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

SE81WE

Installation of two Rajay turbo- chargers, Model 325EF80, P/N 0330-1 and -2, and 9 lb. +- 1 lb. sonic nozzle on Lycoming engine Model IO-540-S1A5. Held by Aerostar Aircraft Corporation, which holds 12 approved modifications in all. Last revised April 11, 1978. System: engine.

What it applies to

Kind of product
Engine
Design holder
Textron Lycoming AVCO Corporation
Models
IO-540-S1A5
Type certificate
1E4
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 7, 2026.