FAR 91.851 — Noise Stage Definitions
FAR 91.851 defines key terms for Part 91 noise rules, including Stage 2, 3, 4, and 5 airplanes, contiguous U.S., and import requirements.
In Plain English
FAR 91.851 is the definitions section for the noise-limit rules in §§ 91.851 through 91.877. It doesn't impose operating limits itself — it tells you what the terms mean when you read the rest of Subpart I.
Key definitions include:
- Contiguous United States: the 48 states plus the District of Columbia.
- Subsonic airplane: civil subsonic jet (turbojet) airplanes over 75,000 lb maximum certificated weight listed on an operator's ops specs as eligible to operate in the contiguous U.S.
- Import: a change of ownership from a non-U.S. person to a U.S. person when the airplane is brought into the U.S. for operation.
- Operator: a person with enough indicia of ownership to register the airplane under Part 47.
- Stage 2 / Stage 3 airplane: a turbojet of 75,000 lb or more that meets the Stage 2 or Stage 3 noise levels in Part 36.
- Stage 4 / Stage 5 airplane: an airplane shown not to exceed the Stage 4 (or Stage 5) noise limit in Part 36; both comply with all Part 91 noise operating rules.
Why it matters: the noise stage of your airplane drives whether it can legally operate to or from airports in the contiguous U.S. under Subpart I.
Regulation Text
14 CFR § 91.851§ 91.851 Definitions.
For the purposes of §§ 91.851 through 91.877 of this subpart:
means a noise level at or below the maximum noise level prescribed in Chapter 4, Paragraph 4.4, Maximum Noise Levels, of the International Civil Aviation Organization (ICAO) Annex 16, Volume I, Amendment 7, effective March 21, 2002. The Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 approved the incorporation by reference of this document, which can be obtained from the International Civil Aviation Organization (ICAO), Document Sales Unit, 999 University Street, Montreal, Quebec H3C 5H7, Canada. Also, you may obtain documents on the Internet atCopies may be reviewed at the U.S. Department of Transportation, Docket Operations, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590 or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to:
means the area encompassed by the 48 contiguous United States and the District of Columbia.
means those civil subsonic jet (turbojet) airplanes with a maximum certificated weight of more than 75,000 pounds that are listed on an operator's operations specifications as eligible for operation in the contiguous United States.
means a change in ownership of an airplane from a non-U.S. person to a U.S. person when the airplane is brought into the United States for operation.
means an enumeration of airplanes by type, model, series, and serial number operated by the operator or foreign air carrier on a given day, regardless of how or whether such airplanes are formally listed or designated by the operator.
means any person that has indicia of ownership sufficient to register the airplane in the United States pursuant to part 47 of this chapter.
means an air carrier or foreign air carrier that, on or before November 5, 1990, did not conduct operations under part 121 or 129 of this chapter using an airplane covered by this subpart to or from any airport in the contiguous United States, but that initiates such operation after that date.
mean the requirements for Stage 2 noise levels as defined in part 36 of this chapter in effect on November 5, 1990.
mean the requirements for Stage 3 noise levels as defined in part 36 of this chapter in effect on November 5, 1990.
means a noise level at or below the Stage 4 noise limit prescribed in part 36 of this chapter.
means a civil subsonic jet (turbojet) airplane with a maximum certificated weight of 75,000 pounds or more that complies with Stage 2 noise levels as defined in part 36 of this chapter.
means a civil subsonic jet (turbojet) airplane with a maximum certificated weight of 75,000 pounds or more that complies with Stage 3 noise levels as defined in part 36 of this chapter.
means an airplane that has been shown not to exceed the Stage 4 noise limit prescribed in part 36 of this chapter. A Stage 4 airplane complies with all of the noise operating rules of this part.
means an airplane that has been shown not to exceed the Stage 5 noise limit prescribed in part 36 of this chapter. A Stage 5 airplane complies with all of the noise operating rules of this part.
means a noise level at or below the Stage 5 noise limit prescribed in part 36 of this chapter.
[Docket 26433, 56 FR 48658, Sept. 25, 1991, as amended by Amdt. 91-252, 61 FR 66185, Dec. 16, 1996; Amdt. 91-275, 67 FR 45237, July 8, 2002; Amdt. 91-288, 70 FR 38749, July 5, 2005; 72 FR 68475, Dec. 5, 2007; Docket FAA-2015-3782, Amdt. 91-349, 82 FR 46132, Oct. 4, 2017]
Oral Exam Questions a DPE Might Ask
Q1What's the difference between a Stage 3 and a Stage 4 airplane?
Per FAR 91.851, a Stage 3 airplane is a turbojet of 75,000 lb or more meeting Stage 3 noise levels in Part 36, while a Stage 4 airplane is one shown not to exceed the Stage 4 noise limit in Part 36 and complies with all Part 91 noise operating rules.
Q2What does 'contiguous United States' mean for the noise rules?
FAR 91.851 defines the contiguous United States as the area encompassed by the 48 contiguous states plus the District of Columbia.
Q3Under FAR 91.851, when is an airplane considered 'imported'?
FAR 91.851 defines an import as a change in ownership of an airplane from a non-U.S. person to a U.S. person when the airplane is brought into the United States for operation.
Studying for a checkride?
Related Sections in Part 91