245:, where Captain Selmer Sundby took over test-flying duties. The HZ-1 had been designed to be very easy to fly, and early testing indicated that untrained soldiers could learn to operate the craft in less than 20 minutes, and some claiming that only 5 minutes of instruction were required. In addition, the HZ-1 proved to be faster than other flying platform designs evaluated by the Army. Sundby, however, quickly determined that the craft was much more difficult to fly than had been expected and would not be safe in the hands of an inexperienced pilot. In addition, the low-mounted rotors proved to be prone to kicking up small rocks and other debris.
218:
36:
476:
257:, and it was discovered that the Aerocycle's forwards speed was limited by an uncontrollable pitching motion, but rotor-tip clearance was always sufficient. The inability to determine the precise cause of the intermeshing, combined with the fact that the "personal lifting device" concept was failing to live up to its expectations, led to the decision to terminate the project.
230:. Over 160 flights totaling more than 15 hours of flight time were conducted, and the results of this early test flight program were considered promising enough that a dozen examples of the type were ordered (serial numbers 56-6928 to 56-6939). Predictions were made that the craft could provide transport to a modern version of the old horse
289:
184:
The concept proposed by de
Lackner Helicopters was a one-man flying platform and received the company designation "DH-4". The DH-4 was expected to be able to carry up to 120 pounds (54 kg) of cargo or an auxiliary 5-US-gallon (19 L; 4.2 imp gal) fuel tank to extend its range up to
248:
Over a series of tethered and free-flying test flights lasting up to 43 minutes, the HZ-1 suffered a pair of accidents. Both crashes occurred under similar conditions – the contra-rotating rotors intermeshed and collided, the blades shattering, causing an immediate loss of
208:
motorcycle-style throttle and transferred power to the 15-foot (4.6 m) diameter, contra-rotating rotors via belt drive with a chain reduction unit. The aircraft's landing gear consisted of airbags at the end of each arm of the frame along with a large rubber float in the middle, providing
165:(NACA) developed a system for control of a rotorcraft in which, with the rotors mounted on the underside of the aircraft, the machine could be steered by the pilot through the simple shifting of his weight and kept stable through the actions of his natural reflexes. Known as
225:
Originally designated YHO-2 by the U.S. Army, then later re-designated HZ-1 and named "Aerocycle", the prototype made its first tethered flight on 22 November 1954, with its first free flight taking place in
January 1955 at the
304:
flying platforms. Designed for use from 0 to 50 miles per hour (0–80 km/h) and at altitudes as low as 25 feet (7.6 m), the XMP-2 proved to have insufficient reliability for use as a personnel parachute.
173:, it was hoped that the concept would allow pilots to operate an aircraft with little to no training time. NACA testing proved that the idea had merit, and several companies, including
1282:
765:
130:
69:
817:
348:
Of the dozen examples of the type ordered by the U.S. Army, only a single example of the HZ-1 has survived, and this aircraft is currently on display in the
166:
133:
in the mid-1950s. Intended to be operated by inexperienced pilots with a minimum of 20 minutes of instruction, the HZ-1 was expected to become a standard
1262:
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with extremely fast opening characteristics, the "Ultra-Fast
Opening Personnel Parachute Type XMP-2", was developed for use in testing of the HZ-1 and
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50 miles (80 km) in addition to its pilot. A cargo lifting line could be threaded through the rotor shaft for the carrying of
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amphibious capability, although this arrangement was later replaced by a pair of conventional helicopter-type skids.
145:, more extensive evaluation proved that the aircraft was in fact too difficult to control for operation by untrained
1302:
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149:, and after a pair of crashes the project was abandoned. A single model of the craft was put on display.
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The machine was a simple, cross-shaped frame, with the pilot standing on a platform, secured by a
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891:. Moffett Field, CA: NASA Ames Research Center. NASA Technical Paper 3675. Archived from
141:. Although early testing showed that the craft had promise for providing mobility on the
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control resulting in a crash. Aerodynamic testing was conducted in the full-scale
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181:, and de Lackner Helicopters, began development of rotorcraft using the concept.
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A Survey of
Theoretical and Experimental Coaxial Rotor Aerodynamic Research
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800:. San Carlos, CA: Hiller Aviation Museum. November 1999. Archived from
205:
126:
20:
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297:
170:
16:
1954 experimental personal helicopter model by de
Lackner Helicopters
844:. Robbinsdale, MN: Fawcett Publications. August 1955. Archived from
782:. London: Sampson Low, Marston & Company, Ltd. pp. 263–264.
242:
169:
and similar in principle to the mechanics of riding a bicycle or a
820:. Fort Eustis, VA: U.S. Army Transportation Museum. Archived from
330:
264:
for his test-flying work with the HZ-1, going on to test-fly the
231:
196:. The harness also secured the aircraft's engine, which was an
323:
Company designation for the development prototype of the HZ-1.
768:. Defense Technical Information Center. Accessed 27 May 2010.
976:"Duplications in U.S. Military Aircraft Designation Series"
913:
Yesterday's
Tomorrows: Past Visions of the American Future
869:. 33–40. New York: American Helicopter Magazine, Inc.: 104
756:. U.S. Army Aviation Museum website. Accessed 27 May 2010.
1283:
Cancelled military aircraft projects of the United States
818:"The de Lackner Aerocycle – An early "Flying Platform""
993:"Helicopters of the World: de Lackner Helicopters Inc"
317:
Initial prototype of the
Aerocycle design; one built.
973:
471:
766:"Ultra-fast Opening Personnel Parachute Type XMP-2"
506:
Aircraft of comparable role, configuration, and era
386:
7 ft (2.1 m) from air bags to handle bars
234:, providing airborne "eyes and ears" for the Army.
952:
910:
359:
990:
959:. Atglen, Pennsylvania: Schiffer Publishing Ltd.
915:. Baltimore, MD: Johns Hopkins University Press.
329:the limited production aircraft delivered to the
1244:
551:
404:1 US gallon (3.8 L; 0.83 imp gal)
529:List of military aircraft of the United States
1122:
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272:helicopters, as well as seeing combat in the
237:In 1956, the test program was transferred to
617:
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163:National Advisory Committee for Aeronautics
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991:Smith, Maurice A., ed. (2 November 1956).
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1263:1950s United States experimental aircraft
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1081:flying platform designations (1955–1956)
911:Corn, Joseph J.; Brian Horrigan (1996).
860:
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780:Jane's All the World's Aircraft 1956-57
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439:75 mph (121 km/h, 65 kn)
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445:55 mph (89 km/h, 48 kn)
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121:and by the manufacturer's designation
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974:Heyman, Jos; Andreas Parsch (2004).
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451:15 mi (24 km, 13 nmi)
339:Designation in the US Army HO series
125:, was an American one-man "personal
1140:helicopter designations (1956–1962)
13:
1258:United States military helicopters
1003:(2493). London: Hiffe and Sons Ltd
932:"The Flying Platforms & Jeeps"
598:
564:
221:Captain Sundby test-flies the HZ-1
19:For the World War One bomber, see
14:
1314:
1288:Single-engined piston helicopters
1017:
681:
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276:before retiring with the rank of
204:. The engine was controlled by a
1039:. 9 January 1956. Archived from
711:Corn and Horrigan, 1996, p. 127.
595:U.S. Army Transportation Museum.
474:
34:
1278:1950s United States helicopters
778:Bridgman, Leonard, ed. (1956).
759:
739:
730:
714:
705:
696:
657:, 2 November 1956, p. 724.
560:. Hearst Magazines. p. 88.
552:Hearst Magazines (April 1956).
360:Specifications (HZ-1 Aerocycle)
350:U.S. Army Transportation Museum
545:
1:
955:U.S. Army Aircraft Since 1947
534:
1293:Aircraft first flown in 1954
1031:"Science: Vertical Mobility"
997:Flight and Aircraft Engineer
934:. VectorSite. Archived from
655:Flight and Aircraft Engineer
463:5,000 ft (1,500 m)
7:
930:Goebel, Greg (1 May 2011).
467:
424:2 Ă— 15 ft (4.6 m)
308:
10:
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882:Coleman, Colin P. (1997).
262:Distinguished Flying Cross
212:
18:
1268:Coaxial rotor helicopters
1222:
1206:
1165:
1145:
1086:
978:. designation-systems.net
951:Harding, Stephen (1997).
554:"Aerocycle Lifts Soldier"
418:, 40 hp (30 kW)
398:454 lb (206 kg)
33:
28:
1223:Helicopter, experimental
693:, vol. 88, 1955, p. 443.
392:172 lb (78 kg)
296:An entirely new type of
292:A HZ-1 following a crash
157:During the early 1950s,
1303:Single seat helicopters
1298:Standing pilot aircraft
1166:Helicopter, observation
861:Champlin, G.F. (1953).
702:Heyman and Parsch 2004.
607:Hiller Aviation Museum.
371:General characteristics
260:Sundby was awarded the
255:Langley Research Center
47:Experimental rotorcraft
1024:The Sky-High Invention
293:
228:Brooklyn Army Terminal
222:
189:underneath the craft.
153:Design and development
131:de Lackner Helicopters
70:de Lackner Helicopters
678:Harding 1997, p. 112.
291:
284:Parachute development
220:
79:Lewis C. McCarty Jr.
640:Mechanix Illustrated
422:Main rotor diameter:
159:Charles H. Zimmerman
117:, also known as the
1253:De Lackner aircraft
1207:Helicopter, utility
1043:on 1 February 2005.
867:American Helicopter
848:on 26 December 2011
752:6 July 2010 at the
736:Coleman 1997, p. 4.
500:AĂ©rospatiale Ludion
344:Aircraft on display
167:kinesthetic control
1138:United States Army
1079:United States Army
1026:at howtoadvice.com
938:on 24 October 2011
838:"Stand Up and Fly"
746:"Selmer A. Sundby"
517:Hiller VZ-1 Pawnee
294:
223:
143:atomic battlefield
139:United States Army
96:United States Army
92:Primary user
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1146:Helicopter, cargo
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863:"de Lackner DH-4"
798:"Flying Platform"
558:Popular Mechanics
137:machine with the
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871:. Retrieved
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790:Bibliography
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103:Number built
512:Bensen B-10
430:Performance
408:Powerplant:
333:; 12 built.
302:Hiller VZ-1
274:Vietnam War
251:wind tunnel
239:Fort Eustis
187:slung loads
147:infantrymen
1247:Categories
982:3 December
942:26 October
902:3 December
535:References
457:45 minutes
455:Endurance:
206:twist-grip
127:helicopter
21:Airco DH.4
495:Discopter
380:1 (pilot)
365:Data from
298:parachute
171:surfboard
76:Designer
750:Archived
468:See also
309:Variants
243:Virginia
727:, 1955.
725:vol. 15
384:Height:
331:US Army
278:colonel
253:at the
232:cavalry
213:Testing
161:of the
963:
919:
852:27 May
828:27 May
808:27 May
449:Range:
1157:HC-1B
1153:HC-1A
896:(PDF)
889:(PDF)
642:1955.
540:Notes
378:Crew:
119:YHO-2
43:Role
1230:HZ-1
1214:HU-1
1198:HO-6
1193:HO-5
1188:HO-4
1183:HO-3
1178:HO-2
1173:HO-1
1096:HO-2
1091:HO-1
1036:Time
1009:2011
984:2010
961:ISBN
944:2011
917:ISBN
904:2010
875:2011
854:2010
830:2010
810:2010
414:20H
410:1 Ă—
270:H-34
268:and
266:H-21
113:The
107:12
1249::
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1001:70
999:.
995:.
865:.
840:.
748:.
723:,
683:^
671:^
647:^
626:^
612:^
600:^
566:^
556:.
280:.
241:,
177:,
1155:/
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