Except in an emergency, or if otherwise necessary for safety of flight, or unless otherwise authorized by the responsible Flight Standards Office for a purpose listed in § 93.309, no person may operate an aircraft in the Special Flight Rules Area at an altitude lower than the following:

(a) Minimum sector altitudes—(1) Commercial air tours—(i) Marble Canyon Sector. Lees Ferry to Boundary Ridge: 6,000 feet MSL.

(ii) Supai Sector. Boundary Ridge to Supai Point: 7,500 feet MSL.

(iii) Diamond Creek Sector. Supai Point to Diamond Creek: 6,500 feet MSL.

(iv) Pearce Ferry Sector. Diamond Creek to the Grand Wash Cliffs: 5,000 feet MSL.

(2) Transient and general aviation operations—(i) Marble Canyon Sector. Lees Ferry to Boundary Ridge: 8,000 feet MSL.

(ii) Supai Sector. Boundary Ridge to Supai Point: 10,000 feet MSL.

(iii) Diamond Creek Sector. Supai Point to Diamond Creek: 9,000 feet MSL.

(iv) Pearce Ferry Sector. Diamond Creek to the Grand Wash Cliffs: 8,000 feet MSL.

(b) Minimum corridor altitudes—(1) Commercial air tours—(i) Zuni Point Corridors. 7,500 feet MSL.

(ii) Dragon Corridor. 7,500 feet MSL.

(2) Transient and general aviation operations—(i) Zuni Point Corridor. 10,500 feet MSL.

(ii) Dragon Corridor. 10,500 feet MSL.

(iii) Tuckup Corridor. 10,500 feet MSL.

(iv) Fossil Canyon Corridor. 10,500 feet