Metal parts upgrade for the 1:48 Kitty Hawk kit

Sometimes we get into a mindset and forget that we’re (usually!) talking with actual people on the “other end” of things.

Case in point is when I recently offered my Seasprite reference material to the folks at Scale Aircraft Conversions (SAC) to help with a replacement gear for the Kitty Hawk kit that I assumed they’d be working on shortly.  I used the ‘contact’ info on their website and before too long, Ross from SAC came back to let me know thanks, but they had already created the tooling for the kit using – as they often do – the original kit parts as masters.

Scale Aircraft Conversion’s typical packaging

After just a bit more ‘chat’ about my original desire to work up a landing gear upgrade for the old Matchbox SH-2F kit, Ross offered me a copy of the new set to see if it might work as well.  I thought this was pretty cool of him and so have agreed to post my findings here as a way to share with other ‘Hookie-Twok’ fans still wanting to use the kits in their stashes.

Overall view of the HH-2D held at the American Helicopter Museum in West Chester, PA.

Matchbox kit in original release (note price tag!) Since reissued by Revell Gmbh.

Parts closeup showing basic accuracy of the Kitty Hawk parts

As promised, an envelope arrived in a few days and  I dug out the Matchbox (MB) kit (one of four!) to assess if the SAC gear (AKA the Kitty Hawk parts) could work to replace the admittedly basic MB parts.  The metal parts came in SAC’s standard card & bubble packaging which allows the parts to rattle about inside – though with no damage even after a trip through the USPS.  Basically the parts don’t have enough mass to create enough momentum to be a problem anyway.

First, a basic assessment of the KT/SAC parts.  The set includes seven pewter copies of the Kitty Hawk main & tail landing strut parts (no wheels) and so should fit the KH kit just fine (at least, as well as the originals…)  As for accuracy, KH has done a credible job representing the SH-2’s main & tail wheel landing gear struts.  This is broken down into three parts per side: the main “Y” gear leg, the retraction strut and the compression arm assembly.  The real thing relies on a short but highly charged hydraulic strut atop the ‘swing arm’ between the “Y” leg and the dual-wheel axle to absorb the landing loads.  The kit parts have the swing arm and strut molded as one piece that is glued into an irregularly- shaped, over-sized socket at the lower end of the “Y” leg (which is a pivot point on the prototype.)

Starboard landing gear showing the configuration of the real thing.

One note: the circular footstep mid way up the retraction strut should have a center hole drilled in it.  The gear doesn’t have any of the tiny plumbing & wiring molded on it, but that is easy enough to add (check the SH-2F & HH-2D galleries Here.)

It should be understood this is a fairly complex geometry requiring care to get a proper ‘sit’ to the model.  Not only is the landing gear not directly under the model, it has a ‘splay’ angle nearly perpendicular to the vertical center plane.  Then it has a near 90 deg angle for the wheel mounting at the end of leg that creates a sizable torque moment concentrated right in elbow.  Overall, I’d not be surprised if the plastic landing gear suffers ‘sag’ & breakage over time.  A metal gear is almost required!

Given the tough job presented by this geometry, if I had engineered these replacement  parts, I would have made the “Y” leg and compression arm assembly all one piece to 1) incorporate the correct angles and 2) reinforce the point of highest stress.  The only advantage to keeping the original plastic part layout is to allow for a prototypical adjustment in compression angle to simulate higher load weights (such as torpedo, full sonobouy rack and large auxiliary full tank…)

To correct for this design weakness in the Kitty Hawk parts, a bit of ‘drill & pin’ and gluing with epoxy could be used.  Drilling on the elbow pivot line and inserting a brass rod ‘pin’ will also look more prototypical.  Using epoxy glue is recommended as I’m not sure CA cement would hold up over time though the joint avoids direct ‘shear’ force.

Now, how about using the SAC set with the Matchbox kit?  Well, as flimsy as it is, the MB gear is basically of the correct configuration in spite of it’s crude representation.  The MB parts include the landing gear fairing doors which were apparently abandoned fairly early in the ‘Foxtrots’ career though still applicable to earlier versions.

Note the extraneous ‘web’ of the landing gear fairing part. The red lines represent the ‘cut lines’ to modify the part to be more prototypical.

Also, the gear fairing ‘canoe’ part has a ‘web’ to reinforce what would have been a pretty “floppy” part otherwise.  However, the aft part of the fairing and the web should be removed to allow mounting of the landing gear leg directly to the fuselage surface.  Using the SAC gear, small rectangular holes would have to be

Little test fit of the fairing; compare to reference images to see how the fairing was modified over the life of the airframe. The kit parts could be used “as is” to do a conversion to an earlier, single-engine version.

accurately cut into the fuselage to accept the gear mounting blocks.  Fortunately, the gear is symmetrical (unlike so much on the H-2) to the center line, so a ‘flip’ placement template (made from card stock or thin sheet metal) referenced to the center line, would work perfectly.  The MB & KH geometry are in good ‘agreement’, with any extra length making up for the removed ‘fairing web’ – which a test fit confirms.

Tail wheel struts comparison. The SAC part is better detailed but the set lacks a tail wheel so the Matchbox part would have to modified to ‘recover’ the wheel.

Even the tail wheel struts very closely share the same height, though a wheel would either come from the parts box or through careful removal & cleanup of the MB wheel.

Real deal – note the strut is not pressurized on this HH-2D museum ‘bird’.

In short, the SAC set *can* be used to upgrade & detail the MB kit with a little prep work.  A little bit more effort to drill & pin the ‘elbow’ joints will improve the gear’s durability beyond even the basic strength of the pewter parts which are needed to support the weight of this model.