Bell Model 427

Light Twin-Engine Multirole Utility Helicopter

Aviation / Aerospace

The Bell Model 427 failed to net market interest so the line was eventually discontinued in favor of the more promising Model 429 instead.

Authored By: Staff Writer | Last Edited: 11/18/2017 | Content ©www.MilitaryFactory.com

The Bell Model 427 was a failed attempt by Bell Helicopters to produce a new twin-engine light platform for the civilian market (competing with the Agusta AW109, Airbus Helicopters EC145 and HAL Dhruv) based on its successful single-engined Bell Model 206/407. The Model 427 was differentiated by a twin-engine arrangement but carried the same four-bladed main rotor / two-bladed tail rotor configuration. First-flying on December 11th, 1997 and introduced in 2000, the series saw production span from 1997 and 2010 before the company nixed the model from its lineup in favor of the Model 429 offering instead (detailed elsewhere on this site). Only Argentina and the Czech Republic became operators of the short-lived Model 427.

The Model 427 was essentially another Bell attempt to generate market interest in a twin-engined form of its successful Model 206/407 lines. Work began, in conjunction with Samsung Aerospace Industries of South Korea, in the mid-1990s and its development was largely tied to Computer Aided Design (CAD) to keep costs in check. A prototype went airborne for the first time on December 11th, 1997 and certification followed in 1999-2000.

Much like the Model 206/407, the Model 427's design seated its crew in a side-by-side arrangement at the front with large transparent panels offering excellent vision out-of-the-cockpit. Entry-exit was by automobile-style hinged doors along the fuselage sides with larger doors featured at the passenger cabin area. Up to seven passengers could be carried. The cockpit showcased modern elements including two large interactive screens coupled with steam-type gauges.

Outwardly, the helicopter was given fine contouring where even its engine installations were well-embedded into the design to promote a sleek offering. The tail stem was elevated and held outboard horizontal/vertical planes and the main vertical stabilizer was featured at the extreme aft end of the aircraft. The stem also housed the drive shaft powering the two-bladed tail rotor (seated to portside). Over the passenger cabin were the two engines driving the four-bladed main rotor arrangement. The hub was of composite construction and the main rotor blades rigid.

The engines were given full FADEC (Full-Authority Digital Engine Control) capability and encompassed 2 x Pratt & Whitney Canada PW207D turboshaft types rated at 710 horsepower apiece. Performance specs included a maximum speed of 160 miles per hour, a cruising speed of 160 mph, a range out to 395 miles and a service ceiling of 10,000 feet. Rate-of-climb reached 2,000 feet-per-minute.

Dimensions included a length of 37.5 feet, a width (including the main rotor) of 37 feet and a height of 10.5 feet. Empty weight became 3,880lb against an MTOW of 6,550lb.

In 2004 the Model 427i was proposed which involved both South Korea and Japan industries. However, this product was given up in favor of the more promising Model 429. In 2008, the Model 427 line was officially axed by Bell Helicopters after only two foreign customers were secured (Argentine police and a private Czech operator).

The new Iranian PANHA Saba-248 helicopter is believed to be based on the short-lived Bell Model 427. This helicopter is detailed in its own entry elsewhere on this site.