I believe the cranks and cases are where the big problems are- or rather, can appear. My assumption from hearing/talking/reading mostly stems from "letting the props power the engine."

Other than that, I think it's mostly just normal big tickets you'd come to expect from a cabin class twin. Issues we don't hear a lot about because there just aren't as many around as say barons.

Glass windshield is the big thing other than engines/props. Make sure it meets all the instructions for continued airworthiness - scratches, bubbles, delamination, acceptable current draw.

A test flight to determine every single switch works to spec, critical altitude, pressurization differential, etc.

Other than that it's death by 1000 cuts. Find someone who knows the machine - $3K here, 3K there pretty soon you're talking real money.

If the engines have Ram cases check and see if they have ever been reamed out and how many times. If they have you might need to buy new cases fron TCM at the next OH.

CASES
WINDSHIELS IN COCKPIT
STARTER ADAPTORS
EXHAUST AD

Above is what I've uncovered.

The STOL mod has had some great reviews as a benefit to shot field ops but the down side is the MOD requires additional maintenance to up keep.

The STOL weighs a bunch. I would not believe any promises of a high useful if it has the STOL. I'd want to weigh the plane.

An issue with STOL is a lot of near-unobtanium airframe parts. I believe Sierra still supports the mod but lead times might be long.

It's possible to land a 421 quite short using book technique. Between that and VGs I think 3000' is quite doable.

The STOL mod is an additional 90 pounds. The flaps only work at 1/2 speed and parts can be hard to find. IF you don't have a good reason or need for the STOL I would avoid it.

Looking at a runway, how doable is an asphalt 3,300x60' runway for a 421b/c?

You will not have accelerate stop. But in terms of acceptable ground roll with both engines operating, it's fine. (I'd have to look at chart for hot and heavy, but with typical loads, temps that would be fine).

You'll not want to use that runway right off the bat. Give it 50 hours or so.

You will not have accelerate stop. But in terms of acceptable ground roll with both engines operating, it's fine. (I'd have to look at chart for hot and heavy, but with typical loads, temps that would be fine).

You'll not want to use that runway right off the bat. Give it 50 hours or so.

Elevation? Obstacles?

Here's the takeoff distance table from our POH. 1981 421C

If I didn't have accelerate stop distance I'd want to know what's past the runway too.

At 3300' you don't really have accelerate go either. I agree, obstacles go into the planning but that's a strip where you can plan to land in many engine failure scenarios.

Elevation? Obstacles?