History

A ramjet is the simplest jet engine in existence. It has no moving parts, relying on the intake geometry to achieve the compression necessary to produce the required thrust. The Marquardt Company was responsible for the early development of ramjet engines in the United States. A ramjet's largest handicap is that it cannot produce thrust at airspeeds less than approximately mach 0.5, so it needs to “hitch a ride” behind another engine in order to reach that speed. In early 1946 two Marquardt ramjets were installed on the wingtips of a P-51 Mustang and created an increase in the Mustang's maximum speed of 40 miles per hour. Although this was not phenomenal, the 50 cm Marquardt engine, which weighed slightly more than 50 Kg, could provide as much thrust as a turbojet engine that weighed 10 times more. This success was sufficient for the US military to continue funding ramjet development, which eventually resulted in several operational missile types in the 1950s and -60s (most notably the Bomarc SAM). Ramjet development has continued into the present day, with several different projects investigating propulsion systems for hypersonic flight.



Hasegawa's kit provides an opportunity to model this stage in the development of high speed flight technology.

First Impressions

The kit contains a complete wartime Mustang, which will result in a good deal of armament and drop tanks going to feed the spares box. The instruction sheet was lifted from Kit # J14, and is supplemented by a one page addendum sheet showing the ramjet motor installation on the wingtips. The ramjets themselves are each made up from a resin inlet and main body. Some minor trimming needs to be done before assembly to remove the pour stubs.

Fuselage

The fuselage is made from two halves from nose to tail. The cockpit, exhaust pipes, radiator assembly and tail wheel all need to be trapped between the halves before they're closed. The instructions call for the interior to be painted olive drab rather than interior green. Since this is a post-war Mustang, the interior should probably be suitably beaten up and looking weary. The seat has seatbelts moulded to it. It's not bad looking, but if you wish to replace it, an Ultracast seat will really dress up the cockpit. The instrument panel has nice moulded detail and also a decal which will make it look good without much effort. The radiator trunking area is shown as being painted green. It should actually be silver instead.

Wings

The wings are made up of a one piece lower wing and one each upper left and right halves. The wingtips must be cut off as shown in the addendum sheet in order to fit the ramjet motors. The engines are handed, so take care to attach them to their respective wingtips. The wheel well rear bulkhead is incorrect; it should follow the line of the main spar rather than the outline of the wheel well cutout. It would take some doing to correct it. The wheel well looks a little shallow, but if you don't turn the model upside down it's acceptably busy inside. Vector offers a correction set that will satisfy even the terminal AMS sufferer. I believe that it's intended for the Tamiya kit, but it should be possible to make it fit this one.

There is no option for lowered flaps, one point were the Hasegawa kit loses out to the Tamiya. If you wish to have lowered flaps, you must resort to aftermarket relacements. Ultracast offers Red Roo flaps designed to fit this kit. The surgery required to fit them is relatively minor.

The addendm sheet shows painting directions for the teardrop drop tanks and pylons, so presumably the aircraft was flown with them in place. I have not found photographic proof of this, however.

Empennage

The fin and rudder are part of the fuselage. The tailplanes are offered as one piece mouldings which are interchangable. The elevators are moulded in the neutral position. Mustangs are often as not seen parked with the elevators in the neutral position so it's up to each modeller to decide whether to perform the surgery needed to pose them deflected. The tailplanes are moulded on sprue C among the weapons. This sprue is duplicated so one tailplane will come from each sprue.

Landing gear

The landing gear is simple yet detailed enough to look the part. The wheels are acceptable as-is, but could easily be replaced by resin replacements. The only missing detail is the brake lines.

Accuracy

I don't compare models to drawings. When completed, it looks like a Mustang.

Decals and Markings

One marking option is offered, for 44-63528 in its guise as the ramjet testbed. The aircraft is overall silver/natural metal with no special trim colours. All in all it's a suitably boring scheme worn by a workaday test aircraft. The only spot of colour is the black anti-glare panel on the nose. The decals are typical Hasegawa quality with typical Hasegawa off-white insignia. These could be replaced if desired. Each marking is crisply printed and in register. Hasegawa's decals generally respond well to Micro Sol. The red bars in the insignia are offered as separate decals but it is not mentioned whether the aircraft flew without them. Presumably it did, since it was first converted in 1946. The instuctions showing them in place date the aircraft to 1948.

the real thing

463528 looking grubby.


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