View source for Northrop M2-F2

{{Short description|Lifting body prototype}}
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. -->
{{Infobox aircraft
 |name = M2-F2
 |image = Northrop_M2-F2.jpg
 |caption = 
 |type = Lifting body [[technology demonstrator]]
 |national_origin=United States
 |manufacturer = [[Northrop Corporation|Northrop]]
 |designer =
 |first_flight = 12 July 1966
 |introduction =
 |retired = 10 May 1967
 |produced =
 |number_built = 1
 |status = Rebuilt as M2-F3
 |unit cost =
 |primary_user = [[NASA]]
 |more_users = 
 |developed_from = [[NASA M2-F1]]
 |variants = [[Northrop M2-F3]]
}}

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 Flight Research Center|Dryden's]] [[NASA M2-F1|M2-F1]] program led to NASA's development and construction of two heavyweight lifting bodies based on studies at NASA's [[NASA Ames Research Center|Ames]] and [[Langley Research Center|Langley]] research centers—the M2-F2 and the [[Northrop HL-10|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.

On March 23, 1966 the M2-F2 made its first captive flight—attached to the [[B-52 Stratofortress|B-52]] carrier aircraft throughout. The first free [[gliding]] flight of the M2-F2 was on July 12, 1966, piloted by [[Milton O. Thompson]]. He was [[drop launch|dropped]] from the B-52 carrier aircraft's wing pylon at an altitude of {{convert|45,000|ft|abbr=on}} and reached a speed of about {{convert|450|mph|kph+kn|abbr=on}}.

==Operational history==
[[File:M2-F2 Crash on Rogers Dry Lake - GPN-2000-000089.jpg|thumb|right|The crash site of the M2-F2]]
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|pilot induced oscillation]] (PIO) as it neared the lake bed. At the core of this problem was that the wings of the M2-F2 (essentially the body of the aircraft) produced considerably less roll authority than most aircraft. This resulted in less force available to the pilot to control the aircraft in roll. 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 (the markers provided on the lake bed runway).<ref>{{cite web|title=1967 M2-F2 Crash at Edwards|url=http://www.check-six.com/Crash_Sites/NASA-803-1967|website=Check-Six.com|access-date=14 April 2017}}</ref>

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 [[University of California, Los Angeles|UCLA]] Hospital. He recovered but lost vision in his right [[human eye|eye]] due to a [[Staphylococcus|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]]''<ref name=at20120906>
{{cite journal |last=Klingler|first=Dave |title=50 years to orbit: Dream Chaser's crazy Cold War backstory: The reusable mini-spaceplane is back from the dead—again—and prepping for space |journal=Ars Technical|date=2012-09-06 |url=https://arstechnica.com/science/2012/09/the-long-complicated-voyage-of-the-dream-chaser-may-yet-end-in-space/ |access-date=2012-09-07 |quote=''The M2-F2 went on to star in the opening credits of "The Six Million Dollar Man,"''}}</ref>  though some shots during the opening credits of the series showed the later [[Northrop HL-10|HL-10]] model, during release from its carrier plane, a modified [[B-52 Stratofortress|B-52]].

Four pilots flew the M2-F2 on its 16 glide flights. They were [[Milton O. Thompson]] (five flights), [[Bruce Peterson]] (three flights), Don Sorlie (three flights) and [[Jerry Gentry]] (five flights).{{citation needed|date=September 2012}}

[[NASA]] [[Aviator|pilot]]s and [[research]]ers 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 [[Northrop M2-F3|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==

*'''NASA M2-F2''' - NASA 803, 16 unpowered flights

{| class="wikitable"
|- 
! Vehicle<br>Flight #
! width=125| Date
! Pilot
! Mach
! Velocity<br> (km/h)
! Altitude<br> (meters)
! Duration
! Comments
|-
| '''M2-F2 #1'''
| July 12, 1966
| Thompson
| 0.646
| 727
| 13,716
| 00:03:37
| First M2-F2 Flight. Unpowered glide. 320&nbsp;km/h landing. 
|-
| '''M2-F2 #2'''
| July 19, 1966
| Thompson
| 0.598
| 634
| 13,716
| 00:04:05
| Unpowered glide. Determination of lateral stability control, longitudinal trim, vehicle performance and landing characteristics.
|-
| '''M2-F2 #3'''
| August 12, 1966
| Thompson
| 0.619
| 692
| 13,716
| 00:04:38
| Unpowered glide. Determine effect of increasing Mach number, minimum damper requirements, testing of longitudinal and lateral stability and control.
|-
| '''M2-F2 #4'''
| August 24, 1966
| Thompson
| 0.676
| 718
| 13,716
| 00:04:01
| Unpowered glide. Determine control damper requirements, lift-drag ratio, elevon response, flap effectiveness and longitudinal stability and control.
|-
| '''M2-F2 #5'''
| September 2, 1966
| Thompson
| 0.707
| 750
| 13,716
| 00:03:46 
| Unpowered glide. Evaluate 360 degree overhead approach, determine control damper-off handling qualities.
|-
| '''M2-F2 #6'''
| September 15, 1966
| Peterson
| 0.705
| 750
| 13,716
| 00:03:30
| Unpowered glide. Pilot checkout. 
|-
| '''M2-F2 #7'''
| September 20, 1966
| Sorlie
| 0.635
| 678
| 13,716
| 00:03:31
| Unpowered glide. Pilot checkout. 
|-
| '''M2-F2 #8'''
| September 22, 1966
| Peterson
| 0.661
| 702
| 13,716
| 00:03:53
| Unpowered glide. Longitudinal and lateral stability and control with dampers. 
|-
| '''M2-F2 #9'''
| September 28, 1966
| Sorlie
| 0.672
| 713
| 13,716
| 00:03:53
| Unpowered glide. Complete pilot checkout and extend flight envelope. 
|-
| '''M2-F2 #10'''
| October 5, 1966
| Sorlie
| 0.615
| 692
| 13,716
| 00:03:45
| Unpowered glide. Explore lateral and longitudinal stability and control characteristics with dampers on and off. 
|-
| '''M2-F2 #11'''
| October 12, 1966
| Gentry
| 0.662
| 702
| 13,716
| 00:03:54
| Unpowered glide. Pilot checkout. 
|-
| '''M2-F2 #12'''
| October 26, 1966
| Gentry
| 0.605
| 642
| 13,716
| 00:03:47
| Unpowered glide. Obtain stability and control data at 7 and 11 degree attack angles and upper flap effectiveness. 
|-
| '''M2-F2 #13'''
| November 14, 1966
| Gentry
| 0.681
| 716
| 13,716
| 00:04:21
| Unpowered glide. Test stability and control, determine vehicle performance characteristics. 
|-
| '''M2-F2 #14'''
| November 21, 1966
| Gentry
| 0.695
| 735
| 13,716
| 00:03:50
| Unpowered glide. Test stability and control, determine vehicle performance characteristics. 
|-
| '''M2-F2 #15'''
| May 2, 1967
| Gentry
| 0.623
| 661
| 13,716
| 00:03:51
| Unpowered glide.
|-
| '''M2-F2 #16'''
| May 10, 1967
| Peterson
| 0.612
| 649
| 13,716
| 00:03:43
| Unpowered glide<br>Crash landing<ref>{{cite web|title=1967 M2-F2 Crash at Edwards|url=http://www.check-six.com/Crash_Sites/NASA-803-1967|website=Check-Six.com|access-date=14 April 2017}}</ref>
|}

==Specifications (M2-F2)==
[[File:Northrop M2-F2 diagram.png|right|350px|NASA M2-F2 Lifting body diagram]]
{{Aircraft specs
|ref={{citation needed|date=September 2019}}
|prime units?=kts
<!--
        General characteristics
-->
|crew=1
|length ft=22
|length in=2
|length note=
|span ft=9
|span in=8
|span note=
|height ft=9
|height in=6
|height note=
|wing area sqft=160
|wing area note=
|aspect ratio=<!-- sailplanes -->
|airfoil=<!--'''root:''' [[NACA airfoil|NACA ]]; '''tip:''' [[NACA airfoil|NACA ]]<ref name="Selig">{{cite web |last1=Lednicer |first1=David |title=The Incomplete Guide to Airfoil Usage |url=https://m-selig.ae.illinois.edu/ads/aircraft.html |website=m-selig.ae.illinois.edu |access-date=16 April 2019}}</ref>-->
|empty weight lb=4620
|empty weight note=
|gross weight lb=6000
|gross weight note=
|max takeoff weight lb=7485
|max takeoff weight note=
|fuel capacity=
|more general=
<!--
        Powerplant
-->
|eng1 number=1
|eng1 name=[[Reaction Motors XLR-11]]
|eng1 type=liquid-fuelled rocket motor
|eng1 lbf=8000
|eng1 note= with four combustion chamber/nozzle assemblies
<!--
        Performance
-->
|max speed kts=405
|max speed note=
|max speed mach=0.707
|cruise speed kts=
|cruise speed note=
|stall speed kts=
|stall speed note=
|never exceed speed kts=
|never exceed speed note=
|range nmi=8.6
|range note=
|combat range nmi=
|combat range note=
|ferry range nmi=
|ferry range note=
|endurance=<!-- if range unknown -->
|ceiling ft=45000
|ceiling note=
|g limits=<!-- aerobatic -->
|roll rate=<!-- aerobatic -->
|glide ratio=<!-- sailplanes -->
|climb rate ftmin=
|climb rate note=
|time to altitude=
|wing loading lb/sqft=43.2
|wing loading note=
|fuel consumption lb/mi=
|thrust/weight=1.3

|more performance=
|avionics=
}}

==See also==
{{Aircontent|
|related=
|similar aircraft=
*[[Martin-Marietta X-24|X-24]]
*[[NASA M2-F1|M2-F1]]
*[[Northrop M2-F3|M2-F3]]
*[[Northrop HL-10|HL-10]]
|sequence=
|lists=
|see also=
}}

==References==
{{Reflist}}

==External links==
{{Commons category|Northrop M2-F2}}
*[http://www.dfrc.nasa.gov/Gallery/Photo/M2-F2/HTML/index.html Most of text taken from NASA Dryden webpage.]
*[https://web.archive.org/web/20020527051125/http://www.dfrc.nasa.gov/gallery/photo/M2-F2/ NASA Dryden M2-F2 Photo Collection]
*[https://web.archive.org/web/20000817200526/http://www.dfrc.nasa.gov/gallery/movie/M2-F2/index.html NASA Dryden M2-F2 Video Collection]
*[https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980169231_1998082126.pdf Wingless Flight: The Lifting Body Story. NASA History Series SP-4220 1997 PDF]
*[https://www.youtube.com/watch?v=3jvGJhJINlc Video] of Peterson's crash

{{Northrop aircraft}}
{{X-planes}}
{{Authority control}}

[[Category:Lifting bodies]]
[[Category:1960s United States experimental aircraft|M2-F2, Northrop]]
[[Category:Gliding in the United States|M2-F2, Northrop]]
[[Category:Rocket-powered aircraft|M2-F2, Northrop]]
[[Category:Northrop aircraft|M2-F2]]