What has the ability to leap over tall trees on takeoff, land in mountainous terrain, and practically stop on a dime— all the while carrying 19 passengers?
“Superman” would be a pretty good guess but an aircraft with a supercritical wing (or airfoil) would be even better since these “short takeoff and landing” (STOL) flying machines aren’t affected by kryptonite (at least as far as we know). You can get the aeronautical scoop on supercritical airfoil design here but for now we’ll just say it’s designed to delay the onset of wave drag in the transonic speed range.
A great example of a popular STOL is the Dornier Do 228, a twin-engine turboprop utility aircraft that was manufactured by Dornier GmbH from 1981 until 1998, and is still performing its super duties in airports from Nepal to Aspen, Colorado. Demand is such that Honeywell channel partner, RUAG, placed the aircraft back in production in 2009.
The Do 228 is typically promoted for its versatility, low operational costs and an incredibly high level of reliability—possessing a dispatch reliability of 99% thanks to its Honeywell TPE331 engines.
Designed from scratch for the military in 1959 by one of our legacy companies, Garrett AiResearch, the TPE331 was the first Honeywell turboprop engine. The series now includes 18 engine models and 106 configurations. Today, with nearly 14,000 engines delivered to date and upwards of 130 million hours of flight time and counting, the TPE331 is one of the most reliable and proven turboprop engines in the world. In fact, year after year it has been called “the most reliable and best supported” according to user surveys conducted by magazine, Aviation International News.
For takeoff, large power-to-weight ratios and low drag help the plane to accelerate for flight. The landing run is minimized by strong brakes, low landing speed, thrust reversers or spoilers. Of course it’s important to clear pesky obstacles, such as trees, on both takeoff and landing.
Many small, isolated communities, especially in mountainous regions such as the Lukla Tenzing-Hillary Airport in Nepal—considered one of most extreme and dangerous airports in the world—rely on STOL aircraft. Check out how the pilot nailed this landing.
These aircraft may be their only transportation link to the outside world for passengers or cargo including many communities in the Canadian north and Alaska.
Honeywell engineers continue to collaborate with aircraft manufacturers from across the aerospace industry to ensure that the TPE331 will meet the needs of the aviation community for the next 50 years.
As an example, we recently added the capability to upgrade older TPE331s to the TPE331-10 configuration to expand engine power while saving customers money on fuel and operations.
Saying these aircraft can “stop on a dime” might be overzealous, but getting passengers and cargo in and out of tight spots is still a super job.