The Kikka (Orange Blossom), though a bit smaller than the
Messerschmitt Me 262, was clearly inspired by the German jet fighter. Its
primary claim to fame is that it was the very first Japanese aircraft to take
off under jet power, even if it did so only once. Aside from that, it was yet
again a case of too little, too late, since only the one prototype actually
flew, although a second one was just a few days short of readiness when Japan
capitulated.
Enthusiastic reports from the Japanese air attaché in Berlin
on the development of the Me 262 led the Naval Air Staff, in September of 1944,
to instruct Nakajima to design and build a similar aircraft for use as a
high-speed attack bomber relying on speed to evade interceptors. The formal
requirements included the following: (a) a top speed of 432 mph; (b) a range of
127 statute miles with a 1,102-lb. bombload, or 173 st. miles with a 551-lb.
bombload; (c) a landing speed of 92 mph; and (d) a take-off run of just 1,150
feet when using two 992-lb. thrust RATOG bottles under the wings. Additionally,
the new jet was to be easily built by semi-skilled labour, and the outer wing
panels were to be foldable, enabling the aircraft to be concealed in caves and
tunnels.
Designers Kazuo Ohno and Kenichi Matsumura created a plane
that could be called a 2/3 rd or ¾ th-scale mimic of the Messerschmitt fighter.
Whereas the Me 262 had a wingspan of about 40 feet and a length of around 34
feet, the Japanese aircraft was just a bit over 26 ½ feet long with a wingspan
of just over 32 ¾ feet. Its wing was nicely swept, but the tail surfaces were
not, and all control surfaces were, oddly enough, fabric-covered in an
otherwise-all-metal airplane. The canopy was a three-piece sliding type,
instead of the Messerschmitt’s three-piece hinged “coffin-lid” arrangement.
The twin turbojets were mounted beneath the wings in
separate nacelles, allowing, with a minimum of changes, the installation of a
variety of engines as they were developed. As it turned out, this feature was
quite useful, as engine development fell behind that of the airframe.
Initially, the plane was to have been powered by two Campini-type Tsu-11
engines, but these were replaced by a pair of 750-lb. thrust Ne-12 turbojets.
But the future of the Navy Special Attacker Kikka (as it was designated) was
made uncertain by the failure of the Ne-12 to develop its designed power during
ground tests. By a stroke of luck, Engineer Eichi Iwaya of the Navy had
obtained detailed photographs of the BMW 003 axial-flow turbojets used in the
Me 262, and from those photos the Japanese were able to create a similar
engine, designated Ne-20, with a theoretical power output of 1,047 pounds of
static thrust. Everyone concerned felt the Ne-20 was perfect for the Kikka, and
so the project’s pace was speeded up during the summer of 1945.
At this point, a note about the aircraft’s designation would
be in order. Although it was dubbed a "Special Attacker", this writer
believes that the Kikka was not actually intended for kamikaze attacks, except
in extremis (i.e., if the pilot were wounded or the airplane was damaged, and
could not return to base). It seems very foolish to go to the trouble to design
a very expensive jet-powered plane and then assign it to one-way missions. The
Me 262 was notorious for requiring a skilled pilot to fly it, and even then the
pilot, if he had previous experience in aircraft with reciprocating engines,
had to unlearn a lot of habits which were all right for flying conventional
fighters but which could be fatal in the 262. For example, the Me 262’s
throttles could not be “chopped”, i.e., quickly brought from high power to a
lower-power setting, or shoved forward swiftly, “balls to the wall” as American
flying slang put it.
Jet throttles had to manipulated carefully and slowly, or
else the jet engines would flame out, either from fuel starvation or fuel
satiation. Thus, by analogy, only skillful pilots could fly the Kikka.
Undoubtedly the Japanese were aware, from reports from their air attaché in
Germany, of the unique problems involved in flying a jet as opposed to flying a
more conventional aircraft. Thus, the Kikka could not have been intended as a
kamikaze aircraft. Indeed, it was intended for other roles besides being a fast
attack bomber, as will be seen. The term “Special Attacker” refers, in this
writer’s opinion, to the special way the Kikka was powered (by jets) rather
than to its being intended for “special”, i.e., suicide, attacks.
With its Ne-20 engines installed, the Kikka prototype was
given its first ground tests on June 30, 1945. Late in July, it was dismantled
and taken to Kisarazu Naval Airfield, where after re-assembly it was flown for
the first time on August 7, with Lt. Cdr. Susumu Takaoka as test pilot. The
Kikka taxied for a long time before it gained enough speed to lift off the
ground; the flight itself lasted just 20 minutes, and the aircraft was never
taken above 2000 feet. The slowness with which it gained take-off speed delayed
the second flight until August 11, when it attempted to lift off with RATOG
bottles beneath the wings. Unfortunately, the rocket bottles were not installed
at the correct angle to lift the Kikka off the runway, and after the rockets
burned out, the pilot aborted the take-off and crashed into the rough ground
beyond the runway’s end. The second prototype was almost ready for its own
first flight when the war ended on August 15. Eighteen additional prototypes
and pre-production examples were left in various stages of construction on that
date.
Aside from the basic attack bomber, there was a projected
unarmed two-seat trainer, and the third Kikka was to be the prototype for this
variant. An unarmed two-seat reconnaissance version and a cannon-armed
single-seat fighter were also under development at the war’s end. The fighter
variant was to have been powered by either a pair of 1,984-lb. thrust Ne-130 or
a pair of 1,951-lb. thrust Ne-330 axial-flow turbojets, and armed with a pair
of nose-mounted 30mm cannon.
Nakajima Kikka
Technical Data
Type:
Single-seat twin-jet attack bomber, of all-metal construction
with fabric-covered tail surfaces.
Accommodation:
Pilot in enclosed cockpit.
Powerplant:
Two Ne-20 axial-flow turbojets, rated at 1,047-lb. of static
thrust.
Armament: One
1,102-lb. or 1,764-lb. bomb under the fuselage centre section.
Dimensions, weights,
and performance:
Wingspan: 32 ft. 9 11/16 in.;
length, 26 ft. 7 7/8 in.;
height, 9 ft. 8 5/32 in.;
wing area, 142.083 sq. ft.;
empty weight, 5,071 lb.;
loaded weight, 7,716 lb.;
maximum weight, 8,995 lb.;
wing loading, 54.3 lb./sq. ft.;
power loading, 3.7 lb./lb. s. t.;
maximum speed, 387 mph at sea level, (estimated) 433 mph at
32,810 ft.;
(estimated) climb to 32,810 ft., 26 minutes;
(estimated) service ceiling, 39,370 ft.;
(estimated) range, 586 statute miles.
In the section devoted to this aircraft he refers to the
aircraft as the Nakajima Kitsuka (I had always thought it the Kikka).
At the end of the section he says this .....
'A note about the use of the name Kitsuka as opposed to the
more commonly used Kikka. Kitsuka is the proper translation of the kanji
characters. However, it is pronounced 'kikka'. Kikka was used in post-war
reports as phonetically it approximated to Kitsuka and thus has become the
accepted name of the aircraft. Neither name is incorrect.'
Now, quite apart from the fact that our high school teachers
would be aghast at the last sentence containing a double negative, I would have
thought that the translation of kanji characters in an English language book
would be phonetic (the same as Russian words and names are) with perhaps slight
differences in spelling.
So how then do you get Kitsuka pronounced Kikka if it isn't
Kikka......As I see it Kitsuka has 3 syllables and Kikka has 2?
If Kitsuka is pronounced Kikka, then if someone asks me what
this aircraft is then should I say Nakajima Kikka, but write down Nakajima
Kitsuka?
