Professor Langley was a respected astronomer. He invented the bolometer, an instrument that measures small amounts of microwave or infared radiation by detecting changes in electrical resistance on a thin heat sensitive metal conductor. (This will be on the test) His name lives on in a unit of energy flux. At the end of the 19th Century he was head of the Smithsonian Institute, which in those days was a serious scientific organization. He started to experiment with model airplanes. These experiments culminated in a couple of Steam Models that earned him a permanent place in pre Wright Brothers aviation.
These successes lead to his being asked by the Department of War to construct a man carrying air craft. It didn't fly. Twice the Aerodrome, as he called it, was catapulted off the roof of a house boat and twice it fell into the Potomac river "Like a handful of wet mortar." Soon after he died, some say broken by the ridicule with which the press treated the event. And the airplane languished in the Smithsonian.
In the meantime the Wright Brothers flew, and patented, their airplane. They were quite aggressive about pursuing what they considered violations of this patent, and set American aviation back by years. Glen Curtiss was one of the individuals who wanted to avoid paying the Wright's considerable royalties and he embarked on a series of lawsuits that was to drag on for years.
In about 1914, in an effort to show that the Wright Brothers didn't make the first airplane capable of flight he approached the Smithsonian with an offer to see if he could make the remains of the Aerodrome fly. The Smithsonian who stood to recover from shame and ridicule agreed to this. But the Aerodrome was fundamentally unsound, so Curtiss took it upon himself to make many modifications. He eventually achieved limited flight. Among the changes were, replacing the motor and the two primitive propellers mounted behind the forward wing with a tractor prop powered by a more modern engine. He also gave up on catapulting it off a houseboat and fitted it with floats. Orville Wright was particularly insistant that Langley had the center of pressure in the wrong places and that Curtiss applied the Wright Bros discoveries to rerig the wing bracing.
I was unable to find a 3 vu of the Curtiss. So I applied what I learned
from the pictures and Orville Wright's published outrage to a 3vu of the
Langley version. I have his list of these changes but am unable to OCR
it and have no intention of transcribing it all. Anyone that wants a copy
should contact me at ...
I was hoping to build a quickie, but soon enough it got away from me and now I have a model I am a little afraid to fly. What ever happens, it is an interesting and still ongoing research project. And the pictures are fun.
I like this pic because it makes the model look good, but note the loose landing wires in the upper right. When I get it trimmed I hope to fix this. But in the mean time I claim they are scale loose wires. The propeller in all these pictures is for show. I have a big old rubber prop that I hope to fly the model with.
|1 SIZE: 11'6" x 22'6" (L.M.p. 206)||SIZE: 10' 11-3/4" X 22" 6"|
|2 AREA:1040 Sq.ft. (L.M, p. 206)||AREA: 988sq. ft.|
|3 ASPECT RATIO 1.96||ASPECT RATIO: 2.05|
|4 CAMBER: 1/12 (L.M. p. 205)||CAMBER: 1/18|
|5 LEADING EDGE: Wire 1/16" di-
ameter (L.M. P1.66)
|LEADING EDGE: Cylindrical spar 1-1/2"
dia. at inner end, tapering to 1" dia. at
|6 COVERING: Cotton fabric, not
|COVERING: Cotton fabric, varnished.|
|7 CENTER SPAR: Cylindrical wood-
en spar, measuring 1-1/2" dia.
for half its length and tapering
to 1" at its tip. (L.M. p. 204·)
Located on upper side of wing.
|CENTER SPAR: Cylindrical spar about
I-1/2" dia. at inner end, tapering to about
1" dia. at outer end. Located on upper
side of wing. This center spar was
reinforced (I) by an extra wooden
member on the under side of the wing,
which measured I"x 13" and extended
to the 7th rib from the center of the
machine; and (2) by another wooden
reinforcement on the under side ex-
tending out about one-fourth of the
length of the wing.
|8 RIBS: Hollow box construction.
(L.M. Plates 64, 67.)
|RIBS: Most of the original Langley
box ribs were replaced with others
made at Hammondsport. (Manly let-
ter, I9I4)· The Hammondsport ribs
were of solid construction and made
of laminated wood. That part of the
rib in front of the forward spar was
|9 LOWER GUY-POSTS: A Single
round wooden post for each
pair of wings (see Fig. 3), I-1/4"
in dia. 6-1/2' long. (L.M. Plate
|LOWER GUY-POSTS: Four for each
pair of wings (see Fig. 4), two of
which were of streamline form mea-
suring 1-1/4" x 3-1/2 x 54" long; and 2
measuring 2"X2" With rounded cor-
ners, 3'9" long.
|10 The front wing guy-post was
located 28-1/2" in front of the
main center spar. (L.M. Plate
|The front wing guy-posts were lo-
cated directly underneath the main
center spar, 28-1/2" further rearward
than in 1903·
|11 The rear wing guy-post was
located 31-1/2" in front of the
main center spar. (L.M. Plate
|The rear wing guy-posts were located
directly under the main center spar,
31-1/2" further rearward than in 1903
|12 UPPER GUY-POSTS: For each
pair of wings a single steel tube 1/4"
dia., 43" long. (L.M. p. 1.84,
|UPPER GUY-POSTS: For each pair of
wings, two streamline wooden posts
each I-1/4" x 3-1/2:" x 76" long,
forming an inverted V. (See Pig. 4).
|13 Front wing upper guy-post lo-
cated 28-1/2" in front of the
main center spar. (L.M pl. 53)
|Front wing upper guy posts located
directly over main spar 28-1/2"
further rearward than in 1903
|14 The rear wing upper guy-post
was located 31-1/2" in front of
the main center spar. (L.M.
|The rear wing guy-posts were located
directly over the main center spar,
31-1/2" further rearward than in I903
|15 TRUSSING: The wing trussing
wires were attached to the
spars at the 5th, 7th and 9th
ribs out from the center (L.M.
pl 54) The angles between
these wires and the spars to
which they were attached are
shown in Fig, 3.
|TRUSSING: A different system of wing
trussing was used, and the wing trus-
sing wires were attached to the spars
at the 3rd, 6th and 9th ribs from the
center. The angles between these wires
and the spars to which they were at-
tached were all different from those
in the original Langley machine. (See
|16 VANE RUDDER: A Split vane
composed of two surfaces
united at their leading edges
and separated 15" at their trail-
ing edges, thus forming a
wedge. Each surface measured
2'3" x 4'6", with aspect ratio.5
(L.M. p. 214, pls. 53, 54·)
|VERTICAL RUDDER: The Langley vane
rudder was replaced by a single plane
vertical rudder which measured 3'6"x
5', with aspect ratio of .7.
|17 Operated by means of a wheel
located slightly in front of the
flier at his right side and at
the height of his shoulder
(L.M. p 216, pls. 53, 54·)
|Operated at Hammondsport through
the Curtiss steering wheel in some
tests, (Zahm affidavit pp. 5, 6)
through the Curtiss shoulder yoke in
some others (Manly letter, 1914), and
fixed so as not to be operable at all in
still others, (Zahm affidavit p. 7).
|18 Used for steering only. (L.M.
|Used "as a vertical aileron to control
the lateral poise of the machine",
(Zahm affidavit p. 6) as well as for
steering, (Zahm affidavit p. 7).
|19 PENAUD TAIL: This was a dart-
shaped tail having a vertical
and horizontal surface (Pe-
naud tail), each measuring 95
sq. ft. It was located in the
rear of the main frame.
Same size and con-
struction as in 1903.
|20 Attached to a bracket extend-
ing below the main frame.
|Attached to same bracket at a point
about 8" higher than in 1903·
|21 "Normally inactive," (L.M. p.
216) but adjustable about a
transverse horizontal axis by
means of a self-locking wheel
located at the right side of the
pilot, even with his back, and
at the height of his shoulder.
(L.M. pls. 51, 53.)
|Operable about a transverse horizontal
axis and connected to a regular Curtiss
elevator control post directly in front
of the pilot (Zahm affidavit p. 5).
|22 Immovable about a vertical
axis. (L.M. p. 214, pl. 56, Fig.
I.) No means were provided
for adjusting this rudder about
a vertical axis in flight. "Al-
though it was necessary that
the large aerodrome should be
capable of being steered in a
horizontal direction, it was felt
to be unwise to give the
Penaud tail and rudder motion
in the horizontal plane in order
to attain this end." (L.M. p.
|Immovable about a vertical axis on
May 28, 1914, only. Thereafter it was
made movable about a vertical axis
and was connected through cables to
a Curtiss steering wheel mounted on a
Curtiss control post directly in front
of the pilot.
|23 KEEL: A fixed vertical surface
underneath the main frame mea-
suring 3'2" in height by 6' aver-
age length. Area 19 sq. ft. (L.M..
|KEEL: Entirely omitted|
|24 LATERAL STABILITY: The dihedral
only was used for maintaining
lateral balance. (L.M. p. 45)
|LATERAL STABILITY: Three means
were used for securing lateral balance
at Hammondsport: The dihedral
angle as used by Langley, A rudder
which "serves as a vertical aileron"
(Zahm affidavit p. 6) and the Penaud
tail rudder. The last two constituted
a system "identical in principle with
that of Complainant's [Wright] com-
bined warping of the wings and the
use of the vertical rudder". (Zahm
affidavit p. 6).
|25 LONGITUDINAL STABILITY: Lang-
ley relied upon the Penaud system
of inherent stability for maintain-
ing the longitudinal equilibrium.
"For the preservation of the equi-
librium [longitudinal] of the aero-
drome, though the aviator might
assist by such slight movements
as he was able to make in the
limited space of the aviator's car,
the main reliance was upon the
Penaud tail." (L.M. p. 215).
|LONGITUDINAL STABILITY: At Ham-
mondsport the Penaud inherent longi-
tudinal stability was supplemented
with an elevator system of control.
|26 STEERING: Steering in the-hori-
zontal plane was done entirely by
the split-vane steering rudder lo-
cated underneath the main frame.
(L.M. p. 214)
|STEERING: On one day, May 28, I9I4
steering in the horizontal plane was
done with the vertical rudder which
had been substituted for the original
Langrley split-vane steering rudder.
After May 28th the steering was done
by the vertical surface of the tail rud-
der (Zahm affidavit p. 7), which in
1903 was immovable about a vertical
axis, (L.M. p. 214)
|27 MOTOR: Langley 5 cylinder radial.||MOTOR: Langley motor modified.|
|28 IGNITION: Jump spark with dry
cell batteries. (L.M. p. 262).
|IGNITION: Jump spark with magneto.|
|29 CARBURETOR: Balzer carburetor consisting of a chamber
lumps of porous cellular wood
saturated with gasoline. The air
was drawn through this wood.
There was no float feed. (L.M.
|CARBURETOR: Automobile type with
a float feed.
|30 RADIATOR: Tubes with radiating
|RADIATOR: Automobile radiator of
|31 PROPELLERS: Langley propellers
(L.M. p1.53~ PP· 178-182).
|PROPELLERS: Langley propellers modi-
fied "after fashion of early Wright
|32 LAUNCHING: Catapult mounted
on a houseboat.
|LAUNCIIING: Hydroplanes, developed
1909-1914, attached to the machine.
|33 FLOATS: Five cylindrical
floats, with conical ends, attached
to underside of main frame at ap-
propriate points, and about six
feet above lowest part of machine.
|FLOATS: Two wooden hydroplane
floats, mounted beneath and about 6
feet to either side of the center of the
machine at the lateral extremities of
the Pratt system of trussing used for
bracing the wing spars of the forward
wings; and one (part of the time two)
tin cylindrical floats with conical ends,
similar to but larger than the Lang-
ley floats, mounted at the center of the
Pratt system of trussing used for
bracing the rear wings. All of the
floats were mounted from four to
five feet lower than the floats of the
original Langley, thus keeping the en-
tire machine above the water.
|34 TOTAL WEIGHT: With pilot 850
pounds (L.M. p. 256).
|TOTAL WEIGHT: With pilot, 1170
|35 CENTER GRAVITY: 3/8" above line
|CENTER GRAVITY: About one foot be-
low line of thrust.
LANGLEY'S EARLY RUBBER MODELS (Click)
LANGLEY'S LATER RUBBER MODELS (Click)
Please feel free to write me at email@example.com
The 2nd Picture- As the caption says it is from the SmithsonianI got this fromThe World in the Air by Francis Trevelyan Miller. More about this book can be found in the fantasy Zepplelin page.
The 3rd Picture- Another Smithsonain pic. I found this copy in a reprint of an ancient Janes
The 4th Picture- The picture of the Bridges &c. is
by Thomas de Thomon an 18th century Frenchman