Gulfstream Aerospace released a maintenance and operations letter on April 29, notifying Gulfstream G500 operators that it is working on a long-term software fix for its fly-by-wire flight controls after a hard landing event by a jet in gusty winds.
“The aircraft flight control system entered Angle of Attack (AOA) limiting mode at approximately 12 feet Above Ground Level (AGL) following a series of large, rapidly alternating pitch stick inputs,” the letter said.
AOA limiting mode is a flight control mode that has the ability to limit the aircraft’s response to pilot input and command nose-down elevator input.
Gulfstream highlighted the available Airplane Flight Manual (AFM) with respect to inputs and approach speeds when landing in gusty conditions. The manufacturer also noted in the letter it has released Revision 2 for the GVII-G500 Issue 1 AFM to give updated operational procedures, limitations, and warning notes.
New limitations released in the AFM include maximum wind speeds for landing (including gusts) of 15 knots; maximum wind gust for landing of 5 knots; all approaches stabilized by 1,000 feet, including visual maneuvers; vertical guidance from ILS or FMS-based approaches required for night landings; approach speed additives (Flaps 39) are half the steady state wind plus the gust increment up to a maximum additive of 20 knots; minimum approach speeds during all approaches of Vref+10 knots; use of autothrottle for approach and landing is required during normal operations.
The FAA is expected to issue an Alternate Method of Compliance (AMOC) approval that will allow the new AFM revision to comply with the existing Airworthiness Directive (AD 2020-05-12). The AD from 2020 was issued by the FAA in response to an incident that involved the activation of a Gulfstream G500’s AOA limiter mode during a landing flare in unstable air.
“The new/revised limitations are intended to provide an interim mitigation solution until Gulfstream can implement a flight control system software update to modify the AOA Limiter performance and remove these new limitations,” noted the letter.
Gulfstream is expecting this update to be completed later this year.
The move comes just days after Gulfstream said that the certification of its upcoming Gulfstream G700 jet could be moved back by three to six months as the FAA adds new requirements to the process. This includes a line-by-line examination of the aircraft software.
While no fingers have been publicly pointed towards the reason for the requirements, it is evident that the FAA is being more rigorous in its vetting process in the wake of the two Boeing 737 MAX crashes.
RELATED: Gulfstream G700 certification delayed as FAA adds requirements
Recent Comments