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handle the heavier take-off weight were required. New plastic fuel tanks, still mounted between the front and rear wing spars, were of 21.5 imperial gallons capacity each, giving a total capacity of 43 gallons (195 lit.). Therefore, the practical working endurance remained at two hours or so. The fuselage was an all new design optimized for the topdressing role. The hopper remained in the same position but was of considerably increased capacity. Hopper load on topdressing would have varied between 12 and 17 cwt. (611/865 kg). The area from the hopper to the tail was to be of monocoque construction with an access hatch to permit loading of cargo/work equipment or (no doubt) the odd passenger. The cockpit section forward of the hopper was to be built on a steel tube frame and featured side by side seating for the pilot and a passenger (typically the landholder or the loader driver).
170:
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194:
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spray run at
Highbury near Narrogin. Also in 1965 Bill Pearson flying Bender's VH-RPB at Kempton went in from a hundred feet or so, just after lift-off. Non-fatal misadventures included wire strike, jammed elevators after fence strike, getting trapped in a blind gully, Hartzell propeller blade failures and nose-overs.
213:
of the
Wackett's rear cockpit and different external panels of metal and fibreglass (the Wackett fuselage was fabric covered); the Wackett's wooden wing was replaced by a new metal wing. The first five aircraft retained the Wackett's wooden tail, but subsequent aircraft had a metal tail that featured
265:
the
Cropmaster was unable to compete with more modern types of agricultural aircraft. Six of the twenty-one aircraft were the YA-1 250R model and the final three aircraft produced featured relocated main landing gear to counteract a tendency for the type to nose over on the ground. Six Cropmasters
309:
At the time manufacture ceased, metal had been cut on the next evolution, this being the
Cropmaster 300. The existing wing was to be retained with the span increased to 37 ft (11.28 m). The tail group was to remain unchanged. The tailwheel configuration was retained although new oleo legs to
318:
Four pilots were killed in
Cropmasters. In 1961 at Deniliquin, Ralph Dennis ran a tank dry in Marshall's VH-MSS and spun in. In 1964 John Waddell pranged VH-BAQ near Boorowa while doing low level aerobatics. In 1965 Air-Culture's VH-CXQ, with Richard Adams flying, struck a tree whilst entering a
286:
was converted from CA-6 Wackett airframe C/N 257 for trials of a new all-metal empennage, and had the swept fin of later
Cropmasters but retained the Warner Scarab radial engine and fabric-covered aft fuselage of the Wackett.
548:
165:
located in the rear cockpit of the
Wackett, the cutting of a hole in the centre section of the Wackett's wooden wing to allow the dispersal of the chemical load, and re-routing controls to bypass the hopper.
257:
The first
Cropmaster, a YA-1 250, took to the air for the first time on 15 January 1960. Twenty further aircraft were converted before production ceased in 1966, by which time the company was known as
209:
By contrast the YA-1 Cropmaster involved major modifications to the
Wackett airframe. The Wackett fuselage structure of steel tube was retained but had a 23 cubic ft. (650 litre) capacity hopper
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brochure. The YA-1B design proposal also included an early version of the design for the all-metal empennage, with a more upright tail-fin than was actually produced. Another variant was the
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270:
with the last registered example being returned to
Australia in April 2022. Two examples (one flying) are registered in Australia. The second is under rebuild at
656:
661:
632:
https://www.stuff.co.nz/national/128211365/pilot-76-loses-licence-after-flouting-fundamental-tenet-of-aviation-safety-for-more-than-20-years
598:
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to engage in agricultural aircraft production. KSA had obtained a number of Wacketts following the type's retirement from
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with a 285 hp (213 kW) Continental engine, sources disagree as to whether any of this variant were produced.
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227:
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The first Cropmaster YA-1 conversions shared the wooden empennage and fabric-covered aft fuselage of the CA-6 Wackett
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The Yeoman 175 was a one-off test-bed to check the characteristics of the new all-metal empennage
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in the second half of the 1950s. The conversion involved little more than the installation of a
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http://rnzaf.proboards.com/index.cgi?board=agricultural&action=display&thread=12309
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The proposed YA-1B Cropmaster featured a tricycle undercarriage, but was never produced
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23 cu ft (0.65 m) capacity hopper, 1,456 lb (660 kg) payload
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also developing 250 hp (190 kW), driving a Hartzell or McCauley propeller.
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549:
Australian civil aircraft register search, using "Yeoman" as the search parameter.
274:. Several other Cropmasters reportedly still exist in Australia and New Zealand.
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The Cropmaster and the CA-6 Wackett shared the same tubular steel fuselage frame
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The Illustrated Encyclopedia of Aircraft in Australia and New Zealand
298:, none were built. A cut-away drawing of the YA-1B was included in a
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The Observer's Book of Civil Aircraft of Australia and New Zealand
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129 mph (208 km/h, 112 kn) (econ cruise, 60% power)
200:
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176:
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593:
Timothy & Elizabeth Hall. Methuen of Australia Pty. Ltd.
622:
http://dbdesignbureau.buckmasterfamily.id.au/aus_aircraft.htm
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Tiger Moth, CT-4, Wackett & Winjeel in Australian Service
218:, a swept-back fin and larger rudder. The Wackett's fixed
603:
original company documents and plans held by Fred Burke
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service and had converted four for agricultural use as
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152 mph (245 km/h, 132 kn) at sea level
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34 imp gal (41 US gal; 150 L)
476:
Aircraft of comparable role, configuration, and era
574:. London:Sampson Low, Marston & Company, 1965.
580:Stewart Wilson. Aerospace Publications Pty. Ltd.
535:Brogden, Stanley. "Australian Light Aircraft",
226:radial engine of the Wackett was replaced by a
627:http://www.kiwiaircraftimages.com/yeoman.html
8:
519:, p.143. Sunshine Books, Hornsby NSW, 1983.
323:Specifications (Yeoman YA-1 250R Cropmaster)
282:An intermediate flying test-bed, the single
606:research material compiled by Allyn Eckford
147:Kingsford Smith Aviation Services Pty. Ltd.
511:
509:
448:240 mph (390 km/h, 210 kn)
572:Jane's All The World's Aircraft 1965–66
505:
330:Jane's All The World's Aircraft 1965–66
647:1960s Australian agricultural aircraft
439:53 mph (85 km/h, 46 kn)
15:
515:Eyre, David. "KINGSFORD SMITH KS-3",
7:
362:35 ft 0 in (10.67 m)
551:Search conducted 29 December 2008.
356:26 ft 4 in (8.03 m)
14:
374:179 sq ft (16.6 m)
368:9 ft 9 in (2.97 m)
539:magazine, 12 August 1960, p.235.
460:1,100 ft/min (5.6 m/s)
412:2-bladed McCauley constant-speed
33:Cropmaster 250R Series 2 ZK-CTX
24:
657:Single-engined tractor aircraft
1:
386:3,530 lb (1,601 kg)
662:Aircraft first flown in 1960
464:Takeoff run to 50 ft (15 m):
261:. Like its contemporary the
406:, 250 hp (190 kW)
404:horizontally-opposed engine
402:-R six-cylinder air-cooled
380:1,800 lb (816 kg)
228:horizontally-opposed engine
205:The proposed Cropmaster 300
678:
466:1,200 ft (370 m)
155:Royal Australian Air Force
141:The type was developed by
107:Kingsford Smith Cropmaster
32:
23:
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290:A proposed variant with
335:General characteristics
220:tailwheel undercarriage
19:Yeoman Cropmaster YA-1
292:tricycle undercarriage
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145:, a company set up by
137:Design and development
560:Taylor 1965, pp. 7–8.
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120:agricultural aircraft
42:agricultural aircraft
234:being fitted with a
384:Max takeoff weight:
259:Cropmaster Aircraft
122:developed from the
62:C. W. (Bill) Smith
569:Taylor, John W. R.
444:Never exceed speed
400:Continental IO-470
252:Continental IO-470
250:was fitted with a
244:Hartzell Propeller
222:was retained. The
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199:
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118:was an Australian
652:Low-wing aircraft
492:Sasin Spraymaster
266:were exported to
151:Bankstown Airport
116:Yeoman Cropmaster
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159:KS-3 Cropmasters
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70:15 January 1960
54:Yeoman Aviation
45:Type of aircraft
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75:Introduction
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67:First flight
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131:World War II
115:
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92:Number built
418:Performance
410:Propellers:
396:Powerplant:
272:Wagga Wagga
268:New Zealand
124:CAC Wackett
641:Categories
500:References
452:Endurance:
372:Wing area:
284:Yeoman 175
242:driving a
216:stabilator
86:1960–1966
360:Wingspan:
348:Capacity:
328:Data from
314:Accidents
263:CAC Ceres
248:YA-1 250R
149:(KSA) at
83:Produced
59:Designer
471:See also
304:YA-1 285
294:was the
278:Variants
232:YA-1 250
366:Height:
354:Length:
211:in lieu
127:trainer
597:
584:
537:Flight
523:
230:, the
163:hopper
342:Crew:
296:YA-1B
78:1960
38:Role
595:ISBN
582:ISBN
521:ISBN
454:3 hr
398:1 ×
114:The
129:of
96:21
643::
508:^
240:hp
214:a
133:.
446::
344:1
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