(a)  
When an obstruction clearance limit (OCL) is specified, the authorized MDA(H) or DA(H) is the sum of the OCL and the touchdown zone elevation (TDZE).  If the TDZE for a particular runway is not available, threshold elevation shall be used.  If threshold elevation is not available, airport elevation shall be used.  For approaches other than ILS, MLS, or GLS, the MDA(H) may be rounded to the next higher 10-foot increment.

(b)
When an obstacle clearance altitude (OCA)/obstacle clearance height (OCH) is specified, the authorized MDA(H) or DA(H) is equal to the OCA/OCH.  For approaches other than ILS, MLS, or GLS, the authorized MDA(H) may be expressed in intervals of 10 feet.

(c)  
The HAT or HAA used for precision approaches shall not be below those specified in subparagraph a of this operations specification.

(3)
When only an OCL or an OCA/OCH is specified, visibility and/or RVR minimums appropriate to the authorized HAA/HAT values determined in accordance with subparagraph b(2) above will be established in accordance with criteria prescribed by U.S. TERPS or Joint Aviation Authorities, Joint Aviation Requirements, operational agreements, Part 1 (JAR-OPS-1).

(4)
When conducting an instrument approach procedure outside the United States, the certificate holder shall not operate an aircraft below the prescribed MDA(H) or continue an approach below the DA(H), unless the aircraft is in a position from which a normal approach to the runway of intended landing can be made and at least one of the following visual references is clearly visible to the pilot:

(a)  
Runway, runway markings, or runway lights.

(b)
Approach light system (in accordance with 14 CFR section 91.175(c)(3)(i)).

(c)  
Threshold, threshold markings, or threshold lights.

(d)
Touchdown zone, touchdown zone markings, or touchdown zone lights.