Excerpt from FAR Part 91.213

 

(d)Except for operations conducted in accordance with paragraph (a) or (c) of this section, a person may takeoff an aircraft in operations conducted under this part with inoperative instruments and equipment without a minimum equipment list provided-

 

(2) The inoperative instruments and equipment are not-

(i)Part of the VFR-day type certification instruments and equipment prescribed in the applicable airworthiness regulations under which the aircraft was type certificated;

 

Aircraft to which this S,T.C. is applicable were certified under CAR 3

 

Below is the part of CAR 3 that covers flap position indicators showing that the flap position indicator is a required instrument.

 

3.353-1          WING FLAP POSITION INDICATORS .  (CAA policies which apply to section 3.353).

 

(a)                GENERAL.  The following policies will govern the Civil Aeronautics Administration in determining circumstances under which a wing flap position indicator is required.

 

(1)                 FLAP INSTALLATIONS INCORPORATING ONLY THE FULLY EXTENDED AND FULLY RETRACTED POSITIONS.

 

An indicator is required except:

 

(i)                   Where a direct operating mechanism provides a sense of feel and position such as when a mechanical linkage is employed,

or,

 

(ii)                 where the flap positoin is readily determined without seriously detracting from other piloting duties under all conditions of flight, either day or night.

 

(2)                 FLAP INSTALLATIONS INCORPORATING AN INTERMEDIATE FLAP POSITION.

 

An indicator is required except when the installation complies with item (1) (i), above.