Yeoman Aviation YA-1 Cropmaster 250 and 250R1959-69

Drawn by Derek Buckmaster © 2003for the DB Design Bureau website

Scale 1:48 Plate 1 of 4

D

A

C

YA-1 Cropmaster 250 S/N 101 VH-BJF(shown in mid-1960 configuration)

Lycoming O-540-A engineHartzell HC92ZK-1 propellor

E

B

YA-1 Cropmaster 250 S/N 106 VH-CYWMay 1962 configuration showing single pieceblown canopy

Lycoming O-540-A engine

YA-1 Cropmaster 250R Series 2 S/N 119 ZK-CPWin December 1969 configuration

Continental IO-470 engineMcCauley D2A36C33/90M-2or Hartzell HC92ZF-1 propellor(McCauley shown)

1Metres 2 3 4

Feet 1 2 3 4 5 6 7 8 9 10 11 12 13

26' 6"A B C D E

DRAFT ONLY

Proposed YA-1B Cropmaster 250 showing tricyclelanding gear and early metal tail design (mid 1960). Never constructed.

Top view of cowling forContinental IO-470 engine

References:1. YA-1 Cropmaster Pilot's Manual2. YA-1 Cropmaster Maintenance & Repair Manual3. Measurements of components of VH-AGL, VH-TPN and VH-ENM at the Australian NationalAviation Museum, Moorabbin.

Acknowledements:These drawings could not have been prepared without Allyn Eckford's support and attentionto detail. Thanks also to Fred Burke, Ben Dannecker, Michael Ellis for contributions commentsand corrections.

Yeoman Aviation YA-1 Cropmaster 2501959-67

Drawn by Derek Buckmaster © 2003for the DB Design Bureau website

Scale 1:48 Plate 2 of 4

Dimensions:Wing spanLengthHeight (tail down)Wheel trackWing areaWing dihedralWing incidence (root)Wing incidence (tip)Wing LE sweepWing chord (root)Wing aspect ratioTailplane span

Control surface deflections:Ailerons:Rudder:All-moving tail plane:

Flaps:

30° up / 15° down27° left / 27° right

23° up / 23° downUp / 20°/ 30°/ 40° down

Plan view of YA-1 Cropmaster 250 S/N 106VH-CYW May 1962 configuration

Plan view showing 3-piece framed canopy used on production aircraft

DRAFT ONLY

34 ft26 ft 6 in9 ft8 ft178.5 sq ft5°3.5°0.5°3.8°85 in7.6712 ft 2 in

Wing-tip extensions asfitted to S/N 119 ZK-CPWincreased span to 36'

Some aircraft were operated with nospinner fitted

Port scrap view showing fresh air scoop fitted to some aircraft

Maximum flap deflection 40°

0°

20°30°40°

Aerofoil section at root NACA 2215

1Metres 2 3 4

Feet 1 2 3 4 5 6 7 8 9 10 11 12 13

Starboard scrap view showing flap linkage access paneland venturi for instrument vacuum

Yeoman Aviation YA-1 Cropmaster 250 and 250R1959-67

Drawn by Derek Buckmaster © 2003for the DB Design Bureau website

Scale 1:48 Plate 3 of 4

Front view of YA-1 Cropmaster 250 S/N 106VH-CYW

Instrument panelshown at twicedrawing scale (1:24)

Key to instruments:1 Compass2 Airspeed3 Spray boom pressure (if fitted)4 Altimeter5 Turn & bank 6 Cylinder head temperature7 Manifold pressure8 Tachometer9 Oil & fuel pressure, cylinder head temp.10 Fuses (6)11 Ammeter12 Parking brake13 AWA "Skyphone" VHF radio

DRAFT ONLY

Detail of steel tube framework and hopper location

Internal structure of fin and rudder

Internal structure of wings, flaps and ailerons

Continental IO-470-E engine

1Metres 2 3 4

Feet 1 2 3 4 5 6 7 8 9 10 11 12 13

Starboard cockpit controlsPort cockpit controls

Internal structure of all-moving tail-plane

Series 1 landing gearshowing upper mountingpoint attached to main spar

1 2 4 5

6 7 8 9

10

3

1112

13

C o n t i n e n t a lC o n t i n e n t a lC o n t i n e n t a l

Series 2 landing gearshowing upper mountingpoint attached to ribs 3 and 4

Yeoman 175, Yeoman-Hanes 250, Cropmaster 300

Drawn by Derek Buckmaster © 2003for the DB Design Bureau website

Scale 1:48 Plate 4 of 4

Front view of YA-1 Cropmaster 250 S/N 119in December 1969 configuration, showing Series 2landing gear, cowling for Continental IO-470 engineand wing-tip extensions

Yeoman-Hanes 250 S/N 110 ZK-CDI3-seat conversion carried out in 1969

Lycoming O-540-A engine

Yeoman 175 VH-AIV converted from CA-6 Wackett airframe S/N 258 for trials of new all-metal empennage

Warner Scarab engine

McCauley D2A36C33/90M-2 propellor

Power options to 300 hp3-bladed propellor

Proposed Cropmaster 300Featured side-by-side seating, monocoque aft fuselage,37' wingspan, redesigned undercarriage

1Metres 2 3 4

Feet 1 2 3 4 5 6 7 8 9 10 11 12 13DRAFT ONLY