Good morning!
Has anyone flown/used a Cessna 421 airplane.
I have over 1.000 hours in 400 series Cessnas, most of them on the 421, but also some on the 404 (same engines) and the 414 (same cabin). During the nineties I have co-owned a 421 for 8 years that was employed commercially. I still fly occasionally on two 421s (one privately owned late model 421C and a 421B that is used for aerial work (hail prevention)).
I'm interested in its realiablity, opertaing costs, maintenace issues.
The reliability used to be good, but is deteriorating now as the fleet is aging. The last one was built in 1985 - that was 24 years ago! The engines (Continental GTSIO 520) are very powerful, but really pushed to the limit and therefore maybe the most delicate engines to be encountered in any contemorary GA aircraft. I have never heard of "gitsos" that reached their 1600 hour TBO (some variants have only 1200 hours!) without major maintenance. I have experienced myself all of these failures (but not all of them with "my own" aircraft that was only operated with one of the owners on board and was treated accordingly): cracked cylinders, cracked exhausts, turbocharger problems, cracked crancases, worn reduction gears, worn oil pumps, oil leakage from all possible locations.
The situation is worsening quickly as some engine parts (like crancases!) are not manufactured any more / or only in batches when sufficient demand exists. This means, that even "factory new" engines are made with old parts. A 404 that I used to fly got one of those "new" engines early this year and developed a crack in the crancase after less than 50 hours. This is covered by warranty of course, but it means several weeks of downtime.
From what I see, it is becoming more and more difficult to find maintenace organisations with sufficient experience on type. I have witnessed two gear collapses on the ground (one with a 421C on tow and the other with a 404 during takeoff roll), each of them after several unsuccessful attempts to solve hydraulic problems by different maintenance companies. Our own 421 had frequent hydraulic problems too (and it was only 12 years old when we got it - half the age of the newest one existing now). One big advantage of the "B" model over the "C" is the electrically operated gear that seems to create far less trouble.
For the rest (electrics and avionics) it really all depends on the experience of the maintenance company. Spare parts are rare or nonexistent so they must be able to repair many items themselves. We once flew for six months without the autopilot working because that was the time it took to find a replacement part (over 10 years ago, much worse now! The private 421 I fly every now and then was grounded for three month because they could not find a replacement oil pump).
The petrol operated "Janitrol" heater (contrary to what another poster has written here, the heater is really needed because the hot air from the turbochargers is only sufficiently warm in low-level summer operations) is also a troublesome piece of equipment. I have spent quite a few hours in C421s at temperatures below freezing with fogged-up windshields and no way to get the heater going... I know of one commercial 414 operator who had a lawsuit going against his maintenace for several months because of their repeated failures to fix the heater.
I would reckon (luckily, I haven't had to pay a maintenance bill myself for a long time now) that the hourly maintenance cost of a 421 is in the same order of magnitude (if not higher!) than that of the Citations I fly now. As reliability is concerned, the hail prevention 421 that I have flown occasionally during the last couple of years needed one maintenance event per flight (!) during that period. To it's defense I must say that it is stored outside and only flies every two or three weeks on average. And when it flies, it gets a rough beating due to the nature of its work... (it really is not the right aircraft for the job).
How do the passengers like them?
As others already said, it is very quiet and quite comfortable for a piston twin. But for most passengers it is just another "puddle jumper" with propellers on it, so all they really care for is to get out of it as quickly as possible.
How do you like them from a pilots point of view.
Now this is the nice thing about it
It really is a wonderful aeroplane to fly. Lovely harmonised controls, very stable, powerfull and very capable when operated within its limits. A late model 421C with trailing link gear and vortex generators can be flown into (and out of - as long as both engines are running) amazingly short fields. But it is not very fast in the cruise (around 190 KTAS with maintenance-cost friendly powersetting). The older 421Bs are 10 to 20 knots faster in the cruise (they are lighter and have a different wing) but they need more runway and more pilot skill to be landed softly. Single engine performance is marginal at MTOM as in most light twins. I have had one engine failure (turbocharger broken off the exhaust manifold) shortly after rotation and with 4 POB and 2/3 full tank we got between 200 and 300 ft/min climb rate. From that day on, this is my personal weight limit for the 421. And no commercial operation ever again.
So if you really want a 421 (I know, they can be found incredibly cheap now): Find an experienced maintenance organisation first (also for electrics and avionics)! Take them along when you inspect/buy the aircaft. Believe them, when the say "no", even if the airplane seems to look nice. There have been lots and lots and lots of expensive ADs over the last 20 years. Make sure they have all been complied with. Make a long demonstration/test flight. Check everyting including de-icing. If anything does not work, don't buy. For example a replacement heated windscreen (they often do not work in older airctaft) costs more then 20.000 $ / Euros - if you can find one. Remember: no heated windscreen - no flight into known icing.
Get an experienced pilot/instructor to familiarise you with the aircraft.
Operate the engines as if they were raw eggs: No firewalling of the levers ever (spare that red-line for emergencies when you need it). Stay away from the manifold-pressure red line as far as you can. Whenever safeley possible, we did (and do) limited power takeoffs. End-of-green-arc is usually sufficient (32.5 inches as opposed to the 39 red-line setting). Dont climb at max rate, but at a good speed for cooling (like 130 knots). Sacrifice 5 or 10 knots cruise speed in favour of engine life. Always lean the engines but don't lean to peak or above.
Descend slowly: There are no cowl flaps, the airflow thruogh the nacelles is always the same - on the ground (idling in summer in Italy you will reach red line temperatures and red line oil pressure after about 10 minutes!) - during climb (again, during summer in Italy steep max. cont. power climbs will quickly bring everything above the red lines) - and during descent, when it cools much too fast. Do only fly as high as necessary. Above FL 180 the climb rate is so poor that you really need to fly a very long distance to justify the extra expense in fuel and engine wear.
Plan your descent early so that you can stay within 500 ... 1000 ft/min. Reduce power by about 1 in every minute to keep the engines hot. A ham-fisted colleague of mine once cracked 4 cylinders during a single quick descent after a maintenance test flight. Never shut down an engine during trainig or checkrides. Our mechanic (who owns a 421 himself) once told me that the price an inflight shutdown/restart is about 1000 Euros.
And most important: Never ever borrow of hire a 421 to anybody. Not even your closest friend. Unless you are also on board and can prevent him from wrecking the engines.
Greetings, Max