Langley Memoir on Mechanical Flight, Parts I and II / Smithsonian Contributions to Knowledge, Volume 27 Number 3, Publication 1948, 1911

by S. P. Langley; Charles M. Manly

• * H. P. = (Rev. × diam. × pitch ratio × thrust)/33000
• † This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wings have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight: but if the rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

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DATA SHEET No. 11. Weight of Aerodrome No. 5, Superposed Wings and Pénaud Rudder. Certified to by Chas. M. Manly, August 3, 1899.

Parts.	Sizes.		Weight.
	m.	ft.	gr.	lbs.
1 Frame, including everything of metal, permanent and undetachable, such as bed-plate, cross-rods for the support of propellers, bearing points for clutch, etc.			3556
2 Engine, complete			476
3 Pump, 301; pump shaft, 55; support to pump, 33			389
4 Hull covering, 276; apron, 117; piece behind separator			393
5 Gasoline and air tanks, 167, 165; air valve, 17			349
6 Smokestack and piece to protect midrod			385
7 Float, 290; drop piece for rudder, 57; guy-post and clamp, 17			364
8 Reel, fork and float, 128; steam gauge with pipe, 81			209
9 Wing claps, 202; guy-post clamps, 33			235
10 Boiler, 775; burner, 171; counter, 100			1046
11 Rear extension to midrod			227
12 Separator and pipes to engine and pump			513
13 Exhaust pipe			90
14 Front lower bearing points, 84; clutch post, 41			125
15 Rear bearing points, 146; extra strengtheners, 32			178
16
17 Wings (without clamp)
18 Tail (without clamp), part of rudder
19 Rudder			309
20 Guy sticks, each 60			120
21 Propellers, 100 cm. round end			757
22 Extra length of midrod, front			174
23 Wood bowsprit			130
24 Other things, 248 grammes of lead on end of bowsprit			248
25
26
27 Fuel (at starting flight)
28 Water (at starting flight)
29
30
31 Sundries unknown
32
33
34 Total flying weight			14,354
35
36
37
38 Total area of support (not including tail) . . . sq. ft.		87.5
39 Total area of support in feet, divided by total flying weight in lbs.		2.75
40 Total area of horizontal tail. . . . sq. ft.		6.94
41 Total area of rudder (vertical). . . . sq. ft.		7.64
42 Horse-power at brake . . . Horse-power by formula*
43
44 Lift at pendulum (during one minute absolute)
45 Lift at pendulum (during one minute in terms of wt.)
46 Minimum pressure with which wheels turn
47 Position of center of pressure of wings†
48
49
50 Curvature of wings, 1 in 11
51 Root angle of wings, 10°
52 Tip angle of wings, 10°
53 Position of wings
54 How guyed
55
56
57
58 Position of tail
59 Angle of tail
60 Co-efficient elasticity of tail, 200 grammes at center gives deflection of 5°
61 Position rudder
62 Elasticity caused by rubber bands
63 Line of thrust, 1500
64 Center of gravity1 of whole
65 Center of gravity2
66 Center of pressure1 of whole estimate
67 Center of pressure2
68
69
70
71
72

Parts. Remarks.

• 1 C. P. on F. W., 1577.7.
• 2 Line through center of propellers, 1500.
• 6 C. of G., 1498.
• 8 C. P. on R. W., 1372.7.

Footnotes.

• * H. P. = (Rev. × diam. × pitch ratio × thrust) /33000
• † This is calculated on the assumption that the center of pressure on each wing or on pair of wings at a motion of 2000 feet per minute is in ordinary curved wings 2-5 the way from front to rear, that for wings of usual size the rear wings have 2-3 of the efficiency per surface of the front ones and that the tail proper bears no part of the weight; but if rear wing is smaller or larger this efficiency is smaller or larger per unit of surface.

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DATA SHEET No. 12. Weight of Aerodrome, One-Quarter Model. Certified to by Chas. M. Manly, June 11, 1901.