History
The
X-15 rocket-powered aircraft was developed to provide high-speed, high-altitude
flight research information. The X-15 was air launched from a B-52. Depending on
the mission, the rocket engine provided thrust for the first 80 to 120 sec of
flight. The remainder of the normal 10 to 11 min. flight was powerless and ended
with a 200-mph glide landing.
The
No. 2 X-15, crashed and damaged in Nov. 1962, was redesigned to the X-15A-2 and
modified for testing hypersonic ramjet engines.
Among
the most visible modifications were:
·
the fuselage was extended to carry
liquid hydrogen for a supersonic combustion ramjet that was flown (as a dummy)
but never tested. The basic X-15 was a rocket-powered aircraft 50 ft long with a
wingspan of 22 ft, the X-15A-2 had been elongated to 52 ft 5 in.
·
external fuel tanks were added to
increase engine burn time by about 70% (roughly additional 60 seconds). They
were used on the aircraft's Mach 6.7 flight.
In
June 1967 the X-15A-2 received a full-scale ablative coating to protect the
craft from the high temperatures associated with hypersonic flight (above Mach
5). This pink eraser-like substance applied to the X-15A-2 aircraft was then
covered with a white semi-translucent sealant coat before flight. Two flights
were made with this white ablative coating.
In
21 August 1967 was the first test flight with full ablative coating and ramjet
mock-up. Maximum Speed 5419 km/h and the maximum altitude 27740 m were achieved.
As a result the another modifications were performed and included:
·
mechanical “eye-lid” cover over
the left canopy windscreen was added to protect it from the deposition on the
windshield by the ablative sealant,
·
new ventral fin was used after the
original one was damaged.
In
03 October 1967 Pete Knight during the second flight with full ablative coating
set up an unofficial world speed record. Maximum Speed 7273 km/h and maximum
altitude 31120 m was achieved. The dummy ramjet and external fuel tanks were
used again.
On
this cropped photo from NASA web page is X-15A-2 during the speed record
breaking flight just after releasing from B-52 carrier.
|
Click on
image below to see larger image
|
|
|
There
was major damage to the X-15A-2 structure from aerodynamic heating due to shock
wave impingement from the nose of the dummy ramjet. The aircraft was transported
to North American Aviation for reparation but it was to never fly again.
X-15A-2
in his original “black look” with ablative coating removed is displayed at
the USAF Museum, Wright-Patterson AFB, Dayton Ohio now.
Here
is my X-15A-2 together with another record-breaking aircraft, Bell X-1
“Glamorous Glennis”.
The
kit
The
X-15 is one of the „must-to-have“ aircraft kit for me. But for a long
time there was no way to obtain one in 1:48 scale. Fortunately, the Czech
company Special Hobby released X-15 in the 1:48 scale approximately one or two
years ago. The package contains gray plastic and resin parts. Windshields have
to be cut from the included transparent plastic sheet.
I very
appreciated a box design. There are helpful color pictures of the
various X-15A-2 details on the back side of the box.
|
Click on
image below to see larger image
|
|
|
Regarding
the kit itself the best general comment that almost 100% fits also this kit I found
on the Modeling Madness, written by Lee Kolosna:
http://modelingmadness.com/musings.htm
I hope
I do not violate copyright when I quote a bit from Lee’s article:
„...What
does one get in a limited-production kit? Well, the ones that I have
purchased and worked on have been quite challenging, to say the least. Despite
the initial seductive inspections of the finely engraved detail and all the cool
resin cockpit parts, the modeler soon realizes that there are a few things
missing. First, there are no locating pins on any of the fuselage or wing half
parts. No big deal, you say, as the pins aren't really needed anyway. Then
you notice that there are no tabs for attaching the wings or stabilizers. This
means a butt-join -- not the strongest way to attach major assemblies together.
A closer look at the smaller plastic parts reveals some amount of flash to deal
with, and the detail is sometimes quite soft. Some kits have landing gear doors
that are molded all as one piece, which the modeler has to scribe and cut into
individual components. More often than not, the larger pieces like wing and
fuselage halves have large plugs where the injection ports squirted in the
molten styrene. These need to be cut off before they can be glued together.
Recessed panel lines tend to be very finely rendered, sometimes too petitely.
I'll often have to scribe the lines a bit deeper to avoid having them disappear
under a layer or two of paint …
In
the end, I get a model of a really cool and unique aircraft that stands out from
the legions of Mustangs and 109s, but I end up killing myself to do it....“
A
conversion sets NW015 1/48 X-15A-2 World Speed Record Flight Configuration
and NWD005 1/48 X-15A-2 tank decals from Czech company New Ware were used.
Link to this company producing mainly a broad range of space rockets,
modules etc. is: http://mek.kosmo.cz/newware/index.htm#Prodlist
Very recommended to visit. |
Click on
image below to see larger image
|
|
|
Assembling
I browsed
a lot of web pages searching some info and detail pictures of this
record-breaking aircraft. After I decided that I have enough
information I had started to build the kit, approximately a year ago.
Regarding the kit quality almost all was written before. Fitting the plastic and
resin parts was at least challenging. It required endless probing, sanding,
putting, probing, sanding, putting... Sometimes I wondered whether all that
parts are from one producer.
Some
parts did not have correct shape (right wing leading edge, landing gear
leg, etc.). I had not time, experience and skills to correct them so
I had problems to fit geometry. |
Click on
image below to see larger image
|
|
|
In
the meantime, I found perfect books on www.amazon.com – see
references.
I bought
them both. A lot of questions were answered, but a lot of new questions and
ideas arose. Unfortunately the fuselage with cockpit and both fins were already
completed and glued together. As I worked on the kit only a couple of
hours per week, sometime per month, I decided not take apart already
completed parts and started again but live with it.
Based
on the referenced photos from mentioned books other details like exhaust
pipes, all cockpit canopy interior details and fuel tank details were made
from wiring, paperclips, pins, baby milk can cover and plastic from my
spare box.
|
Click on
image below to see larger image
|
|
|
Canopy
“eye-lid” cover supplied in the conversion set is in the closed
position. I wanted it open. So I cut it apart and then only
a frame glued together. The “eye-lids” itself in open position
were cut from old used PE parts frame.
|
Click on
image below to see larger image
|
|
|
Trolley
was completely rebuilt to look more realistic and to keep engine part of
the aircraft higher as it is more usual according to the photos. Again
paper clips, wiring and plastic parts from my spare box were used.
|
Click on
image below to see larger image
|
|
|
Painting,
Marking & Weathering
Original
X-15 is well known with its standard black surface with a lot of colorful
marking and stencils. However, I have decided to build the plane in its
speed record-breaking configuration and appearance – covered by white ablator.
In
reality, before ablator was applied aircraft had been washed to remove any oil,
marking etc. from surface. All removable panels were taped. The pre-molded
details like leading edges were applied and then entire aircraft was sprayed
with pink ablator that was sanded then to the required thickness. The taped
panel edges were masked off to allow panels to be opened, now visible as the
black lines. Finally white wear layer was brushed over the entire aircraft. This
white layer was translucent, so it did not cover pink areas and black lines
totally. Therefore additional coats of this white layer were applied generally
to the upper surfaces.
After
the first ablator test flight some damaged pre-molded parts were replaced and
charred areas were refurbished. The surface of the canopy pre-molded leading
edge was sanded to remove the white layer to minimize deposition on the
windshield during the next flight.
I partially
repeated the described process on my kit. I used Humbrol and Revell enamels.
The
complete kit was airbrushed with matt white (only cockpit was brushed
before and masked). After drying I used a shred and Sidolux (acrylate
liquid to polish stones, concrete, rubber, etc.) to polish kit. Then
I draw black lines by a permanent black marker and airbrushed
the kit with thinned white again to emulate translucent coat.
Basically
no rivets and lines of permanently closed panels were visible as ablator
coat covered them safely.
|
Click on
image below to see larger image
|
|
|
The
fuel tanks were airbrushed by matt aluminum. After drying I masked aluminum
areas and airbrushed white. The white color was airbrushed also on the front
part of the both tanks after small rectangular areas for stencils were masked.
Then my own mixture of the orange was applied. The white basement made it much
more bright.
Click on
images below to see larger images
|
|
|
All small parts like
front landing leg & gears, trolley, engine area etc. were brushed. The kit
plus fuel tanks were polished with Sidolux again and decals and stencils were
applied. Despite the decals of the orange warnings, rescue arrow etc. located on
sides of the cockpit seem to be bigger then they should be when compared with
referenced photos I decided to use them.
In
fact, I used instructions supplied with the kit only for stencils. For the
main, more visible decals and painting, especially on the fuel tanks
I rather used reference photos.
Some
panel lines were highlighted by strongly thinned oil black&brown color
mixture. Then another matt coat was airbrushed over the entire kit.
As
the white plane flew only once before it’s second, record-breaking flight,
I would rather use an expression „thermal degradation“ then weathering.
So
all thermal degradation of the ablative coat on the fuselage, fins, wings etc.
as well as of the rocket engine exhaust nozzle was simulated by orange, brown,
gray and black chalk using brush and shred.
After
all final matt coat was applied again.
Click on
images below to see larger images
|
|
|
Finally, after more
then one-year effort I was happy that it was finished. However, problems
are already gone and there is only a big, white, quite dominant kit in
the gray-green-brown mass on my shelf I am happy with.
Taking
Photos
The
shots were taken in the indirect sunlight using digital Sony camera and then
modified in the PC. You can see the damaged dummy ramjet (broken tip) on one
photo. Bu sure it is not my attempt to simulate high-speed damage. After
I put it on the table during photo session with X-15 in the second hand it
started to roll and roll... The table edge was too close and ground too hard
References
·
Hypersonic: The Story of the North American X-15 by Dennis R. Jenkins,
Tony Landis, Scott Crossfield (Foreword), William H. Dana (Foreword),
·
X-15 Photo Scrapbook by Tony R.
Landis, Dennis R. Jenkins,
·
Dozens of
the Internet web pages.
I hope
you enjoy it.
Misos
|