Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-08-18
NEW NAVY A|RSH|P
READY FOR FLIGHT
ZMC-2, Metal Clad, Passes
Inspection and Will Take
Air Tuesday.
Special Dispatch to The Star.

Special Dispatch to The Star.
DETROIT, Mich, August 17.-With
its formal inspection by the United
States Navy Survey Board completed
and its initial flight scheduled for Tues
day of next week, the ZMC-2, metal
clad airship, built by the Detroit Air
craft Corporation for the Navy Depart
ment, the new style dirigible. is ready
for the air. On its successful maiden
flights and formal acceptance by the
Government hinges the future of metal
clad, lighter-than-ai craft product. as
the ZMC-2 Is the first ship Of its type
ever built.
In its successful performance is ex-
pected to not only revolutioniZe dirag-
ible construction the world over. but
will also serve as the engineering AND
building of airships OF larger size, &C.
cording to officials.
The new dirigible resembles the
Zeppelin type airship in that 1t Is a
rigid ship, built to carry the strains
and stresses due to flight by means OF
a rigid hull. However, the means OF
carrying these strains and stresses have
been worked out along entirely dtferen.
engineering lines from those conceived
by, and developed by the great Count
Ferdinand Zeppelin.
After SUFFICIENT progress had been
made in the underlying engineering
work, Congress appropriated $500, O06
for the purpose Of building an expert
mental, all-metal airship for the United
States Navy.
The construction of this craft was
authorized by Congress for the purpose
Of determining the advantages Of all
metal lighter -than-air craft. This par
ticular ship was designed and built in
the most convenient size to provide a
practical test Of all-metal construction
and to enable aeronautical engineers to
develop the relative advantages thereof.
Eminent aeronautical authorities con-
slider the ZMC.2 one of the most i'm
portant innovations in the history OF
aviation. Summarizing their reasons
for this statement, 1t Is found that the
all-metal dirigible combines three dis
tinct characteristics, none Of which
have ever been incorporated in light
er-than-air ship. They are as follows:
l. It is built entirely Of metal, instead
of a sheathing fabric which hitherto
has been used in dirigibles. It has a
gas capacity of 100000 cubic feet.
in shape; that Is. its diameter, so feet,
will be only about one-third Of its
length, $50 feet, whereas the familiar
Zeppelin type Of airship have been from
z to IL as long as they have been thick.
3. Its method Of control differs radi-
cally from previous dirigibles. Its ele-
vatorS and rudderS, which regulate its
maneuvers up, down and sideways, in
stead of being at the rear. are in the
form of eight fms projecting from the
hull about 80 feet forward Of the stern.
Constantly increasing knowledge OF
the science Of erodynamics and the de-
velopment Of alclad. an alloy Of alumni
mum and copper alloy which Is almost
as strong as steel, have made possible
the building of this all-metal airship.
The design of the ship itself Is the
result of more than seven years Of
study, beginning with the early Yep
pelin and coming down through the
period Of the late war to the present.
In performance characteristics the
ZMC-2 is similar to the non-rigid fabric
blimp, but in the magnitude Of its i'm
portance as an engineering achievement
1t Is at least equal that Of any rigid
airship ever built.
determined upon as sufficient to fulhll
Government experimental requirements.
Prior, however, to submitting a definite
proposal to the Government, various
systematic experiments were conducted.
General specifications Of ZMC-2:
Length. of hull, 149 feet inches.
Diameter of hull ,(maximum), So feet
8 inches. Fineness ratio. 2.83. Dis
placement Of hull, 100000 cubic feet.
Total ballonet displacement, $4,000
cubic feet. Ratio Of ballonet volume
to hull volume, rs per cent. Thickness
of skin, 0o95 inch. Length of car,
"a feet. Width of car, 6 feet inches.
Number Of air valves, 3. Number Of gas
valves, g. Number Of fms, 8. Total
fin area. 44o square feet. Total elevator
area, 100 square feet. Total auto
matte rudder area, 95 square feet.
Engines Wright Whirlwind J-5), 2.
Power at 1900 r. P. NJ, 440 horse
power. Propeller diameter Gall metaO
9 feet inches.
Owing to the vast amount of expert
mental work the ship cost approximately
$1,150,000. A survey board has been
appointed by the Secretary Of the Navy
to make the preliminary, inspection Of
the zMC-2, and to accompany the ship
on its trial flights. Lieut. Comdr. VIII
liam K. Harrill, senior member Of the
board; Lieut.. C. v. S. Knox. resident
naval inspector during the ships con-
struction, and Lieuts. G. E. Bauch and
G.. H. Duggan and George v. Whittle
compose the board.