Christmas tree (aviation)



A Christmas tree was a type of alert area constructed by the Strategic Air Command during the Cold War. Oftentimes, bombers or tanker aircraft were stationed next to mole hole facilities. It received this name due to the fact that it looked like the tree of the same name.

History
Before the development of the B-52 Stratofortress, aircraft were parked on alert aprons at right angles. Due to the size of the aircraft, this created a problem in launching aircraft efficiently, requiring a different solution to be devised. To fix this, aircraft were repositioned in herringbone configurations, which then allowed the planes to pull out onto the runway as quickly as possible.

This meant that the aircraft would be positioned at 45 degrees in relation to the center line. Two aircraft would be positioned on either side of the center line, with one being positioned furthest back. The success of this formation also led to the adoption of the setup for the KC-97 Stratotanker.

During an alert, airmen would run out of the mole hole and to their awaiting planes. There was no order to which planes would leave first, as whatever plane had their engines running first would be the first to leave. At this point, the aircraft would perform an elephant walk to the runway, which was typically located close to the Christmas tree, due to the need to launch the aircraft as quickly as possible. If the aircraft were to be launched as quickly as possible, then a MITO would be performed, in order to lessen the chance that the aircraft would be caught on the ground in the event of a nuclear strike.

Although it is unknown how much each christmas tree cost to construct and maintain, the Christmas tree at Loring Air Force Base in Maine is estimated to have cost $400,000 when it was constructed between 1959 and 1960.