A pilot in prone position is lying on
his stomach. There are 2 types: prone and semi-prone. Semi-prone is
if the knees of the pilot are remarkably lower than his upper body.
Reimar Horten did use this technique in several of his
Sometimes it is hard to find out who is the first to use a certain
system. Here it is easy. The first was the first. I do mean the
first motorized airplane capable of flying, namely the Wright
Flyer. The Wright brother did later change this pilot position into
the now classic seated position.
A long time passed by without further use of prone pilots … till
around WW II.
Akaflieg Stuttgart built the FS17, a research glider. The study
had as purpose checking if a prone pilot could endure higher
g-forces. Lets first explain to the inexperienced what g-forces
G-forces are created in airplanes when they make turns or pulls
up. Sometimes these forces are that high, one can't barely move his
hand. You can compare it with making a tight turn with a car. The
people inside the car get "pushed" sideways. In a airplane the
pilot get pushed downward (positive g-forces) or upwards (negative
g-forces). In normal life the g-force is 1. If making tight turns
or pulling up, the g-forces increase and your hand starts to weight
more. At a certain level you can't move your hand. It seems like it
is glued to the armrest.
Lying on your belly doesn't make you move your hand, but it helps
not to pass out. Yes, sometimes the g-forces are that high that the
blood "gets sucked out of your brain". Your vision gets black and
in a further phase you pass out (= gets unconscious). Lying on your
belly reduces the height between your head and your heart. So the
heart doesn't need to pump the blood as far upwards as it needs to
do in seated position. Reducing this height makes a pilot pass out
at higher g-forces.
Black-outs are much experienced during WW II. Dive bombing, a
technique much used in WW II, always ends up in a pull-up at the
end of the bomb-run. Fighter pilots having a dogfight sometimes
make sharp turns, they were also having black-outs. So, looking for
a solution for this problem seemed obvious at that time.
I got the following information about the Akaflieg FS 17 from
Peter F. Selinger: "The FS 17 is a very small wooden sailplane. The
students started construction in 1937 with a maximum load of
n.j=14. The open fuselage in the cockpit area required special
enforcements to spend the pilot a safe "bed". They made first
flight 21st March 1938 at the Teck gliderfield nearby
Dettingen/Teck, which is a small village south of Kirchheim/Teck.
Neither in the book 50 years Akaflieg Stuttgart, nor in other
publications I have, there was a complete 3-view, nor dimensions.
The maiden flight pilot reports, that the prone position didn't
caused any problems, except the arm should have a longer rest to
reduce PIOs on the elevator. It's to suppose that the input to make
such a plane is the result of medical research, that people could
withstand high g-load far better in prone position, higher gs as
well as these higher gs for a far longer time. But I don't know who
initiated the construction."
Horten did know about this study. He mentioned it to Jan Scott
as his inspiration to use prone pilots in his own designs. But
Reimar used a semi-prone position. The upper body of the pilot was
placed at 30° from the horizontal. This made that the pilot didn't
need to turn his head that much upwards, as in the prone position,
to look forward. It made the position less tiring.
Sometimes a radical idea won't get into production because it gets
critics out of prejudgment from higher placed persons. Well, that
was not the case with the Horten IV because it was designed and
build …without official approval or knowledge.
You probably wonder why the Horten brothers wanted to use this
"obsolete" pilot technique. Besides the ability to withstand higher
g-forces they had 4 other reasons. It found these in the book
"Nurflugel" by Reimar Horten and Peter F. Selinger (ISBN
3-900310-09-2)(part German, part English).
- less tiring on long flights
- visibility to the front and down is excellent
- a small cockpit cross section can be used. (note of me: This
leads to less drag. Less drag leads to higher top speeds and higher
- crash survival seemed to be very good.
I guess that the main reason was visibility. The Horten brothers
always did use wings with backwards sweep (for more explanation, go
see flying wings). When you place a pilot near the center of
gravity (CG), which is normally done in gliders, the pilot is
placed further backwards in relation to a pilot in a straight wing
airplane. The reason is that the CG is placed more backwards in
backswept airplanes. This makes that the pilot needs to look over a
large portion of the wing. Looking over the wing is difficult, but
necessary during landing.
This must have been a problem to the Horten brothers too. The Horten Ho II had a
large transparent leading edge part, which was wider than the basic
cockpit. It gave the reclined pilot (later seated) a better view
forwards and sideways. But it must have weighted a lot in relation
to a classic wing leading edge.
Placing a pilot in prone position in a backswept glider makes the
head of the pilot shift more forwards, more towards the leading
edge. The pilot has less wing to look over. It is now even possible
to place a small transparent part on the lower side of the wing to
have superb vision downwards.
I placed a question about the Horten IV to Mr. Scheidbauer, one of
Hortens test pilots. He did answer through Peter F. Selinger
(member of the Nurflugel Mailinglist): "he told me that he
appreciated the downward view specifically at winch-launch. He
said, riding into the sky nearly vertically and seeing the winch
and airfield was impressive and he never will forget this....."
Proves that the visibility problem got solved using the prone
Not only was the body of the pilot in a new position, his arms
were also placed in a new way. The arms were placed sideways and
nearly at the same height of the shoulders. In this position it
would be hard to push or pull a stick, it is a unpleasant
wrist-movement. Horten solved the problem by using a ramshorn
shaped handle-bar. Pitch control was done by sliding it forwards or
backwards. It solved the problem. Control forces were light at all
The Horten H IV had small sized instruments, so the vision would
not be obscured by large instruments. The further development of
the Ho IV, the Ho VI, had regular sized instruments but they were
placed in the D-tubes (frontal portion of the wing) of the wings
and were viewed using a mirror.
I read about flights with the H IV mentioning flights of 10 hours!
So... long flights could be made in this strange position.
Somewhere I did see a picture of a Horten sitting on his knees,
showing the pilot position to Reichsmarshall Göring. I guess it
shows that the Horten Ho IV got know and that this modern sailplane
and its pilot position made good impressions to the higher
I found several other German projects with prone pilots. But all
had a later date. So I guess once the other German manufacturers
heard about the Horten Ho IV, they got thinking about prone pilots
The DVL (Deutsche Versuchanstalt für Luftfahrt) gave a order to
build a powered aircraft. It was built by FFG Berlin and was named
the Berlin B9. It flew spring 1943. It could withstand 22g!. The
configuration was a low wing twin engine airplane. It looks kind of
usual except the cockpit. The fully glazed cockpit gave the pilot
superb view between 30° below the horizontal to 40° above the
horizontal. There was no view to the rear. This kind of view was
found to be ideal for 4 types of airplanes:
- Fighter airplanes with speed superior to their opponents
- High speed reconnaissance airplanes
- Airplanes that operate or attack at angles greater than
www.luft46.com has the full
story on the Berlin B9. Go see the prototypes section.
This research airplane test result must have been known to other
firms, because... I found a German dive bomber, a fast, small
fighter and a fast reconnaissance airplane.
The DFS 228 started its life as a idea in the beginning of WW II.
The idea mentioned the use of a rocket propelled sailplane, which
could climb to extreme heights and then soar for a long time. It
was meant as a reconnaissance airplane which would be uncatchable
by the enemy.
In 1941, the Technischen Amt of the RLM gave the specification to
DFS (Deutsches Forschuninstitut für Segelflug (German
researchcenter for gliding). The designwork began, but stopped due
to low priority. In 1943, the idea got into higher priority and the
work was recommenced. The result was a midwing glider with a
classic layout but with a remarkable cockpit. The cabin was
pressurized and the pilot lay in a prone position. There were only
5 small transparent parts in the cabin. One circular part in the
front and 4 smaller rectangular parts more backwards (two on each
Why did they use a prone pilot? It puzzled me. I measured the
height of the cockpit using a 3 view of the DFS 228 and came to
1,25 m (4 feet 1 inch). That is high enough to place a seated pilot
(maybe a bit reclined). OK, the cockpit wall is thicker due to the
pressurized construction, but still I don't think that it was for a
smaller cross-section that they used a prone pilot. I guess the
reason can be found in the transparent parts. At these heights the
thickness of that glass is higher to withstand the pressure. The
smaller they are, the lesser the thickness of the glass has to be
to withstand the pressure and that makes the glass less heavy
(smaller and less thickness). I guess that easy construction and
reduction of weight were the basic ideas to choose a prone pilot
here. But let's not forget the advantage of the view downwards. It
must have been a advantage for this reconnaissance airplane.
At www.luft46.com I did find a
picture of a DFS 228 pilot lying in his cockpit. I could see the
pilot stretching his arms downwards. He was piloting in this
position. One thing is for sure. A prone pilot can place a lot of
instruments under him. The floor of the cockpit can be filled with
instruments (as long as they are within reach). The side of
whatever the pilot is laying on can be filled with devices too (if
the sidewall of the cockpit is a bit further away). OK, all
instruments or levers will not be within view, but do you need to
look for the gear stick in your car to use it (only valid on cars
without automatic gear)? I guess not after some training. Prone
pilots can have more instruments and levers around them than a
classic seated pilot, I believe. But they need blind operation
whenever you need to be forced to look forwards (landing for
instance). But you can always choose to place items related to
landing within view and the other stuff out of your forward view.
Don't you need to turn your head too if you want to adjust your car
radio (only valid on car radios without steeringwheel
The DFS 228 never got operational due to the end of the war, but
two prototypes were build and the production of 10 DFS 228 A-0 had
already started. Plans were made for a further development, the DFS
346, which was planned to be supersonic (Mach 1.9) at 66.000 feet
The Henschel HS 132 looks similar to the better known Heinkel He
162. It has its jet-engine on its back for better maintenance, it
has a tail consisting out of a horizontal part which is a bit
angled upwards and at each end a vertical rudder. The difference
can be found in its function and its cockpit. The He 162 is a
fighter, the HS 132 is a bomber. The pilot of the HS 132 is in a
prone position. Why? Well, if you read the 5 reasons to use a prone
pilot mentioned by Horten, you would remember the higher G-forces a
pilot can endure. The book "The Warplanes of the Third Reich" by
William Green mentions that seated pilots black out (vision
disappear due to less blood in brains) at 4-5 g, a prone pilot
black out at 10-11 g. Dive bomber-pilots sure need to endure
g-forces in their last part of the bombing, namely the pull-up.
That and the superb vision downward (see test results Berlin B9)
are the reasons to use a prone pilot in the Hs 132. The Hs 132 V1
was nearly assembled for initial flight trials when the factory was
captured by Soviet forced.
The Gotha factory was building the radar-equipped Horten HIX, a
for that time futuristic jet-engine flying wing. Using the
knowledge they gathered from the construction of these now named
Gotha Go 229 (other name used for the Horten Ho IX), they made a
proposal for a fighter, the Gotha P60. The P60 used nearly the same
wing layout as the Go 229. The first proposal, the P60A, used a
cockpit with the crew (2) in a prone position laying side-to-side.
There were no extra bulbs needed to place the crew. All fitted
inside the wing. Well, not exactly all. The engines of the P60 were
placed outside the wing. One on top of the central part, one under
the central part. Maybe this was done for better maintenance of the
engines. Steve Reichmuth remarked that the lower engine might cause
problems due to ingestion of foreign objects during take-off and
landing. I bet he is right. Just look at the front wheel. What is
right behind it? Yes, the lower engine. What will happen if the
front wheel hits a small rock or dirt? ... Trouble, because
jet-engines don't like to eat things like that. That is enough
about the engines, this page is about prone pilots.
A few 3D's of the Gotha P60A I received from
The second proposal, the Gotha P60B, no longer has the prone
pilots. I did ask myself why. The answer seems to be that Gotha
needed to make a simplified cockpit. Maybe they wanted to speed up
development or production. Gotha got approval to start building the
P60B-prototype, but work was stopped in favor of the final
proposal, the P60C.
The most remarkable German WW II airplane is definitely (to me)
the Blohm und Voss BV 40. Let's follow the thoughts of its
designer, Dr. Ing. Richard Vogt (known for several other unusual
designs, go see asymmetric airplanes): the front area of a
Focke-Wulf Fw 190 (about 1,6 m2 (17 sq. ft.)) is a capable target
of a average gunner at a range of more than 914 m (1000 yards). The
reason for this large frontal area is the size of the engine. So
reducing the chance to be hit can be done by reducing the frontal
area. And reducing the frontal area can be done by ... placing no
engine! The idea of the BV 40 is born.
He must have thought about other ways to reduce the frontal area
even more. So the decision to use a prone pilot was not far away.
Richard Vogt believed that the tiny "glider-fighter" would be
invisible to the gunners before the BV 40 struck with its 30 mm
(1.18 inch) cannons.
The pilot was to be positioned behind a 120 mm (4.7 inch)
armor-glass windscreen and he was further protected with heavy
metal sheets. The airplane was made mostly out of wood. The general
layout was classic (highwing with classic tail) and the instruments
were kept to a minimum. Simplicity all over.
The BV 40 was to be towed by a fighter. It took off on a
jettisonable trolley and landed on a skid. The BV 40 had to deliver
as much as possible damage on its single pass. That is why it had
two 30 mm cannons.
Several prototypes were made. Flight characteristics were good,
but the stall was terrible. At 140 km/h (87 mph) the plane fell out
of the sky without warning. But the plane got through the first
tests with a idea that handling was good enough. One thing I read
is the opposite of what Horten said. The BV 40 V6 was towed from
Stade to Wenzendorf behind a Bf 110 as a long flight test. The
pilot did complain about the prone position as tiring. Maybe the
difference with the Hortens can be found in the fact that Horten
did use semi-prone positions and that the pilot of the BV 40 was
fully prone. The pilots of the Horten gliders didn't have to turn
their head that much upwards as a fully prone pilot.
Heinkel made also a airplane with a prone pilot, the Heinkel
P.1077 Julia. It was a rocket-powered fighter. Like the BV 40,
simplicity was the main goal (except for the engine). It was a
small high wing aircraft with a tail like the Hs 132 (but not
angled upwards). Wood was the main construction material. The
prototype was build only using normal workbenches of carpenters.
Like I said … simplicity.
Take-off was to be made vertically and the Julia landed on tandem
skids (two behind each other, the first could be lowered and both
had a shock-absorber).
A second version was designed using a seated pilot. But because
the chief-designers of this project couldn't come to a compromise,
both versions would be build.
Production was not without problems. Not due to the design, but
due to the situation of Germany in the war. I didn't find any
record of flights with a Julia. So I assume that the prototypes
never were finished.
The classic question I ask again is "Why did they use a prone
pilot?" I cannot find the reason. Ok, the version with the seated
pilot is a bit higher. It might have been that. But I could also be
that the designers were influenced by the test result report of the
Berlin B9 (I don't know how much this paper got spread within the
aviation firms). It mentions a prone pilot as good for a fighter
with speed superior to their opponents. Remember: the Julia is
powered by a rocket-engine.
The rocket-engine in the Messerschmitt Me 163 Komet made it
uncathable during powered flight. But the Me 163's were shot down
during its glide downwards. Would the Julia have suffered the same
All the WWII planes mentioned till now were German. But there were
experiments with prone pilots too in the USA. But how did they come
to this idea? I have my own theory. But I cannot prove it. It is
based on something I read in the book "Nurflugel". It mentions a
flight with the H II by Reimar Horten. The pilot saw another plane
with a photographer inside. The next month the Horten brothers got
a copy of the "New York Times" with a picture of the H II inside.
The title mentions "German flying wing over Berlin!". That same
month Northrop Aircraft Company got a Government contract to
develop a flying wing. Knowing this, it is easy to think that the
Horten Brothers became possible targets for Allied spies. The prone
position could have been reported the same way. I recall a picture
of the Horten H IV. It was a shot taken from long distance between
trees. Could it have been taken by a spy? Pity, I don't recall the
reference of that picture. But like I said … this theory is my own
Since we are back to the Horten Brothers, I quickly give you
another prone pilot project of them. It was a modified Horten H
III, a glider which was first flown in the 1938 Rhön Contest.
They gave the modified version the designation Horten H III f. It
was intended as a way to familiarize pilots with the prone pilot
position. We are now 1943. I got a great drawing of a Sharkit resin
model of this Horten H III f. It clearly shows the position of the
pilot and the glazing of the cockpit. No wonder that the view was
John K. Northrop proposed a small, light flying wing pursuit
interceptor in September 1942 to the USAAF. The USAAF first wanted
to look closer to the flying wing configuration and ordered three
gliders in Secret Project MX 324. These gliders had the pilot in
prone position. Why? No idea. Northrop made other flying wings and
those had seated pilots. Why did he choose for a prone pilot in
this one? Euh… let's go back to my theory, which I mentioned just
above. If Northrop had pictures of the Horten H II and maybe later
of the H IV, H VI or H IIIf, he could have wanted to test this new
idea as well. If it worked for the Germans, it might as well work
One of the gliders was later equipped with a rocket engine. It got
a new designation, MX 334. Testing did prove enough trust to evolve
to a larger airplane, the XP-79. Three XP-79's were ordered in
Secret Project MX-365. But the intended rocket engine got seriously
behind schedule. So they gave one of the X-97 airframes two
jet-engines. It became the XP-79B. The pilot was prone.
Some mention that the XP-79 was intended to ram enemies, but Steve
Pace wrote in his book "X-fighters" (ISBN: 0-87938-540-5) that Jack
Northrop himself denied it and said that only gunfire would be
Knowing the prone position of the pilot I believe him. A pilot who
gets a knock on his head by ramming a enemy is useless when
unconscious (or dead). A pilot who gets some knock on his feet or
legs could maybe be capable of steering the plane back to its base.
So if it would be a rammer, the pilot would have more chance to
survive if he would be in a seated position.
Those lines above were made in the first version of my text. Was I
surprised to find a German project of a rammer with a prone pilot,
while working on the rest of the text. In the book "Natter und
andere deutsche Kleinstraketenjäger" by Joachim Dressel
(ISBN:3-7909-0361-2) I found the Messerschmitt Me P 1103. It was a
rocket-powered airplane with a 10 mm (0,3937 inch) thick
Panzerzylinder( reinforced cylinder body) of 79 cm (31,1023 inch)
diameter. Here it is mentioned to be first intended as a rammer. I
guess the nose was heavily reinforced and it had small transparent
parts (reinforced too). In a later faze the project became a
fighter. None were built. The Bachem Ba 349 Natter won the
production order. www.luft46.com has info about this
one too, but doesn't mention the rammer-info.
The Northrop XP-79 crashed on its first real flight (only
taxi-runs were done before). I got a nurflugel-mailing list
response which has the story. I quote: "Jack Northrop described
this (XP-79B) flight in his talk to the Royal Aeronautical Society
in 1947: "The takeoff for this flight was normal, and for 15
minutes the airplane was flown in a beautiful demonstration. The
pilot indicated mounting confidence by executing more and more
maneuvers of a type that would not be expected unless he were
thoroughly satisfied with the behavior of the airplane. After about
15 minutes of flying, the airplane entered what appeared to be a
normal slow roll from which it did not recover. As the rotation
about the longitudinal axis continued the nose gradually dropped,
and at the time of impact the airplane appeared to be in a steep
vertical spin. The pilot endeavored to leave the ship, but the
speed was so high that he was unable to clear it successfully.
Unfortunately, there was insufficient evidence to fully determine
the cause of the disaster. However, in view of his prone position,
a powerful, electrically controlled trim tab had been installed in
the lateral controls to relieve the pilot of excessive loads. It is
believed that a deliberate slow roll may have been attempted (as
the pilot had previously slow rolled and looped other flying wing
aircraft developed by the company) and that during this maneuver
something failed in the lateral controls in such a way that the
pilot was overpowered by the electrical trim mechanism.""
The Italians had a prone pilot too. In 1942 SIAI Marchetti
proposed the S.93, a single engined dive bomber. The pilot was in a
prone position nearly on top of the engine. Germany overran Italy
during the construction of the prototype. But the Germans continued
the construction. It flew in 1944, but the project stopped because
the German control commission thought the prone position was not
When I read this in "Regia Aeronautica, vol. 2" by F.D'Amico &
G. Valentini (ISBN: 0-89747-185-7) my reaction was "Huh … not for
Luftwaffe-pilots ?! Didn't they know about the other German
projects with prone pilots?". The answer probably is "No". Mostly
projects are kept secret. A German once mentioned the hype about
the German secrecy. He mentioned the secrecy as being very secure.
It was almost "First burn, then read.".
Another thing that puzzles me is the question "How did the
Italians came tot he idea to use a prone pilot?" and "Did they know
about the Akaflieg Stuttgart FS 17 or the prone Hortens?"
Any more data on this Italian project is very welcome. Any 3view
Till now we had Germany, America and Italy. But the UK also had
its prone pilots. In the early post-war years the British most
researched item was high speed. Maneuvers at high speed generate
I know of two British military projects concerning prone pilots.
One was a conversion of a Reid & Sigrist. The other was a
conversion of a Gloster Meteor. Both had 2 seats. The original one
and a place for a prone pilot in a extended nose. The fact that
they kept the original seat gives me the feeling that they didn't
trust the pilot position. Or is it pure British conservatory?
The Reid & Sigrist "Bobleigh" (name of conversion) had a round
nose with a transparent part which covered a large section of the
nose and two separate transparent parts to give some sideways and
rearwards view. The Gloster Meteor F8 (name of conversion) had a
pointy nose with a classic looking cockpit glazing on top.
The pilot of the Meteor was in a semi-prone position, which gave
him the opportunity to control pedals. The Bobsleigh had a control
column which had the three controls (pitch, roll and yaw) in it.
The complaint about the Bobsleigh was its difficult steering
device. And that is not hard to understand. The complaint about the
Meteor was the lack of sideways and rearwards view. Looking at the
type of glazing it is not hard to understand. The glazing in the
Bobsleigh was better when it comes to sideways and downwards view.
Maybe some rearwards (3/4 view) view was possible too. Another
complaint for the Meteor was the lack of freedom of movement. The
steering controls all had to be boosted with hydraulics. I guess
that the rams horn steering "stick" of the Horten H IV would have
been able to have a unboosted control. But I doubt if the cockpit
was wide enough to install such a device. A last complaint I found
in "British research and development aircraft" by Ray Sturtivant
(ISBN: 0-85429-697-2) and in "Meteor" by Steven J. Bond (ISBN:
O-904597-55-5). It was the difficulty in ejecting. I quote the book
"Meteor": "You can't eject in any direction lying down. The only
way out of the prone Meteor was to slip feet-first off the rear end
of the couch and through the floor. One trusted that 'g' would be
acting normally at the crucial moment. To depart in a hurry, the
pilot first pulled a lever to jettison the ventral fuel tank and to
retract the nose wheel, if it was extended. Both would be bad news
to a passing body. He was then to pull a plunger to make an
hydraulic jack force the leg portion of the couch down into the air
stream so that he was hanging over the abyss, so to speak. A final
lever under the couch was to release the body to fall out of the
aircraft and a long static line would open the parachute.". Sure
sounds a lot of work at such a critical time.
Charles H. Zimmerman, a designer known for his "flying pancake"
(see low aspect ratio) made a patent (2.431.293) which also used a
prone pilot. The prototype of the more developed design, the Vought
V-173, which he later built had a seated pilot. But the V-173
clearly had problems with overall view. So using a prone pilot in a
"small" low aspect ratio was not such a bad idea.
Why did he change his idea? I don't know. Did he want to gain
interest by making the design a bit less weird? Maybe. Answers from
you are very welcome.
I found this rather bizarre airplane. It is the WeeBee. As you can
see, the pilot is on top of the airplane.
I got the following info on this airplane from Andy Kecskes
(President of "The Wing Is The Thing" (TWITT), a club about flying
wings): "The WeeBee is a conventional tailed airplane where the
pilot lays on top of the fuselage since the fuselage isn't a lot
bigger than the pilot. According to the book (editor's note:
"Unconventional Aircraft" by Peter Bowers), it was proclaimed to be
the world's smallest airplane in 1948. The span was 18 feet with an
empty weight of 210 pounds. The engine was listed as a 20 hp
two-stroke like those used on unmanned military antiaircraft target
For some time this airplane was the smallest powered airplane to
be controlled by a pilot.
Why did they use a prone pilot you might ask. Well, I think that
they wanted to keep the wing dimensions as small as possible.
Reducing the weight of the airplane by deleted a cockpit made it
possible to use less wing area and that reduced of course the size
of the wings.
The newer "smallest powered airplane" did use another philosophy.
They used a short but wide wing in bi-plane configuration. That
made it possible to get the airplane smaller, but it made it also
rather hard to steer. It became a airplane only for experienced
The only type of airplane where prone pilots became "usual" is the
hangglider. In its early development the hanggliderpilot was
hanging upright. But this is a rather dragy pilot position.
Somebody came to the idea to rotate the pilot forwards and place
the pilot in a nearly flat position. This gave the pilot less
frontal area and the drag reduced. It still gave full easy control
of the hangglider, but it placed the head in a tilted position. The
pilot always has to keep his head up. And this can be tiring. Also
pilots (some) complain on the unsafety of this position in a bad
landing. Several fatal accidents could have been non-fatal if the
pilot was not head first. Anyhow, the hanggliders are still using
the prone position and it seems like they will do so for many, many
Still there are some pilots who don't use the prone position. They
prefer the supine position, which is a "seated" position. I got a
few mails from the Nurflugelmailinglist from Al Bowers, employee
NASA. Just read them and you will know more about the difference
between prone and supine hanggliding. He gives a clear and full
explanation of the history and the advantages of the prone
"I used to fly supine almost exclusively in my hang glider days. I
flew some prone also, but I always seemed to end up with supine
gliders. One thing I did notice (and it wasn't solved until much
later) was there was a limited pitch travel. Prone, the pitch
travel was much larger, and it did make a difference. Now, with the
fully supported airfoils and much better penetration, prone is the
much more common pilot suspension method in hang gliders.
The supine solution to try and "fix" the problem was a harness
with a curved suspension line. The curve matched the control bar,
and allowed the bar to pull in farther. It still wasn't as good as
any prone harness.
A final thought. With the greatly improved pitch authority of
current generation hang gliders, the supine limitation on pitch
travel may not be as much of a limitation any longer.
Of course, aerodynamic controls eliminate all of this. :-)
Later I got another mail from Al Bowers.
"I have to start with a short story, and then perhaps all will be
clearer. There is a saying: everyone is three different people. 1/
the person we think we are. 2/ the person others think we are. 3/
the person we REALLY are.
With that said, given the duration of the flights I made (most
were very short) the comfort of the position was immaterial. I
aspired to greater things (the person I thought I was), but of
course one always has an inflated view of self as a teenager (the
person I really was). When I first started, there were only a
couple of manufacturers of REAL prone harnesses, and they were
somewhat expensive (about half the cost of a glider). However, I
could make my own seated harness very easily. So that was what I
did. I did eventually learn to fly prone, but I was instructed (by
Russ Velderrain) to be very careful. It seems there were some fatal
accidents from pilots becoming disoriented when switching from
seated to prone (there was some speculation this is what happened
to a friend of mine, Pat Conniry). At the same time, Dave Cronk,
Bill Liscomb, and Jack Schroeder were doing very well in
competitions flying supine. Mike Riggs offered a very simple supine
harness for the Seagull III, so that was what I bought and flew
(Mike's harness was a seat with webbing and a long backstrap and a
simple over-the-shoulder strap to keep the backstrap from getting
tangled during launch). I still flew prone quite a bit, but as my
own glider was supine, that was what I flew the most.
It was shortly after this time that the complexity of the supine
harness caught up with prone harnesses and there was no longer any
difference in cost. When this happened, prone won over supine
amongst most pilots.
It should be noted there is a slight performance advantage to
prone over supine. And certainly, there is a greater control range
What I didn't ask Al Bowers was his comment about the safety of
prone pilots in hanggliding. But with some common sense you can
easily understand my comment.
Prone hanggliders have their heads first. A very bad landing gets
a pilot in a very dangerous position. A head can not take that much
of a beating. Many sites tell that many fatal accidents would not
be fatal if the pilot was not prone. A supine pilot has more chance
on surviving a crash. His legs could be broken, but he could
survive and heal to... fly again.
But change could be coming in this kind of aviation. The SWIFT of
Bright Star Gliders is a rigid wing hangglider which uses a
nearly-lying-on-its-back pilot position. Aeriane in Belgium has the
building license of the SWIFT. The SWIFTs pilot position is new to
hanggliding and did get some critics. Some French magazine did
mention a bad frontal view. The team of Aeriane, who are always
further developing the SWIFT, did react by lowering the pilots
feet. It seems that this did solve the problem. The Utopia, another
Bright Star Gliders product, did tilt the complete pilot a bit
forwards to solve the problem.
The view of the nearly lying position is good now, the safety of
the pilot is better than the prone pilot (head first). Will this
pilot position take over the prone position in hanggliders? Time
Now that I did talk about recent rigid wing hanggliders. Let's go
back to the first modern (post-Lilienthal) rigid wing hangglider.
It was a design by Reimar Horten. During his stay in Argentina, he
designed a lightweight glider which could be launched by foot. At
that time, foot launching was totally obsolete. Reimar Horten did
revive the idea. His Horten H X was a flying wing of classic Horten
layout but here Reimar only placed elevons instead of his rather
complex control areas like he used on the Horten H IV. The H X was
a swepted back flying wing and Reimar Horten, a true believer in
pure flying wings, would have desired to place the pilot inside the
wing. To get sufficient groundview the pilot had to be placed in
The H Xa (or l' Alita) was built and tested. It needed a skid
because the landing speed was too high to land on foot (flaring
like now used by hanggliders was maybe not known). The H X b was
built but never covered because the crude plans for a more advanced
H Xc were already made. The H Xc (or Piernifero 3) was never built
by Horten, but a version was made using the plans of Reimar
Horten.But they didn't use the same span load system. This gave it
different performance than Reimar Horten calculated. Bill Moyes
owns this glider. The H Xb was recently restored by Juan Manuel
Mascarello. He is a teacher in a technical school in Buenos Aries.
The restored H X b can be seen on the site of TWITT (The Wing Is
Beware !!! These drawings are sketches based on pictures I
found. The wing planform can be trusted, but not the airfoil. I
couldn't draw it exactly the same.
I made a special page about the Horten HXb. Go see Flying Wings to
first better understand the concept of Flying Wings. Then go see
what we found about the Horten HXb.
One thing I haven't figured out is why Reimar Horten used a
classic flightstick (a tiny one). Why did he not use his ramshorn-
shaped flightstick? Did he want to reduce weight, was he afraid
that running might shift the stick front- and backwards? I don't
Some other rigidwing hanggliders, which uses the (non-suspended)
prone pilot position (like the Horten H X), are the Exulans I (a
flying wing hangglider project from South Africa with inflight
variable wingsweep) and the Flair 30 (also a flying wing with the
pilot laying on top of the wing). But the one that really got my
attention was the Aviafiber Canard 2 FL (a canard of course). I
found a drawing of this one with the pilot in a seated position.
But the prototype did use a prone pilot. The pilot does control
pitch by sliding his body for- and backwards.
The pilot here is placed in a fuselage which hangs under the main
wing by a V-shaped "strut-wing" (own chosen word). So there is no
problem with having to look over the wing. I guess that the reason
for choosing a prone position will be the reduction of frontal
area. This would be one of the items which made the Aviafiber
Canard 2 FL a real winner in performance.
It was years ahead of its time. Pity, but that was the reason for
its commercial failure. Too new. Many pilots regret the fact that
they didn't buy one when it still was available.
A new feature on some of these lightweight airplanes with prone
pilots is the use of a BRS parachute. The parachute is connected to
the airplane. It gets airplane and pilot safely down. So there are
no problems with ejecting pilots like I mentioned for the Gloster
Meteor F8 WK935.
- Question: Now I have a question for help on the next airplane.
I found this one on a site. No name, no reference, nothing. What is
it? Did it fly? I guess that it was a VTOL project. It could be
that it just was a mock-up of a project which was cancelled. A:
(from Anthony N Morgan) "A Coleopter constructed by Hiller in
- Answer: (from Harry (Thode3@aol.com)): "If memory serves me
right the government was experimenting with such a device back in
the 1940s. The idea was to have them on small warships and
merchants ships as anti sub protection. Many ideas were around at
that time but all were vtol. The exact configuration escapes me . I
believe that such aircrafts were scrapped as being impractical due
to the lack of pilot visibility."
Funny, I got these remarks even before I placed the page on my
site. Thanks to the members of the Nurflugelmailingglist at Yahoo
The reason for choosing a prone pilot is probably the shape of the
fuselage. The fuselage does look like a waterdrop shaped spinner.
If the pilot would be seated, the fuselage would be wider near the
duct and that would be not so good for the air flowing into the
duct. It would be a obstruction in the airflow.
I wonder how a pilot ejects safely from this one.
I found the picture on the site vula.org (Vintage Ultralight &
Lightplane Association) and I got permission to use it in my site.
I asked on this site for more info because I found ... none. See
the mails below for more info.
From Robert Ford I got this answer:
"That is the O'neill Pea Pod, built by Terrence O'neill
from Ft. Wayne, Indiana, USA about 1963.
The engine is a 35HP Kiekhaefer O-4-35 ; it was a 4
cylinder 2 stroke engine from target drones. This
engine used to be popular with gyrocopter builders.
Notice that there is no exhaust muffler. Ferociously
I love the prop! He was obviously trying to absorb 35
HP in a very small diameter.
Note the "drag rudders".
Registration #: N10T
Top speed 132 mph
Cruising speed 115 mph
Landing speed 55 mph
range (est): 350 miles.
Aspect Ratio 1.6
High-speed taxi tests were performed, but I don't
think he ever got up enough nerve to fly it."
With that info I found myself at http://www.aerofiles.com/_o.html:
"Pea Pod 1963 = 1pCmwM canard; 35hp Kiekhaefer O-4-35 mounted
inside the vertical fin; span: 8'0" length: 9'0" load: 220# v
(est): 132/115/55 range (est): 350. This odd ship might best be
described as a flying barn door with its angular wing of 1.6 aspect
ratio. The pilot had a prone position, with most of his body inside
the wing. The plane could be carried atop the family auto. Taxi
tests were performed, but it reportedly never flew. POP: 1 [N10T].
Thanks to the site of TWITT, you can find more info about the
Nighthawk. Another prone pilot project.
Go see http://members.cox.net/akecs/nhawk.htm
Will there be prone pilots in the future? To give a answer to this
question we need to look at the different types of airplanes.
- large airplanes (fighters, bombers and so): No future for prone
pilots. The larger airplanes have enough cargo room and usefull
load to place the instruments of a G-suit. A G-suit is a overall
with airbags at several places. If the pilot endures a lot of
g-forces, the airbags inflate and push against the pilots legs. The
blood vessels in the legs are squeezed together. The amount of
blood that can stay in the legs is reduced. So the airbags pump the
blood upwards. The pilot can endure higher g-forces. This g-suit
made prone pilots obsolete in these types of airplanes.
- small airplanes (sport, observation): I think that one could
use a prone pilot in this section. If it will be used it will be
for better view.
- hanggliders: Time will tell if the seated pilot position of the
SWIFT will become the new standard in this section of aviation. I
guess it might become the new standard to hanggliders which are
controlled by a steeringstick (not using weight shifting). I doubt
it strongly if it change the weightshifted hanggliders
- Acrobatics: Now here we have a section of aviation where
g-forces still are high. The airplane needs to be (relatively)
light, so there is no use of a G-suit and its needed machinery. I
am sure that acrobatics-pilots would have a nicer flight if they
would be prone. They would have to use less force (tensing muscles)
to withstand the black-out. If flying alone there would not be the
disadvantage of the not so good rearview. To fly in team will be a
bit harder. Here view all around is essential. I could be mistaken.
My knowledge of acrobatics is a bit (read: a lot) limited.
I heard about some projects in development which also would use a
prone pilot, but I have no detailed info about them.