Why should I not buy a Cessna 421.??

[Ted]

They are finicky. You can run cool tank fuel to the fuel control unit with the electric pump but the injector lines and divider will remain heat soaked. They will start up on the first try with good technique.

The issue is most don't know or use proper technique.

If that's true of the 425, then the issue with the 340/414/421 seems to revolve around the engines, no?

The engines are a big part of it. No spark plugs, no equivalent oil change, no mixture fumbling, starter clutch, no magneto, etc. I’m not an expert, but from what I’ve seen the 425 systems/structures are generally beefier also. I think max gross on a 421 is 6800-7000 depending upon year and STC’s. My 425 has a max ramp weight of 8675. Empty my 425 is 5345 vs the 421 at 4200 - 4300. A PT6-135 only weighs 320 lbs also. 421 will hold around 1400 lbs of fuel where I can take 2450lbs. The vibration factor of the turbine vs a piston beating accessories to death is also significant.

Bleed air for pressurization, instruments, cabin heat, and boots is also a significant difference.

Eggman got it right. My 2 cents is the engines are a large part of it because they're much more complex, Cessna did a crappy job designing the turbo exhaust (hence why it's got a pretty restrictive, and very necessary, AD on it). On Continentals the turbos seem to add a whole lot of MX. I would say they probably double the MX needs. The 310's engines needed virtually nothing in the time I had it, whereas the 414's engines couldn't stop getting maintained.

There's no doubt to me that the piston systems aren't built as sturdy as the turbine systems. Much of that in my mind comes down to the need to keep things as light as possible on a piston, otherwise the thing just wouldn't get off the ground. If you look at piston cabin class twins vs. their turboprop equivalents, there's a 50-100% increase in horsepower for the turboprop in general. One friend of mine went from a PA-31-310 to a PA-31T-620. So more power means you can build the systems tougher. Incidentally, this is also a reason why a 421 with a turbine conversion is less appealing to me than a 425.

@jeff Allen probably will report back to the Twin Cessna folks that I'm a traitor. But in reality, I loved the 310 - I still miss that airplane, and on a crisp morning like this one, I would love to hear those 520s roar to life and scream down the runway. I also still would make the same decisions regarding acquisition of the 414, and I think that the people who bought it will be much better off since they got the benefit of the significant amount of work I put into it. There are certain missions for which the cabin class piston twin still has value. In @Zeldman 's position, though, I just don't think it's a good choice.

 

[Lance F]

OK, after 81 posts on this subject I feel I have to at least say something. I have about 250 hours in C414s and C414As in the last 12 months. I have a 414, I fly and manage a 414A and fly a couple others from time to time on a contract basis. The piston versions of these pressurized twin Cessnas are not cheap to fly. But neither should they be categorized as mx black holes unless neglected and that applies to any aircraft.
I am somewhat astounded though by the concept that the step to a twin engine turboprop is a better solution from a cost standpoint. Fortunately my JetA burning flight hours have all been on someone else's credit card. It's great flying them...fast, quiet, smooth, easy to fly. But cheaper than a piston twin, all other things being equal, no way.
Continental engines are not hard to hot start. And you don't need three hands to do it.
Exhaust system crappy with a pretty restrictive AD??? An A/P has to visually inspect it every 50 hours. At 12 years it has to come off for a more thorough inspection. The STC for the PowerFlow exhaust I had on my IO360 Mooney says it has to come off every annual for inspection.
The turbos themselves, at least the ones on the common RAM conversions, have been totally trouble free to me. They get overhauled when the engine does.
I don't think the pressurization system on these piston twin Cessnas is any more or less mx prone than a comparably sized TP or other pressurized twin (Aerostar, 58P, Duke).
I haven't had to put a dime into the A/C system in the two years I've owned my plane, and it works well.
The landing gear is robust and has no mandatory overhauls.
I control costs by doing whatever mx I can, which fortunately I enjoy doing. Before I take an issue to a mechanic I read the Cessna or Continental factory service manual on the subject, so I can properly inform the mechanic about the issue.
I'll gladly share my cost experience with anybody. As I'll freely admit, it isn't cheap, but the 414 fits MY mission very well right now. That's the most important thing.
And as a PS I'm very glad to see Jeff Allen on the Forum. He also involves himself with the maintenance and upgrades to his 340. Welcome to POA.

 

[N747JB]

If that's true of the 425, then the issue with the 340/414/421 seems to revolve around the engines, no?

Turbines are generally more reliable than piston engines, but depending on the model the piston ones can have electric gear and the torque tubes are $3K each plus labor. The issues I’ve had on my 425 have been air conditioning, same isssue on all 400 series Cessnas that are 30-40 years old. Heated windshields are the same and cost the same amount on any of the airframes. Also a lot of the 425’s have been owned by either corporations or people that can afford to maintain them to a pretty good standard. Some of the 414/421’s fall into the same category! But, a lot of them are maintained occording to how much they can afford! YMMV