"Bigger is better." That is a phrase many pilots of larger
airplanes use. We will not say that they are wrong or right. We
will simply try to tell why there are huge airplanes.
Two of the three reasons to build a giant are range and payload.
Since the beginning of aviation designers made plans of giants to
have a longer range. The Germans made plans for a huge bomber, the
Mannesmann Poll, to attack the United States of
America. It was a ten-engine tri-plane. It had 5 engine gondolas
with each 2 engines. 4 gondolas were mounted on the mid wing, 1
gondola was mounted on the lower wing (in the middle of the wing).
At the end of that war the Allied forces found a wheel of that
bomber, so production of parts had already begun. The wheel had a
diameter of 2.2 meter!

Engines 10
Span 50 m 164.04 ft
Length 45.7 m 150 ft
Range 10 500 km (130 km/h)
6524 mi
Between the wars there were many firms who wanted to have larger
airplanes, so they could move more people over a longer range.
Larger airplanes need longer airstrips. Since there were no long
airstrips available at that time, flying boats were introduced.
Most of the giants between the wars were flying boats. Sikorsky,
Short and several other firms built their flying boats. But the
most remarkable flying boat of that time was surely the German
Dornier Do X. This giant had 12 engines mounted on
top of the wing. The interior was pure glitter and glamour. But the
project itself was an economical disaster. Even 12 engines were not
enough to put some speed or height into this plane. Even Lufthansa
(German airlines) was not interested to buy a Dornier X.
Own remark: learning a bit more about airplanes, I changed my
point of view on the Dornier X. I now wonder if the airplane really
was underpowered. Could it be that the pilots flew low on purpose
to use the Wing In Ground-effect (WIG)? This could have given the
wing more lift and would result in less fuel consumption during a
long flight. People, who have more info about this, please send me
your remark.
Thomas Labruyère gave me a link to a GOOD site about WIG. http://www.se-technology.com/wig .

Thomas Labruyère wrote me:"I've seen a picture of this huge plane
over New York Harbour, at an altitude of several hundred meters, so
it could be flown out of ground effect. Of course, flying low would
increase on such aircafts the overall range and even maybe the
speed (the Cx being reduced due to the absence of turbulence over
the wing upper surface (my technical english is getting a bit rusty
lately). But you've got to fly at less than half the wingspan to
benefit from ground effect. It would bring the Dornier really low,
especially when the wing is above the fuselage. Just a thought of
my own, of course, I have no real expertise in that field."
Dornier Do X
Power 12 x 391.5 kW (525 hp)
12 x 477 kW (640 hp)
12 x 432 kW (580 hp) (Do X2 en Do X3)
Span 48 m 157.4 ft
Length 40 m 131.2 ft
Height 10 m 32.8 ft
Wing area 450 m2 4844
sq.ft.
Weight (empty) 32 675 kg 72
035 lb
Weight (maximum take-off) 56 000 kg
123 457 lb
Speed (maximum) 214 km/h 133
mph
Speed (cruise) 190 km/h 118
mph
Ceiling 1250 m 4100 ft
Range 1700 km 1056 mi
I got a email from Rit Staalman:
"Yes the Dornier Do-X was
underpowered.
In 1929 sufficiently powerful and reliable engines were
simply not available
also the design ran overweight during
production, some 5000 kilogram, or ten percent of the design weight
(48000 kg)
which is enough to kill any design, because the netto useful
load on a real airplane of that time was normally <
10%
Also designers of that time had little idea of the
drag that was caused by struts and things like the
anchor carried on the bow.
Yes the pilots flew low to make use of the ground effect of
the stubby wings.
But it must be admitted: most (long distance)
pilots of that era flew low (read
Lindbergh)
Winds were usually less near the ground and the
stratosphere had not yet been conquered.
And also: for long distance flight the wings should not have
been stubby, but long and slender (see an
albatross)
but that would have given a much heavier construction at the
wing root;
or Dornier should have taken for granted smaller
wings,
but smaller wings would have meant higher wing
loads
and higher wingloads imply more powerful
engines,
so we are in a quandary,
or rather HE, Dornier, was.
Still, he was the first to build a real large
airplane OUT OF METAL
and it flew!
Chapeau!"
The Dornier Do X was an answer to the request of the
Reichsverkehrministerium (RVM). Their "Vorbereiting des
Transozeanischen Luftverkehrs" (preparation for transatlantic air
travel) got several proposals. There were several proposals that
couldn't be achieved in that time.
Rumpler made
one of these designs. The design used 10 engines of 1000 hp with
pusher props. Span would be 94 m (308.4 ft). The design had 4 hulls
and 2 stabilizers. Tails were connected to each other. Passengers
were seated in the wing. The design of Dornier was easier to
construct than this design.

Norman Bel Geddes (1893-1958), an American
industrial designer, came in 1932 with a proposal for another
giant. His Airliner # 4 was designed with assistance of the German
engineer, Dr Otto Koller. Geddes design would be veeeery big. Span
160 m (525 ft), nine decks, two elevators, place for 451 passengers
and a crew of 155. The hulls contained kitchens, crew quarters,
lifeboats and … 2 aircraft's. These aircrafts could be launched in
flight to the rear. If that would not be enough. There were also
luxurious staterooms, a gymnasium, dining room with dance floor,
promenade decks, verandas, bar and many more. To me this sounds
more like a cruise ship than to an airplane. To get the plane in
the air there were 20 engines. Typical for this design … there were
also 6 reserve engines, which could be placed in flight. This power
would get the plane to a cruise speed of 160 km/h (99 mph).
http://hotgates.stanford.edu/Bucky/dymaxion/belgeddes.htm
Go check it out.
Several thought that this design could only be operational when
using ground effect. I believe that his thought is right. Ground
effect … to me is the way to create the giants of tomorrow.
At the beginning of WW II the Germans built another giant. It was
a glider! The Messerschmidt 321 would be used
during the invasion of England. The glider could carry a
lightweight tank or many equipped soldiers. The Battle of Britain
gave the Allied control over their own air. Using German gliders
would be suicide under these conditions. So the plan for using the
gliders dropped. But they equipped the glider with engines so they
could use them as transport airplanes. First they used 4 engines,
quickly they placed 2 more. The name changed to
Messerschmidt 323. The nickname was
"Gigant".

Control over the air was not the only problem of the Messerschmidt
321. Getting it into the air was another. There were no giant tow
planes at that time. And the pilots were a bit skeptic about this
plane made of wood, bars and fabric. They had to use 3 airplanes
("Troika-Schlepp") at once to tow the prototype into the air. The
pilots of the test flights found out that the airplane was very
stable in the air, but that you needed a lot of arm muscles to
steer the plane. Soon they added place for a co-pilot. The problem
with the tow plane dropped when Heinkel made their He 111
"Zwilling" ("Twin"). This was a combination of two He
111's with a extra engine in the middle. It became nearly a giant
itself. This airplane had the necessary power for the Messerschmidt
321. Still they used rocket assistance to get the fully loaded
gliders in the air.

The Messerschmidt 321 had several new features. It has a landing
gear that it could drop. Well, it was not a landing gear, it was
more sort of a take-off gear. The glider landed on skids. Also new
was a loading door at the front. Using a ramp tanks, trucks,
artillery or soldiers could easily enter the glider. When the
glider landed, the tank drove through the front door. The
Messerschmidt 323 gave the possibility to check the center of
gravity while loading. Somehow they could see this at the landing
gear (the "Gigant" had a new landing gear configuration of 10
landing wheels). But the most remarkable thing were the gunners who
were placed in the wing. You can place pilots, gunners or other
personnel anywhere you like in a giant.
As you can see, the Messeschmidt 323 is one of my favorites. I
really love the simplicity of the design.
Messerschmidt 321
Span 55 m 180 ft 5 1/3
in
Length 28,15 m 92 ft 4 1/4
in
Height (on take-off dolly) 10,15 m
33 ft 3 1/2 in
Wing area 300 m2 3 229,17 sq
ft
Maximum towing speed (He 111Z) 220,5 km/h
137 mph
Maximum towing speed (Troika-Schlepp) 212,5
km/h 132 mph
Minimum towing speed 159 km/h
99 mph
Normal gliding speed 140 km/h
87 mph
Glide ratio 1:8
Take-off distance (Troika-Schlepp and four 1102 lb rockets at
normal loaded weight) 1204 m
3 950 ft
landing distance 400 m 1 310
ft
Messerschmidt 323 E-2 "Gigant"
Span 55 m 180 ft 5 1/3
in
Length 28,5 m 93 ft 6
in
Height 9,6 m 31 ft 6
in
Wing area 300 m2 3 229,17 sq
ft
Weight (empty equipped) 29 208 kg
64 066 lb
Weight (maximum loaded) 45 230 kg
99 210 lb
Engines (Gnôme-Rhône 14N 48/49) 6 x 1140
hp
Speed (no load) 252 km/h 157
mph at sea level
Speed (maximum load) 238 km/h
148 mph at sea level
Economical cruising speed 225 km/h
140 mph at sea level
Range (normal tanks, maximum load) 1 100 km
684 mls at sea level
Climbing speed (maximum load) 264 m/min
866 ft/min
During WW II another giant was born on paper. Howard
Hughes was a man who loved to create airplanes which
reaches the limits. It had to be the fastest, the smallest or ...
the largest. And this is the third reason to create a giant. The
will to have the greatest (sounds like a typical male problem).
Hughes design, named the "Hercules" (but better
known under the name "The Spruce Goose"), was a
answer to the need for transport in the Pacific. At that time
transport by boat was dangerous. Many U-boats were waiting. So
Howard Hughes wanted a large airplane to transport all what was
needed by air. The design was on paper during the war, but the
airplane flew after the war.
Hughes had many problems building the prototype. Mostly thanks to
himself. He never could make up his mind. He changed the design
several times. We will not bore you to death explaining all the
other problems he had. But we can tell you ... the plane was
huge.
It flew once. Not that it lacked the power, but Howard Hughes
didn't get permission to take off. Hughes wouldn't be Hughes if he
didn't show to the public that it could take off. So he got
permission to make a taxi-run on water. During this taxi-run, he
applied power, set the flaps on take-off and ... took off. Yes, it
could fly. After this flight it was stored in a dome near the place
where it flew. Recently they moved the whole airplane to Evergreen
Aviation Educational Center in Mc Minnville in Oregon.
The Hughes HK-1 is still the largest airplane build.
Hughes HK-1 "Spruce Goose"
Wingspan 97,54 m 319.92
ft
Fuselage height Approx. 9,14m
Approx. 30 ft
Cruising speed Approx. 322 km/h
Approx. 200 mph
Maximum range Approx. 4828 km
Approx. 3 000 miles
Endurance (cruise) 20,9 hrs.
Service ceiling 6 370 m 20
900 ft
Engines 8 Pratt and Whitney R-4360, 3 000 hp
each
Propellers 8 four bladed Hamilton Standards,
diameter 5,23 m (17' 2'').
There is another plane that is quite remarkable in design and size.
What happened? Several airline companies dropped their
Stratocruisers when turboprop and jet-engines became available in
civil air transport. Stratocruisers could be bought at a cheap
price. Most were bought by Lee Mansdorf and were stocked in
California. Former bomber- and transport pilot John M. "Jack"
Conroy lived there. NASA had in that time problems moving segments
of the Saturn-rocket for the Apollo space project. Conroy left his
job, took a loan and started work on a conversion of a
Stratocruiser. He added 5 meter (16.40 ft) to the fuselage and
placed a enormous "tube" in top of the lower deck. Total
internal stock volume became 826,5 m3 (29 187 cubic ft). The
"Guppy" was born.
In 1960 he presented the concept to NASA-officers. NASA was
pleased with the idea and asked for exclusive user-rights for two
models. Airbus Industries was also interested and bought some
models to transport Airbus-components to the final assembly. There
were several sorts of Guppy's. The last version was the 201 with
Allison turboprops.
I once saw a weird airplane over Aalst, Belgium at rather high
altitude. It had a very fat fuselage. It could only have been a
Guppy.
Conroy / Aero Spacelines Guppy 201
Span 47,62 m 156.2 ft
Length 43,84 m 143.8
ft
Wing area 182,52 m2 1965
sq.ft.
Cargo room diameter 7,5 m
24.6 ft
Cargo room length 34 m 111.5
ft
Weight (empty) 45 359 kg 100
000 lb
Weight (maximum take-off) 77 110 kg
170 000 lb
Maximum loading 24 494 kg 54
000 lb
Cruise (on 7620 m) 407 km/h
253 mph
Maximum cruise 463 km/h 288
mph
Climbing speed 457 m/min 1
500 ft/min
Ceiling 7 620 m 25 000
ft
Range (max cargo) 813 km 505
mi
Engines (Allison 501-D22 C turboprop) 4 x 3663
kW (4912 hp)
I know that the largest operational airplane is a design of the
Russian firm Antanov. I will describe his forerunner, the
Lockheed C-5 Galaxy. "Huh? Forerunner?" I hear you
think. Let's say that the main difference between the Antanov and
the earlier produced (first flight 30 June 1968) Galaxy is the
tail. The stabilisator of the Galaxy is placed on top of the
vertical tail. The Antanov has a conventional tail. The difference
in size is a few meters (feet). I don't blame the Russians of
making a copy, it is like the Russians said about their own design
of the Space Shuttle "The laws of aerodynamics are the same to
Americans or Russians".
The Galaxy was possible thanks to his engines. These new engines
made it possible to design this airplane with just 4 engines. Using
any other engine would lead to a lot more engines needed. It has
the same basic shape as the smaller C-141Starlifter. A high wing
with engines mounted in gondolas underneath, a T-tail and a raised
back section with loading doors. But it has also a new design of
nose. The nose can be raised to clear access to the cargo room. The
Galaxy has the unique feature of "Roll in - Roll out". This means
that a vehicle can ride onboard and ride off without turning or
riding backwards.
The airplane has in a upper deck a roomy cockpit in the nose and a
extra room for 73 passengers behind the main wing spar. The cargo
room is 5,79 m (19 ft) wide and 36,88 m (121 ft) long and has a
volume of 985 m2 (34786 cubic ft.). Height varies between 2,9 m
(9.5 ft) (under the wing) to 4,11 m (13.5 ft) in the back
section.
Lockheed C-5 Galaxy
Span 67,88 m
Length 75,54 m
Height 19,85 m
Wing area 575,98 m2
Weight (empty operated) 169 643 kg
Weight (maximum take-off) 379 657 kg
Maximum Speed 919 km/h
Maximum cruise speed 908 km/h
Climbing speed (at sea level) 525 m/min
Ceiling (at 278 960 kg) 10 895 m
Range (maximum) 10 411 km
Range (max. cargo) 5526 km
Engines (General Electric TF39-GE-1C turbofans
4 x 19 522 kg (191,27 kN)
I know that there are many other giants. But this collection has
some unique features.
What will happen in the future? Will airplanes become bigger? Will
a operational airplane be build that is even larger than the
"Spruce Goose"?
I read that McDonnell-Douglas has a "Megaplane" on paper. It would
be a two deck blended wing body (BWB) for 800 passengers. Range
will be 7000 miles (11 250 km). Cruise speed 590 mph (900 km/h).
Airbus Industries studies a "FW-900". It is a giant flying wing for
900 passengers. Range 7 457 miles (12 000 km). 4 turbofan engines
would be mounted on pylons on the back of the wing-fuselage. Each
would deliver 100 000 lbst (444 kN). Span 315 ft (96 m). And this
span is very near the span of the Hughes HK-1.
Why such a large planes for passengers transport? Studies showed
that bigger planes made the price for a flight cheaper. That is not
hard to believe. I have one question. Where will they find
airfields for these giants? Will there be flying boats again? Only
the future will tell.