I’ve never flown a turbocharged aircraft, and there are a wide variety of certified & experimental aircraft with turbo such as the C182, SR22T, Mooneys, Sling tsi, some Lancairs, JMB VL3 915/916, etc. Being required to stay below 18k ft, could a Basic Med pilot still enjoy the improved cruise speed due to sea level power in the thinner air? Or would that not be high enough to really take advantage of turbocharging? I’ve read of some Mooney pilots cruising at FL250. I’ve also seen a video in a Turbo C182 at 19k ft. Do you need to be in Class A airspace to get the full advantage of turbocharging, or can 14-17.5k ft still do nicely?
Do turbocharged GA aircraft perform well under 18k ft (Basic Med limitation)?
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MauleSkinner
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You’ll get improved cruise speed, but it’s hard to make up the time lost climbing. The biggest advantage IMO is getting into the teens where traffic is lighter.
Someone once said “you can turbocharge the engine but you can’t turbocharge the wing and the prop”.
Not only does turbocharging let you maintain higher cruise speeds below 18,000', it will let you take off shorter at high DA airports. The shorter takeoff in high DA conditions is the biggest advantage in my book. You retain sea level power even at an airport with 11,000' density altitude. That is a HUGE advantage!
This^^^^
I bought a turbocharged 210 last December. No regrets. I fly heavily loaded, near MGTOW, on most of my long XC trips. In high DA situations, I can still get sea level horsepower up to the upper teens. I typically fly between 10K and 17K if flying legs over 2hrs. I can maintain 600fpm or better to top of climb if CHT’s cooperate. I like being able to get high enough to be over the low cloud layers and navigate around the towering cumulus in a convective environment. I also like the peacefulness of being handled by Center most of the time instead of being passed from TRACON to TRACON when flying lower. So, what are the downsides…. More maintenance cost due to a more complex exhaust, a wastegate to maintain, reduced access to routine maintenance items due to induction elements that must be removed for access. I anticipated and budgeted for this increased costs.
RussR
Final Approach
Turbocharging is an absolute game changer even if you don't go above 18k. Actually, I'd bet that MOST turbocharged (unpressurized) aircraft never go that high, or very rarely.
With a non-turbo aircraft, your TAS generally drops off above about 7000 feet. So your effective range of cruising altitudes is something like 5000 to 9000 ft. Pretty narrow range, and it's often where even the smallest cumulus clouds hang out. Plus, if you try getting up higher your climb rate really suffers.
But in a turbo aircraft, you can cruise just fine at 5000 if you want to, and at 12000 if you don't want to use oxygen, so that's automatically a larger range of altitude choices. Of course, if you're willing to wear oxygen, you open up a LOT of capability and options - avoiding weather, finding tailwinds, getting above the summer bumps, getting into cool air, all that stuff. And it doesn't take you that long to get there, either. But even the no-oxygen altitudes show an advantage.
I remember a loose formation flight I did with a friend of mine. His was NA, mine was a turbo. At 6500 we were evenly matched, both running 75% power our speeds were the same. We decided to climb up to 8500 to get into cooler, smoother air. Once we got up there it was immediately obvious I had a few knots on him, since I could keep 75% power and he couldn't. Just in the 2000 feet altitude change the difference was apparent. Higher would have been even more advantageous.
You do not loose all that time climbing. I did my climbs at 100 indicated, in a plane with a 19,000 foot ceiling, cruised at 8 to 12, and 120/130 indicated, brought it back down with power on, and 150 indicated. Depending on the wind direction, the cruise speed was about130 true. Into the wind, higher power was used to get more ground speed and cut the overall trip time.
The trick to getting the time back is maintaining cruise power all the way down.
The trick to getting the time back is maintaining cruise power all the way down.
N747JB
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I have two turbocharged engines, and 90% of my flying in my 414 is below 18,000 ft. Depending on where you live and where you’re planning on flying, a turbo might be a great idea.
bbchien
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Tremendous difference between 12K and 17K. You're above most of the weather, making 65% and that means really GOOD airspeed.
There's almost nobody at those alitudes, and you're on top of the embed.
In the past two months i've gone
CHI to Yakima in 1 day.
CHI to Bangor in 1/2 a day,
Not possible without turbos.....and look at the Montana Aztec crash swing. Had they had the power to go clear on top, I doubt that would have been the outcome ( I keep thinking it was an ice accident...induction ice, etc).
B
There's almost nobody at those alitudes, and you're on top of the embed.
In the past two months i've gone
CHI to Yakima in 1 day.
CHI to Bangor in 1/2 a day,
Not possible without turbos.....and look at the Montana Aztec crash swing. Had they had the power to go clear on top, I doubt that would have been the outcome ( I keep thinking it was an ice accident...induction ice, etc).
B
flyingcheesehead
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A normally aspirated plane will do the best around 8,000-11,000 feet.
An otherwise equivalent turbo(charged/normalized) plane will do better any time you go higher than that. The higher you go (up to the critical altitude plus a few thousand), the better true airspeed you can achieve in cruise.
Sure, lots of turbo piston airplanes are certified to 25,000 feet and higher, but it's fairly rare for them to fly up there. For one thing, it takes a while to get up and down so you need to be flying really long legs to make it worth climbing higher than 18,000. However, for the same reason, if you're not planning on flying longer legs, there's no point in a turbo. I fly a normally aspirated plane that's also available in a very similar turbo model, but unless I were to fly legs of mostly 300nm or more, the turbo would be a waste.
So, if you're planning on flying lots of longer legs, or being based out of a shorter/obstructed strip in the Rockies, sure, go for it!
I would venture to guess that many planes capable of FL250 never get there. Take a look at all the airborne SR22Ts here and see what you find: https://www.flightaware.com/live/aircrafttype/S22T
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I flew a number of turbocharged airplanes from Cessna, Piper, Mooney, during my 20 years in Colorado and have never flown above 18,000’. Made a difference in takeoff performance, cruise speed, and the like.
So, I’d say yes.
But if we’re talking below about 9-10,000’, I’d say it was overkill.
So, I’d say yes.
But if we’re talking below about 9-10,000’, I’d say it was overkill.
I own a Duke. I rarely take it much above 20-21-22. It would be perfectly happy, albeit a few knots slower, flying around at 16-17k (and I routinely do fly it in the teens). You get a few knots extra TAS for every 1000ft you go up, but the difference between my TAS at 16-17-18 (around 195) and my TAS at say 22 (around 205) doesn't make a huge difference in the long run, and fuel burn is the same either way.
BillTIZ
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or cruise better when MEAs are in the teens
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And have a wider range of escape routes when the MEA is 10,000 or higher and there’s icing from the MEA up into the teens.
AA5Bman
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I love our turbo 206, it’s incredible. It’s never been over 12,500 in my year of ownership. But I don’t feel like that’s a waste at all - the real benefit is takeoff power and climb at high DA. Simpler to operate, much better climb, basically immune to hot/high concerns (not actually, but it feels like that). I can theoretically see living in Florida and flying around to islands, never climbing above 4,000’ and not needing a turbo, but IMO basically anyone else would like them.
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On the flip side, flying home on Sunday in non turbo plane, at 7000 I again had the throttle all the way in and the manifold pressure was just putzing/wheezing. Instead of 230 HP, it felt like 23. OK, I exaggerate, but wouldn't it be nice to at least have the option at altitude to make more power if you wanted it? Or be able to get to and fly at 11, 12, 13,000 to get above icing, turbulence, etc.?
The value of the ability to climb above, even if you don't often use it, cannot be understated. Over the summer, was able to make a flight (mostly) direct because I was able to climb to FL250 in the Duke to clear some weather. In a non-turbo airplane, would have been a lot more diverting, etc. I rarely take the airplane up the high, but the capability to do it is really helpful.
Let'sgoflying!
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I have benefited from my turbos
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So….. whats the extra cost for a turbo in maintenance, reliability, engine life span, potential to push a lever too far and hurt the engine?
Is a TurboNormalized the best option?
Asking as a non turbo curious ……
Is a TurboNormalized the best option?
Asking as a non turbo curious ……
Seriously though, I have not had to have work done on the turbo/wastegate yet, but they both are an item that will eventually need OH/replacement. The associated plumbing will make maintenance for difficult due to having to remove/replace components to gain access to routing maintenance items such as an oil filter, in my case. This will be airframe dependent.
AA5Bman
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I have owned two turbo planes. In my experience, turbos (and associated systems) either break or they don't. So they either cost nothing during your period of ownership, or there is a pretty good expense tied to overhauling them. In my cases - SO FAR, KNOCK ON WOOD - they've cost essentially zero (okay, okay, I replaced a clamp on mine per AD this year for like $500). Most people don't own their planes long enough to incur the "average increased cost of maintaining a turbo". They either cost a bundle or not, there is no averages.
midwestpa24
Final Approach
My only time in a turbocharged piston is a Piper Chieftain. No pressurization or oxygen, and we typically operated below 10,000. I wasn't paying the bills, so couldn't tell you if it was worth it. In my opinion, the purpose of TC on that airplane was to get more power out of the 540 instead of going higher, although you could with oxygen.
RussR
Final Approach
That depends on the airplane model, and more accurately, the wastegate design. Some (such as the Turbo Arrows and Seneca II's) have a fixed wastegate - which means that you CAN (or WILL at most takeoff altitudes) overboost the engine if you go to full throttle. This is especially important to realize and train for in a go-around scenario where you may be used to just going full throttle and pitching up.
Others, like the older Piper Turbo Saratogas, have a wastegate that is linked to the throttle lever. Which is a little better but you can still overboost. The ones I flew had a relief valve that was supposed to prevent this but often didn't seem to work too well.
The best option is an automatic wastegate where you just go full throttle and it adjusts the wastegate to make full power. With these, you don't have to worry about overboosting the engine unless something breaks.
@NordicDave flies a 182P except that it has a STC for TN. I don't think it's available any more, but you can always dream.
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My first turbo was the Arrow. I’ve flown both the III and IV. This is a real issue. Consider that redline is an insane 41” MP and that it will still over-boost.
The other thing about the Arrow is that it is one of those which actually makes a speed difference even at altitudes below 10,000’. Turbo Arrow cruises about 15-20 KTS faster than the NA,
Just as another point of reference regarding altitude and turbocharging. My 414 is certified to 30,000' 
. I can't imagine (even if it were legal) going that high. The real world facts are that it takes time to climb and fuel flow is a LOT higher in climb. So to make it practical to go even into the low 20s it needs to be a longer trip or being able to get to a nice strong tailwind or to get above weather that you just don't want to go through. The fuel flow in climb is a bigee. Typical total fuel flow in climb for me is ~58gph (ROP) and in cruise ~31gph (LOP). Both for operating costs and range the time in climb makes a big difference. The bottom line is that all other things being equal (weather & winds aloft especially) I'll cruise in the mid teens for shorter flights up to a couple of hours and in the low 20's for longer flights up to my 4 hour limit. Anywhere in this range is good because few planes are flying there (too high for NA pistons and too low for jets and TPs) and it keeps my cabin altitude at a safe and comfortable 7 or 8,000' .
. I can't imagine (even if it were legal) going that high. The real world facts are that it takes time to climb and fuel flow is a LOT higher in climb. So to make it practical to go even into the low 20s it needs to be a longer trip or being able to get to a nice strong tailwind or to get above weather that you just don't want to go through. The fuel flow in climb is a bigee. Typical total fuel flow in climb for me is ~58gph (ROP) and in cruise ~31gph (LOP). Both for operating costs and range the time in climb makes a big difference. The bottom line is that all other things being equal (weather & winds aloft especially) I'll cruise in the mid teens for shorter flights up to a couple of hours and in the low 20's for longer flights up to my 4 hour limit. Anywhere in this range is good because few planes are flying there (too high for NA pistons and too low for jets and TPs) and it keeps my cabin altitude at a safe and comfortable 7 or 8,000' .