Inop flap indicator

Jim Logajan

Administrator
Staff member
The flap indicator on our C-150 is inop, though the flaps themselves work fine. What little secondary info I could find suggests that an inop indicator makes the plane un-airworthy, while ironically if the flaps themselves were inop a simple placarding would maintain the plane's airworthiness. Anyone have any guidance as to the plane's airworthiness?
 
Are the flaps and indicator on the aircraft's equipment list? Probably not. According to the bold method that means you can't fly without them.

 
Are the flaps and indicator on the aircraft's equipment list? Probably not. According to the bold method that means you can't fly without them.

Their argument rests on flaps being secondary control surfaces rather than "instruments and equipment".
And that seems reasonable since the article dealt only with the actual flaps. But in this scenario the flaps work, only the flap position indicator is inop. The flap position indicator itself is an instrument and not a control per the FAA definition:

"Instrument means a device using an internal mechanism to show visually or aurally the attitude, altitude, or operation of an aircraft or aircraft part. It includes electronic devices for automatically controlling an aircraft in flight."
 
An inop flap indicator could be considered hazardously misleading informations, which is normally a big no-no.

The counter argument is that the pilot can visually see the position of the flaps in a cessna 150, right?... and probably shouldn't rely solely on the flap indicator anyway. I don't think I paid much attention to the flap indicator in any of the 172s I flew. I always looked at the flaps.

yeah, I know, I'm no help.
 
"Instrument means a device using an internal mechanism to show visually or aurally the attitude, altitude, or operation of an aircraft or aircraft part. It includes electronic devices for automatically controlling an aircraft in flight."
Is the flap indicator listed as equipment in the aircraft's type certificate or equipment list? I imagine it likely is. If so, it strikes me you can inop it.

Nonetheless, I think I would like to getting it fixed, for the reason which Bob mentions.
 
Anyone have any guidance as to the plane's airworthiness?

Are the flaps and indicator on the aircraft's equipment list? Probably not. According to the bold method that means you can't fly without them.
Interesting points, but I don’t think I would consider Bold an authoritative source. Without getting into that discussion, here’s my take on how I would deal with the 150.

Per 91.213(d) I would check to see if the indicator is required under (d)(2). I don’t see it listed under 91.205. I can’t find it required per any aircraft equipment list or KOL list. And no ADs are evident. So per the 213(d) guidance I would determine it does not constitute a hazard and placard it INOP with a corresponding log entry. And given it requires no maintenance a pilot could accomplish this as well.

Now if this were a flap issue then it would be different. If you needed to fly with flaps stuck in the up position, I would recommend a special flight permit to get it home. While it might appear you could use 91.213(d) since the POH gives the option to operate with no flaps, I’ll bet a nickel there would be one or more emergency procedures you could not perform without the use of some flaps, i.e., create a hazard. This is all provided you wanted to remain legal.

As to items not listed on the aircraft equipment list I have no clue where Bold or the “FSDO” got that from. The aircraft equipment list is strictly a certification requirement to certify the aircraft empty weight. I do have a hunch that they were actually discussing Minimum Equipment Lists (MELs) which if the “equipment” is not listed on that specific list then there is no option to defer.

And to add, the aircraft equipment list is not even technically a maintenance record per 91.417. Plus the fact for some mechanics to include me, we will create/update a new aircraft equipment list every time we reweigh for a new certified empty weight and balance record. If it were a control document as mentioned by Bold where is the guidance to maintain that document?

There’s more to this topic but I think the above covers the high points.
 
The Cessna 150 was type certificated under CAR rules so a minimum equipment list would not likely exist (and I have searched.)
 
Aren't minimum equipment lists (MELs) normally put together by an operator that wants to have one for the plane? The question which I think the Bold Method people were driving at was the list of equipment and instruments listed in the original type certificate or STCs.
 
The Cessna 150 was type certificated under CAR rules so a minimum equipment list would not likely exist

Aren't minimum equipment lists (MELs) normally put together by an operator that wants to have one for the plane?
Perhaps we should clarify our terms. From the regulatory side when the term Minimum Equipment List is used it refers to an optional, FAA-approved operations document per 91.213 and is technically available to any aircraft regardless if certified under the CARs or FARs.

The aircraft equipment list (or list of equipment) I mentioned above is a support document to the certified empty weight (EW) and required during the aircraft certification process. Below is a reference to it on a 150 TCDS. Since the EW is a condition of type certification, every aircraft must have a current signed EW along with its supporting equipment list on board. However, in my experience you'll find 50%+ of aircraft have outdated EW equipment lists which is one of the top 5 favorites for a ramp check.

However, there can be some confusion as Cessna and other OEMs also use this same EW equipment list to indicate what equipment was required (R) or is standard (S) or is optional (O) and its status to be installed on that particular aircraft. So some people think this makes it a “minimum” equipment list which it is not.

Now if you really wanted to apply for a 91.213 Minimum Equipment List or MEL for your 150, you will need to first review the FAA Master Minimum Equip List (MMEL) applicable to your aircraft. Then start the approval process with your local FSDO. However, I highly recommend against this as it will create way more problem for you than help.

150 TCDS
1693425846662.png
 
Appreciate the clarifications re MEL. I think my original question was answered with the considered opinion "So per the 213(d) guidance I would determine it does not constitute a hazard and placard it INOP with a corresponding log entry. And given it requires no maintenance a pilot could accomplish this as well."

The Wikipedia entry, https://en.wikipedia.org/wiki/Master_minimum_equipment_list has this claim:
A minimum equipment list is required in the United States by the Federal Aviation Administration:[3]
  • When operating any turbine-powered aircraft such as jets or turboprops.
  • When operating under part 135 (Commuter and on-demand operations)
  • When operating under part 125 (Non-airline large aircraft operations)
Their supporting link is no longer valid.
 
has this claim:
Technically, an MEL program is not mandatory for any operation or aircraft. HOWEVER, if one wishes to fly with inoperative equipment, certain aircraft and operations only have one option -- an approved MEL program. No (d)(2) exemption possible. And those certain aircraft/ops include the list you provided.
 
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