History
To
provide the fleet with an Airborne Early Warning aircraft designed to detect
enemy aircraft and direct fighters to intercept them, Grumman developed the
model G-117. The G-117 was basically a C-1 airframe modified to accept an
airborne radar system. The aerodynamic prototype carrying the large disc shaped
antenna above the fuselage first flew ion 17th December 1956. The
first production Tracer made an initial flight on 28th February 1958.
In
the first case, Grumman developed the TF-1 Trader from the S-2 Tracker as a
small transport for Carrier On-board Delivery (COD) of personnel and supplies.
This differed basically in having a new fuselage to accommodate up to nine
passengers or 3,500 lbs of freight. The designation was changed to C-1A. A
further variant of the same basic airframe is the E-1B (Originally WF-2) Tracer,
the airborne early warning station. This is basically a C-1A with APS-82 surveillance radar in a
tortoise shell shaped radome above the fuselage, necessitating a three-fin tail
unit. The Tracer differed from the S-2A design in having the twin fin and rudder
arrangement to counterbalance the large radome, and a deepened fuselage just
like the Trader with the same 18 inch extension of the forward fuselage as
featured on the later models of the Trackers. The overhead wing folding
arrangement of the S-2A and C-1A was replaced on a Tracer with a rear
ward-folding wing similar to those used on the F4F or F6F fighters. A steerable
tail wheel was installed to help manoeuvre the Tracer on the flight deck, since
the aircraft was tail-heavy with the wings in the folded position. The Tracer
pioneered the ‘Airborne Command Post’ technique which it finally
relinquished some 15 years later to its successor, the purpose-designed E-2
Hawkeye. An aerodynamic test
version of the Tracer flew for the first time on December 17th, 1956.
Production of the E-1B totalled 88,
and some remained in service with the US Navy in 1970.
The
E-1 was eventually succeeded by the E-2 Hawkeye having a saucer shaped radome
above the fuselage and is more familiar of the early warning type these days.
While the S2F was nicknamed Stoof, the Tracer became the ‘Stoof with a roof’
and in its original WF designation the Tracer was nicknamed Willy Fad. These
aircraft saw extensive service during the early Vietnam War, providing combat
air patrol (CAP) fighters with target vectors, and controlling Alpha strikes
over North Vietnam. With a radius of 250-300 miles, the E-1B served as an early
warning to strike aircraft of enemy Migs activity.
By
May 1973 most E-1B were retired from service with only 4 Tracer of RVAW-110 and
which were based at NAS North Island, California remained in service. These were
soon retired during mid summer of 1973, and were ferried to the Davis-Montan
storage facility.
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Kit:
Tracker into Tracer
Type:
Scratch building conversion parts to merge with rest of Tracker kit.
Planning
the kit
It
is interesting how the Grumman Tracker design has led its way to the evolvement
of the C-1A which had a deepened fuselage of a COD cargo plane and the E-1B
Tracer, the Early Warning aircraft. The Tracer carried an enormous radome in
shape of a carapace permanently stuck to the upper fuselage making it look a
totally different design to the Tracker. The Tracer also differed from the
Tracker design in having a twin fin and rudder, arrangement suited for the large
radome. Apart from the Trader style deeper fuselage there is a 1’6”
extension to the forward fuselage.
This
somewhat challenging conversion involved use of the Hasegawa/ Revell Tracker
kit. In doing so it would involve replacing the sonobuoy bays, located at the
rear of the engine nacelles with shaped fairings made of pine. This also
involves cutting the fuselage in half forward of the wing and inserting a spacer
exactly ¼” wide and deepening the bottom of the fuselage from a pine insert
and fair it to conform to rest of the lower fuselage with filler. The radome
itself is fashioned out of pine. In a nutshell this was a conversion involving
several stages and should be an interesting task for experienced modellers using
the most basic techniques. In the end this would turn into a satisfactory model
suited for those keen on Navy 6th
and 7th Fleet aircraft aircraft.
Construction
Fuselage
and cockpit area are assembled as per instructions and allowed to dry
thoroughly, the fuselage was cut across at a point at the front of wing rear
location and a spacer inserted so that the fuselage is increased by ¼”. The
insert could equally be balsa or pine but as I had a spare Tracker fuselage
since I built the Trader, (Falcon kit conversion), I cut the spacer from the
spare redundant fuselage.
The
next step was to modify the weapons bay area of the fuselage by building it up
to a more rounded and fatter shape of the Tracer. This was achieved by fitting a
piece of shaped pine underneath as mentioned earlier. The aft section of the
fuselage was also different shape from the Tracker. This was made using a shaped
piece of pine, joined to the rest of fuselage and the assembly was set aside to
allow to dry well.
The
next step was modifying the engine nacelles, where the rear section behind the
wheel well was removed. This was first marked with a narrow strip of tape across
and cut with an X-acto saw blade. A block of pine was glued to each nacelle to
form the new shape of rear nacelle extension. Again these were allowed to set
and dry and given the final shape with the aid of files and sanding. The next
step was to carve the radome out of pine. Incidentally yellow pine is ideal for
this purpose as it is soft and easy to work with, free from knots and does not
distort. I made cardboard templates to check the cross sections of the radome
while it was being shaped. Reference was made to scale plans in Aviation News
Vol.1. No 16. When the final shape was achieved I applied coats of sanding
sealer to bring radome into a smooth sheen finish. Any imperfections were
attended to using a mix of talc powder and dope to the right consistency. Smooth
sanding brought the final shape and finish. It was the turn of the Tracer
shallow central rear fin which was also shaped out of pine and glued in place
utilising a spigot that was formed to slot in. The area around the wooden tail
was faired with more filler.
The
cabin windows were drilled and filed to shape with needle file. The engine and
wings were assembled as per kit instructions and gaps above and at rear of
engine nacelle to wing joints were filled and sanded smooth as more sanding
sealer was added to rear pine section. The fins were cut and shaped from thick
plastic card reclaimed from surplus back plastic of vac form kits I made. Two
twin fins were made and sanded to the correct taper. The tail planes were also
made out of plastic card and panel lines were carefully scraped with a blunt
blade. Tail planes and fins were put together to take correct dihedral and slid
into the central fin from the rear of a cut slot. The open rear of the slot was
then filled up with correct amount of filer. The detail structure under the
Radome was also made out of pine, shaped sprue, and a plastic shaped web. Metal
pins inserted to strengthen the assembly when put together and fixed firmly to
the radome and upper fuselage. The radome should have sufficient play in it to
be able to adjust it slightly if need be to ensure that it is in the correct
position and exact angle when viewed from the side.
Painting
and markings.
The
complete assembly had the cockpit area masked and was given an overall coat of
matt white as a base colour. This was then followed by the standard US Navy
colour scheme of semi matt insignia white and gull grey FS 36440. The leading
edge de icing boots and nose anti glare panel painted in Humbrol matt black.
Yellow masking tape strips were used to obtain perfectly straight line edges.
All lettering and US insignia came from different sheets of Micro Scale brand.
In the end the completed model was given a coat of micro flat and micro gloss
varnish mixed 50:50.
Conclusion
In
a way this was an ambitious project that I built some time before I got hold of
the Falcon conversion kit of the Tracer which appears to involve less work for
sure. And there was so much fun going step by step. Out of two Tracker kits I
was able to build a Tracer and later a Trader using the ‘Falcon’ Trader
fuselage conversion.
Carmel J Attard
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