Lufthansa has expressed interest in a newly-launched higher-capacity version of the Bombardier CS300 that drove a miniature redesign of the larger of the two CSeries variants and contributed to the six-month delay for first flight.

Lufthansa's Swiss subsidiary, which expects to receive its first CS100 in early 2015, is also considering the extra capacity version of the CS300, Nico Buchholz, executive vice president of fleet management for the Lufthansa Group, says on the sidelines of Bombardier's formal unveiling of the first flight-test aircraft.

Bombardier confirmed on 7 March that Air Baltic will be the launch customer for the extra capacity CS300 by converting its order to a 148-seat configuration of the aircraft, which can now accommodate up to 160 seats.

Buchholz notes that Swiss is already taking the maximum capacity, 125-seat layout of the baseline 110-seat CS100, so moving up to a 148-seat configuration of the CS300 is not a giant leap for the carrier.

The extra-capacity version of the aircraft was first disclosed at the Farnborough air show last July by AirAsia chief executive Tony Fernandes, who ultimately selected the A320neo several months later.

By launching the high-density design, Bombardier agreed to make several changes beyond the addition of two extra over-wing exit doors which it had previously declared.

Bombardier added 0.6m (1.97ft) to the length of the CS300, which was previously limited to a maximum of 145 seats, says CSeries programme director Rob Dewar.

The additional length and seating capacity caused Bombardier to also increase the maximum take-off weight by 2.4% to 65,300kg (144,000lb).

Those changes caused some spill-over design tweaks to the CS100 and contributed to Bombardier's decision to delay first flight until late June. Issues with certain suppliers also drove the slippage.

The airframer formally unveiled the first CSeries CS100 flight test aircraft on 7 March, more than three months ahead of first flight.

Bombardier is sticking by its plan to complete first flight by the end of June. The unveiling revealed that the CSeries is structurally almost complete, with the last major element - a wing-to-body join fairing - expected to be installed in the coming days.

Source: Air Transport Intelligence news