It’s a myth – “Turbos are only for the mountains.” It’s typically heard from pilots that fly normally aspirated engines because they’re focused on single-digit cruise altitudes; or from pilots experienced with old turbocharged designs which ran hot, added workload and were expensive to maintain.
When I began looking at pre-owned planes my focus was on normally aspirated models because pilots were not talking about the benefits of turbocharged Cirrus aircraft.
I’m based in Houston Texas, the flat lands – not the mountains.
Myth: “TURBOS ARE ONLY FOR THE MOUNTAINS”
But you don’t have to start at a mountain altitude to experience the difference. Even at sea level, you’ll notice faster acceleration the moment brakes are released for take-off. The turbocharged Cirrus will deliver better performance than normally aspirated engines from sea level all the way up to cruise altitude – even if you’re going to 25,000 feet.
This past year, departing as a flight of two, a Cirrus Turbo SR22TN and a SR22 NA normally aspirated, traveled together between Austin and Houston Texas (104 nautical miles, less than an hour flight time). Both planes carried three adults.
With a full load, the Cirrus Turbo made a quick VFR climb on top to 8,500 where the plane was clear of clouds, in smooth blue sky, and picked up a slight tailwind. VFR climbs on top are easier in the Turbo because the climb rate can remain consistent with a powerful angle of attack. We watched our traffic advisory system (TAS) which displayed our sister Cirrus dropping behind.
Being slower in the climb, they decided to stayed below where they dodged clouds and rode the bumps of summer thermals. It was a short trip, and with a normally aspirated engine, it was just not worth the slower climb to get up to our altitude.
We began our decent early, picked up speed, and were out of the plane and on the ramp before they taxied up. Even on short trips, from sea level, the turbocharged Cirrus performance out paces its normally aspirated Cirrus brethren.
Yes, density altitude was a factor that day. Mid-summer Texas temperatures can be hot. That’s when you’ll hear more pilots talk about climb performance and weight because their normally aspirated engines can barely get 500 feet per minute.
With piston engines, time-in-climb affects a pilot’s choice of altitude. Normally aspirated planes breed lower cruise altitudes chosen to suit the engine, and not so much weather considerations or comfort.
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