Northrop M2-F2


The Northrop M2-F2 was a heavyweight lifting body based on studies at NASA's Ames and Langley research centers and built by the Northrop Corporation in 1966.

Development

The success of Dryden's M2-F1 program led to NASA's development and construction of two heavyweight lifting bodies based on studies at NASA's Ames and Langley research centers—the M2-F2 and the HL-10, both built by the Northrop Corporation. The "M" refers to "manned" and "F" refers to "flight" version. "HL" comes from "horizontal landing" and 10 is for the tenth lifting body model to be investigated by Langley.
The M2-F2 made its first captive flight on March 23, 1966.
The first flight of the M2-F2 - which looked much like the M2-F1 - was on July 12, 1966. Milton O. Thompson was the pilot.
By then, the same B-52 used to air launch the famed X-15 rocket research aircraft was modified to also carry the lifting bodies. Thompson was dropped from the B-52's wing pylon mount at an altitude of 45,000 feet on that maiden glide flight. He reached a gliding speed of about 450 miles per hour.

Operational history

Before powered flights were undertaken, a series of glide flights were conducted. On May 10, 1967, the sixteenth and last glide flight ended in disaster as the vehicle slammed into the lake bed on landing. With test pilot Bruce Peterson at the controls, the M2-F2 suffered a pilot induced oscillation as it neared the lake bed. At the core of this problem was the fact that the wings of the M2-F2 produced considerably less roll authority than most aircraft. This resulted in less force available to the pilot to control the aircraft in roll. As a consequence, when Peterson attempted to perform roll maneuvers the response of the vehicle was substantially less than expected, thus lending to a "soft" feel for this control which often leads to PIO in the roll axis. The vehicle rolled from side to side in flight as he tried to bring it under control. Peterson recovered, but then observed a rescue helicopter that seemed to pose a collision threat. Distracted, Peterson drifted in a crosswind to an unmarked area of the lake bed where it was very difficult to judge the height over the ground because of a lack of guidance.
Peterson fired the landing rockets to provide additional lift, but he hit the lake bed before the landing gear was fully down and locked. The M2-F2 rolled over six times, coming to rest upside down. Pulled from the vehicle by Jay King and Joseph Huxman, Peterson was rushed to the base hospital, transferred to the March Air Force Base Hospital and then the UCLA Hospital. He recovered but lost vision in his right eye due to a staphylococcal infection.
Portions of M2-F2 footage including Peterson's spectacular crash landing were used for the 1973 television series The Six Million Dollar Man though some shots during the opening credits of the series showed the later HL-10 model, during release from its carrier plane, a modified B-52.
Four pilots flew the M2-F2 on its 16 glide flights. They were Milton O. Thompson, Bruce Peterson, Don Sorlie and Jerry Gentry.
NASA pilots and researchers realized the M2-F2 had lateral control problems, even though it had a stability augmentation control system. When the M2-F2 was rebuilt at Dryden and redesignated the M2-F3, it was modified with an additional third vertical fin—centered between the tip fins to improve control characteristics.
The M2-F2/F3 was the first of the heavyweight, entry-configuration lifting bodies. Its successful development as a research test vehicle answered many of the generic questions about these vehicles.

M2-F2 flights

Vehicle
Flight #		DatePilotMachVelocity
Altitude
DurationComments
M2-F2 #1July 12, 1966Thompson0.64672713,71600:03:37First M2-F2 Flight. Unpowered glide. 320 km/h landing.
M2-F2 #2July 19, 1966Thompson0.59863413,71600:04:05Unpowered glide. Determination of lateral stability control, longitudinal trim, vehicle performance and landing characteristics.
M2-F2 #3August 12, 1966Thompson0.61969213,71600:04:38Unpowered glide. Determine effect of increasing Mach number, minimum damper requirements, testing of longitudinal and lateral stability and control.
M2-F2 #4August 24, 1966Thompson0.67671813,71600:04:01Unpowered glide. Determine control damper requirements, lift-drag ratio, elevon response, flap effectiveness and longitudinal stability and control.
M2-F2 #5September 2, 1966Thompson0.70775013,71600:03:46Unpowered glide. Evaluate 360 degree overhead approach, determine control damper-off handling qualities.
M2-F2 #6September 15, 1966Peterson0.70575013,71600:03:30Unpowered glide. Pilot checkout.
M2-F2 #7September 20, 1966Sorlie0.63567813,71600:03:31Unpowered glide. Pilot checkout.
M2-F2 #8September 22, 1966Peterson0.66170213,71600:03:53Unpowered glide. Longitudinal and lateral stability and control with dampers.
M2-F2 #9September 28, 1966Sorlie0.67271313,71600:03:53Unpowered glide. Complete pilot checkout and extend flight envelope.
M2-F2 #10October 5, 1966Sorlie0.61569213,71600:03:45Unpowered glide. Explore lateral and longitudinal stability and control characteristics with dampers on and off.
M2-F2 #11October 12, 1966Gentry0.66270213,71600:03:54Unpowered glide. Pilot checkout.
M2-F2 #12October 26, 1966Gentry0.60564213,71600:03:47Unpowered glide. Obtain stability and control data at 7 and 11 degree attack angles and upper flap effectiveness.
M2-F2 #13November 14, 1966Gentry0.68171613,71600:04:21Unpowered glide. Test stability and control, determine vehicle performance characteristics.
M2-F2 #14November 21, 1966Gentry0.69573513,71600:03:50Unpowered glide. Test stability and control, determine vehicle performance characteristics.
M2-F2 #15May 2, 1967Gentry0.62366113,71600:03:51Unpowered glide.
M2-F2 #16May 10, 1967Peterson0.61264913,71600:03:43Unpowered glide
Crash landing

Specifications (M2-F2)