PW123

Overview

The Pratt & Whitney Canada PW123 is a turboprop engine from the PW100 family, delivering 2,150 shaft horsepower (SHP) and designed specifically for the regional commuter airliner market. It is the primary powerplant for the de Havilland Canada Dash 8 Series 300 (DHC-8-300), a stretched 50-seat regional turboprop operated by commuter carriers worldwide. The PW123 entered service in 1989 and represents the mid-range member of the PW100 turboprop family that Pratt & Whitney Canada has developed into a comprehensive line spanning from approximately 1,800 to 5,000 SHP.

The PW100 family architecture — adopted across all variants including the PW123 — uses a two-shaft free turbine arrangement with a centrifugal high-pressure compressor. This configuration, combined with a compact flat design oriented horizontally in the Dash 8's wing nacelles, gives the engine excellent power-to-weight characteristics and relatively simple maintenance access compared to axial-flow turboprops of similar output.

Technical Specifications

Variants

Within the PW100 family the PW123 sits between the lower-powered PW120 (1,800 SHP, powering the DHC-8-100) and the more powerful PW127 series. The PW123B is a detail-improved version with enhanced hot-and-high performance. The PW123AF is a firefighting/special-mission variant with modified ratings for the demanding continuous high-power operations associated with tanker aircraft. The PW123D incorporates electronic engine control updates for improved dispatch reliability and reduced pilot workload.

Aircraft Applications

The PW123 is the exclusive powerplant for the de Havilland Canada DHC-8-300 (Dash 8 Series 300), a 50-seat stretched derivative of the original DHC-8-100. The Dash 8-300's combination of short-field performance, fuel efficiency relative to jets at stage lengths below 500 km, and modest airport infrastructure requirements made it popular with regional airlines serving thinner routes, particularly in Canada, Scandinavia, Australia, and island networks in Southeast Asia. The aircraft has also served extensively in government and special mission roles, and several examples have been converted to surveillance and maritime patrol configurations.

Development History

The PW100 family was launched by Pratt & Whitney Canada in the late 1970s to address a gap in the turboprop market between the 500–700 SHP PT6A class and larger turboprops above 3,000 SHP. The PW120, the founding member of the family, first ran in 1981. The PW123 derivative targeting the higher-powered DHC-8-300 followed, with first run in 1983 and entry into service in 1989 when de Havilland Canada introduced the stretched Dash 8 Series 300. Pratt & Whitney Canada's decision to use centrifugal rather than axial compressor stages was deliberate: the centrifugal design offers higher pressure ratio per stage, fewer parts, and greater resistance to foreign object damage, which is significant for turboprops that operate closer to the ground and in unimproved airfields compared to pure jets.