was little difference in range – the SR-71 carried more fuel – the A-12 had an altitude advantage of from over the SR-71 at the same Mach number, being a lighter aircraft. The radar cross section of both aircraft in a clean configuration was relatively low; the SR-71 in a full sensor configuration was somewhat higher due to its larger size and was appreciably larger again with the side-looking radar antenna installed. The A-12 was designed to optionally utilize one of three different types of high resolution cameras; the highest of which provided a wide continuous swath of resolution. The SR-71 had the simultaneous capability for photography and ELINT. Its imagery was one foot resolution of two separate swath wide strips positioned up to apart on either side of the aircraft. 26 January 1968: North Korea A-12 overflight by Jack Weeks photo-locates the captured USS Pueblo in Changjahwan Bay harbor. 5 February 1968: Lockheed ordered to destroy A-12, YF-12 and SR-71 tooling. 8 March 1968: First SR-71A (#61-7978) arrives at Kadena AB to replace A-12s. 21 March 1968: First SR-71 (#61-7976) operational mission flown from Kadena AB over Vietnam. 8 May 1968: Jack Layton flies last operational A-12 sortie, over North Korea. 5 June 1968: Loss of last A-12 (#60-6932) during Functional Checkout Flight (FCF) flown from Kadena, Jack W. Weeks became the second and last CIA pilot killed in the line of duty during Oxcart and is so honored in the "Book of Honor" at CIA Headquarters. The A-12 had a radio telemetry system called "Birdwatcher", monitoring the most critical aircraft systems and transmitting data to ground monitoring stations. Following aerial refueling, the ground station was informed via "Birdwatcher" that the starboard engine exhaust gas temperature was in excess of , the fuel flow on that engine was less than per hour and that the aircraft was below . Several attempts to make contact were made without success. Monitoring continued until the time that the aircraft's fuel would have been depleted. The aircraft was declared missing east of the Philippines and south of Okinawa in the South China Sea. The loss was due to an in-flight emergency. To maintain security the official news release identified the loss as an SR-71. An intense air and sea search was conducted but no wreckage of "Article 129" was ever recovered. It was presumed totally destroyed at sea. The "Birdwatcher" system provided the