mode C requirement and "engine driven electrical system"

Discussion in 'Instruments / Avionics / Electrical System' started by Dana, Feb 8, 2017.

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  1. Feb 8, 2017 #1

    Dana

    Dana

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    We all know that Mode C (and soon, ADS out) is required in certain airspace, except:

    So what does "subsequently certified" actually mean? Obviously, an aircraft that has an electrical system when the airworthiness certificate was first issued ("certificated") is not exempt, and you can't remove it later to become exempt, but what about an aircraft that has an engine driven alternator added later. Is it "certified" again? It would be if it's a standard aircraft (e.g. a no electric Piper Cub) and you install new engine with an alternator under an STC, but you don't need an STC to make a change to a homebuilt. Or is it "subsequently certified" when the A&P doing the condition inspection writes in the logbook, "I certify that this aircraft has been inspected..."?

    Dana
     
  2. Feb 8, 2017 #2

    BBerson

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    Certificated and certify are not defined in FAR 1, Definitions.
    Type is defined.
     
  3. Feb 8, 2017 #3

    Victor Bravo

    Victor Bravo

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    This question will apply to me pretty soon. I bought an E-LSA aircraft that had originally been "Certified" (experimental) with a Rotax 2 stroke that did not have a generator/alternator. So it would have been able to fly legally without the TXP.

    Then I come along and buy the airplane, remove the Rotax, and install a different engine which does have an alternator. The aircraft will soon have an annual condition inspection, but this is not an aircraft type certification.

    If I were being a Boy Scout and following the rules perfectly, I would have to go back and do some flight testing after installing the new engine. But this also does not represent a new certification, and it's definitely not the original certification.

    Interested to hear what the FAA interpretation would be on this. Might save me a couple of grand :)
     
  4. Feb 8, 2017 #4

    davidb

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    I'm guessing this would be considered a major modification and would require notifying the FAA. They could then require the flight testing hours again. Not sure if they reissue a new airworthiness certificate in that process, but if they do, that might be the "subsequently been certified" gotcha.

    I'd bet the intent is if you now have the engine driven electrical system, you now need the mode C. However, operationally I can't see how this would be enforced nor how they would penalize you should you be caught other than tell you not to enter said airspace again until you install the mode C.
     
  5. Feb 8, 2017 #5

    Marc Zeitlin

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    I have no idea what "subsequently certified" might mean in the context of a Type Certificated aircraft, but for EAB aircraft, some Operating Limitations stated that if a major change was performed per 14 CFR Part 21.93 (and an engine swap to a different engine is most certainly in that category), the Airworthiness Certificate was invalidated and a new inspection by the FAA or a DAR was required, with a new AC being issued at the time. For EAB aircraft, that would be "subsequently certificated".

    Now, at this point, most EAB L's do NOT state that - they generally say that the plane must be put back into Phase I for a minimum of 5 hours, with the test area being approved by the geographically responsible FSDO. But SOME older OL's still state that the AC is invalid.

    I do not know if the rules are the same for ELSA's, or ever were - since ELSA's didn't come into being until after 2004 and the OL's I'm referencing were from the 70's and 80's, my assumption would be there is no requirement for "subsequent certification" for ELSA's.

    HOWEVER, I would expect that if your aircraft is now an EAB aircraft, your OL's will require a new Phase I period after an engine swap, which is almost by definition a major change per 21.93. But since there are at least three types of ELSA's, and you didn't say which yours was, I don't know if this applies.

    And if I had to guess, whether or not an engine driven electrical system was on an EAB or ELSA plane when the AC was issued, if there's one on it now and a ramp check occurred, with no transponder or ADS-B (after 1/1/2020) in the plane, you'd get written up. But that's just my guess.
     
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  6. Feb 8, 2017 #6

    bmcj

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    Excellent question Dana. I don't know the answer, but it prompts an outgrowth from that question... If, let's say (correctly or incorrectly), that the Champ was originally certified without electrical, but if they certified later models of the Champ with electrical, does the "subsequent" phrase retroactively apply to ALL Champs?
     
  7. Feb 8, 2017 #7

    Dana

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    That, at least, I can answer. It applies to THAT aircraft, regardless of how other examples were certified, so no.

    Dana
     
  8. Feb 9, 2017 #8

    lr27

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    Can one use some sort of non-certified ADS-B out on an experimental plane, or does it all have to be certified? I know that there's a very small and light one available for UAV's but, judging by the expense, it must be certified.
     
  9. Feb 9, 2017 #9

    BBerson

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    Probably needs to comply with FCC rules, as any transmitter.
     
  10. Feb 9, 2017 #10

    Dana

    Dana

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    The issue a new AWC if the operating limitations say that any major change invalidates it. The old op limitations for my Fisher said that. I got new op limitations (and new AWC) that don't have that language. The main reason I wanted new limitations was to change the test area to my part of the country, and get the new language that removes the congested area prohibition.

    If you replace an engine with a new one of the same power and weight, I don't think that needs to be considered a "major change", since it doesn't affect the aircraft's performance or handling.

    There is no issue with removing a transponder and/or electrical system, as long as you stay out of airspace requiring the transponder. If you then go into such airspace, it's a violation of the appropriate Part 91 regulation, dealt with in the normal manner.


    The coming ADS requirement is for the same airspace as the current Mode C requirement, correct? Only in class A, B, or C, or in the Mode C veil around the larger B's? I have no need to enter A, B, or C, but the mode C veil could be an issue.

    Dana
     
  11. Feb 9, 2017 #11

    Turd Ferguson

    Turd Ferguson

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    The reg says the equipment has to meet performance requirements of TSO-C166b and TSO-C154c.
     
  12. Feb 9, 2017 #12

    Turd Ferguson

    Turd Ferguson

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    In certificated aircraft, sometimes several engines are specified for a single model in the specifications and changing from one to the other is just an entry in the records.

    For an experimental, if the plane is licensed with an O-320 series, then I would say any O-320 series will suffice and changing from one to the other is not a major change.
     

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