The Grob SPn Utility Jet’s flight-test program has been progressing well since the twinjet made its first flight last July 20, according to a company spokesman. As of early last month, German-based Grob had already verified the twinjet’s flight characteristics throughout the full c.g. envelope.
Grob test pilots have also performed initial takeoff performance tests. Gérard Guillaumaud, Grob SPn chief test pilot, told AIN, “These initial takeoff tests have demonstrated better performance figures than expected.” Last fall, Grob estimated that the SPn, powered by a pair of Williams FJ44-3As, would have a 3,000-foot balanced field length, though Guillaumaud didn’t specify how much better the actual numbers are.
Between flights, the prototype has been upgraded to fly in IMC and has been equipped with the special test equipment required to perform the low-speed portion of the test program.
Meanwhile, a second, production-conforming SPn is being manufactured, with first flight scheduled for this quarter. According to Grob, the second aircraft will be dedicated to systems testing, while the first prototype will be used for aircraft performance.
Certification of the $7.1 million twinjet is still expected in the first quarter of next year, with deliveries planned to start in the following quarter.