Meteor F Mk.8 Article & Plans
January 1974 American Aircraft Modeler
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"The
Gloster Meteor F Mk.8 was the last and best day fighter version
of the Meteor, and equipped the majority of home based RAF fighter
squadrons in the early 1950s. The
Meteor T Mk.7 two seat trainer had featured a longer nose, added
to carry the second crewman, which was found to improved the directional
stability of the Meteor. This longer nose was installed on late
production
F Mk.4s, but produced new problems of its own, causing unacceptably
large changes in the centre of gravity as fuel or ammunition supplies
were used up. " -- from the
HistoryOfWar.org
website Meteor F Mk.8
Ducted fans fascinate many modelers, and soon there will be commercially
available fan systems. Here's one of the best aircraft for DF propulsion
and a practical model for you to build. Takes two strong 40s.
by David D. Nelson
The Gloster Meteor first flew
on March 5, 1943 and was Britain's first Jet Fighter. Meteor Mark
Is took part in the final stages of the war against Germany. By
1948, the design had progressed to the F. Mark 8 and this Mark
was Britain's No. 1 Fighter for five years. It also served with
many other nations well into the 1960s taking part, for example,
in the Korean war in the hands of the Royal Australian Air Force.

Your happy author holding his plane illustrates that this is
a big model. By the way, the real plane also has a smooth skin
since most of it was plywood covered.

It is a most inspiring model made up of three cylindrical shapes.
Someone could easily make these in fiberglass. Many pleasing
color schemes apply to this plane.

How nice to see a jet that doesn't fake it with a propeller.
The model Is a fine CL Scale ship, but also suitable for RC-almost
as is. Imagine the sound It must make-a roaring whoosh.

The heart of the matter is the fan system. The author has been
working with DFs for a long time to learn how big, how many
fans, what airfoils, etc. The installation is like a pusher's.

In the air.

As it is designed, the Meteor takes lots of careful planking
around many bulkheads. The end result is a light, strong, monocoque
assembly. Wings are quite strong when sheeted.

Inside surface of duct is lightly fiberglassed for protection
and smoothness. The flow straighteners and internal cone are
essential to proper performance of the fan system. Note a disc
is used here to keep the shroud perfectly round and close fitting
for the fan.

The rather big wheels on the model are actually scale. Obviously.
they produce gobs of drag. Retracts would help performance
as well as the jet impression.

Engine sits on an aluminum plate sandwiched in a plywood mount.
This must be exceptionally rigid. Any vibrations could cause
the fan to hit Its shroud with disastrous results. Note fuel
tank location in the wing.
The model presented here was scaled from original drawings kindly
supplied by Hawker Siddeley Aviation Ltd., with additional information
and details from Profile Publications No. 12 and The Gloster Meteor,
a Macdonald Aircraft Monograph by Edward Shacklady. The only deviation
from scale outline concerns the jet pipe diameter which has been
enlarged.
Experiments carried out on a Mig 17 using restrictors
in the tail pipe to cut down the effective diameter proved that
with this power unit setup 31/4 in. dia. was the smallest allowable
without encountering a serious loss of thrust. A tail pipe diameter
which is the same as the fan would be ideal, but would rule out
99% of possible subjects. By the same ruling, the intake area should
be greater than that of the fan. Again, this is not practical, so
additional intake area must be incorporated by providing cutouts
forward of the fan covered with mesh to make them less conspicuous.
Construction
It is assumed
that only the experienced modeler will tackle a model of this type.
Although the structure is more or less conventional, a more than
usual amount of time and patience is required.
Special construction
techniques described on the plans apply mainly to the nacelle and
fan construction. I am convinced that the thought of having to make
a fan propulsion is the reason most modelers are reluctant to try
ducted fan propulsion. It is a great pity because the fans are very
easy to construct, and both fans plus a spare can be completed in
a couple of evenings' work. Who knows? If you persevere, you may
even come to enjoy building them. In fact, it can be fascinating
to experiment with different blade shapes, numbers of blades, pitch,
etc.
Although the plans describe fan construction, it may
help if the material used for the blades is described more fully.
It is a laminated, cotton fabric, phenolic resin-based, plastic
sheet called Tufnol. The grade I use is Carp brand. It is available
in the U.S., but queries about your local engineers' sources of
supplies should unearth a homegrown equivalent in other countries.
Try asking for Conolite, Phenolite or Tayloron to specifications
NEMA LI 1-1965 LE.
To bend the curve into the blade, grip
the short edge in a vice about 1/8". Apply gentle pressure to the
top edge. At the same time, heat the bottom half of the blade with
a butane torch keeping the flame moving back and forth at all times
to avoid blistering the material. The material will be felt to give
when the heat has sufficiently softened it. When the curve has been
formed, keep the pressure on until it has cooled slightly. Obviously,
pressure cannot be applied by the bare hands and an asbestos glove
is one form of protection. Alternatively, use a piece of hardwood
as a pusher shielded on one side by a patch of metal or wood screwed
on as a flame shield.
As the flame should be moving back
and forth continually, the patch should not become hot enough to
scorch the wood underneath. Practice will be required before consistency
is achieved and a few blades will be blistered in the process. Persevere,
however, and it will soon become second nature. Full instructions
for assembling the fan will be found on the plan.
The nacelle
construction is rather laborious, but it should be possible to make
one half shell per evening. 5and each half shell smooth and silk
or nylon cover before removing from jig. Then sand the insides smooth
before applying fiberglass. If you can dream up a quicker form of
construction, remember that the nacelle adds rigidity to the wing
and, therefore, must be of reasonably rigid construction itself.
The main airframe assembly is built up around the sub-assembly
of 51 and 52, plus the main undercarriage members, bellcrank and
aluminum engine mounting plates. Add formers F6, F7 and F8 noting
that these do not lie square to 51. Glue the 1 x 1/4" crutch to
these formers and add the rest of the fuselage formers, taking care
that assembly is true. F1, F2 and F3 are glued to F1A, the nosewheel
leg is installed, and the complete unit added in one go. Fit one
or two strips of planking to hold assembly rigid, always checking
that no distortion creeps in. Assemble fin with bellcrank fitted,
and glue in place. Note that the leading edge of the fin includes
the front outline of the bullet fairing. Fit all push rods and leadout
wires. Glue ribs R 1, R2 and R3 in position plus the 1/2 x 1/4"
rear spar which is glued to former F9.
Complete all planking.
Fit ribs R4 and ply spars 53 and 54; and rib R5, then the 1/4" sq.
spars and the remaining ribs. Add 1/2 x 1/4" rear spars and the
leading edge.
Bolt motors in place with shroud ring template
and shroud ring positioned. Fit top half of nacelles, add flow straighteners,
lead out tubes and balsa cone, then fit bottom half. Use strong
rubber bands to hold the two halves together while setting. Reinforce
seam inside with fiberglass tape and fill any gaps outside with
balsa and filler. Finally cover with a strip of silk or nylon. Keep
a ply disc or tin lid of suitable size wedged in the end of the
tail pipe to assist in maintaining a circular section. Remove when
necessary and always replace after work is finished. Do not discard
completely until model is finished.
Fit fuel tanks and sheet
wings. Add fairings and wing tip blocks. Cover with tissue. The
tail plane is the only part that can be built flat on the plan.
After sheeting and carving, the leading and trailing edges fit to
fin. Connect elevator horn, add elevators and sheet fin. Carve to
section the rudders. Glue fixed portion in place first and build
up bullet fairings. Add top and bottom rudders. Offset can be incorporated
if desired. Remove hatch areas on the nacelles with a razor saw,
make fiberglass hatch cover and fit. Cut out auxiliary intake area
and cover with aluminum mesh.
The cockpit canopy was adapted
from a commercial canopy cut to fit the aluminum framed windscreen.
Fit remaining details, e.g., undercarriage doors, gun covers, tail
bumper, etc. If desired, the ailerons can be cut free, reinforced
and fitted back as separate items.
All that remains is the
finishing and this is up to the individual. A wide choice of color
schemes can be found in Profile Publications No. 12.
The
Meteor is the fifth ducted fan model built over the last four years
starting with the Saab J21 R, following with a Mig 17, Saab Viggen
and Meteor Mark 4. All flew and the lessons learned have been used
on the Meteor Mark 8. The model flies well, but requires careful
handling until flying speed is attained. Acceleration is notoriously
slow and a smooth paved takeoff area is desirable as 1 to 1/½ laps
will be required to get airborne followed by a shallow smooth climb
out. Once airborne, the model is a spectacular sight, flight is
stable and shallow climbs and dives are permissible. Always remember,
however, to keep control actions smooth and gentle.
Make
no mistake, this model is no rat racer or stunter. If, for example,
sufficient speed for takeoff cannot be obtained, it is possible
that the model is tracking out of the circle causing excessive
drag. Cure by twisting the undercarriage legs so that when the
model is pushed from behind it travels in a straight line or even
turns slightly into the circle. The all up weight of the model should
be between 12 and 13 lb. which will include about 12 oz. of lead
in the nose. I cannot over emphasize the need to use light wood
only for the tail assembly; an ounce or two saved here could save
several ounces of nose weight. Any saving of weight is reflected
by an increase in performance.
Starting the engines using
a pulley cord is not difficult as long as you have a helper to hold
the model on the ground firm and steady. Hold the pulley cord with
one end in each hand so that a loop is formed. Drop the bottom of
the loop to fit in the pulley groove. Turn engine over a few times
to pressurize the fuel tank. Then pull cord sharply with the left
hand letting go of the cord with the right hand at the last moment.
Stand in front of the nacelle facing the rear of the model for starting.
Always use a clothes peg type clip on plug connector. Do not use
the push on type as these can come adrift and get sucked into the
fan with disastrous results. I speak from experience. See that the
glow clip is secure at all times during starting and when tuning
the engine. To install engine and fan, place fan in the shroud ring.
Then put the engine in position placing fan and pulley on shaft.
Add nut and tighten up finger tight only. Bolt engine securely in
place. Insert tommy bar in pulley and tighten nut with a spanner.
Always use the tommy bar to stop the fan assembly from turning.
Gripping the fan by the blades will stress and possibly crack the
blade at the root causing it to shear under running stresses.
Even if you have no intention of building this particular
model, my objective will have been achieved if your interest in
ducted fan propulsion has been aroused. Models nowadays have a tendency
to become stereotyped and even scale modeling suffers from an excess
of Mustangs, Zlinns, Spitfires, Fokker DVIIs, set.
Ducted
fan propulsion is not new. It has just never been fully exploited.
Yet it can open up a completely new field of experimentation and
prototypes. It has recently been proven with model helicopter design
that, if a sufficient number of people tackle the problems involved
and are enthusiastic enough, wonders can be achieved in a very short
time. Maybe this could happen with ducted fan design, even to the
extent of manufacturers getting interested. The model jet aircraft
is an ideal subject for the application of foam core wings, molded
fiberglass or ABS plastic fuselages and nacelles. Perhaps one day
we will be complaining about an excess of F86 Sabres, Phantoms,
etc., in Scale competition.

<click for larger version>
Notice:
The AMA Plans Service offers a full-size
version of many of the plans show here at a very reasonable cost. They will scale the plans any size for you. It is always
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Posted January 8, 2011
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