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Supplemental Type CertificatesSupplemental Type Certificates

Guide to Supplemental Type Certificates

Table of Contents

Part 1: Obtaining an STC Certificate

Advisory Circular 21-40: Application Guide for Obtaining a Supplemental Type Certificate, May 6, 1998
This AC is intended as a certification guide and checklist for obtaining a supplemental type certificate (STC). It describes procedures for typical modification projects. Unusual or complex projects may require deviations from these procedures. Early and frequent coordination with the FAA is critical on all projects.

Part 2: FAA Certification for General Aviation Alterations

Advisory Circular 21.101-1: Establishing the Certification Basis of Changed Aeronautical Products, April 28, 2003
This AC provides guidance for establishing the certification basis for changed aeronautical products and identifying the conditions under which it will be necessary to apply for a new type certificate.

Advisory Circular 23-24: Airworthiness Compliance Checklists for Common Part 23 Supplemental Type Certificate (STC) Projects, August 24, 2005
This AC provides information to create compliance checklists for some common Title 14 of the Code of Federal Regulations (14 CFR) part 23 Supplemental Type Certificate (STC) projects. These checklists may be used to fulfill some of the requirements for a Certification Plan for STC projects. The standard compliance checklist provided with this AC shows typical methods of compliance with the regulations and provides a cross-reference to other related guidance material. Guidance specific to STCs for autopilot, engine, propeller, auxiliary fuel tank, and gross weight changes is included in sections 12 through 19 of this AC. The checklists created using the information in this AC complement the guidance in the Guides for Certification of Part 23 Airplanes (ACs 23-8B, 23-16A, 23-17B, and 23-19A) and other more project-specific guidance.

Part 3: STC Database

FAA's Supplemental Type Certificate Database
This database is a repository of approved STCs. Within each view, you can sort many of the columns by clicking on the double arrow to the right of the column heading. You can find a copy of the STC certificate under the section titled "Full Text of STC." If a full-text STC document is not listed, contact the responsible Aircraft Certification Office to request a copy.

Part 4: Selected STC-related articles from AOPA Pilot and AOPA Flight Training

Note: Dozens of additional relevant articles can be accessed at At the search box, click on ”Go," click “Advanced Search”, check "Pilot magazine" and/or “Flight Training Magazine Articles” and type "STC" in the search box, then press the search button

The Skylane Mod Market
There are 577 STCs in the FAA registry for Cessna's 182
By Steven W. Ells
AOPA Pilot, December 2000

The pilot who had chosen the 182 as his one and only airplane actually could have many airplanes. This is because of the amazing number of FAA-approved modifications — supplemental type certificates (STCs) that have been developed for owners and operators by maintenance facilities and modification shops.

A Gathering of Parts
You Can Still Buy a New PA-18, but Not from Piper
By Alton K. Marsh
AOPA Pilot, October 2000

The new name Top Cub is appropriate, since the aircraft far outperforms the highly popular Super Cub. Over the years there have been nearly 100 modifications approved by the FAA for the PA-18. Of those, Cub Crafters owns more than 30 STCs, and even has approval to make some of the aircraft's parts.

AOPA Millennium Mooney 2000 Sweepstakes
By Marc E. Cook
AOPA Pilot, June 2000

The Mod Works STC for the VM1000 system calls for using VMI's capacitance gauges. We didn't have the option of complying with just part of the STC; it's all or nothing where the feds are concerned.

Cessna T206H Stationair: Two-Faced 206
A bush airplane that pampers you with luxury and cruises at 175 knots
By Peter A. Bedell
AOPA Pilot, June 2000

Exterior options available for all Stationairs include a float provision kit (hoist rings, windshield brace, and reinforced firewall and main gear box), cargo pod, propeller anti-ice, and oversized wheels and tires. Floats are available via STC from Wipaire. On the interior, leather seats or a utility vinyl interior can be had. For the panel, an HSI, ADF, IFR GPS, and two-axis autopilot with electric trim can be installed. In addition to options available from the factory, the availability of several aftermarket STCs is an attractive advantage of buying a Cessna. One STC likely to be popular is the installation of auxiliary fuel tanks to supply that thirsty Lycoming and raise the airplane's useful load.

Waypoints: Flight to the Factory
By Thomas B. Haines
AOPA Pilot, November 1999

S-Tec currently has more than 1,600 supplemental type certificates (STCs) to install its systems in various aircraft and is adding more at the rate of about five a month.

Aero SUV 1999 Sweepstakes: Persuasion of Power
A new Continental Platinum engine heads up our firewall-forward rejuvenation
By Marc E. Cook
AOPA Pilot, October 1999

Modifying airplanes to accept different or more powerful engines has become a big part of the general aviation aftermarket. With the carrot of extra power or more modern-specification engines dangling over their heads, more aircraft owners are yanking out old reliable for something a bit — or, in some cases, a lot — different from what mother manufacturer put there in the first place.

Ultimate Arrow: Finishing Touches
Adding a Modern Flair to a 1970s Airframe
By Peter A. Bedell
AOPA Pilot, October 1997

After refurbishing everything ahead of the fire wall, installing a new instrument panel, and adding a plethora of lighting and aerodynamic speed modifications, it was finally time to put a new cosmetic shell on our 1997 Sweepstakes Piper Arrow.

Used Airplane Review: Twin Comanche
Speed, economy, style — and a few warnings
By Thomas A. Horne
AOPA Pilot, May 1996

Discusses the development of the airplane from early models through the 1970s and includes STC modifications.

Better Than New 172: Upping the Horsepower Ante
By Thomas B. Haines
AOPA Pilot, May 1994

A number of companies can perform engine upgrades for Cessna 172s. One of the most prolific is Air Plains Services of Wellington, Kansas. In the 12 years it has owned the supplemental type certificate to replace the stock Lycomings in post-1967 172s with 180-hp O-360 engines, the company has completed some 500 deliveries, according to Darrin Jacobs, general manager. Penn Yan Aero Services of Penn Yan, New York, is another company that owns a similar STC.

A Swifter Centurion
Adding sizzle to Cessna's sedan
By Mark R. Twombly
AOPA Pilot, November 1992

Atlantic Aero, in Greensboro, North Carolina, has been granted a supplemental type certificate to replace the 210's stock 520 with a 550. The first conversion was performed on 78M. Atlantic Aero has since done several more. Atlantic calls its re-engined 210 the 550 Centurion. The STC also includes new Lord engine mounts, a new McCauley Black Mac propeller, Precise Flight speed brakes, new metal instrument panel, and re-marked fuel-flow gauge and tachometer. The STC covers normally aspirated Cessna 210K through N models produced from 1970 through 1984.

Updated Wednesday, January 11, 2006 10:58:07 AM