Definition
The set of FAA-mandated rules that air carriers operating under 14 CFR Parts 121 and 135 must follow to ensure their aircraft can safely clear terrain and obstacles during takeoff, departure, en route, and landing phases. These requirements specify minimum climb performance, weight limitations, and obstacle clearance margins that must be met based on aircraft performance data, departure path, and operating environment.
Plain English
Rules that airlines and commercial operators must follow to make sure their planes can safely climb over and stay above mountains, buildings, and other obstacles during every phase of flight. These rules dictate how heavy the plane can be, how steeply it must climb, and how much room it must leave between itself and obstacles below.
Context Anchor
Seen in takeoff performance planning for air carrier operations, especially when checking whether a departure can be made safely from a particular runway at a particular weight.
Why Pilots Care
These requirements determine whether a flight can legally depart a runway or must reduce weight, directly affecting payload, fuel, and safety margins for passenger operations.
Grounding Statement
Picture the airplane leaving the runway and following a planned climb path that must remain safely above every known obstacle ahead.
Intuition Check
Do not confuse obstacle clearance requirements with an ATC clearance or with simply checking that the runway is clear. Here, clearance means planned vertical and horizontal space between the airplane’s climb path and obstacles after takeoff.
Example Sentence 1
Before dispatch, the airline's flight planning system checks Air Carrier Obstacle Clearance Requirements to confirm the aircraft can safely depart at its planned takeoff weight.
Example Sentence 2
Before takeoff the captain reviewed the air carrier obstacle clearance requirements to verify the planned flap setting provided adequate margin.