31st of March 1975, ATA 32, Blog #740
- V2Aviation
- Mar 31
- 2 min read
Landing Gear — ATA Chapter 32
Wheels, brakes, shock absorbers, lock braces, and side stays are all familiar terms within the aviation industry. But have you ever heard of ACLS?
ACLS stands for Air-Cushion Landing System—an innovative concept that replaces conventional landing gear with a cushion of air.
The Air Cushion Landing System (ACLS) was invented by T. Desmond Earl and
Wilfred J. Eggington at Bell Aerospace in Buffalo, New York. Development began on December 1, 1963, as a company-funded project that later gained support from the Flight Dynamics Laboratory. The system’s first successful demonstration took place in 1967 at Niagara Falls International Airport using a Lake LA-4 Buccaneer. During these tests, the aircraft proved it could take off and land on almost any surface, including water, ice, snow, grass, and standard runways.
On the 31st of March, 1975, a Royal Canadian Air Force de Havilland CC-115 (DHC-5 Buffalo), manufacturer’s serial number (MSN) 5, heavily modified and redesignated as the XC-8A ACLS, made its first flight equipped with this unique system. MSN 5 holds a special place in aviation history as the sole Buffalo modified to test the Air-Cushion Landing System, and it was on loan to the USAF Flight Dynamics Laboratory for this purpose.
Rather than traditional landing gear, the aircraft featured a hovercraft-like skirt beneath the fuselage. This skirt could be inflated using a PT6F-70 engine-powered, two-stage axial flow fan mounted under each wing. To enhance ground stability, a skid/float assembly was installed beneath each wing.
On April 11, 1975, MSN 5 successfully completed its first landing using the ACLS. Flight testing was conducted by the 4950th Test Wing of the Aeronautical Systems Division at Wright-Patterson Air Force Base.
Following the conclusion of the test program, MSN 5 was returned to the Canadian Air Force on April 30, 1979. It was subsequently converted back to a standard CC-115 (DHC-5A Buffalo) configuration and continues to serve in search and rescue (SAR) operations with 442 Squadron in British Columbia, preserving its legacy as a unique pioneer in experimental landing systems.
** Editorial note **
This blog is based on several internet sources. Should there be an inconsistency in the blog, don't hesitate to get in touch with us. There are two possibilities to do that: via the comments function at the bottom of this page or via the contact page of the website.
Comments