I read the original post because coincidentally I am building a diorama with a Huey in it. I've actually built a couple featuring Hueys in the past. Can you tell I like Hueys? So I thought all the info I'd gather might help anyone considering this subject.
Scale is obviously a big consideration, my previous two goes at this subject were in 1/72 and 1/24. 1/72 is probably the easiest to attempt as there are a wealth of figures suitable for adaptation into Infantry, pilots, doorgunners, airmobile troops and indeed NVA/VC troops and civilians. Using a smaller scale such as 1/72 presents one with the opportunity to create a helicopter LZ of realistic proportions too. My attempt in this scale featured seven, yes seven! Hueys plus two AH1 Cobras, a large treeline. plus a lot of figures on the ground. Take it from me that's a lot of building. In order to get around having to mod too many figures, I chose to depict the scene at a moment where most of the troops had disembarked, as it's tricky to fit many figures into a 1/72 scale Huey in a realistic fashion.
If it sounds like an ambition undertaking, you should bear in mind that, building more than one of the same model at one time enables you to get into mass production in a lot of areas, so it's not the massive undertaking it at first appears and the scale enabled me to create a diorama which didn't look forced yet was no bigger than a smallish railway layout.
Many aircraft, in particular troop transports and bombers, appear more realistic if they are depicted as they would appear in the real world, ie in formation. Most pictures of Hueys you'll see feature more than one, and in modelling terms this adds a sense of a realistic operation. If a few appear in the scene.
One thing i was aware of was that it would not be realistic to depict all of the aircraft sat on the ground waiting to be zeroed in by a VC mortar crew.
This of course presents a problem, how do you depict them flying? The first big fly in the ointment is the rotor blades and after considerable experimentation, I determined that a fairly realistic portrayal can be made by discarding the main rotor blades (just the blades, keep the hub and balance weights etc) the blades can then be made from the clear material of 'blister packs' having them splaying out to around three times their normal width at the tip. This is easy to do if you score a circle out of the material and it has the advantage of yeilding enough material to create several sets of blades. They can then be airbrushed darker in the middle going clearer as you reach the tip. As an alternative, you might consider spinning the acetate disk on a sheet of sandpaper as this scores lines in a rotary pattern and helps create a sense of motion. I did consider using an entire disk of acetate to depict the rotor disk, but this doesn't actually look that good and its difficult to maintain a flat disk with such thin material. Experiment and see which you prefer, the material is freely available from discarded packaging so you can afford to have a few goes. The tail rotor on the other hand, doesn't look bad as a full disk. One other possibility with regard to the main rotor, is to consider motorising it with an electric motor concealed under the baseboard utilising an extended driveshaft, which can be concealed with 'elephant grass' common in LZs in Vietnam, the downdraught would also make it move if you used very light material to create it!
Next problem, how do you make it 'fly'? Well fortunately, if you are depicting 'Nam', pilots tried to keep as low as possible to reduce exposure on the way in and out of LZs and this is your saviour as you can simply conceal their support by having them coming in low over the trees! Another possibility if you are depicting a 'Hog' or a Cobra is to conceal a supporting rod in the smoke trail of a rocket impacting a target although I must admit I haven't tried this.
The other Huey diorama I built in the past was based around a large scale Huey C which I think was produced by Monogram and came in a box with artwork tied into the TV series 'Tour of Duty' pilot figues were included, but troops were not, however, at such a large scale, scratchbuilding becomes a lot easier! Also at this scale you can build in LEDs to depict the position and anti collision lights which really makes the model come alive.
I've just started a new Huey diorama which will use the 1/35 Panda UH-1D and of course, finding troops for this will be a lot easier, however, it has no pilot figures included. To remedy this I am modding figures from a couple of Tamiya's 1/35 US Armoured troops box set (item 35117) as this includes two figures wearing helmets which, suitably modified with visors, mike booms and headphone bulges, will be a good match for the aircrew of a Huey.
Other possibilities for dioramas on this theme are the 1/48th scale Huey D/AB205 recent re-issue (Italieri I think). Various Hasegawa 1/72 models including a UH-1N to add a bit of variety if you're depicting the latter part of the conflict. I can recommend the ESCI/Ertl 1/72 scale Huey too, not sure where you'll find one, try E-Bay, bit of mould flash but it scales out well. I don't rate the 1/48 scale Mongram Huey C though. The windows aren't at all accurate!
Books I can recommend for reference are the obligatory Squadron/Signal Huey book and another Squadron/Signal book 'Airmobile - The Helicopter War in Vietnam'. For inspiration you could also try 'Chickenhawk' by Robert Mason, as it will yield a wealth of operational information with regard to mods etc. For example, the co-pilot and pilot often traded places so that the main pilot sat where the smaller panel was to improve his view downward. Also, the quilted sound deadening material in the cabin would get mildewed in the climate of Vietnam and was usually removed from Hueys that had been in the theatre for a while. Another frequent mod with door gunners was an empty can of peaches welded to the side of the M60 to help prevent feed jams caused by the airflow shaking the ammo belt around!
Good film references include all the obvious war films such as, Platoon, We Were Soldiers, Hamburger Hill etc, but bear in mind that since they were not filmed 'at the time' innacuracies can creep in. For example, the pilots in Hamburger Hill are wearing white helmets. Not a good idea with all those VC snipers about!
Enjoy!
