Private jet friction-welded titanium startup

Brief mention as another example of speculative private-aircraft scams — $1M down before design existed; all friction-stir-welded titanium-skin Cessna-class plane.

These things go on all the time. There was a guy I know who actually bought into another one — an all friction-stir-welded titanium skin plane, like a little Cessna, very light. You had to pay a million dollars down before the thing had even been designed. There are lots of these. I call them scams, but they wouldn't call them scams. When you're doing these things there are lots of uncertainties.

Failed venture used to illustrate friction-welding limits above aluminum (mandrel wear with reactive titanium).

There was a firm that was going to build a private jet, all friction-welded titanium. They went belly up, but they had a lot of Wall Street Journal press about how they were going to be lighter because they wouldn't have these big heavy joints. Mechanical joints add weight. If you can make a good weld, it's going to be lighter weight in general. Friction welding is a problem for anything above aluminum because you've got to have a mandrel that doesn't get consumed by the heat. You can do it with titanium, but titanium is pretty reactive and you get a lot of wear and tear on your mandrel, whereas aluminum works great.