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Transponder “Within 10 miles of certain designated airports”

Asked by: 1142 views Airspace, FAA Regulations

AIM 4-1-20 says you need a transponder:

Within 10 miles of certain designated airports, excluding that airspace which is both outside the Class D surface area and below 1,200 feet AGL.

Where are these airports designated?  Does anyone know of some examples I can show a student?


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1 Answers

  1. Best Answer

    Russ Roslewski on Oct 06, 2016

    You’re going to love this.

    First, the paragraph you reference is AIM 4-1-20 (f)(2)(d). If you go to the top of that section, paragraph (f)(1), you see that it states:

    1. Specific details concerning requirements to
    carry and operate Mode C transponders, as well as
    exceptions and ATC authorized deviations from the
    requirements are found in 14 CFR Section 91.215 and
    14 CFR Section 99.12.

    Looking in 91.215, paragraph (b)(5)(ii) has similar wording to the AIM:

    [Transponders must be used:]
    (ii) In the airspace from the surface to 10,000 feet MSL within a 10-nautical-mile radius of any airport listed in appendix D, section 2 of this part, excluding the airspace below 1,200 feet outside of the lateral boundaries of the surface area of the airspace designated for that airport.

    So we go to Part 91, Appendix D, Section 2, and it consists of this amazing tidbit:

    “Section 2. Airports at which the requirements of §91.215(b)(5)(ii) apply. [Reserved]”

    So, there are no airports currently established where this rule applies. But that’s where you’d find them if there were!

    +7 Votes Thumb up 7 Votes Thumb down 0 Votes

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