Piasecki HUP Retriever

H-25 / HUP Retriever
Type:	helicopter
Design country:	United States
Manufacturer:	Piasecki Helicopter Corporation
First flight:	March 1948
Commissioning:	February 1949
Production time:	1949-1954
Number of pieces:	339

The Piasecki HUP Retriever / H-25 Army Mule is a small, single-engine, universal helicopter in tandem configuration that was built by the Piasecki Helicopter Corporation of Morton , Pennsylvania . Designed according to the specifications of the United States Navy , the helicopter was built from 1949 to 1954 and was also used by the United States Army and by navies in other countries. The HUP / H-25 was the first helicopter to flow a loop and the first with an autopilot .

development and construction

The H-25 was developed based on a tender by the US Navy in 1945. This tender called for a compact utility and rescue helicopter that could operate from ships such as aircraft carriers , battleships and cruisers . Depending on the source, two or three prototypes with the designation PV-14 (designated by the US Navy XHJP-1) were built and evaluated in a direct comparison in a flight together with three prototypes of the Sikorsky XHJS-1 . The XHJS-1 was basically an enlarged version of the Sikorsky H-5 . The higher weight increased the problems of construction with a workable weight and balance in different loading situations. In the end, Piasecki won the tender and series production was started under the name HUP-1.

The helicopter has two three-bladed rotors 35 ft (11 m) in diameter in a tandem configuration, the blades of which can be folded for storage. Due to the relatively small rotor diameter, the helicopter can be transported in aircraft carrier lifts with the rotors folded out. The tandem configuration with overlapping rotors was developed by Piasecki and also used in other models such as the H-21 , the HRB-1 / CH-46 and the CH-47 . Initially, the HUP-1 was from one of Continental Motors built air-cooled R-975-34 Continental - radial engine with a power driven by 525 horsepower (386 kW), the later by a R-975-42 or R-975-46A 550 HP (405 kW) was replaced.

For search and rescue missions , the helicopter is equipped with a cable winch with a lifting capacity of 400 lb (181 kg), which can be lowered through an electrically operated door when the co-pilot seat is folded forward.

During a flight to demonstrate its resistance to high g-forces , the H-25 was the first helicopter to loop - albeit unintentionally .

In the 1960s, attempts were made to develop a rescue system. For this purpose, the cockpit was designed as a rescue capsule that could be detached and should land on parachutes . In addition to partial tests, unmanned tests were also carried out with remote-controlled machines. The tests were successful and the feasibility was thus proven, but such a system found no further use in helicopter construction. The tests are documented, among other things, by film recordings that are now freely accessible.

Usage history

H-25A Army Mule in the US Army Aviation Museum in Alabama

With the delivery of 32 HUP-1s to the US Navy , the first copies were put into service in February 1949. Soon afterwards, the improved HUP-2 (factory designation PV-18) with a more powerful engine , without the inwardly inclined, horizontal fins and with various minor changes to the equipment, as well as a variant with a diving sonar for fighting submarines called HUP- 2S introduced. The HUP-2 was the first helicopter with an autopilot . The U.S. Navy also tested a system called the Raydist , which could be used to remotely control an unmanned HUP-2 from a ground station and instruct it to hover within five feet of a specified point. The Edo Aircraft Corporation tested a HUP-2 with GRP -Hülle and floating booms for amphibious operations. A further improved version of the HUP-2 was built for the US Army under the designation H-25A Army Mule . Most of the specimens, however, were quickly taken out of service in the Army and converted as HUP-3 for service in the US Navy.

In 1954, the Royal Canadian Navy received three US Army H-25As that had been converted into HUP-3s. The machines were stationed on the HMCS Labrador for search and rescue missions and other operations. It was later used in the construction of the Distant Early Warning Line . Thereafter, the helicopters were relocated to Patricia Bay Military Airfield and Canadian Forces Base Shearwater . After the last two copies were retired on January 18, 1964, one was donated to a technical school and two more were sold.

In 1962 the US Army designation H-25 was adopted by the US Navy as part of the introduction of the designation system for aircraft of the US armed forces . The last units were retired in 1964. The H-25 was also used by the Aéronavale between 1953 and 1965.

A total of 339 helicopters were delivered during the six-year production period. Many of the decommissioned US Navy helicopters were later registered as civilian machines, and at least seven were sold to the French Navy.

Incidents

7 November 2009 collided a HUP-1 with the license plate N183YP in Adelanto , California with a landline and crashed. In the crash and the resulting fire, all three occupants were killed and the aircraft destroyed. The helicopter operated in cooperation with the Classic Rotors Museum was the last airworthy example in the world. The NTSB attributed the crash to the fact that the pilot had not kept a sufficient distance from the overhead line.

variants

XHJP-1

Prototype powered by a Continental R-975 -34 with 525  PS (386  kW ), equipped with large, inclined fins on the horizontal stabilizers, factory designation PV-14 , two or three built copies

HUP-1

Transport and rescue helicopter for the US Navy , largely identical to the XHJP-1, factory designation PV-18 , 32 copies built

US Navy HUP rescuing a pilot near USS Block Island (CVE-106), August 12, 1953

HUP-2

improved version, powered by a Continental R-975-42 with 550 PS (405 kW), horizontal stabilizers removed, 165 units for the US Navy, 15 units for the French Navy, designation changed to UH-25B in 1962

HUP-2S

Version for fighting submarines, equipped with diving sonar, built 12 units

HUP-3

Conversion of the US Army model H-25A for the US Navy, 50 units went to the US Navy and 3 units to the Royal Canadian Navy , US Navy machines were renamed UH-25C in 1962

H-25A Army Mule

Universal transport helicopter of the US Army, identical in construction to the HUP-2, but powered by a Continental R-975-46A with 550 HP (405 kW), equipped with larger doors and reinforced floor, 70 copies were delivered from 1953, but were unusable for the front line, 53 units were delivered between 1954 and 1955 to the Royal Canadian Navy and the US Navy , the rest used for training and retired in 1958.

UH-25B

1962 renamed HUP-2

UH-25C

1962 renamed HUP-3

operator

 Canada

• Royal Canadian Navy

 France

• Aéronavale

 United States

• United States Army
• United States Navy

Preserved copies

Royal Canadian Navy HUP-3 51-16621 in the Canadian Museum of Flight ; was later sold to Classic Rotors .

Canada

Displayed

UH-25B (HUP-2)

• Shearwater Aviation Museum in Shearwater , Nova Scotia

UH-25C (HUP-3)

• Canada Aviation and Space Museum in Ottawa , Ontario

Netherlands

Displayed

UH-25B (HUP-2)

• Roundabout at Baris Business Park Roadway in Rotterdam

United Kingdom

Displayed

UH-25C (HUP-3)

• The Helicopter Museum in Weston-super-Mare , England

United States

Displayed

H-25A Army Mule

• United States Army Aviation Museum in Fort Rucker , Alabama

HUP-1

• USS Hornet Museum in Alameda , California

UH-25B (HUP-2)

• American Helicopter Museum in West Chester , Pennsylvania
• Wings of Freedom Aviation Museum in Horsham , Pennsylvania
• Intrepid Sea, Air & Space Museum in New York City , New York
• Flying Leatherneck Aviation Museum in San Diego , California
• USS Midway Museum in San Diego, California
• On the deck of the USS Iowa Museum in San Pedro , California

UH-25C (HUP-3)

HUP-3 Retriever in the Kalamazoo Aviation History Museum

• Pima Air & Space Museum in Tucson , Arizona
• Kalamazoo Aviation History Museum in Kalamazoo , Michigan
• National Museum of Naval Aviation in Pensacola , Florida
• Mid-America Air Museum in Liberal , Kansas
• Classic Rotors Museum in Ramona , California

Not in exhibition

UH-25C (HUP-3)

• Yanks Air Museum in Chino , California

Technical data (HUP-2)

crew	2
Passengers	4th
length	56.9  ft (Err  m )
Rotor diameter	35 ft (10.7 m)
height	13.2 ft (Err m)
Empty mass	4,132  lb (1,874.2  kg )
MTOW	6,100  lb (2,766.9  kg )
Top speed	91  kn (169  km / h )
Cruising speed	70 kn (130 km / h)
Range	295  NM (546  km )
Service ceiling	10,000 ft (3,048 m)
Max. Rate of climb	1000 ft / min

literature

• Leonard Bridgman: Jane's All The World's Aircraft 1956-57 . The McGraw-Hill Book Company, New York 1956 (English).
• Stephen Harding: US Army Aircraft Since 1947 . Airlife, Shrewsbury 1990, ISBN 1-85310-102-8 (English).
• Gordon Swanborough, Peter M. Bowers: United States Navy Aircraft since 1911 . 2nd Edition. Naval Institute Press, Annapolis, Maryland 1976, ISBN 0-87021-968-5 (English).

Web links

Commons : Piasecki HUP Retriever  - collection of images, videos and audio files

Individual evidence

1. ↑ ^{a b c d e f g h i j k l} Gordon Swanborough, Peter M. Bowers: United States Navy Aircraft since 1911 . 2nd Edition. Naval Institute Press, Annapolis, Maryland 1976, ISBN 0-87021-968-5 , pp. 461 (English).
2. ↑ ^{a b c d e f g h i j k l} HUP-1 Retriever / H-25 Army Mule Helicopter. Boeing , accessed January 30, 2020 . 
3. ↑ ^{a b} Joe Baugher: US Navy and US Marine Corps BuNos, Third Series. August 24, 2018, accessed November 1, 2018 . 
4. ↑ ^{a b c d} Vinny Devince: S-53 (USNavy (XHJS-1). Igor Sikorsky Historical Archives, April 10, 2013, accessed September 1, 2018 (English). 
5. ↑ ^{a b} Ray Watkins Collection. 1000aircraftphotos, April 30, 2009, accessed January 26, 2014 . 
6. ↑ US Navy Helicopter Escape Capsule Ballistic System Ejection Development Program Film 17104. US Navy , accessed January 31, 2020 . 
7. ↑ Radio Waves Hold Helicopter In Fixed Hovering Position . In: Popular Mechanics . Hearst Magazines, May 1954, pp. 122 (English, google.com ).
8. ↑ Picture News: Watertight hull makes helicopter amphibious . In: Popular Science . tape 172 , no. 2 , February 1958, p. 149 (English).
9. ↑ ^{a b c} Joe Baugher: US Navy and US Marine Corps BuNos, Third Series (120341 to 126256). joebaugher.co, July 26, 2018, accessed on January 31, 2020 . 
10. ↑ ^{a b c d e f g} R.WR Walker: Royal Canadian Navy - HUP detailed list. Canadian Military Aircraft Serial Numbers, accessed October 31, 2018 . 
11. ↑ ^{a b} Joe Baugher: US Navy and US Marine Corps BuNos, Third Series (145,062 to 150,138). October 2, 2018, accessed October 31, 2018 . 
12. ↑ ^{a b c} Joe Baugher: 1951 USAF Serial Numbers. September 2, 2018, accessed October 31, 2018 . 
13. ↑ Piasecki HUP-3. Ingenium Canada - Canada Air and Space Museum, accessed January 31, 2020 . 
14. ↑ ^{a b c d} Piasecki HUP-3. Shearwater Aviation Museum, accessed January 31, 2020 . 
15. ↑ ^{a b} National Transportation Safety Board Aviation Accident Final Report. National Transportation Safety Board , November 7, 2009; accessed January 31, 2020 . 
16. ^ Richard Mallory Allnutt: Piasecki crash claims three lives . In: Aircraft Illustrated . Key Publishing Ltd., December 25, 2009, ISSN  0002-2675 (English).
17. ↑ ^{a b} Stephen Harding: US Army Aircraft Since 1947 . Airlife, Shrewsbury 1990, ISBN 1-85310-102-8 , pp. 197-198 (English).
18. ↑ ^{a b c d} HUP-1 RETRIEVER / H-25 ARMY MULE HELICOPTER. Boeing, accessed January 31, 2020 . 
19. ^ Howard Skaarup: Canadian Warplanes . iUniverse, Bloomington, Indiana 2009, ISBN 978-1-4401-6758-4 , pp. 520 (English).
20. ↑ Piasecki H-25 / HUP Retriever. aerialvisuals.ca, accessed January 31, 2020 . 
21. ↑ De helicopter. Baris Groep, accessed January 31, 2020 (Dutch). 
22. ↑ Piasecki HUP Retriever / 51-16616. aerialvisuals.ca, accessed January 31, 2020 . 
23. ↑ Piasecki HUP Retriever / 124915. aerialvisuals.ca, accessed January 31, 2020 . 
24. ↑ Piasecki HUP Retriever / 128479. aerialvisuals.ca, accessed January 31, 2020 . 
25. ^ Piasecki HUP-2 "Retriever". Wings of Freedom Aviation Museum, accessed January 31, 2020 . 
26. ↑ Piasecki HUP Retriever / 128519. aerialvisuals.ca, accessed January 31, 2020 . 
27. ↑ Piasecki HUP Retriever / 128596. aerialvisuals.ca, accessed January 31, 2020 . 
28. ↑ Piasecki HUP Retriever / 130059. aerialvisuals.ca, accessed January 31, 2020 . 
29. ↑ Donna Littlejohn: Historic wartime helicopter to be pieced together for San Pedro's Battleship Iowa. Daily Breeze, El Segundo, California, September 26, 2017, accessed January 31, 2020 . 
30. ↑ Piasecki HUP Retriever / 147595. aerialvisuals.ca, accessed January 31, 2020 . 
31. ↑ Piasecki HUP Retriever / 147600. aerialvisuals.ca, accessed January 31, 2020 . 
32. ↑ Piasecki HUP Retriever / 147607. aerialvisuals.ca, accessed January 31, 2020 . 
33. ↑ Piasecki HUP Retriever / 147628. aerialvisuals.ca, accessed January 31, 2020 . 
34. ↑ N-Number Inquiry Results N7089F. Federal Aviation Administration , November 1, 2018, accessed January 31, 2020 . 
35. ↑ Piasecki HUP Retriever / 147610. aerialvisuals.ca, accessed January 31, 2020 .