Sikorsky S-67 Blackhawk

Last updated
S-67 Blackhawk
Sikorsky S-67 research and development.jpg
S-67 Blackhawk in 1972
General information
TypeAttack/assault helicopter
Manufacturer Sikorsky Aircraft
StatusDestroyed (1974 crash)
Number built1
History
First flight20 August 1970
Developed from Sikorsky SH-3 Sea King

The Sikorsky S-67 Blackhawk was a private-venture, prototype attack helicopter built in 1970 with Sikorsky Aircraft research and development (R&D) funds. A tandem, two-seat aircraft designed around the dynamic drive and rotor systems of the Sikorsky S-61, it was designed to serve as an attack helicopter or to transport up to eight troops into combat.

Contents

Design and development

AAFSS and S-66 bid

The United States Army issued a request for proposals (RFP) for its Advanced Aerial Fire Support System (AAFSS) program on 1 August 1964. [1] Lockheed offered its CL-840 design, a rigid-rotor compound helicopter. [2] Sikorsky submitted the S-66, which featured a "Rotorprop" serving as a tail rotor but as speeds increased would rotate 90° to act as pusher prop. [3] The S-66 had short, fixed wings and was powered by a 3,400 shp (2,500 kW) Lycoming T55 turboshaft engine. The design was to have a speed of 200 knots (370 km/h) with the ability for 250 knots (460 km/h) for brief periods. [4]

The U.S. Army awarded Lockheed and Sikorsky contracts for further study on 19 February 1965. [1] On 3 November 1965, the Army announced Lockheed as the winner of the AAFSS program selection. The Army perceived Lockheed's design as less expensive, able to be available earlier, and that it would have less technical risk than Sikorsky's Rotorprop. [1]

S-67 development

Lockheed's design soon ran into development problems and cost and timelines began to grow. Sensing an opportunity, Sikorsky offered an armed SH-3 Sea King (Sikorsky S-61) version. After further AAFSS problems, the company developed an intermediate, high-speed attack aircraft named the Sikorsky S-67 Blackhawk in 1970. [1] [3] [5] Design work on the S-67 began in November 1969 with manufacturing following in February 1970. The Blackhawk first flew on 20 August 1970. [6]

S-67 Blackhawk in head on view Sikorsky S-67 bw lo-res.jpg
S-67 Blackhawk in head on view

The S-67 featured a five-bladed main rotor and tail rotor. The main rotor was taken from the S-61, but was modified to have a hub fairing, swept main rotor blade tips and a special "alpha-1" linkage which was added to the main rotor controls to increase collective pitch sensitivity and so extend the collective pitch range. The 20° swept main rotor blade tips help to overcome a phenomenon called sub-multiple oscillating track (SMOT) that causes variations in tip track at high Mach numbers. [5] [7] These allowed the S-67 to achieve and maintain high cruise speeds. To reduce drag at high speed, the main wheels retracted fully into the stub wing sponsons. It had speed brakes on the wing trailing edges [8] that could be used to decrease speed or increase maneuverability. [3]

The S-67 was fitted with a moving map display, a hands-on-collective radio tune control, and night vision systems. Its armament included a Tactical Armament Turret (TAT-140) with a three barrel 20 mm (0.79 in) cannon, and could carry 16 TOW missiles, 2.75-inch (70 mm) rockets, or AIM-9 Sidewinder air-to-air missiles. [3] The Blackhawk was powered by two General Electric T58-GE-5 1,500 shaft horsepower (1,100 kW) engines. [9]

Operational history

Evaluation and records

The S-67 Blackhawk, along with the Bell 309 KingCobra, was put through a series of flight test evaluations in 1972 by the U.S. Army. [10] Neither aircraft was selected to replace the AH-56 Cheyenne. Instead, the Army chose to create the new Advanced Attack Helicopter program, which would lead to the AH-64 Apache several years later.

The S-67 performed a series of aerobatic maneuvers during its various marketing tours, including rolls, split-S, and loops. The S-67 was reputed to be very smooth and responsive, in spite of its size and speed.

Piloted by Sikorsky Test Pilots Kurt Cannon and Byron Graham, the S-67 established two E-1 class world speed records on 14 December 1970 by flying at 348.97 km/h (217 mph) over a 3 km (1.9 mi) course, [11] and 355.48 km/h (221 mph) on 15 to 25 km (9.3 to 16 mi) course on 19 December 1970. [12] These records stood for eight years.

As part of internal Sikorsky R&D efforts, in 1974, the S-67 had a 3.5-foot-diameter (1.1 m) ducted fan fitted instead of its original conventional tail rotor. [3] The S-67 with fan was tested over 29 flight hours to compare to the conventional tail. [13] In this configuration it reached a speed of 230 mph (370 km/h) in a test dive. [3] The original tail rotor and vertical tail fin were re-installed in August 1974.

Fatal crash and aftermath

The lone S-67 prototype crashed while conducting a low-level aerobatic demonstration at the Farnborough Airshow on 1 September 1974. The crew misjudged their pitch in a low-level roll maneuver causing the nose to drop below the horizon: they attempted to recover from their inverted position by performing a Split S maneuver, but they were too close to the ground. The aircraft struck the ground in a level attitude and immediately burst into flames. Sikorsky test pilot Stu Craig died on impact, and test pilot Kurt Cannon died nine days later from his injuries. [14] Development work on the S-67 ceased after the accident. [9]

The U.S. Army later assigned the name Black Hawk to the Sikorsky UH-60 Black Hawk helicopter.

Specifications (S-67 Blackhawk)

S-67 3-view Sikorsky S-67 3 View.jpg
S-67 3-view

Data from Jane's all the World's Aircraft 1973–74 [15] Illustrated Encyclopedia of Helicopters, [3] Attack Helicopter Evaluation [16]

General characteristics

Performance

162 kn (186 mph; 300 km/h) maximum cruise

Armament

See also

Related development

Aircraft of comparable role, configuration, and era

Related lists

Related Research Articles

<span class="mw-page-title-main">Sikorsky S-70</span> Family of medium transport/utility military helicopters

The Sikorsky S-70 is an American medium transport/utility helicopter family manufactured by Sikorsky Aircraft. It was developed for the United States Army in the 1970s, winning a competition to be designated the UH-60 Black Hawk and spawning a large family in U.S. military service. New and improved versions of the UH-60 have been developed since. Civilian versions, and some military versions, are produced under various S-70 model designations.

<span class="mw-page-title-main">Lockheed AH-56 Cheyenne</span> Canceled US helicopter program

The Lockheed AH-56 Cheyenne is an attack helicopter developed by Lockheed for the United States Army. It rose from the Army's Advanced Aerial Fire Support System (AAFSS) program to field the service's first dedicated attack helicopter. Lockheed designed the Cheyenne using a four-blade rigid-rotor system and configured the aircraft as a compound helicopter with low-mounted wings and a tail-mounted thrusting propeller driven by a General Electric T64 turboshaft engine. The Cheyenne was to have a high-speed dash capability to provide armed escort for the Army's transport helicopters, such as the Bell UH-1 Iroquois.

<span class="mw-page-title-main">Hughes XH-17</span>

The Hughes XH-17 "Flying Crane" was the first helicopter project for the helicopter division of Hughes Aircraft Company. The XH-17, which had a two-bladed main rotor system with a diameter of 134 feet, still holds the world record for flying with the largest rotor system. It was capable of flying at a gross weight of more than 50,000 pounds (23,000 kg), but proved too inefficient and cumbersome to be mass-produced beyond the prototype unit.

<span class="mw-page-title-main">Lockheed XH-51</span> 1962 experimental helicopter series by Lockheed

The Lockheed XH-51 is an American single-engine experimental helicopter designed by Lockheed Aircraft, utilizing a rigid rotor and retractable skid landing gear. The XH-51 was selected as the test vehicle for a joint research program conducted by the United States Army and United States Navy to explore rigid rotor technology.

<span class="mw-page-title-main">Sikorsky S-72</span> US experimental compound helicopter (hybrid helicopter/fixed-wing aircraft)

The Sikorsky S-72 was an experimental Sikorsky Aircraft compound helicopter developed as the Rotor Systems Research Aircraft (RSRA) for the National Aeronautics and Space Administration (NASA) and the United States Army. The RSRA was a testbed for rotor and propulsion systems for high-speed.

<span class="mw-page-title-main">Sikorsky S-69</span> US experimental co-axial compound helicopter

The Sikorsky S-69 is an American experimental compound helicopter developed by Sikorsky Aircraft as the demonstrator of the co-axial Advancing Blade Concept (ABC) with United States Army and NASA funding.

<span class="mw-page-title-main">Bell YAH-63</span> Pre-production attack helicopter

The Bell YAH-63 was an experimental attack helicopter for the Advanced Attack Helicopter (AAH) competition. Hughes' Model 77/YAH-64, later developed into the AH-64 Apache, was selected over Bell's entry.

<span class="mw-page-title-main">Bell 309 KingCobra</span> Prototype attack helicopter

The Bell Model 309 KingCobra was an experimental attack helicopter developed by Bell Helicopter, based on the Bell AH-1 Cobra.

<span class="mw-page-title-main">Cierva W.11 Air Horse</span> Type of aircraft

The Cierva W.11 Air Horse was a helicopter developed by the Cierva Autogiro Company in the United Kingdom during the mid-1940s. The largest helicopter in the world at the time of its debut, the Air Horse was unusual for using three rotors mounted on outriggers, and driven by a single engine mounted inside the fuselage.

<span class="mw-page-title-main">Fairey FB-1 Gyrodyne</span> Type of aircraft

The Fairey FB-1 Gyrodyne is an experimental British rotorcraft that used single lifting rotor and a tractor propeller mounted on the tip of the starboard stub wing to provide both propulsion and anti-torque reaction.

<span class="mw-page-title-main">Firestone XR-9</span> 1940s American experimental helicopter

The Firestone XR-9, also known by the company designation Model 45, was a 1940s American experimental helicopter built by the Firestone Aircraft Company for the United States Army Air Forces. Only two were built.

<span class="mw-page-title-main">Boeing Model 360</span> American experimental helicopter

The Boeing Model 360 is an American experimental medium-lift tandem rotor cargo helicopter developed privately by Boeing to demonstrate advanced helicopter technology. The aircraft was intended as a technology demonstrator, with no plans to put the type into production, and many of its design features were carried onto other programs including the RAH-66 Comanche and V-22 Osprey. The sole prototype has been preserved and is a static exhibit at the American Helicopter Museum in West Chester, Pennsylvania.

<span class="mw-page-title-main">Sikorsky XH-39</span> Type of aircraft

The Sikorsky XH-39, developed by Sikorsky Aircraft in 1954, was the U.S. Army's first turbine-powered helicopter. It was fast and innovative, but ultimately rejected by the United States Army in favor of the Bell UH-1 Iroquois.

<span class="mw-page-title-main">Sikorsky S-52</span> Type of aircraft

The Sikorsky S-52 is a utility helicopter developed by Sikorsky Aircraft in the late 1940s. It was used by the U.S. Navy, Marine Corps, and Coast Guard. The S-52 was the first US helicopter with all-metal rotor blades. Initially a two-seater, it was developed into the four-seat S-52-2 and S-52-3. It was designated HO5S-1 by the U.S. Navy and Marine Corps, HO5S-1G by the Coast Guard, and YH-18A by the U.S. Army, and was used extensively by civil operators after being retired by the military.

<span class="mw-page-title-main">Kellett XR-8</span> Type of aircraft

The Kellett XR-8 was a helicopter built in the United States during World War II. It was a two-seat machine intended to demonstrate the feasibility of a twin-rotor system and, while it accomplished this, it also demonstrated a number of problems that prevented further development of this particular design.

<span class="mw-page-title-main">Pitcairn PA-34</span> Type of aircraft

The Pitcairn PA-34 and Pitcairn PA-33, given the United States Navy (USN) designation Pitcairn OP-2 and United States Army designation Pitcairn YG-2 respectively were reconnaissance autogyros designed and built in 1936 for evaluation.

The Famà Kiss 209M is an Italian ultralight two-seat helicopter, built from composite materials around a steel frame and with an optional retractable undercarriage. The moniker "Kiss" stands for "keep it stupidly simple", reflecting the philosophy of its designer, Nino Famà.

<span class="mw-page-title-main">Dynali H2S</span> Belgian kit helicopter

The Dynali H2S is a Belgian helicopter, designed by Jacky Tonet and produced by Dynali of the Thines district of Nivelles. When it was available the aircraft was supplied as a kit for amateur construction or fully assembled, supplied ready-to-fly.

<span class="mw-page-title-main">RotorWay A600 Talon</span> American helicopter

The RotorWay A600 Talon is an American helicopter, designed and produced by RotorWay International of Chandler, Arizona. The aircraft is supplied as a kit for amateur construction.

The Midwest Zodiac Talon-Turbine is an American helicopter that was designed and produced by Midwest Engineering & Design of Overland Park, Kansas. When it was available the aircraft was supplied in the form of plans for amateur construction, but the plans are no longer advertised for sale.

References

Notes

  1. 1 2 3 4 Office of the Assistant Vice Chief of Staff of the Army (OAVCSA). An Abridged History of the Army Attack Helicopter Program, pp. 4–5, 9. Washington, DC: Department of the Army. 1973.
  2. ↑ Landis and Jenkins 2000, pp. 25, 85–87.
  3. 1 2 3 4 5 6 7 Apostolo 1984, p. 89.
  4. ↑ Landis and Jenkins 2000, p. 21.
  5. 1 2 Leoni, Ray. Black Hawk: The Story of a World Class Helicopter, p. 70. American Institute of Aeronautics and Astronautics, 2007. ISBN   978-1-56347-918-2.
  6. ↑ Yamakawa, et al. 1972, p. 1.
  7. ↑ US Patent: Blade for High Speed Helicopter
  8. ↑ Yamakawa, et al. 1972, p. 49.
  9. 1 2 Donald 1998. p. 845.
  10. ↑ Verier, Mike. Bell AH-1 Cobra, p. 138. Osprey Publishing, 1990. ISBN   0-85045-934-6.
  11. ↑ "Speed over a straight 3 km course at restricted altitude : km/h". Fédération Aéronautique Internationale. Archived from the original on 2007-09-27. Retrieved 2007-08-05.
  12. ↑ "Speed over a straight 15/25 km course : 355.48 km/h". Fédération Aéronautique Internationale. Archived from the original on 2007-10-11. Retrieved 2007-08-05.
  13. ↑ Cocke, Karl E. Department of the Army Historical Summary: FY 1974, Chapter XI Archived 2017-07-10 at the Wayback Machine . U.S. Army Center of Military History, 1978.
  14. ↑ Great Britain 1976.
  15. ↑ Taylor, John W.R., ed. (1973). Jane's all the World's Aircraft 1973–74 (63rd ed.). London: Sampson Low, Marston & Co. Ltd. pp. 439–440. ISBN   978-0070320215.
  16. ↑ Yamakawa, et al. 1972, pp. 49–51.

Bibliography

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.