The tweeter seems to switch the term "envelope" with "sector"

They based their work on an enormous database including detailed documentation of every sortie conducted in the Gaza sector on October 7. This database was overlaid on an interactive map showing with a mouse click every attack carried out by the Air Force, including precise time and location, type of munition fired, the aircraft that fired it, the relevant squadron and the result of the hit (destruction of a vehicle, elimination of a fighter, etc.).

The investigation further reveals that besides the attack formations, the Air Force's special units – Shaldag and Unit 669 – took a significant part in combat operations, and that Air Force transport helicopters landed about 1,700 infantry fighters in the Gaza sector during the fighting and evacuated more than 150 casualties. During one mission a Yasur helicopter was hit and destroyed by an RPG after making an emergency landing. The air defense array also dealt, with relative success, with the heaviest barrage ever fired at Israel. In other words, the skies were not completely empty.

Yea I'm lost.