User:BillCJ/Sandbox/Piasecki X-49

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This is a sandbox for the updated Sikorsky/Piasecki X-49 article.
X-49 "Speedhawk"

The X-49 "Speedhawk" technology demonstrator showing its wings and tail-mounted variable-thrust ducted propeller

Type Experimental high-speed helicopter
Manufacturer Sikorsky (original airframe)
Piasecki Aircraft (modifications ad testing)
Maiden flight Projected for 2007
Status Under development
Primary user United States Army
Number built 1
Developed from SH-60 Seahawk

The X-49A "Speedhawk" is an experimental helicopter under development by Piasecki Aircraft using the airframe of a Sikorsky YSH-60F Seahawk.

Contents

[edit] Development

It is the subject of a $US 26.1-million U.S. Navy-sponsored project that consists of a Sikorsky YSH-60F helicopter modified by Piasecki as a testbed to test the "Vectored Thrust Ducted Propeller" (VTDP) system. One YSH-60F will be converted to test the feasibility of VTDP under an advanced technology demonstration program. The YSH-60F is powered by two General Electric T700-GE-401C engines.

The demonstration contract was awarded in October 2000 by the Naval Air Systems Command to Piasecki Aircraft. Piasecki will install a lifting wing with flaperons and a vectored-thrust ducted propeller (VTDP), or "ring tail," to a U.S. Navy Sikorsky YSH-60F.

The compound helicopter technology that will be added to the YSH-60F was first demonstrated in trials of the Piasecki 16H-1 and 16H-1A in the early 1960's, when the helicopters were flown at speeds up to 225 mph (360 km/h).

In 2004, the X-49A YSH-60F/VTDP demonstration program was being transitioned from the US Navy to the US Army.

[edit] Design

The X-49A YSH-60F flight demonstrator will be updated with a lifting wing taken from an Aerostar FJ-100 business jet. A ring tail will also be added and the helicopter drive train will be modified to accommodate VTDP. Piasecki will conduct integrated tests of the modified drive train at the Navy's helicopter transmission test facility.

The cockpit controls will be modified with the addition of a manual prop pitch override on the collective for the ring tail. This will be the only visible change to the aircraft's existing mechanical controls in the cockpit. The other controls needed to operate the compound helicopter's systems will be integrated into the aircraft's existing mechanical controls to reduce pilot workload. Weight added to the X-49A YSH-60F will be about 1,600 lb (725 kg).

[edit] Operational history

First fight is planned for mid-2007. [1]

[edit] Text

[edit] Text 1

Trials to start using Piasecki-modified Sikorsky H-60 helicopter planned to achieve speeds of up to 200kt.

Piasecki Aircraft is preparing its X-49 experimental compound helicopter for a first flight before the end of June.

The modified Sikorsky H-60, with wings and tail-mounted variable-thrust ducted propeller (VTDP), has been moved to Boeing's Wilmington, Delaware facility for ground and flight testing.


© Piasecki SpeedHawk has wings and tail-mounted variable-thrust ducted propeller


Dubbed the SpeedHawk by Piasecki, the X-49 is being developed with incremental funding from the US Army's Aviation Applied Technology Division to demonstrate the ability to increase the speed of existing helicopters to 200kt (360km/h).

The VTDP replaces the tail rotor and provides thrust for forward flight, while the wing unloads the rotor and allows the helicopter to fly faster.

Initially the aircraft will be flown within the SH-60's existing flight envelope, but the company then plans to install a third engine and push the helicopter to 200kt, says vice-president John Piasecki.

In forward flight most of the more than 2,100shp (1,560kW) from the two main engines will go to the VTDP, says Piasecki.

The third engine, called a secondary power unit, will replace the existing auxiliary power unit and provide another 600-700shp to the ducted propeller to push the compound helicopter to higher speed.

"This technology gives the helicopter the ability to productively use the extra power in forward flight," says Piasecki.

"Traditionally we add power to lift more, but we are at the outer edge of the envelope on the H-60, where a marginal increase in power brings a significant reduction in forward speed."

This is because the heavily loaded rotor stalls at higher speeds.

"The UH-60 is a 90kt helicopter in Afghanistan," claims Piasecki. "The power that goes into the high/hot hover cannot be used in forward flight."

While the SpeedHawk wing and tail add weight and download, "the aircraft has adequate margin in the hover to carry the payload, then can harness the power to fly at 200kt", he says.

Funding permitting, Piasecki plans about 100h of flight testing in the X-49 programme's first phase.

Funding to install the SPU and perform a nine-month drag clean-up for high-speed flight testing, which includes fitting retractable gear and a rotor-hub fairing, has yet to be secured.

[edit] Operators

Flag of the United States United States

[edit] Specifications

[edit] X-49A

[edit] SH-60B (for comparison)

Data from Brassey's World Aircraft & Systems Directory[2]

General characteristics

  • Crew: 3
  • Capacity: 8 passengers or slung load of 6,000 lb or internal load of 4,100 lb for -B, -F and -H models and 11 passengers or slung load of 9,000 lb for -S
  • Length: 64 ft 10 in (19.76 m)
  • Rotor diameter: 53 ft 8 in (16.36 m)
  • Height: 17 ft 2 in (5.23 m)
  • Disc area: 2,262 ft² (210 m²)
  • Empty weight: 13,648 lb (6,190 kg)
  • Loaded weight: 20,110 lb (9,575 kg)
  • Max takeoff weight: 21,884 lb (9,927 kg)
  • Powerplant: 2× General Electric T-700-GE-401C turboshaft, 1,620 hp (1,208 kW) continuous each

Performance

Armament

[edit] References

  1. ^ Graham Warwick (2007-05-30). High speed helicopter set for first flight in June. FlightGlobal.com. Retrieved on 2007-07-01.
  2. ^ Taylor, M J H (editor) (1999). Brassey's World Aircraft & Systems Directory 1999/2000 Edition. Brassey's. ISBN 1 85753 245 7. 

[edit] External links

[edit] See also


Related development

Related lists

Category:Helicopters Category:VTOL aircraft X-49, Sikorsky Piasecki