Dash 7

Dash 7. The de Havilland Canada DHC-7, popularly known as the Dash 7, is a Canadian four-engine STOL (Short Takeoff and Landing) turboprop airliner designed and manufactured by de Havilland Canada. It was developed specifically to serve regional routes with minimal ground infrastructure, capable of operating from short, rough airstrips. The aircraft entered service in the late 1970s and was noted for its quiet operation and excellent STOL performance, though it was ultimately outsold by more conventional twin-engine rivals.

Development and design

The Dash 7 program was launched by de Havilland Canada in 1972, aiming to create a quiet, STOL airliner that could operate from downtown airports like Toronto City Airport and Vancouver Harbour Flight Centre. The design leveraged the company's extensive experience with STOL aircraft like the DHC-6 Twin Otter. Key features included four Pratt & Whitney Canada PT6A-50 turboprop engines driving large-diameter propellers, a sophisticated double-slotted flap system, and a T-tail configuration. The airframe was designed for low noise levels to meet stringent community noise regulations in cities such as London City Airport. The prototype, funded in part by the Government of Canada, first flew on 27 March 1975 from the company's Downsview facility in Toronto.

Operational history

The Dash 7 entered commercial service on 3 February 1978 with Rocky Mountain Airways, serving routes in the Colorado Rockies. It found niche success with operators requiring true STOL capability, including Air Ontario, Widerøe in Norway, and Tyrolean Airways in the Alps. The aircraft was also adopted for military and special missions; the United States Army operated it as the RC-7 for reconnaissance, and Transport Canada used it for aerial surveillance. Despite its technical achievements, high fuel consumption relative to twin-engine competitors like the Dash 8 limited its sales. Major airlines such as Pan Am and Eastern Air Lines briefly operated it on shuttle services, but most were phased out of passenger service by the 1990s.

Variants

* DHC-7-1: Initial production passenger variant. * DHC-7-101: Improved version with increased maximum takeoff weight. * DHC-7-102: Similar to -101 but with different avionics options. * DHC-7-103: A combi variant with a large cargo door. * 'DHC-7-150**: A "hot and high" performance variant. * DHC-7R (Ranger): A maritime patrol variant proposed for the Canadian Forces. * C-7A Caribou: This designation is incorrect and belongs to the unrelated DHC-4 Caribou.

Operators

Primary civil operators have included Rocky Mountain Airways, Air Ontario, Widerøe, Tyrolean Airways, and Pelita Air Service. The largest current operator is Voyageur Airways, which uses the type for charter and cargo operations. Military and government operators included the United States Army, the Royal Canadian Mounted Police, Transport Canada, and the Swedish Coast Guard. A number of aircraft are also operated by United Nations agencies and humanitarian organizations like the World Food Programme in remote regions such as Antarctica and Papua New Guinea.

Specifications (DHC-7)

Accidents and incidents

The Dash 7 has been involved in several notable accidents. On 10 February 1984, a Widerøe Flight 710 crashed near Bergen Airport, Flesland in poor weather, resulting in fatalities. On 17 December 1997, an Air Ontario aircraft overran the runway at Dryden Regional Airport in Ontario. A Royal Canadian Mounted Police Dash 7 was damaged beyond repair in a landing accident at Alert, Nunavut in 1991. The hull-loss accident with the highest fatalities occurred on 2 October 1990, when a Xiamen Airlines flight was hijacked and crashed at Guangzhou Baiyun International Airport, colliding with other aircraft.