Bombardier has decided to incorporate several new features in the Learjet 85 as it works on finalising a design for the all-composite midsize jet ahead of 2013 entry into service.

Learjet 85 programme director Larry Thimmesch says a revised mock-up, which will debut at the NBAA annual convention in Orlando next month, will include a hand tiller for steering. The tiller will replace rudder pedals, which is used for steering all earlier Learjet models and was included in the original design and mock-up for the Learjet 85.

Thimmesch says Bombardier also had adjusted the location of several switches and sidewalls in the cockpit section of the mock-up, which was first unveiled at NBAA last year. All the changes have been made in response to the programme's cockpit user group, one of three user groups Bombardier has been liaising with in developing the new jet.

Learjet 85 vice-president Ralph Acs says about 10% of the cockpit has been changed and the result is a cleaner cockpit with an easier to use layout, reduced pilot workload, improved situational awareness and better ergonomics. Thimmesch says members of the cockpit user group, which is composed of Learjet customers, will have an opportunity to sit in the new cockpit at NBAA to make sure Bombardier "got it right and we interpreted their inputs right".

Learjet 85
 © Bombardier

Thimmesch adds the revised mock-up "will be 99% representative of the cockpit" in the actual aircraft. "There are a few switches that aren't in the right place and the nomenclature is a little bit different but they [customers] will know exactly what the cockpit will look like," he says.

He says Bombardier also has decided to offer synthetic vision as standard equipment with enhanced vision and two head-up displays as options as part of the Rockwell Collins Pro Line Fusion-based avionics suite. Bombardier in 2008 selected Pro Line Fusion for the Learjet 85 but until now was still evaluating whether to offer enhanced vision and head-up displays.

To meet a request from the cabin user group, Thimmesch says the manufacturer has decided over the last few months to go with a flush toilet for the Learjet 85. Earlier Learjet models have featured a cheaper chemical toilet.

The Learjet 85, which was launched in 2007 and is now going through the joint definition phase of the development programme, is the first new Learjet in more than a decade. Bombardier's manufacturing facility in the Mexican city of Queretaro, which will produce all the major sections of the aircraft with final assembly taking place in Wichita, is starting to work this month on composite coupons as it prepares to begin producing the first fuselage next March.

Acs say Bombardier has used Learjet customers to identify potential areas of improvement while retaining the basic performance specs of earlier models that operators appreciate, including 19mins time to climb. Acs says areas of performance improvement over older models include a 5,550km (3,000nm) range and a take-off distance of under 1,525m (5,000ft) for the Learjet 85 compared to a 4,070km range and 1,586m take-off distance for the Learjet 60.

But Thimmesch says Bombardier has decided to go with a 49,000ft ceiling instead of the 51,000ft ceiling in earlier Learjet models. He says "49,000ft gave [customers] a much better product and no one cruises at 51,000ft anyway".

Source: Flight International