In April 1958 Lockheed corporation won a US Navy competition to find a replacement for the Navy's aging P2V Neptune series of long range antisubmarine warfare and maritime patrol aircraft. Lockheed's
... winning proposal was designated "P3V Orion". Named for the winter constellation of the mighty hunter, the Orion was actually derived from the famous Lockheed Electra civil airliner.
[Text provided by:
http://www.geocities.com/lucktam/awacs/orion/orion.htm ]
[Photo provided by:
http://www.farfromglory.com/images/p3b.jpg ]