GENEVA—Gulfstream hopes to receive FAA validation of the software change for G500 and G600 aircraft so it can start updating the fleet in the third quarter, says Mark Burns, president of the OEM. The software changes should limit the effects of large pitch inputs by pilots at low altitude, which can cause a hard landing.

Gulfstream had planned to receive FAA certification for the G700 this year, but in a recent earnings call parent company General Dynamics Chairman Phebe Novakovic said the program could slip 3-6 months based on this certification change.

The company has completed all of the testing it normally would have done before implementing the software, but it now is going through FAA’s model-based design methodology, which is a new FAA process to evaluate complex aircraft software. 

“It is a line-by-line code evaluation to determine that the requirements are as intended and there are no unintended consequences,” said Burns, speaking May 22 at EBACE in Geneva. “I will tell you that that we agree that it will make a safer and more robust airplane, but I will also tell you that it is a very labor intense effort to do that validation,” he added.

“We’ve flown many thousands of hours on the airplane and we’ve flown many thousands of simulated hours in our laboratory, and we’re highly confident that the software that we’ve developed resolves the issue of significant input by the pilot in command,” Burns said.

Gulfstream hopes to wrap up the validation and testing so it can start implementing it into the fleet in the third quarter. The software update will take about a day for each aircraft.

Gulfstream has 25 teams trained to upgrade the fleet once it receives FAA approval, so the whole fleet should be updated in less than 30 days, he says.

“I feel very confident based on our total transparency with the FAA and the maturity of the software that we’ve been flying, that this should go according to plan,” Burns said.

Gulfstream started going through a similar model-base design for its new 7,500-nm G700, which it planned to enter into service later this year.

The G700 software is based on something similar developed for the G500 and G600.

Gulfstream agreed to do this for the G700 program in 2020, but in 2021, “the rules were solidified and it was more than we anticipated,” Burns said. 

Previously the supplier that made the boxes where the software resides would perform the coding evaluation, but now that duty falls to the OEM. “We’re now responsible to go through all of those integration points and to ensure that everything has a reason for being in the code and that there’s nothing that doesn’t have a precise need,” he said.

Similar to the G500 and G600 process, Gulfstream does not anticipate finding any problems with the G700 software.

G700s have flown nearly 3,000 hours in the test program and are performing reliably, Burns added.