Fifty-one years ago this week, USAF Captain Joe B. Jordan zoomed a modified USAF/Lockheed F-104C Starfighter to a world altitude record of 103,395.5 feet above mean sea level. The flight originated from and recovered to the Air Force Flight Test Center (AFFTC) at Edwards Air Force Base, California.
On Tuesday, 14 July 1959, the USSR established a world altitude record for turbojet-powered aircraft when Soviet test pilot Vladimir S. Ilyushin zoomed the Sukhoi T-43-1 (a prototype of the Su-9) to an absolute altitude of 94,661 feet. By year’s end, the Soviet achievement would be topped by several American aircraft.
FAI rules stipulate that an existing absolute altitude record be surpassed by at least 3 percent for a new mark to be established. In the case of the Soviet’s 1959 altitude record, this meant that an altitude of at least 97,501 feet would need to be achieved in a record attempt.
On Sunday, 06 December 1959, USN Commander Lawrence E. Flint wrested the months-old absolute altitude record from the Soviets by zooming to 98,561 feet. Flint piloted the second USN/McDonnell Douglas YF4H-1 (F4 Phantom II prototype) in accomplishing the feat. In a show of inter-service cooperation, the record flight was made from the AFFTC at Edwards Air Force Base.
Meanwhile, USAF was feverishly working on its own record attempt. The aircraft of choice was the Lockheed F-104C Starfighter. However, with the record now held by the Navy, the Starfighter would have to achieve an absolute altitude of at least 101,518 feet to set a new mark. (Per the FAI 3 percent rule.)
On Tuesday, 24 November 1959, the AFFTC accepted delivery of the record attempt aircraft, F-104C (S/N 56-0885), from the Air Force Special Weapons Center at Kirtland AFB in New Mexico. This aircraft was configured with a J79-GE-7 turbojet capable of generating nearly 18,000 pounds of sea level thrust in afterburner.
Modifications were made to the J79 to maximize the aircraft’s zoom kinematic performance. The primary enhancements included increasing afterburner fuel flow rate by 10 percent and maximum RPM from 100 to 103.5 percent. Top reset RPM was rated at 104.5 percent. Both the ‘A’ and ‘B’ engine flow bypass flaps were operated in the open position as well. These changes provided for increased thrust and stall margin.
An additional engine mod involved reducing the minimum engine fuel flow rate from 500 to 250 pounds per hour. Doing so increased the altitude at which the engine needed to be shut down to prevent overspeed or over-temperature conditions. Another change included increasing the maximum allowable compressor face temperature from 250 F to 390 F.
The F-104C external airframe was modified for the maximum altitude mission as well. The compression cones were lengthened on the bifurcated inlets to allow optimal pressure recovery at the higher Mach number expected during the record attempt. High Mach number directional stability was improved by swapping out the F-104C empannage with the larger F-104B tail assembly.
USAF Captain Joe B. Jordan was assigned as the altitude record attempt Project Pilot. USAF 1st Lt and future AFFTC icon Johnny G. Armstrong was assigned as the Project Engineer. Following an 8-flight test series to shake out the bugs on the modified aircraft, the record attempt proper started on Thursday, 10 December 1959.
On Monday, 14 December 1959, F-104C (S/N 56-0885) broke the existing absolute altitude record for turbojet-powered aircraft on its 5th attempt. Jordan did so by accelerating the aircraft to Mach 2.36 at 39,600 feet. He then executed a 3.15-g pull to an inertial climb angle of 49.5 degrees. Jordan came out of afterburner at 70,000 feet and stop-cocked the J79 turbojet at 81,700 feet.
Roughly 105 seconds from initiation of the pull-up, Joe Jordan reached the top of the zoom. The official altitude achieved was 103,395.5 feet above mean sea level based on range radar and Askania camera tracking. True airspeed over the top was on the order of 455 knots. Jordan started the pull-up to level flight at 60,000 feet; completing the recovery at 25,000 feet. Landing was entirely uneventful.
Jordan’s piloting achievement in setting the new altitude record was truly remarkable. His conversion of kinetic energy to altitude (potential energy) during the zoom was extremely efficient; realizing only a 2.5 percent energy loss from pull-up to apex. Jordan also exhibited exceptional piloting skill in controlling the aircraft over the top of the zoom where the dynamic pressure was a mere 14 psf. He did so using aerodynamic controls only. The aircraft did not have a reaction control system ala the X-15.
Armstrong’s contributions to shattering the existing altitude record were equally substantial. Skillful flight planning and effective use of available resources (including time available for the record attempt) were pivotal to mission success. Armstrong significantly helped maximize aircraft zoom performance through proper selection of pull-up flight conditions and intelligent use of accurate day-of-flight meteorological information.
For his skillful piloting efforts in setting the world absolute altitude record for turbojet-powered aircraft in December of 1959, Joe Jordan received the 1959 Harmon Trophy.