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Eine sehr interessanter Artikel kam mir heute in die Finger. Piasecki testet den Speedhawk, ein Prototyp abgeleitet aus dem normalen H-60 Blackhawk. Am Heck soll ein "variable-thrust ducted propeller" installiert werden. Ebenfalls werden kleine Flügel installiert. Der Speedhawk soll dann bis zu 200kts erreichen, mehr als doppelt so viel wie ein Blackhawk derzeit im Einsatz.
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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.
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.
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Quelle: piasecki.com
Hierzu einige Fragen:
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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.
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.
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Quelle: piasecki.com
Hierzu einige Fragen:
- Ich lese erstaunt, dass der H-60 nur 90kts Geschwindigkeit schafft, wohingegen 130kts/160kts/193kts angegeben sind (Reise/Max/NeverExceed).
- Meint Ihr, dass dieses System tatsächlich Verwendung findet als Kompromisslösung zwischen den etablierten Drehflüglern und leistungsfähigeren aber bisher eher enttäuschenden Lösungen wie der V-22?
- Was ist denn die tatsächliche, zwecksmäßige Höchstgeschwindigkeit der meisten Hubschrauber? Ich meine zu wissen, dass der UH-1 in etwa 120kts gemacht hat, lieber aber bei 90kts geflogen wurde.