Legal Interpretations
Ziemer-SeaborneAirlines 2012
Summary
The Question
Does the cockpit voice recorder requirement in 14 CFR 121.359(i) for turbine engine-powered airplanes apply to a turbopropeller-powered DeHavilland DHC-6?
Background
Seaborne Airlines argued that its DHC-6 is excluded because the definitions in 14 CFR 121.358(d) separate out turbopropeller-powered airplanes, and "turbine engine-powered" is not defined in 14 CFR part 1.
The FAA’s Interpretation
Yes. In 14 CFR 121.359, "turbine engine-powered airplanes" simply distinguishes airplanes powered by any type of turbine engine from those with reciprocating engines, and the DHC-6's turbine engine powers a propeller. The definitions in 14 CFR 121.358(d) apply only for purposes of that windshear-equipment section, and the terminology of the two sections is not interchangeable.
- Requester
- Ziemer
- Organization
- SeaborneAirlines
- Issued
- July 25, 2012
- Subjects
- Air Carrier & Commercial Operations · Definitions
Regulations Cited
- 14 CFR Part 1
- 14 CFR 121.3
- 14 CFR 121.358
- 14 CFR 121.359
Page 1
U.S. Department
of Transportation
Federal Aviation
AdTinistration
David Ziemer, Chief Operating Officer
Seaborne Airlines
1210 Watergut
Christiansted, USVI 00820
Dear Mr. Ziemer,
This letter responds to your request for an interpretation of 14 CFR § 121.359(i) that you sent to FAA Deputy Chief Counsel Marc Warren on March 26, 2012.
Your request notes that §121.359(i) uses the phrase "all turbine engine-powered airplanes" in describing the applicability of the cockpit voice recorder requirements of that section. Your position is that the section should not apply to your airplane, a DeHavilland DHC-6, a "turbopropeller powered" airplane.
You indicate that the applicability of§ 121.359 "hinges on the definition of a "turbine engine powered" airplane," which is not defined in 14 CFR Part 1. You suggest that the definition in§ 121.358(d) should apply because it "does identify each category of engine described as "turbine engine-powered," as well as specifically eliminating "turbopropeller powered airplanes"" from its definition and therefore from applicability. We do not agree with your conclusion. First, the term "turbine engine powered airplanes" as used in §121.359 is intended as a simple delineator between airplanes that are powered by any type of turbine engine, versus those that have a reciprocating engine. Your DHC-6 has a turbine engine that powers a propeller; it is a turbine engine-powered aircraft and is subject to the requirements of §121.359(i).
Second, §121.358 addresses the requirements for low-altitude windshear system equipment. The distinction made in § 121.358 between the type of turbine engine airplanes described was done specifically for the described windshear equipment, in some cases by aircraft model. The paragraph you cite, § 121.358(d), states that the definitions therein are "for the purposes of this section." Accordingly, the definition does not apply to the term as used in any other regulatory section. Sections 121.358 and 121.359 address completely separate equipment systems and their terminology is not interchangeable.
Page 2
We trust that this information responds to your inquiry. If you need further assistance, please contact my staff at 202-267-3073. This response was prepared by Karen Petronis, Senior Attorney on my staff, and was coordinated with the Aircraft Maintenance Division of the Flight Standards Service.
Sincerely,
~#.~e~J--Assistant Chief Counsel for Regulations
Regulations Referenced
Snapshot retrieved August 6, 2026.