I am in the process of purchasing a G6 cirrus and will be flying mostly from an air strip based at sea level. Does anyone have information on which of these 2 options will climb faster to 7,000 feet. (same fuel quantity, same passengers, same everything) I read an article that stated that the non turbo would climb faster to 7,000 feet, then the turbo would take over. this article was posted on 2007, I would imagine things are different with the G6. Anyone with experience in this matter?
Per the POH Sea Level @ Gross Weight to 7k feet
- SR-22T = 3.7 Gallons, 6.2 minutes and 13.2 miles
- SR-22 = 2.5 Gallons, 6.9 minutes and 12.9 miles
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My question is, why would you ever stop the climb at 7,000 feet in a turbo?
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Thx for doing, interesting to see written this way.
Worth noting “both at gross” I think means you are carrying 100+ pounds more stuff in the NA.
The carbon prop I bet diminishes the NA perf a bit. But too sweet looking to not check that box.
You are most likely correct @chris.gio884 based on the overage useful loads. Sadly the only real performance chart that we have with these calculations in the POH is at gross, it would be interesting to see these same numbers at less than gross.
I tried finding numbers for metal vs carbon prop on the NA but couldn’t
One thing to consider, and that may surprise you at sea level, is that the 22T’s total take off distance is about 40% greater than the 22NA.
I don’t think that’s true for the TN
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I will clarify that it’s the ground roll that is 40% greater, the total take off distance is only 12% longer. I am not sure how 5hp makes up the difference but that’s what it says.
I fly both from a 2500ft runway and you can really see the difference so my perspective is one of practical experience and feel.
The POH take off and landing numbers are from a pro pilot using short field procedures not practiced regularly by most.
The Hartzel composite prop vs metal climb performance can be derived by comparing the carbon prop supplement to the performance data in the POH. At 3600 lbs, climbing in an NA at best climb, the metal prop seems to climb about 50 fpm faster. There’s not much difference apparently.
In the case of T vs NA, here is a side-by-side of enroute climb rates. Note that, for cooling, the T is at 120 IAS in a full power climb. The NA performance numbers are for a Vy climb. But, you would more typically climb the NA 5-10 kts faster for engine cooling. So, you won’t necessarily get these book numbers at a lower AoA as you lose available thrust in the climb relative to a T engine.
You can adjust the NA numbers for lower weight by interpolation. There’s also a graphical depiction in the NA POH that uses density altitude.
Yup. This is why I see much higher climb rates in my T than I did in my NA. A solid 1200 in the T vs 800 in the NA down low that drops to 400-500 as you climb.
As far as anecdote re the difference in rwy perf between the two, I agree w Ed in that they’re both super quick off the rwy. I can’t perceive a difference.
Is the rotation speed the same in these aircraft? I guess it is different between the G3 and G6?
Here is a climb rate table from the G6 SR22 NA POH, annotated with ISA climb rates taken from the G6 SR22 T POH. Dotted line shows the cross-over altitude at various gross weights. At this cross-over altitude, a T climbing at full power 120 KIAS climb would start to out-pace the NA in a Vy climb. This point is approximately 1500ft DA at max gross, and a little under 4000ft DA at 2900#.
One caveat. I don’t see a reference note stating whether this data is for a clean wing. We know that FIKI aircraft give up 4-5 kts in cruise speed, which suggests there’s added drag from the panels that has to be overcome. That means less net thrust available for climb. A FIKI SR22T climbing at 120 KIAS would be expected to suffer from slightly more total drag than a FIKI NA climbing at Vy.
For even more fun, consider where the NA vs T climb performance gets interesting in my opinion. Take a look at the FIKI climb performance tables with ice adhering to the aircraft. These data reflect increased drag due to ice. And, where the numbers get extremely interesting is the altitude where performance degrades to the point that climb rate turns negative. At 0C OAT and max gross, the NA can’t climb above 10,000 ft, while the T would still be making almost 700 fpm (and its climb rate only turns negative way up into the flight levels).
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Great Chart, So a NA at max gross only has a climb advantage for about 1 min departing from sea level on a standard day and No advantage at 1500 DA or above. The pumping losses of the Turbo seem to be trivial…
The above data all compares T climb performance in a full power climb at 120 KIAS with the MAP boosted to 36"+ and fuel flow to match. It may be thermodynamically less efficient in a theoretical sense. But, the T engine still puts out 315 rated HP when operated at full power. The NA starts at 310 (rated) and drops from there.
I used to do LOP climbs in my TN fairly often when I had long legs, which would save about 5 gallons of fuel. In the summer months I’d have to revert to ROP in the low 'teens to keep CHT’s under 380. Can you do LOP climbs in the T, and is there a similar advantage?
You have to calculate it from the LOP climb data in the SR22 T POH.
Here is the chart annotated to include LOP climb data for the T at ISA. This is at max gross wt.
Going only by book numbers…
For the T, climb to 18,000 ft PA at full throttle would take 16.8 minutes, 10.1 gal, and 39.2 NM. For a LOP climb, the numbers are: 21.6 minutes, 6.6 gallons, and 50.3 NM. This presumes you can hold 120 KIAS.
In the TN, the supplement says to use 130 KIAS for LOP climb. At 3400 lbs, the TN still took 30.7 minutes, 8.8 gal, and 77.9 NM to reach 18,000 ft PA. For a full rich climb you’d have used 120 KIAS to 7,000 ft, then transitioned to 130. [And FWIW, at 3400 lbs, the TN (full rich climb) took 20.4 min., 12.1 gal, and 50.8 NM to reach 18,000 ft].
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I flew both planes last week to make the comparison as evenly as possible. Same pilot, same crew and same airstrip. Also tried to takeoff with the same amount of fuel on both planes.
The airstrip was at sea level, and the takeoff distance was measured precisely.
The pilot used the same KIAS on both planes to make the comparison as equal as possible.
Both planes had composite props and oxygen. Only the sr 22T with FIKI.
I was gathering the information every thousand feet from 0 to 12,000. the wind direction and speed varied a bit from day to day but the rest was the same.
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Is that typical to see 94% power on the T? I would have assumed higher 90s?
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