Thanks Kent, My P2 is a great plane and I enjoy flying it with my 421C.

I flew my first set of Factory new GTISO’s out to TBO. They were running great, but I replaced them with another set of factory new engines just because I could.

The second set had a crack at the top of the case because the factory forgot the string at the top of the case halves. Then they tried over torquing the thru bolt to stop the leak and cracked the case. The bad part is the factory shipped the engine anyway.

The factory gave me a new case and repaired the engine under warranty. Both engines are running great with no issues.

The GTISO is great engine and only requires good maintenance and a knowledgeable pilot with an IQ higher than room temperature. If they are poorly maintained and flown by a ham fisted pilot there will eventually be problems.

I knew Ted Smith because his mother lived close to my airport and he would fly in to see her in his old Aero Commander 500. I looked carefully at Aerostar’s before I bought my 421C.
I chose the 421C because it’s quiet, had room for my family , the potty ,the short field ability and FIKI.
Both the Aerostar and 421C are great planes providing you buy one with good maintenance and in good condition.
One is a hot rod and the other is the family or Corporate Suburban.

I've had a 601P with short props and machen intercoolers for 8 years.
Nicest most honest flying airplane I've ever flown.
Pressurization will change your life.


I looked at an MU-2 thought I could not afford the maximum probably maintenance event. My guess was bad day in an MU2 could cost 250K to 500K if you lunched an engine. Thought bad day in the aerostar would max out at 75K, I was wrong.

I had an aerostar motor swallow a lifter, filling the sump with shredded steel and continuing to run on 5 cylinders. That was 5 years ago and when all done cost $125K
Trashed the motor, two turbos, prop, prop governor, turbo controller.
Got a big reduction on the core value due to the trashed parts.

I'm told you can get a mid time replacement garret for an MU2 for 150K.

I upgraded the avionics to exactly how I wanted, I've got two factory zero timed engines I converted from electric to engine driven A/C. ...I've had it painted. Its a nice reliable plane. I have my A+P and I do some work on the plane, for anything serious I take it to the FlightShop in Utah. I've taken it from CA to Alaska (2x) , fl,(2x) , WA, OR, east coast, oshkosh, brownsville to watch starship, etc... My milk run is San Diego (KCRQ) to San Francisco (KHAF) to see my son and granddaughter. its a traveling machine. My home airport is now $7.50/gal. That's getting painful.

One nice thing is I can fly the Aerostar Basic-Med I believe I could still get a third class, SI, but I was SI and it was an annual hassle. So I'm now limited to <18K ft.

After 5 years maint is probably 15 to 20K a year. This year was 19K. (I replaced a turbo)

For either of these aircraft an aircraft with deferred maintenance could easily cost 200K in the first year. Well maintained I'd plan 40K first year 20K second. then it will settle down.

Great information, and from what I’ve researched neither airframe has a life limit, correct?

This story of the $125k Aerostar engine makes me think maybe 501sp isn’t that bad.

One of the things I hated about my 421 was the carb adjustments and fuel pressure. I had the plane for 3 years and took it to a lot of expert shops and non of them could get them to idle well. They would die when hot on the ground. I even took it to the guys in Texas that build the engines (forget their name). I think I paid to replace every part in the system and still wasn’t right. that just added a lot of frustration and stress. Made me feel like the engines could die at anytime. I think my heart rate and stress was the highest it could be on all those 421 departures when heavy. My hands would be shaking, literally.

Now my heart rate doesn’t change at all on departure in the Jet. Cool as a cucumber. For me that’s worth the extra risk and cost of a jet.

Here is a video of one of the many attempts to adjust it. Haha I think we finally after years go them pretty good but it was a major project and took a lot of money.

https://youtube.com/shorts/w7DHJ-rRaaw? ... TMrydS3khP

[YouTube] https://youtube.com/shorts/w7DHJ-rRaaw? ... TMrydS3khP[/YouTube]


Mike

I had the exact same experience with my C340A. Spent many hours with my mechanic trying to get the fuel flows right and even if we succeeded, we had to do it again in a few months.

Well, there's the problem, someone modified it and installed carb's!

I knew I was going to get that. Was trying to simplify. Ok Servo. Haha.

Trust me I know way more about that system than I want to.

The worst part is I would drop it off for a week. They would say we got it dialed in come get it. Then I would be taxing out and it would die. LOL. Had to turn back and spend a few more days then finally would leave.

Mike.

After the initial design issues with the GTSIO's in the 60's, they become a very good engine. We were able to trace 95% of the engine issues down to particular pilots.

The 421C I managed had almost no issues with the engines in the four years we flew it. Another pilot at a nearby airport installed three engines during the same time period. The owner had enough and bought a King Air 350. It took six months before it needed engines. I'll stand on my grave and preach if you are having many cylinder or other issues with a GTSIO, it's either maintenance or pilot induced.

Micheal, what year was your 421C? 1982 thru 1985 had the N Engine with the two stage fuel pump. N engine requires a knowledgeable person to adjust them. The main problem is they don’t put the interstage pressure to the max. Not many left?

1976 thru 1980 had the L engine with a single stage fuel pump which is easily adjusted.
Continental quit making the N engine with those two stage pumps because the vendor quit making them.

Now it’s possible to convert an N engine to an L engine by changing pumps.That solves the adjustment problem and the engine uses less fuel and is more efficient.

Gerald

I don’t want to re live it. Haha.

It was a 1979 but had the new engines from whatever the big shop is in Texas that does the rebuilds. Yeah everyone said sure we can adjust them we are experts. It obviously had some issue that was hard to find.

I had 4 different shops in the west coast say they could do it. Then finally
Took it to the main guys that build the engines and even they struggled.

But I always seem to have the problems that nobody can fix on planes. LOL.

Mike.

Sounds like a manufacturing defect. Probably bad pumps. Sorry that happened to you.

Yeah I think after we replaced everything it got fixed.

That’s when I said maybe a jet would be better. Haha. Now I just chase issues on that plane and get even larger bills. Haha.

Now that I have paid to fix everything it’s probably time to sell it. That seems to be my MO. Get a decent plane. Spend a ton of time and money making it really good then sell it and move on to the next project. I want to find a guy like me to buy my next plane from. Haha.


Mike

That was the worst case scenario at the time. I think there was no core credit issued on that engine as I recall. That and/or a dissimilar core charge that was significant.

If you have a workable core and some first run steel cylinders you can do a pretty good engine much cheaper. There have been some huge price increases on some of this stuff, so it is almost hour by hour pricing!

We get that a lot with Aerostars. These guys buy an $80k Aerostar with no knowledgable assistance and when they can’t keep it running it is the Aerostar that is at fault, not the phd in dumbass that bought it.

Then once it runs at all they destroy it with the way they operate it.

For whatever reason, mechanics just love to torture Aerostars! I think it is that they think they know maintenance with some Baron and twin cessna experience, and they get overwhelmed with anything different. The Aerostar is a well designed and built plane, but when you are in a hurry to fix something and don’t know how it makes them look like they don’t know what they are doing. Then they get rash and defensive!

The pressurized Aerostar has life limited windows. That is about it. 4870 on the windshield unless you have the 5.5 psi kit. 15,000 hours on the rest of the glass.

I don’t think the 421 has a life limit on the airframe.