Small jets can fly as high as big jets. They’re ‘pressurized’ inside so pilots and passengers have plenty of oxygen without wearing masks. Jet engines can perform will at higher altitudes and regularly fly at and way above 18,000 feet, where the ‘Jet Routes’ are.
A Cirrus Vision is the smallest of them, has a service ceiling of 30,000+ feet. A Bombardier Challenger is a small jet that can fly at 45,000 feet.
Our atmosphere has less and less pressure and oxygen the higher we go, either up a mountain or up in a plane. It affects people and piston-driven engines pretty much the same. Supplemental oxygen’ is required at 10,000 feet, and some passengers start to get drowsy before then, so ordinary piston-driven planes without turbochargers, large or small, don’t fly much above 10,000 feet and 7,000 or 8,000 is the ‘sweet spot’ for altitude in cruise for them, is where they get the best speed and fuel efficiency, and it’s cooler up there and more comfortable for passengers in an un-pressurized, un-air-conditioned small airplane.
Some small piston-drive airplanes, single or multi-engine, have turbochargers on the engines that compress the intake air and can deliver good power up past 10,000 feet, some of them past 20,000 feet, and they’re pressurized and comfortable up there. If they’re not pressurized, pilots and passengers need to wear oxygen masks. These are not usually flown much past 10,000 feet or so, but the turbocharger lets them produce more power at those altitudes and they can get another 20% or so of cruise speed and get places faster.
A Piper Mirage is a ‘small plane’ with a single, turbocharged piston engine, is pressurized and can fly up to 25,000 feet, up above most weather. This one has a small weather radar under the wing.
A Cessna 310, arguably the best-looking small airplane ever, is available ‘normally aspirated’ with fuel injectors or turbocharged. The fuel injectors get it to 10,000 feet comfortably, a turbocharged 310 climbs like a homesick angel up to 20,000+ feet.
A Cessna 172, maybe the world’s most popular ‘small plane’, is comfortable at 8,000 feet or so, can fly a bit higher but there’s seldom a good reason.
There are lots of trade-offs between pistons, turbines, and jets. Jets are the best for long routes at high altitudes and great big airplanes. Turbines are OK for shorter routes, smaller planes, and are simpler to operate. Pistons are less expensive to buy and will get a small plane there later than sooner, down in the weather, may be a bumpy ride. There are practically no big, piston-driven aircraft flying any more except antiques.
Author – G Saunders
Retired IT Instructor, Pilot, Drones at Virginia Commonwealth University
