The Helijet was used in four episodes of Thunderbirds. “City of fire” (green), “End of the road” (red), “Pit of peril” (yellow) and “Desperate intruder” (red and white).
Like some of the other vehicles in Thunderbirds, this was made by combining plastic model kits in unusual ways to make new designs.
It is most likely that there was only one model made and repainted for each episode. But, if you look at the two screen grabs from the episode “City of Fire”, you can see quite a few differences in the model between the two shots. Were there two different models, and if not, why was it changed. One explanation could be that it was repainted for another episode, and then had to be painted green again to film an extra shot for this one.
Below is the only picture of the original model I could find that is not a screen capture. If you know of any others please email me.
The first problem with making this model is obtaining the kits. The body is made from two 1/32 scale Huskie helicopters stuck back to back. The engines and vertical wings are from the Aurora B58 Hustler. You will also need the main body of a Revell Atlas Booster. The Huskie kit was made by Hawk in the 60’s, then later by Testors. These are not too difficult to find, and can be obtained relatively cheaply. The Atlas booster is also not that rare. The Aurora model however, hasn’t been made since the 70’s, is difficult to obtain, and can be expensive. You need two of them to make a helijet, So it may be cheaper to cast the parts you need from the kit. (If you can get hold of one). Note: that Aurora made three different scale B58 kits. The one you need is the largest, which is approximately 1/72 scale (kit number 375).
You can email me at email@example.com