SA3-111

Removed 18 from the outboard end of each wing. Removed the first rib inboard of bow, and also the bow. Manufactured from .032 24ST al. Alloy sheet, a full size rib, installed on wing in place of the rib removed. Manufactured skin from .025 24ST and installed on wing, fastened to the first and second rib with #4 sheet metal screws. Three 4 lightning holes were cut in the new rib for inspection purposes and 8-32 nutplates were riveted to inside of rib for attaching of tip plate. The outboard ends of the ailerons were modified to conform to the chord length of the wing. The completed assembly is fabric covered upon covering of wing. The material for the Tip Plate is Prestwood T. and protrudes in a chordwise manner 1-3/4 . Held by Forrest Alan Frazier. Last revised January 12, 2007. System: airframe structure.

What it applies to

Kind of product: Aircraft
Design holder: Piper Aircraft Inc.
Models: J3C-65 (Army L-4; L-4A; L-4B (Navy NE-1); L-4H; L-4J (Navy NE-2))
Type certificate: A-691
On this site: Piper J-3 Cub 3,804 registered
The FAA's record: On the FAA's site

What an approved modification is

A supplemental type certificate is the FAA's approval of a change to a certified design: a new engine or propeller, avionics, an autopilot, floats, a parachute, a larger fuel tank, an ice-protection kit. The company holding it may sell the kit and the paperwork to owners of the listed models; the modification then becomes part of that aircraft's record. The FAA's list says what was approved and for which models, not how many aircraft carry it.

Source: FAA supplemental type certificates (Dynamic Regulatory System). Register counts from the FAA register of October 20, 2026.