The Gulfstream G550 has two primary hydraulic systems: the bulk of the airplane, including flight controls, is operated by the left system and critical flight control systems are backed up by the right system. Because so much is on the left system, there are multiple back ups. The wheel brakes are normally powered by the left system. If the left system pumps go bad, the right system can provide pressure using left system quantity. If left system quantity is depleted, an auxiliary system can power the brakes, depending on where the left system leak is. If all left system quantity is gone, a brake accumulator can provide emergency braking.
Figure: G550 Hydraulic System Schematic, from G550 Quick Reference Handbook, pg. EE-2.
[NTSB Factual Report, pg. 1]
Figure: N535GA Route of Flight, from flightware.com
[Voice Recorder Transcript, p.12-52
13:12:17.8 HOT-2 — should we go around to check it out?
13:12:19.5 HOT-1 — no . . . we're gonna land cause it's leakin'
13:12:20.8 HOT-2 — we're gonna need thirty eight
13:12:23.7 HOT-1 — just tell me our brake situation
[Gulfstream Submission, ¶1.2
Photo: G550 N535GA Landing incident runway (Gulfstream submission), from NTSB Accident Docket
[Gulfstream Submission, ¶2.3
[PF's Statement to the NTSB] "Throughout my 20 year military carrier I was always taught that if you had a problem inside the final approach fix and your gear was down it was always better to land. We lost several aircraft because pilots delayed their landings. At Flight Safety in the GV and GIV training that I receive every 6 months I have never been given a scenario with a system malfunction were I would go around inside the final approach fix."
[NTSB Factual Report, pg. 1j] The National Transportation Safety Board determines that the probable cause of this accident was the captain's decision to attempt a go-around late in the landing roll with insufficient runway remaining. Contributing to the accident were (1) the pilots' poor crew coordination and lack of cockpit discipline; (2) fatigue, which likely impaired both pilots' performance; and (3) the failure of the Federal Aviation Administration (FAA) to require crew resource management (CRM) training and standard operating procedures (SOPs) for 14 CFR Part 135 operators.
. . . and other Case Studies
Gulfstream G550 Quick Reference Handbook, GAC-AC-G550-OPS-0003, Revision 27, 24 July 2008
Gulfstream G550 Outfitting Check Flight Accident Gulfstream Party Submission, CEN11FA193, March 25th, 2013
NTSB Factual Report Aviation, CEN11FA193, N535GA, 02/14/2011, Appleton, WI.
NTSB Statement from the PF, CEN11FA193, N535GA, 02/14/2011, Appleton, WI.
NTSB Voice Recorder Transcript, CEN11FA193, N535GA, 02/14/2011, Appleton, WI.
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