Skip to Content

Proposed Rule

Airworthiness Criteria: Glider Design Criteria for Stemme AG Model Stemme S12 Powered Glider

Document Details

Information about this document as published in the Federal Register.

Enhanced Content

Relevant information about this document from provides additional context. This information is not part of the official Federal Register document.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble


Federal Aviation Administration (FAA), DOT.


Notice of proposed design criteria.


This notice announces the availability of and requests comments on the proposed design criteria for the Stemme AG model Stemme S12 powered glider. The Administrator finds the proposed design criteria, which make up the certification basis for the Stemme S12, acceptable.These final design criteria will be published in the Federal Register.


Comments must be received on or before December 30, 2016.


Send comments identified by docket number FAA-2016-9452 using any of the following methods:

  • Federal eRegulations Portal: Go to and follow the online instructions for sending your comments electronically.
  • Mail: Send comments to Docket Operations, M-30, U.S. Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room W12-140, West Building Ground Floor, Washington, DC 20590-0001.
  • Hand Delivery of Courier: Take comments to Docket Operations in Room W12-140 of the West Building Ground Floor at 1200 New Jersey Avenue SE., Washington, DC, between 9 a.m., and 5 p.m., Monday through Friday, except Federal holidays.
  • Fax: Fax comments to Docket Operations at 202-493-2251.

Privacy: The FAA will post all comments it receives, without change, to, including any personal information the commenter provides. Using the search function of the docket Web site, anyone can find and read the electronic form of all comments received into any FAA docket, including the name of the individual sending the comment (or signing the comment for an association, business, labor union, etc.). DOT's complete Privacy Act Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478), as well as at

Docket: Background documents or comments received may be read at at any time. Follow the online instructions for accessing the docket or go to the Docket Operations in Room W12-140 of the West Building Ground Floor at 1200 New Jersey Avenue SE., Washington, DC, between 9 a.m., and 5 p.m., Monday through Friday, except Federal holidays.

Start Further Info


Mr. Jim Rutherford, Federal Aviation Administration, Small Airplane Directorate, Aircraft Certification Service, 901 Locust, Room 301, Kansas City, MO 64106, telephone (816) 329-4165, facsimile (816) 329-4090.

End Further Info End Preamble Start Supplemental Information


Comments Invited

We invite interested people to take part in this rulemaking by sending written comments, data, or views. The most helpful comments reference a specific portion of the design criteria, explain the reason for any recommended change, and include supporting data. We ask that you send us two copies of written comments.

We will consider all comments received on or before the closing date for comments. We will consider comments filed late if it is possible to do so without incurring expense or delay. We may change these airworthiness design criteria based on received comments.


On January 08, 2016, Stemme AG submitted an application for type validation of the Stemme S12 in accordance with the Technical Implementation Procedures for Airworthiness and Environmental Certification Between the FAA and the European Aviation Safety Agency (EASA), Revision 5, dated September 15, 2015. The Stemme S12 is a two-seat, self-launching, powered glider with a liquid cooled, turbocharged engine mounted in the center fuselage, an indirect drive shaft, and a fully-foldable, variable-pitch composite propeller in the nose. It is constructed from glass and carbon fiber reinforced composites, features a conventional T-type tailplane, and has a retractable main landing gear. The glider has a maximum weight of 1,984 pounds (900 kilograms) and may be equipped with an optional dual-axis autopilot system. EASA type certificated the Stemme S12 under Type Certificate Number (No.) EASA.A.054 on March 11, 2016. The associated EASA Type Certificate Data Sheet (TCDS) No. EASA.A.054 defined the certification basis Stemme AG submitted to the FAA for review and acceptance.

The applicable requirements for glider certification in the United States can be Start Printed Page 86297found in FAA Advisory Circular (AC) 21.17-2A, “Type Certification—Fixed-Wing Gliders (Sailplanes), Including Powered Gliders,” dated February 10, 1993. AC 21.17-2A has been the basis for certification of gliders and powered gliders in the United States for many years. AC 21.17-2A states that applicants may utilize the Joint Aviation Requirements (JAR)-22, “Sailplanes and Powered Sailplanes”, or another accepted airworthiness criteria, or a combination of both, as the accepted means for showing compliance for glider type certification.

Type Certification Basis

The applicant proposed a Certification Basis based on EASA Certification Specification (CS)-22, “Sailplanes and Powered Sailplanes”, initial issue, dated November 14, 2003. In addition to CS-22 requirements, the applicant proposed to comply with other requirements from the certification basis referenced in EASA TCDS No. EASA.A.054, including special conditions and equivalent safety findings.

The Proposed Design Criteria

Applicable Airworthiness Criteria under § 21.17(b).

Based on the Special Class provisions of § 21.17(b), the following airworthiness requirements form the FAA Certification Basis for this design:

1. 14 CFR part 21, effective February 1, 1965, including amendments 21-1 through 21-93 as applicable.

2. EASA CS-22, initial issue, dated November 14, 2003.

3. EASA Special Condition No. SC-A.22.1.01, “Increase in maximum mass for sailplanes and powered sailplanes.”

4. “Preliminary Standard for the Substantiation of Indirect Drive Shafts in Power Plants of Powered Sailplanes Certified to JAR-22” (with a modification for the Stemme AG model Stemme S 10), Luftfahrt-Bundesamt (LBA) document number (no.) I231-87, issued August 05, 1988.

5. Installation of a Dual-Axis Autopilot System, including—

  • EASA CS-VLA (Very Light Aeroplanes) 1309, “Equipment, systems, and installations”; initial issue, dated November 14, 2003; and
  • EASA CS-23.1329, “Automatic pilot system”, amendment 3, dated July 20, 2012.

6. Drop Testing for Retractable Landing Gear (EASA equivalent safety findings) to include CS-VLA 725, “Limit drop tests”; CS-VLA 726, “Ground load dynamic tests”; and CS-VLA 727, “Reserve energy absorption”; initial issue dated November 14, 2003.

7. “Standards for Structural Substantiation of Sailplane and Powered Sailplane Parts Consisting of Glass or Carbon Fiber Reinforced Plastics”, LBA document no. I4-FVK/91, issued July 1991.

8. “Guideline for the analysis of the electrical system for powered sailplanes”, LBA document no. I334-MS 92, issued September 15, 1992.

9. The following kinds of operation are allowed: VFR-Day.

10. Date of application for FAA Type Certificate: January 08, 2016.

Start Signature

Issued in Kansas City, Missouri on November 18, 2016.

Mel Johnson,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.

End Signature End Supplemental Information

[FR Doc. 2016-28575 Filed 11-29-16; 8:45 am]