Piasecki H-25

"For other uses of "H25" see H25 (disambiguation)." Infobox Aircraft
name=H-25/HUP Retriever


caption= Royal Canadian Navy HUP-3 at the Canadian Museum of Flight
type= Utility helicopter
manufacturer= Piasecki Helicopter
designer=
first flight=March 1948
introduced=1949
retired=1964
status=
primary user=United States Navy
more users=United States Army
produced=
number built=
unit cost=
variants with their own articles=

The Piasecki H-25 Army Mule/HUP Retriever was a compact single radial engine, twin overlapping tandem rotor utility helicopter developed by the Piasecki Helicopter Corporation of Morton, Pennsylvania during the late 1940s and produced during the early 1950s. The company changed its name in the 1956 to Vertol Aircraft Corporation and subsequently was bought by Boeing Aircraft Company in 1960, and became Boeing-Vertol.

Design and development

The design was a product of a competition by the U.S. Navy in 1945 for a compact utility/rescue helicopter to operate from Navy ships including aircraft carriers, battleships, and cruisers. The prototype was designated by the Navy as the XHJP-1, and first flew in March 1948. It was selected by the Navy for production, as the HUP-1 in a side-by-side flight evaluation against the Sikorsky XHJS-1. It entered service with the Navy and USMC from 1949.

Operational history

Versions of the HUP built for the U.S. Army were designated H-25 Army Mule. The tandem overlapping rotor configuration was a development by Piasecki and was used in future helicopter designs by the company and successors including the H-21, HRB-1/CH-46, and CH-47.

The design featured two three bladed 35 foot diameter rotors in tandem in which blades could be folded for storage in ships’ hangars. The HUPs were powered by a single Continental R975-46 radial engine, with a take-off rating of 550 hp. To provide rescue without crew assistance, an electrically operated door, available after folding the copilot’s seat forward, opened through which a rescue sling could be lowered from an overhead winch.The HUP was produced for the Navy in four versions: HUP-1, -2, and -3. The HUP-2 was the first production helicopter equipped with an auto-pilot. In addition to those delivered to the U.S. Navy and Army the HUP/H-25 helicopter was also delivered to the Canadian and French Navies. A total of 339 aircraft were delivered over the 20 year life of the aircraft.

The US Army H-25 designation was adopted by the other services in 1962. The final units were withdrawn from US service in 1964. It also served with the French Navy from 1953 to 1965.

Variants

;XHUP-1:The first two prototypes.

;HUP-1:Utility transport, search and rescue helicopter for the US Navy, powered by a 391-kW (525-hp) Continental R-975-34 piston engine.

;HUP-2:Improved version, powered by a 410-kW (550 hp) Continental R-975-46 piston engine. Later redesignated UH-25B in 1962.

;HUP-2S:This designation was given to number of HUP-2s. The HUP-2S was an anti-submarine warfare helicopter, fitted with a dunking sonar equipment.

;HUP-3:Utility transport helicopter for the US Navy, powered by a 410-kW (550-hp) Continental R-975-46A piston engine. Similar to the H-25A "Army Mule", later redesignated UH-25C in 1962.

;H-25A Army Mule:Utility transport helicopter for the US Army, powered by a 410-kW (550-hp ) Continental R-975-46A piston engine, fitted with large doors, power-boosted controls and strengthened floors. It was called the H-25A "Army Mule".

Operators

*
** Royal Canadian Navy
*
** French Navy
*:
** US Army
** US Navy

pecifications (HUP-2)

aircraft specifications
plane or copter?=copter
jet or prop?=prop

ref={name of first source}
crew=2 pilots
capacity=4 passengers
length main= 32 ft 0 in
length alt= 9.8 m
span main= 35 ft 0 in
span alt= 10.7 m
height main= 12 ft 6 in
height alt= 3.8 m
area main=
area alt=
airfoil=
empty weight main= 4,100 lb
empty weight alt= 1,864 kg
loaded weight main= lb
loaded weight alt= kg
useful load main= 1,650 lb
useful load alt= 341 kg
max takeoff weight main= lb
max takeoff weight alt= kg
more general=

engine (prop)=Continental R-975-42
type of prop=radial engine
number of props=1
power main= 550 hp
power alt= 737 kW
power original=

max speed main= 108 mph
max speed alt= 174 km/h
cruise speed main=
cruise speed alt=
never exceed speed main=
never exceed speed alt=
range main= 360 mi
range alt= 580 km
ceiling main= 10,200 ft
ceiling alt= 3,110 m
climb rate main=
climb rate alt=
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=

armament=
avionics=

pecifications (HUP-3)

aircraft specifications
plane or copter?=copter
jet or prop?=prop

ref={name of first source}
crew=2 pilots
capacity=4 passengers
length main= 56 ft 11 in
length alt= 17.35 m
span main= 35 ft 0 in
span alt= 10.67 m
height main= 12 ft 6 in
height alt= 3.81 m
area main= 1,924 ft²
area alt= 179 m²
airfoil=
empty weight main= 3,928 lb
empty weight alt= 1,782 kg
loaded weight main= 5,750 lb
loaded weight alt= 2,608 kg
useful load main= lb
useful load alt= kg
max takeoff weight main= 6,100 lb
max takeoff weight alt= 2,767 kg
more general=

engine (prop)=Continental R-975-46A
type of prop=radial
number of props=1
power main= 550 hp
power alt= 410 kW
power original=

max speed main= knots
max speed alt= 105 mph, 169 km/h
cruise speed main=
cruise speed alt=
never exceed speed main=
never exceed speed alt=
range main= nmi
range alt= 340 mi, 547 km
ceiling main= 10,000 ft
ceiling alt= 3,048 m
climb rate main= 100 ft/min
climb rate alt= 5.01 m/s
loading main= 3 lb/ft²
loading alt= 15 kg/m²
thrust/weight=
power/mass main= 0.09 hp/lb
power/mass alt= 0.16 kW/kg
more performance=

armament=
avionics=

ee also

aircontent

related=
* Piasecki H-21
* CH-46 Sea Knight

similar aircraft=

lists=

see also=

References

External links

* [http://www.redstone.army.mil/history/aviation/factsheets/h25.html H-25 US Army Aviation history fact sheet]