Alright.
Reasons not to buy a 421:
1) They break. A lot. Everything below is basically a subset of 1. There are plenty of 421 owners who will argue with you about that, but talk to them long enough (and talk to their mechanics long enough) and you'll ultimately realize that getting 25 hours per week out of one is going to be difficult, even if you buy a top-notch one.
2) The airframes aren't supported all that great, which is a problem when 1) comes up. Cessna wants them all gone. When they break, getting parts can challenging and expensive. Fortunately there are enough wrecked/scrapped ones that you can find a lot of parts in junkyards, but that doesn't work for a lot of them. Got an engine beam that goes bad? That's an enormous job to change (did that on the 414, same thing). And you need to buy either a new one from Cessna (which I recall is $10k) or a PMA part from TAS Aviation or RAM Aircraft (who distributes them) for $5k.
3) The geared engines are fine if treated properly, and I have no doubts that
@Zeldman can operate them just fine. The problem is that they still break with regularity and will have little nagging issues, moreso than the direct drive. Oh, but they also have some issues that pop up unexpectedly, moreso than the direct drive equivalents. Issues like losing prime to the oil pump (so start it up and have 0 oil pressure) and engine failures on takeoff (happens much more regularly than direct drive engines). These are the reasons why I went after a 414 instead of the 421, and why 414s fetch more money than their 421 counterparts these days.
At the end of the day, you need a reliable aircraft that you can depend on for a mission like this. A $150k 421C is not going to be it. Going into the 414, I basically didn't have any choice but to go that route if I was going to manage an upgrade for Cloud Nine. We have a lot of advantages - some great sponsors who really helped pull us up, and my ability to turn wrenches. In spite of that, the plane had approximately
50% downtime on that airplane over the 2 years we owned it. We could've improved that some, but in reality I don't see it having been much better than 25% downtime over that period.
Wayne Bower used to say that you could operate a similar turboprop for about the same as a 414/421, and he's right. So, why to buy an MU-2:
1) It's not an airplane for everyone, but it is a good fit for a professional who will fly it the way it needs to be flown. Zeldman is a professional, he will do fine with it
2) Vs. the 414 and even factoring in the cost of the hot section we had to do first thing, the MU-2's operating costs are much cheaper. The plane is a tank - 1500 lbs heavier empty weight than a 425, 700 lbs heavier empty weight than a Cheyenne II. All that weight is in the structure. Yeah, my fuel bill is higher, but not by that much (CAA is a wonderful thing) and that's all I put in it - fuel
3) Because of this, it doesn't break a lot. Support from MHIA is excellent, and there are a lot of wrecked or scrapped aircraft that are available for parts purposes. The inspections are well defined. 100 hour, 200 hour (these two occur at a maximum of 1 year) and then beyond that there's 3-year/600 hour, and various other total airframe time inspections. My 100/200/annual, even going to one of the Mitsubishi service centers with optional items to be done, was cheaper than I managed on the 414 using small, independent A&Ps. It's just a great airplane
A $150k 421C will cost over $150k in the first 1-2 years.
