The U.S. aircraft register, updated daily
Approved modifications · supplemental type certificate · current · reissued

SE02051AK

Grind nitrided high compression cylinder barrels to plus 0.010 overside and install P10 piston, P10 compression rings, and P10 oil rings. Held by Custom Aircraft INC, which holds 2 approved modifications in all. Last revised June 6, 2012. System: engine.

What it applies to

Kind of product
Engine
Design holder
Textron Lycoming AVCO Corporation; Textron Lycoming AVCO Corporation; Textron Lycoming AVCO Corporation
Models
O-540-J3A5D, O-540-J1A5D, O-540-J3C5D
Type certificates
E-295, E-295, E-295
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 21, 2026.