NA or Turbo?

[GrummanBear]

A lot of training and needs to happen in the mountains, with mountain experts, before looking at turbo or NA questions in Colorado. I wouldn’t even consider flying my family there without a mountain course, ir, and experience in the mountains. Even then, please be careful. Family died in Cirrus below... As a teen, I knew a guy who crashed on a ski trip in CO (think in a Bonanza); he survived, his wife and kids didn’t. Know another family (old neighbor in CO) all died landing at their own airstrip in the high country when a gust slapped them to the earth on landing.

I’m mountain born and bred; they can be ridden, but not tamed.

https://www.google.com/amp/s/amp.coloradoan.com/amp/1694082001

 

[Rgbeard]

In Arizona we don't have the "tall stuff" that Colorado has.

That said, by FAA standards, 75 degrees in Flagstaff is a really hot day. And non-turbo airplanes notice it quite well.

When the density altitude is a 5-digit number, lots of planes struggle to get some climb-rate, as they're producing a small fraction of their rated power.

With the Turbo, I don't have to to my take off roll chanting "I think I can... I think I can...." The Turbo 540 does great things.

 

[Snowmass]

You have a high horse power engine and probably no strut cantilever wing for reduced drag.

When the strutless wing came out I asked a Cessna distributor about the speed increase. He said, "One or two knots, if that." However, the weight increases and you also get a very expensive AD.

 

[Snowmass]

In Arizona we don't have the "tall stuff" that Colorado has.

My to most common flights are from my Arizona cattle ranch (03AZ) to my Aspen Colorado second home which has lots of tall stuff. The main reason for a turbo is NOT for clearing mountains nor high altitude takeoffs which I can easily do on the hottest days, it's to get over 28,000' where the icing level seems to stop. I have been to FL230 in my NA C-210D solo but it's not high enough to avoid ice. So I just wait out the winter storms and ski powder.

P.S. Phoenix is not the real Arizona which is above 4000', it's another Los Angeles, yuk. I do not even need any air conditioning mid-summer.

 

[Kristin]

My experience with non-FIKI airplanes in the mountains in the winter involved as much driving as flying, even with an instrument rating, and I can’t think of any flights I’d have made IFR that I couldn’t make VFR.

That is the reality. One either needs to do it VFR or you have to make a quantum leap in the capability of the aircraft. The flat minimum would be a deiced, turbo-Aztec, IMO. A turboprop would be a better call. But as long as you don't box yourself in by planning to end our ski vacation on Sunday and be at work on Monday, it can be done VFR, though there will be times that driving is the best option.

 

[GrummanBear]

When the strutless wing came out I asked a Cessna distributor about the speed increase. He said, "One or two knots, if that." However, the weight increases and you also get a very expensive AD.

I have a lot of interest in the strutted mid sixties 210s...wondering how much beer+fuel I would need to ply you for a ride in the right seat and see how it flies up there...? I’m back in Colorado 10 or 20 times/year.

 

[Kristin]

Turbo-normalizing does not have extra operating costs.

Of course it has extra operating costs. It takes money to buy it, money to maintain it, and money to lift the extra weight. Also, the more convoluted exhaust system and wastegate rob power when not being used.

In some engine applications, extra fuel has to be run through the engine to keep the temperatures down when using the turbos at high altitude. Turbo-anything, is not a free lunch.

 

[Martin Pauly]

Not true. Turbo-normalizing does not have extra operating costs. Fuel burn and oil consumption are the EXACT same as a normally aspirated engine down low, except the turbo is 20 kts faster in the thinner air. 23 squared non-turbo at 3000' is is identical in cost to operate 23 squared at 16,000 msl turbo-normalized. GPH at 23 sq is the same GPH at 23 sq.

The pilots with turbos that I know all fly faster than they would before - naturally, that's one of he reasons why they got the turbo. They also change their oil more often than they used to. I'm not saying that's a bad thing - but it does increase the operational cost.

There is a conflating of turbo-charging with turbo-normalizing. Most turbo normalized systems are simple systems and completely out of the loop until asked to add boost. With 100% total and complete turbo failure in flight, the engine operates like a normally aspirated engine.

You are right, they are not complex systems. But they are more complex than a simple conduit from the air intake to the intake manifold, and yes, their components will break more often than that simple conduit. That super fast spinning/rotation and the extreme temperatures inside the turbocharger (or turbonormalizer) don't come without some risk of failure.

Regards,
Martin

 

[Kenny Phillips]

Of course it has extra operating costs. It takes money to buy it, money to maintain it, and money to lift the extra weight. Also, the more convoluted exhaust system and wastegate rob power when not being used.

In some engine applications, extra fuel has to be run through the engine to keep the temperatures down when using the turbos at high altitude. Turbo-anything, is not a free lunch.

Yes, as soon as you go above the critical altitude for N/A you are burning more fuel, unless you slow down. And I don't slow down.

 

[Snowmass]

I have a lot of interest in the strutted mid sixties 210s...wondering how much beer+fuel I would need to ply you for a ride in the right seat and see how it flies up there...? I’m back in Colorado 10 or 20 times/year.

Possible but I won't be going back until summer, and maybe not then with covid. I land at KGWS (the bizjets ruined Aspen) where the pix was taken with my C-210 in the background. The strutless 210s got good in 1962 with a total gear design change.

 

[NordicDave]

Last November I flew from Bend Or to Salinas Ca. during the seasonal high winds fanning all the wild fires. Severe turbulence below 12,500 MSL and smooth air with 90 kt tail wind above. Only a small number of us with turbos up high and the NA engines down low complaining to ATC they couldn't climb though the winds. Sacramento to Salinas usually takes 60-ish minutes, this trip less than 30 minutes. It was fun cooking along over 250 MPH in a 182.

 

[hindsight2020]

I can get airplane advice anywhere. I come to POA for the blue ribbon choice-supportive bias

 

[Mjg2011]

I guess it really comes down to your 90%/10% mission. If you're only going to fly in the mountains a couple of times a year that might make up a small portion of the missions you plan to accomplish. Maybe get NA for when you just want to fly local for fun and rent for your mountain trips?

I used to think an M20 would be right for me because I wanted an economical aircraft but realized my trips would rarely go past 100nm and that isn't anything a 172 couldn't reasonably do.

 

[Kristin]

Yes, as soon as you go above the critical altitude for N/A you are burning more fuel, unless you slow down. And I don't slow down.

It depends a bit on the aircraft it is installed in, but I have made a number of comparisons between turbo-normalized Twin Comanches and NA Twin Comanches, and I can promise you that the turbo is more expensive from the minute you take off. The NA will get off quicker, climb faster, and cruise faster until above the critical altitude where the turbo can dial in the boost and catch up, but at a price.

 

[Martin Pauly]

The way I understand it, “critical altitude” is a term meaningful only for turbos. It’s the altitude above which you can no longer obtain maximum manifold pressure (or sea level power). In a NA airplane, that would be sea level.

- Martin

 

[Kristin]

The way I understand it, “critical altitude” is a term meaningful only for turbos. It’s the altitude above which you can no longer obtain maximum manifold pressure (or sea level power). In a NA airplane, that would be sea level.

- Martin

Critical altitude can have a variable benchmark. I was using it as the altitude where one can no longer maintain full cruise power, i.e. 75%.