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

SA3797WE

Installation of Elano P/N099001-063 F, or later FAA approved revision, muffler in lieu of original Avcon muffler. (170B LANDPLANE ONLY NORMAL CATEGORY). Held by Del-Air, which holds 43 approved modifications in all. Last revised March 15, 1993. System: other and general.

What it applies to

Kind of product
Aircraft
Design holder
The Cessna Aircraft Company; The Cessna Aircraft Company
Models
170A, 170B
Type certificates
A-799, A-799
On this site
Cessna 170 2,085 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 7, 2026.