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File D 52.1 /Douglas X. 0 . 2/ I NO
· .. ·.· <AVIATION>
·. ·' PUBL\SHED BY THE CHIEF OF AIR SERVICE, WASHINGTON, D. C.
Vol. VI June 1, 1925 No. 509
OFFICIAL PERFORMANCE TEST OF DOUGLAS X0-2
EQUIPPED WITH LIBERTY "12" ENGINE AND
STANDARD STEEL PROPELLER SET AT 18°
(FL YING SECTION REPORT)
. ,.. '
.,,., Engineering Division, Air Service
McCook Field, Dayton, Ohio
February 9, 1925
Ralph Brown D r::.~l'.)i~ .1
.. ,,. LIBRARY
~
.. ,. C·MAY 17 Z013
WASHINGTON
GOVERNMENT PRINTING OFFICE
1925
Non-Depoitory
Auburn University
CERTIFICATE: By direction of the Secretary of War the matter contained herein
is published as administrative information and is required for the proper transaction
of the public business.
( I! )
•'
~
OFFICIAL PERFORMANCE TEST r1""e>
DOUGLAS X0-2 EQUIPPED WITH LIBERTY GINE
AND STANDARD STEEL PROPELLER SET AT 180°
SUMMARY OF RESULTS
Standard Steel Propeller 18° at 48" Radius
Airplane : Douglas X0- 2.
A. S. No.: P- 374.
DECEMBER 18, 1924.
Pilot: Mr. Lockwood; tested December 11, 1924.
Engine: Liberty, 12 cylinder, "V" type, water
cooled, No. 21905.
Rated horsepower: 425 at 1, 715 revolutions per
minute.
Propeller: Standard steel; manufacturer's No.
067861; diameter, 10 feet; pitch, 18° at 48-inch radius.
Required
pounds
Weight empty (w ith
water) ________ _____ ____ 2, 811. 67,
including 2l pounds in-strument
load.
Armament_____ ______ 261. 8
Equipment___ _____ __ 379. 82
Crew ___ _____ ___ ___ ___ 360. 00
Gasoline (92. 5 gallons
at 5.9 pounds)__ ____ 546. 00
Oil (9 gallons at 7.5
pounds) _____ _______ ·67. 50
Total weight loaded 4, 426. 79
Pounds
Presen t, 61.4 pounds; ballast
_--- -- -- ------ ---- ---- 200. 4
Radio, 9. 5 po11nds; ballast _ 104. 09
Electrical, 137. 63 pounds;
ballast. __ ______________ __ _____ _
Miscellaneous equipment,
including parachutes,
49. 8; ballast ______ ____ ___ _ 78. 80
Total ballast_ ________ 383. 29
Allowance ___________ __ _____ 47. 5
'l'otal ballast_ ___ _____ 335. 79
Wing a rea (including ailerons): 411 square feet.
Wing loading: 10.77 pounds per square foot.
Rated power loading: 10.31 pounds per horsepower.
Ground revolutions per minute: 1,540.
Was armament in place during all tests? No
scarff nor rear guns . Ballast.
Center of gravity : 34.5 per cent of mean average
chci'rd.
Data converted to standard
(a) Speed (b) Clim_b Level
'l.'em- Stand- l------·1 ---,----; ---c--~
Density ~~;~- alt1~~de I Time Rate oc in feet M. p.
1
R . p. in feet R . p. M . p.
h. m. min- min- m . h.
utes utes
L 000 ~ --0- ~, 1, 605 --0- I, 075 1, 715 . l37. 2
. 863 +4. 5 5, 000 85. 0 1, 580 5. 4 787 1, 700 132. 2
. 824 + l. 5 6, 500 85. 4 1, 575 7. 4 700 1, 695 130. 7
. 737 - 4. 5 10, 000 86. 4 1, 550 13. 4 499 1, 660 126. 9
. 624 - 12 15, 000 88. 0 I 1, 500 28. 0 210 1, 580 116. 6
-- ------ - -- ----- 20,000 --- - ---- -- --- - - --- -- - - - ------ -- - --- - - ------
- - ------ --- -- --- 25, 000
. 608 - l4 5 I 16, 900
. 576 - ----~- - ' 18, 600
' Absolute ceiling.
Landing speed: 57- 58 miles per hour.
Minimum speed at sea level: Approximately 60
miles per hour.
Endurance, full throttle (including climb), V2 hour
at ground; 372 hours at 15,000 feet.
WITH WINGS OF 41 SQUARE FEET LESS AREA
FEBRUARY 3, 1925.
Airplane : Douglass.
Type : X0- 2.
A. S. No.: P- 374.
Pilot: Lieutenant Barksdale.
Engine : Liberty ; type, 12-cylinder, water-cooled; A.
S. No. 24- 131- YG.
Rated horsepower: 435 at 1,745 revolutions per
minute.
I Propeller manufacturer: Standard steel; drawing or
inspection No. 067861; diameter, 10 feet ; pitch, 18° at
48-inch radius; adjustable on ground.
Weight empty, with water (including 21 Pounds.
pounds instruments) __________ __ __ ___ __ 2, 748. 67
Armament_ __ ____ __ _______ ______ ________ _ . 261. 8
Equipment_ ___ ____________ ______ _______ __ 379. 82
Crew__ __ __ _____ __ __ __ __ _____________ __ 360
Gasoline 3 (9 gallons at 5.9 pounds)_ _____ __ 546
Oil (9 gallons at 7.5 pounds) ____ ________ __ 67. 5
Total weight loaded ___ ___________ _ 4, 363. 79
Wing span : 36 feet 3 inches.
Chord: 5 feet 8 inches.
Incidence: 0°.
Dihedral: 2°.
Gap: 72 inches.
Wing area (including ailerons) : 370 sq uare feet.
Wing loading: 11.79 pounds per square foot.
Rated power loading: 10.03 pounds per horsepower.
Ground revolutions per minute: 1,540.
Was armament in place during all tests? No scarff
nor rear guns. Ballast.
Ground barometer pressure: 29.524.
Ground temperature: + 2° C.
Converted to standard
I
Stand- (a) Speed (b) Climb
Per ard
cent 'f emp. al ti-d
«nsity oc. tu de Time Rate
(actual) in M. p. h. R.p.m. in ft.
feet min. min.
- - - ------ ----------
1.046 + 2.251 0 80. 0 1,582 0 l, 070
. 877 + o.5 5,000 83. 7 1, 579 5. 4 770
.832 - 0.2 6, 500 84. 9 1, 576 7. 4 682
. 733 - 2. 4 10, 000 87. 9 1, 568 13. 65 473
. 622 -10.3 15, 000 92. 7 1,544 -~~!--1 175
. 600 -14.1 116, 250 94. 0 1,534 100
------ -- -- - -·--- ' 17, 900 95. 6 1, 520 0
R.p.m.
--
l, 745
I, 728
1, 720
1, 687
1, 602
1, 570
1, 520
1 Service ceiling. 2 Absolute ceiling.
' Gas capacity, 118.6 gallons total; oil capacity, 13.5 gallons.
M.p.h.
- -
139. 6
135. 9
134. 4
129. 6
117. 5
111. 8
95. 6
i Service ceiling.
46879- 25t (1)
Landing speed: Approximately 61 miles per hour.
Minimum speed at sea level : Approximately 63
miles per hour.
Endurance, full throttle, at 10,000 feet (including
climb), Yz hour at ground, 3Yz hours at 15,000 feet.
DISTRIBUTION OF WEIGHTS
Weight empty (with water) __ __ __ ___ _____ _
Armament and equipment ____ _____ ______ _
Crew ___ __ ___ __ __ __ ___ __ ______________ _
Gasoline __ __________________________ __ Oil __ ________ __ ___ ____ ________________ _
Weight loaded ___ ________________________ Weight on front wheels (flying position) ___ _
Weight on tail skid (flying position) _____ _ _
Pounds.
2, 811. 67
641. 62
360. 00
546. 00
67. 50
4, 426. 79
4, 089. 00
333. 00
Center of gravity (distance from wheels in flying position),
23.35" back of leading edge of lower 0wing or
34.5 mean average chord.
Provisions for special equipment not carried during
test.
DESCRIPTION OF AIRPLANE
DIMENSIONS
Over-all span: 39 feet 8 inches.
Over-all length : 29 feet 3 inches.
Over-all height : 10 feet IO inches.
In flying position: 6 feet 1 inch.
AIRPLANES
Wing curve: Clark- Y; large.
Stagger: None.
Total area, including ailerons: 411 square feet.
Gap: 72 inches.
UPPER PLANE
(Including center section)
Span: 39 feet 8 inches.
Chord: 5 feet 8 inches.
Area, with ailerons : 211 sq uare feet.
Incidence, degrees: 0°.
LOWER PLANE
Span: 39 feet 8 inches.
Chord: 5 feet 8 inches.
Area: 200 square feet.
Incidence, degrees : 0°.
AILERONS OR FLAPS
Number: 4.
Upper length : 10 feet.
Upper chord: 16Yz inches.
Upper area: 23.75 square feet.
Lower length : 10 feet.
Lower chord: 16Yz inches.
Lower area: 23.75 square feet.
Total area : 47.50 square feet.
2
STABILIZER
Area: 35.
Setting: Adjustable_
E LEVATOR
Area: 20.
Distance from leading edge of elevator to center of
gravity of airplane: 18 feet 5.65 inches.
RUDDER
Area: 10.35.
Distance from leading edge of rudder to center of
gravity of airplane : 18 feet 5.65 inches.
FUSELAGE
Maximum cross-section shape __ Maximum cross-section area ___ _
Maximum cross-sion __ ___ __ ___s_e_c_ti_o_n_ __d_im_ _e_n _- _ +Z'-7" __[_
LANDING GEAR
Number of wheels : 2.
Tread: 7 feet 9Yz inches.
Shock-absorbing system: Rubber cord.
Braking device: Tail skid.
F I N
Area: 7 square feet.
DESCRIPTION OF POWER PLANT
ENGINE
Make: Liberty,
Factory No.: 4390.
A. S. No.: 21905.
T ype: 12.
Number in plane: 1.
Location : Nose.
Rated horsepower: 400.
Rated revolutions per minute: 1,700.
Bore: 5 inches.
Stroke: 7 inches.
Compression ratio: 5.42 : 1.
Weight dry: _ 843.69 pounds.
Gas consumption: 216 pounds per hour.
Oil consumpt ion : 16 pounds per hour.
Weight of water in engine: 45 pounds.
I GNlTlON
Battery or magneto: Battery.
Make: Delco.
Number: 2.
Advance, degrees: 30.
Distributor: Delco.
Plugs, make : Mosler.
Type: M- 1.
Gap: 0.015.
CARBURETORS
Make : Zenith.
Type: Liberty US-52.
Number: 2.
-
t
Choke: 36.
Compensator: 170.
Gas drains: Tube direct from carburetor.
Air intake: Vertical overhead scoop outside cowling.
Mixture control: Yes.
Effective at altitude: Yes.
RADIATORS
Make: Douglas.
T ype: Cartridge tube.
Number: 1.
Position: Nose below.
Depth : 9 inches.
Radiator surface: 273 square feet.
Temperature adjustment: Shutters.
Water capacity, pounds: 57.
Flow, gallons per minute: 85.8.
Thermometers, make: Boyce.
Weight, pounds: Empty, 123.
T ype: "C."
Water capacity of whole system: 102 pounds.
EXHAUST PIPES
Description: Short stacks.
LUBRICATION
Capacity oil tank: 13.5 gallons.
Dimensions oil tank: Irregular.
Oil used (brand): 2- 23- D.
Oil pressure: 40.
Type pump: Gear.
TAXI-ING
Taxies very well, responding well to controls.
LANDING ·
Is very easy to land from either cockpit. It has no
t endency to turn after landing.
BALANCE
(a) With the stabilizer adjusted for high-speed
power on, the plane is balanced with power on, and
nose heavy with power off.
(b) With the stabilizer adjusted for speed of best
climb with power on, t he plane is balanced with power
on and nose heavy with power off.
(c) With stabilizer adjusted for landing speed, the
plane is tail heavy with power on and balanced with
power off.
STABILITY
Plane can be made longitudinally stable at all speeds
and throttle settings with adjustable stabilizer.
MANEUVERABILITY
The plane answers well to controls at all speeds.
AILERON CONTROL
Ailerons are easy to move at all speeds and the
plane responds readily to a ilerons at all speeds. The
a ileron control is very good .
RUDDER CONTROL
Wet or dry sump: Dry.
Description lubrication system: Force feed to all The rudder is effective at all speeds and in a stall ,
bearings. bank, sideslip, and skid.
FUEL SYSTEM
Number of tanks: 4.
Location : Fuselage, lower wing, inner bays, and top
wing.
Capacity, main pounds: 951.
Capacity, reserve pounds: 57.
Material: Aluminum.
Description of fu el supply system: Releaseable
tanks, hand pump, and C- 5 gear pump in series with
gravity emergency. /
ENGINE CONTROL
Description: Push and pull rods through bell crank s.
PROPELLER
Make: Standard steel.
Number blades: 2.
Diameter: 10 feet 18° at 48-inch radius.
Manufacturers' number : 067861.
A. S. number: 23- 2572.
Remarks : Adjustable on ground.
PILOT'S OBSERVATIONS
JANUARY 21, 1925.
1. As a result of preliminary observation flights on
the Douglas X0- 2, article No. 1,. by the undersigned,
the following is submitted:
ELEVATOR CONTROL
The elevators are effective in high speed and fairly
effective in low speed. They are effective in a stall,
bank, and sideslip. Elevators are not as effective at
low speed as they should be; more upthrow is needed.
BANKING
Airplane handles well in gentle and vertical banks.
Plane does not skid or squash on turns at full throttle.
It responds readily in the following maneuvers:
Loop, sideslip, and skid .
It will not spin or roll.
ACCESSIBILITY
The acc~ssibility of the cockpit is good. The cockpit
is comfortable and the pilot is well protected from
wind. The location of the controls and instruments is
good.
VISIBILITY
The visibility is good in all directions.
REMARKS
This airplane fulfills the requirements of its type
very well. It could also be used as a cross-country
ship, light bomber, and photo ship.
R. G. LOCKWOOD,
Test Pilot.
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Air Service Information Circulars
