Definition
The end of the runway opposite the threshold from which takeoff is made — in other words, the far end of the runway in the direction of takeoff. The DER is the reference point used in instrument departure procedure design for measuring climb gradients, obstacle clearance requirements, and the start of the departure flight path.
Plain English
The end of the runway you lift off toward. It is the point where the paved takeoff surface ends and your departure flight path is measured from.
Context Anchor
Seen in instrument departure procedures, obstacle notes, and climb requirements after takeoff.
Why Pilots Care
It marks the exact point where published climb requirements and obstacle-avoidance calculations begin for a departure.
Grounding Statement
Picture the aircraft accelerating down the runway; the DER is the far runway end it is heading toward, not the point where the wheels first leave the ground.
Intuition Check
Do not assume the DER is the point where the aircraft departs the ground. Here, “departure end” means the runway end in the takeoff direction used as a planning reference.
Example Sentence 1
The departure procedure required a climb of 250 feet per nautical mile from the DER until reaching 3,000 feet.
Example Sentence 2
Obstacle clearance is measured from the DER outward along the departure path.