601P1999-02-18current
Precision Coil Spring COExtension Spring PC 257DAC PC 257McDonnell Douglas DC-10-10, -10F, -151996-02-19current
Precision Coil Spring COExtension Spring PC 272DAC PC 272McDonnell Douglas DC-9-11, -12, -131996-02-19current
Precision Coil Spring COExtension Spring PC 338DAC PC 338McDonnell Douglas MD-11F1996-02-19current
Precision Coil Spring COExtension Spring PC 256DAC PC 256McDonnell Douglas DC-10-10, -10F, -151996-02-19current

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.