McDonnell Douglas F-15 STOL/MTD

F-15 STOL/MTD / NASA NF-15B Research Aircraft
F-15 ACTIVE in 1997
General information
Type	Technology Demonstrator and Research Aircraft
National origin	United States
Manufacturer	McDonnell Douglas
Status	Retired from both NASA and military service
Primary users	United States Air Force NASA
Number built	1
Registration	NASA 837
Serial	USAF S/N 71-0290
History
First flight	7 September 1988 (STOL/MTD)[1]
Retired	15 August 1991 (STOL/MTD) 30 January 2009
Developed from	McDonnell Douglas F-15 Eagle

The McDonnell Douglas F-15 STOL/MTD (Short Takeoff and Landing/Maneuver Technology Demonstrator) is a modified F-15 Eagle. Developed as a technology demonstrator, the F-15 STOL/MTD carried out research for studying the effects of thrust vectoring and enhanced maneuverability. The aircraft used for the project was pre-production TF-15A (F-15B) No. 1 (USAF S/N 71-0290), the first two-seat F-15 Eagle built by McDonnell Douglas (out of 2 prototypes^[2]), the sixth F-15 off the assembly line, and was the oldest F-15 flying up to its retirement. It was also used as the avionics testbed for the F-15E Strike Eagle program.^[3] The plane was on loan to NASA from the United States Air Force.

This same aircraft would later be used in the F-15 ACTIVE ("Advanced Control Technology for Integrated Vehicles") from 1993 to 1999, and later in the Intelligent Flight Control System programs from 1999 to 2008.

While with NASA, the aircraft's tail number was 837.^[4] The aircraft is now on display at Edwards AFB.^[5]

Design and development

Pre-production F-15B with 2D nozzles, early 1980s, a predecessor of STOL/MTD program

In 1975, Langley Research Center began to conduct sponsored programs studying two-dimensional thrust vectoring nozzles;^[6]: 44 government and industry studies of non-axisymmetric two-dimensional (2-D) nozzles in the early 1970s had identified significant payoffs for thrust-vectoring 2-D nozzle concepts.^[6]: 192

In 1977, Langley started a system integration study of thrust-vectoring, thrust-reversing, and 2-D nozzles on the F-15 with McDonnell Douglas. In 1984, the Flight Dynamics Laboratory, the Air Force Aeronautical Systems Division awarded a contract to McDonnell Douglas for an advanced development STOL/MTD experimental aircraft.^[6]: 192

The aircraft used in the STOL/MTD program^[7] has flown several times since the successful STOL/MTD program completion in 1991 that used thrust vectoring and canard foreplanes to improve low-speed performance. This aircraft tested high-tech methods for operating from a short runway. This F-15 was part of an effort to improve ABO (Air Base Operability), the survival of warplanes and fighting capability at airfields under attack.

The F-15 STOL/MTD tested ways to land and take off from wet, bomb-damaged runways. The aircraft used a combination of reversible engine thrust, jet nozzles that could be deflected by 20 degrees, and canard foreplanes. Pitch vectoring/reversing nozzles and canard foreplanes were fitted to the F-15 in 1988. The canard foreplanes were derived from the F/A-18's stabilators.^[8][9]

Prior to 15 August 1991,^[6]: 194 when McDonnell Douglas ended its program after accomplishing their flight objectives, the F-15 STOL/MTD plane achieved some impressive performance results:

• Demonstrated vectored takeoffs with rotation at speeds as low as 42 mph (68 km/h)^[6]: 194
• A 25-percent reduction in takeoff roll^[6]: 193
• Landing on just 1,650 ft (500 m) of runway compared to 7,500 ft (2,300 m) for the standard F-15^[6]: 193
• Thrust reversal in flight to produce rapid deceleration^[6]: 194

The results of the STOL/MTD would help inform requirements for the Advanced Tactical Fighter program, which resulted in the F-22.^[9]

Further modifications

During the 1990s the same F-15 airframe (USAF S/N 71-0290) was further modified (canards and nozzles were retained) for the ACTIVE ("Advanced Control Technology for Integrated Vehicles") program in which the Pratt & Whitney Pitch/Yaw Balance Beam Nozzles (P/YBBN) and advanced control-logic programming were investigated; NASA acquired the plane in 1993 and replaced the engines with Pratt & Whitney F100-229 engines with P/YBBN.^[10] In the ACTIVE configuration it was also used for the LANCETS ("lift and nozzle change effects on tail shock") program, in which computed supersonic shockwave parameters were compared to those measured in flight. The LANCETS flight tests ended in December 2008.^[11] F-15 ACTIVE lasted from 1993 to 1999, with thrust vectoring demonstrated at up to Mach 1.95 on 31 October 1996.

The aircraft would later be used in the F-15 IFCS (Intelligent Flight Control System) program from 1999 to 2008. The airplane was also used for the Space-Based Range Demonstration and Certification project under the Exploration Communications and Navigation Systems program (SBRDC/ECANS) from 2006 to 2007, High Stability Engine Control (HISTEC) program, and High-Speed Research Acoustics in 1997.^{[citation needed]}

Specifications (F-15 ACTIVE)

F-15 ACTIVE showing its 3D thrust vectoring nozzles, 1996

Top view of the F-15 ACTIVE in 1996

Data from NASA.^[8]

General characteristics

• Crew: 2
• Capacity: 17,000 lb (7,112 kg)
• Length: 63 ft 8 in (19.42 m) excluding flight test nose boom
• Wingspan: 42 ft 10 in (13 m)
• Height: 18 ft 6 in (5.64 m)
• Wing area: 608 sq ft (56.5 m²)
• Empty weight: 35,000 lb (15,876 kg)
• Gross weight: 47,000 lb (21,319 kg)
• Fuel capacity: 11,520 lb (5,225 kg) (approx. 1,700 gal)
• Horizontal tail span: 28.2 ft (8.60 m)
• Canard span: 25.6 ft (7.80 m)
• Powerplant: 2 × Pratt & Whitney F100-PW-229 turbofan engines, equipped with 20° three-dimensional thrust vectoring P/YBBN, 17,800 lbf (79 kN) thrust each dry, 29,000 lbf (130 kN) with afterburner

Performance

• Maximum speed: 1,320 mph (2,120 km/h, 1,150 kn)
• Maximum speed: Mach 2.0
• Service ceiling: 60,000 ft (18,288 m)

In popular culture

Patlabor 2: The Movie

In a scene from the 1993 animated film Patlabor 2: The Movie, set in the year 2002, a flight of three rogue F-16Js (flight "Wyvern") are intercepted by two pairs of a semi-fictional F-15J Kai+ (flights "Wizard" and "Priest"), which feature some of the STOL/MTD's airframe additions.

Ace Combat

Numerous entries in the Ace Combat video game series feature the F-15 STOL/MTD as an unlockable player aircraft, and has also been the aircraft of choice for some antagonists. In Ace Combat Zero: The Belkan War, the Sorcerer Team flies eight F-15 STOL/MTDs. A fictional modernized derivative, the F-15S/MT Eagle+, is used by Abyssal Dision, main antagonist of Ace Combat 3: Electrosphere.

Project Wingman

The plane appears in the Project Wingman video game under the name F/S-15. It is used by allied and enemy units alike and can be unlocked by the player.

See also

Related development

• McDonnell Douglas F-15 Eagle
• McDonnell Douglas F-15E Strike Eagle

Aircraft of comparable role, configuration, and era

• General Dynamics X-62 VISTA
• High Alpha Research Vehicle
• Rockwell-MBB X-31
• Sukhoi Su-37

Related lists

• List of experimental aircraft
• List of military aircraft of the United States

References

1. "Boeing: History -- Chronology – 1988 – 1992". Boeing. c. 2010. Archived from the original on 12 May 2010. Retrieved 10 March 2019.
2. "Fact Sheets: MCDONNELL DOUGLAS F-15A". National Museum of the US Air Force. Archived from the original on 3 September 2014. Retrieved 15 July 2017.
3. Aircraft Description Archived 25 October 2012 at the Wayback Machine NASA 19 April 2010
4. "NASA Armstrong Fact Sheet: NF-15B Research Aircraft". NASA. 28 February 2014. Archived from the original on 8 April 2019. Retrieved 9 April 2019.
5. "NF-15B". The Historical Marker Database. 11 August 2018. Retrieved 25 September 2020.
6. Chambers, Joseph R (2000). "McDonnell Douglas F-15 Eagle" (PDF). Partners in Freedom: Contributions of the Langley Research Center to US Military Aircraft of the 1990. The NASA History Series. NASA. Archived from the original (PDF) on 16 March 2010. Retrieved 20 April 2010.
7. "AFRL Acronyms". Air Force Research Laboratory. USAF. Archived from the original on 13 September 2010. Retrieved 19 April 2010.
8. "NASA Armstrong Fact Sheet: NF-15B Research Aircraft". National Aeronautics and Space Administration. Archived from the original on 20 July 2015. Retrieved 20 October 2014.
9. Aronstein, David C.; Hirschberg., Michael J.; Piccirillo, Albert C. (1998). Advanced Tactical Fighter to F-22 Raptor: Origins of the 21st Century Air Dominance Fighter. Arlington, Virginia: American Institute of Aeronautics & Astronautics. pp. 106, 197–198. ISBN 978-1-56347-282-4.
10. F-15 ACTIVE (graphics collection), Dryden: NASA, archived from the original on 19 February 2003.
11. "Sonic Solutions", Aviation Week & Space Technology, p. 53, 5 January 2009^{[permanent dead link‍]}.

• Aircraft of the World: The Complete Guide.

External links

• NASA Dryden Fact Sheet – NASA NF-15B Research Aircraft Archived 23 October 2012 at the Wayback Machine
• NASA Dryden Fact Sheet – F-15B #837 Archived 30 April 2010 at the Wayback Machine
• McDonnell Douglas F-15SMTD Cutaway at flightglobal.com