Part 125 Noise Rules

FAR 91.803 Part 125 Noise Rules

FAR 91.803 designates which Subpart I noise regulations apply to Part 125 airplane operators based on aircraft type and operational history.

In Plain English

FAR 91.803 tells Part 125 airplane operators which noise limit regulations in Subpart I of Part 91 they must follow. The rule sorts operations into categories based on whether the airplane was already covered by these noise rules before November 29, 1980.

  • Already covered before Nov 29, 1980: The same Subpart I requirements that applied before that date continue to apply.
  • Subsonic airplanes not previously covered (because they weren't operated in the U.S. under Part 91, 121, 129, or 135): The operator must comply with § 91.805.
  • Supersonic airplanes not previously covered: The operator must comply with §§ 91.819 and 91.821.
  • Deviations: If a Part 125 airplane is approved to operate under Part 91, 121, 129, or 135 instead, the noise requirements above still apply.

Why it matters: This section ensures that large airplanes flown under Part 125 meet the appropriate noise standards, regardless of how the aircraft is currently being operated under a deviation.

Regulation Text
14 CFR § 91.803
§ 91.803 Part 125 operators: Designation of applicable regulations. For airplanes covered by this subpart and operated under part 125 of this chapter, the following regulations apply as specified: (a) For each airplane operation to which requirements prescribed under this subpart applied before November 29, 1980, those requirements of this subpart continue to apply. (b) For each subsonic airplane operation to which requirements prescribed under this subpart did not apply before November 29, 1980, because the airplane was not operated in the United States under this part or part 121, 129, or 135 of this chapter, the requirements prescribed under § 91.805 of this subpart apply. (c) For each supersonic airplane operation to which requirements prescribed under this subpart did not apply before November 29, 1980, because the airplane was not operated in the United States under this part or part 121, 129, or 135 of this chapter, the requirements of §§ 91.819 and 91.821 of this subpart apply. (d) For each airplane required to operate under part 125 for which a deviation under that part is approved to operate, in whole or in part, under this part or part 121, 129, or 135 of this chapter, notwithstanding the approval, the requirements prescribed under paragraphs (a), (b), and (c) of this section continue to apply. [Docket 18334, 54 FR 34321, Aug. 18, 1989, as amended by Amdt. 91-276, 67 FR 46571, July 15, 2002]
Oral Exam Questions a DPE Might Ask
Q1Which noise regulations apply to a subsonic airplane operated under Part 125 that was not previously operated in the U.S. under Part 91, 121, 129, or 135 before November 29, 1980?
Per FAR 91.803(b), the requirements of § 91.805 apply to that subsonic airplane operation.
Q2If a Part 125 operator receives a deviation to operate under Part 91 instead, do the Subpart I noise requirements still apply?
Yes. FAR 91.803(d) states that, notwithstanding the deviation approval, the requirements in paragraphs (a), (b), and (c) of § 91.803 continue to apply.
Q3What sections govern a supersonic airplane operation under Part 125 that wasn't previously covered by Subpart I before November 29, 1980?
Under FAR 91.803(c), §§ 91.819 and 91.821 apply to that supersonic airplane operation.
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FAR 91.803 — Part 125 Operators Noise Rules