The projected certification date for Bell’s new 429 light twin has slipped from the first quarter to May. Originally slated for FAA certification in late 2007, the 429 has been dogged by repeated delays as the company juggles military and civil programs, including the $70 million-per-copy V-22 tiltrotor, which is now poised to become the single biggest piece of Bell’s business. The Fort Worth, Texas helicopter maker blamed the latest Model 429 delay on software certification, but said it has completed certification work on all of the helicopter’s hardware and mechanical systems. Bell said it holds “letters of intent and orders” for 330 Model 429s. Twenty-five 429s are currently in production at the manufacturer’s plant in Mirabel, Quebec. Performance numbers for the 429 have improved from numbers released last year, including a new top speed of 150 knots, up from 147 knots, and a maximum range increase to 368 nm from 350 nm.