AD 72-01-07

Airworthiness directive · Failure of Engine Mount · Piper PA-18, PA-18-105 (Special), PA-18-125 (Army L-21A) and 3 more

Effective
April 17, 1972
Published
April 11, 1972
Issued
April 5, 1972
Models
PA-18, PA-18-105 (Special), PA-18-125 (Army L-21A), PA-18-135, PA-18A, PA-18A-135
Data sheet
TCDS1A2
Registered aircraft
1,150 matched by model
Product
Aircraft · Small airplane
Amendment
39-1434

Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed November 21, 2025.

On this page

The airworthiness directive

72-01-07 PIPER: Amdt. 39-1369 as amended by Amendment 39-1434. Applies to Piper Model PA-18, PA-18-105, -125, -135, PA-18A, PA-18A-125, -135, and seaplane versions of those models which have been modified after May 14, 1968 in accordance with Supplemental Type Certificate SA 136 AL to incorporate the installation of the Lycoming O-320 engine (150 HP). Factory delivered models having serial numbers 18-3771 and 18-3781 and above, incorporating the O-320 engine, are not affected by this AD.

Compliance is required as indicated.

To prevent possible failure of the engine mount, within the next 25 hours' time in service after the effective date of this AD, unless already accomplished, install engine mount, P/N 12351- 12, in accordance with Piper Drawing Number 12351, Mount Assembly-engine, including Revision J dated January 16, 1968, or an equivalent approved by the Chief, Engineering and Manufacturing Branch of an FAA region (or in the case of the Western Region, the Chief,Aircraft Engineering Division).

NOTE: Engine mount assembly P/N 12351-12 may be identified by the gage of Tube "A" and Tube "B" which measure .049 inches, and by the incorporation of two reinforcing plates, number 14438, mounted at the lower right engine attachment points as shown on Piper Drawing Number 12351, Mount Assembly-Engine, including Revision J dated January 16, 1968.

Amendment 39-1369 became effective January 27, 1972.

This Amendment 39-1434 becomes effective April 17, 1972.

Affected TCDS · 1

The type certificate data sheets for the models this AD names, matched by model and maker.

Registered aircraft · 1,150

Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.

By aircraft maker
  • Piper1,147 aircraft
  • David B Piper1 aircraft
  • Piper-Coley1 aircraft
  • Piper-Root1 aircraft
By year built
19452021
Registered aircraft by year built: 897 aircraft
19451
19471
19499
1950111
1951122
195291
1953189
1954117
195543
195637
195757
195840
195935
196025
19613
19622
19631
19646
19651
19681
19712
19751
19771
20211

253 with no year recorded

By model

Aircraft

See all 1,150 aircraft