rotormatic
20th Dec 2000, 08:17
What do you think of the compound helicopter being an alternative to the tilt rotor?
Piasecki Aircraft Wins U.S. Navy Contract
by John Persinos
GOVERNMENT "EXPERTS" ARE wonderfully reliable contrarian indicators. For example, in 1899, the Director of the U.S. Patent Office, Charles Duell, said: "Everything that can be invented has been invented." Fortunately, inventors such as Frank Piasecki never subscribe to conventional wisdom.
Piasecki, an aviation legend, has, over the years, introduced a host of trail-blazing innovations in rotorcraft design. In particular, he has spent the last four decades doggedly advocating his proprietary technology for compound helicopters. This fall, his efforts achieved a major milestone, with sweeping consequences for the entire industry.
Piasecki Aircraft Corp., Essington, Pennsylvania, was awarded in late October a $26.1 million four-year U.S. Navy contract for the design, fabrication, and flight test of a Vectored Thrust Ducted Propeller (VTDP) compound helicopter. The compound helicopter is based on a modified Sikorsky H-60 Hawk family airframe.
Sponsored by the Office of Naval Research, the primary objective of this flight demonstration is to show the potential improvements in speed, range, survivability, and reduced life cycle costs attainable with Piasecki's VTDP technology. The VTDP compound helicopter achieves these goals by adding fixed wings and a tail-mounted ducted propeller.
Piasecki Aircraft, founded by Frank Piasecki in 1956, has long proposed this technology as a way to enhance performance and reduce costs of rotorcraft. Today, the company has 50 employees, 20 of them engineers. Starting with Frank's groundbreaking R&D in the early 1960s, the company pioneered the development of compound helicopters. Frank celebrated his 81st birthday in October and still shows up at work, six days a week.
John Piasecki, Frank’s son and company vice president, says that the VTDP compound helicopter is capable of faster cruise speeds, longer range, superior maneuverability, and reduced costs. The VTDP design augments the aircraft’s lift, combating retreating blade stall by unloading the main rotor system as the burden of lift is transferred to the wing.
In addition to the stability conferred by the fixed wing, the aircraft reaches greater speeds because of auxiliary propulsion provided by the tail-mounted VTDP, commonly referred to as the "ringtail." The combination of the VTDP and a lifting wing provides for increased speed over 200 knots in production configurations, as well as greater maneuverability and reduced vibration and fatigue loads.
The compound helicopter confers several advantages to the armed forces. One of the most important, in the post-Cold War era of limited military budgets, is lower operating costs. By lowering fatigue loads and vibration levels, the technology can reduce costs and extend the life of parts. The technology also enables a rotary wing aircraft to fly at up to 220 knots; an attack helicopter fitted with the VTDP system would make for a formidable warship.
John Piasecki says the idea of compound helicopters is coming back into vogue with military planners because of the convergence of limited resources and expanded performance requirements.
"This contract traces its origins to early Cold War competitions, but the compound technology is still very relevant, as armed helos proliferate in Third World countries," he says. "Armed helos are versatile and cost-effective aerial weapons platforms. Navy and Marines Corps aerial assault forces are projected over the sea at greater and greater distances. Emerging military requirements are driving the compound helicopter concept, not the old Fulda Gap scenarios."
The U.S. Marines are committed to the V-22 tiltrotor as an aerial assault platform, but they still rely on conventional helicopters, such as the Cobra and Huey. That’s where compound technology can make a difference. "Compound helicopter technology could extend the performance and life of these legacy aircraft, to reduce their performance shortfall as compared to the V-22," he says.
Piasecki Aircraft’s VTDP was competitively selected by the Navy under the FY00 Advanced Technology Demonstration program, which funds development and testing of high risk/high payoff technologies to address the Navy’s future warfighting needs.
The contract was awarded after Piasecki successfully completed ground testing of a full-scale flightworthy VTDP unit under a $16.1 million concept exploration and development contract. John Piasecki says the VTDP Ground Test results were better than predicted, meeting all of the technical criteria necessary to proceed into the flight demonstration phase of the program.
The flight test program will be conducted by a Joint Piasecki and Naval Rotary Wing Test Squadron Team, starting in 2003. The VTDP compound helicopter concept is being investigated as an affordable means of addressing the Defense Department’s need to upgrade the capabilities and extend the service life of existing single-rotor helicopters.
Based on the services’ current aviation modernization plans, the Defense Department is projected to spend over $41 billion to extend the capability and service life of the H-60, H-1, and AH-64 fleets until Joint Replacement Aircraft are fielded sometime after 2025.
The Air Force selected the H-60/VTDP compound helicopter concept as one of several alternatives under consideration as an upgrade or replacement for its aging HH-60G combat rescue helicopter fleet. The replacement is slated to be fielded as early as FY07.
Piasecki Aircraft Wins U.S. Navy Contract
by John Persinos
GOVERNMENT "EXPERTS" ARE wonderfully reliable contrarian indicators. For example, in 1899, the Director of the U.S. Patent Office, Charles Duell, said: "Everything that can be invented has been invented." Fortunately, inventors such as Frank Piasecki never subscribe to conventional wisdom.
Piasecki, an aviation legend, has, over the years, introduced a host of trail-blazing innovations in rotorcraft design. In particular, he has spent the last four decades doggedly advocating his proprietary technology for compound helicopters. This fall, his efforts achieved a major milestone, with sweeping consequences for the entire industry.
Piasecki Aircraft Corp., Essington, Pennsylvania, was awarded in late October a $26.1 million four-year U.S. Navy contract for the design, fabrication, and flight test of a Vectored Thrust Ducted Propeller (VTDP) compound helicopter. The compound helicopter is based on a modified Sikorsky H-60 Hawk family airframe.
Sponsored by the Office of Naval Research, the primary objective of this flight demonstration is to show the potential improvements in speed, range, survivability, and reduced life cycle costs attainable with Piasecki's VTDP technology. The VTDP compound helicopter achieves these goals by adding fixed wings and a tail-mounted ducted propeller.
Piasecki Aircraft, founded by Frank Piasecki in 1956, has long proposed this technology as a way to enhance performance and reduce costs of rotorcraft. Today, the company has 50 employees, 20 of them engineers. Starting with Frank's groundbreaking R&D in the early 1960s, the company pioneered the development of compound helicopters. Frank celebrated his 81st birthday in October and still shows up at work, six days a week.
John Piasecki, Frank’s son and company vice president, says that the VTDP compound helicopter is capable of faster cruise speeds, longer range, superior maneuverability, and reduced costs. The VTDP design augments the aircraft’s lift, combating retreating blade stall by unloading the main rotor system as the burden of lift is transferred to the wing.
In addition to the stability conferred by the fixed wing, the aircraft reaches greater speeds because of auxiliary propulsion provided by the tail-mounted VTDP, commonly referred to as the "ringtail." The combination of the VTDP and a lifting wing provides for increased speed over 200 knots in production configurations, as well as greater maneuverability and reduced vibration and fatigue loads.
The compound helicopter confers several advantages to the armed forces. One of the most important, in the post-Cold War era of limited military budgets, is lower operating costs. By lowering fatigue loads and vibration levels, the technology can reduce costs and extend the life of parts. The technology also enables a rotary wing aircraft to fly at up to 220 knots; an attack helicopter fitted with the VTDP system would make for a formidable warship.
John Piasecki says the idea of compound helicopters is coming back into vogue with military planners because of the convergence of limited resources and expanded performance requirements.
"This contract traces its origins to early Cold War competitions, but the compound technology is still very relevant, as armed helos proliferate in Third World countries," he says. "Armed helos are versatile and cost-effective aerial weapons platforms. Navy and Marines Corps aerial assault forces are projected over the sea at greater and greater distances. Emerging military requirements are driving the compound helicopter concept, not the old Fulda Gap scenarios."
The U.S. Marines are committed to the V-22 tiltrotor as an aerial assault platform, but they still rely on conventional helicopters, such as the Cobra and Huey. That’s where compound technology can make a difference. "Compound helicopter technology could extend the performance and life of these legacy aircraft, to reduce their performance shortfall as compared to the V-22," he says.
Piasecki Aircraft’s VTDP was competitively selected by the Navy under the FY00 Advanced Technology Demonstration program, which funds development and testing of high risk/high payoff technologies to address the Navy’s future warfighting needs.
The contract was awarded after Piasecki successfully completed ground testing of a full-scale flightworthy VTDP unit under a $16.1 million concept exploration and development contract. John Piasecki says the VTDP Ground Test results were better than predicted, meeting all of the technical criteria necessary to proceed into the flight demonstration phase of the program.
The flight test program will be conducted by a Joint Piasecki and Naval Rotary Wing Test Squadron Team, starting in 2003. The VTDP compound helicopter concept is being investigated as an affordable means of addressing the Defense Department’s need to upgrade the capabilities and extend the service life of existing single-rotor helicopters.
Based on the services’ current aviation modernization plans, the Defense Department is projected to spend over $41 billion to extend the capability and service life of the H-60, H-1, and AH-64 fleets until Joint Replacement Aircraft are fielded sometime after 2025.
The Air Force selected the H-60/VTDP compound helicopter concept as one of several alternatives under consideration as an upgrade or replacement for its aging HH-60G combat rescue helicopter fleet. The replacement is slated to be fielded as early as FY07.