By John Corft, Geneva
Gulfstream is expecting a grand entry later this year as its $65 million flagship G650 ultra long-range business jet, here at EBACE for the first time, enters service with more than 200 orders on the books.
What would be an otherwise triumphant programme conclusion however could be dimmed by an upcoming US National Transportation Safety Board final report on the 2 April 2011 crash of the second of five test aircraft.
Although the NTSB has not yet set a date for publishing the report, where a probable cause and contributing factors are expected to be revealed, documents released to the public in March lay bare a rocky relationship between Gulfstream and the board during the investigation and hint at issues in the test programme.
Of particular note was that the test pilots had experienced two previous wing drops in the accident aircraft 6002, before the wing-drop in Roswell, New Mexico that resulted in a runway excursion and fire. The crew - two pilots and two flight test engineers - did not survive the fire, according to the NTSB documents.
The crew of Flight 153 were performing the ninth flight of the day, a heavy take-off weight field test performance flight with 10˚ of flaps and the right engine at idle, a test used to determine lift-off and climb-out speeds that would later be used for US Federal Aviation Administration certification runs. The data is needed to develop procedures that pilots will follow after engine failure late in a take-off run.
Post-crash analyses of Flight 153 by the NTSB and Gulfstream reveal that the aircraft's right wing had stalled and "rolled-off" just after lift-off, in part as a result of stick-shaker targets that did not give pilots warning of an impending stall. The analysis revealed that the in-ground effect stall angle for the twinjet was significantly lower than Gulfstream had expected.
Along with the technical details, the final NTSB report is likely to discuss Gulfstream's behaviour during the investigation, which the Board has called "obstructive". Gulfstream, though not able to talk to the media as the investigation is not closed, has denied in a letter to the board that it hindered the investigation.
Gulfstream senior vice president of sales and marketing, Scott Neal, says all company flight testing is complete for the G650, with 80% of FAA testing finished. Aircraft number 20 is here at EBACE through Monday.