Gulfstream G650 captain reported that the FMS caused a crossing restriction not to be met; requiring...

Narrative:

The airplane FMS decided to leave 13;000 feet while in VNAV mode before reaching the crossing restriction point zzzzz at 13;000 [feet]. The next crossing restriction would be ZZZZZ1 at 11;000 feet and 250 knots. The airplane would have attempted to violate that restriction as well if we had not intervened; by disengaging the autopilot and manually flying the arrival at the proper altitudes. So technically; we flew below one crossing restriction by a couple of hundred feet; but made the rest [by] hand flying the aircraft.this flight leg originated at ZZZ; and was on a quick turn from ZZZ1 and then back to ZZZ1. So the airplane was never completely shut down after arriving in ZZZ. There are over 3;000 software fixes for the FMS in the works from honeywell; but the release date keeps getting pushed back. In addition there are flight control issues that recently resulted in changes to the aircraft flight manual. 15 emergency procedures involving flight controls were revised to state that the airplane should be landed as soon as possible if a flight control message was displayed on the EICAS. For the gulfstream; that means at the nearest airport that has an approach if one is required; and a runway that the aircraft can be stopped on.there was also an issue recently with the rudder that has restricted the entire G650 fleet to 250 KIAS until the rudder is modified with a trailing edge strip.clearly; gulfstream does not have a handle on their new fly-by-wire technology; their revised FMS software; and the aerodynamics of their flagship high speed long range aircraft.many of the changes gulfstream implemented were driven by the FAA demanding that gulfstream could not continue to build on their old type certificate designs; but to start with a clean sheet designs. If we had shut the airplane down on the ground; to a black aircraft; then restarted; the FMS issues probably [would] not have happened. We will do that on every leg from now on.

Original NASA ASRS Text

Title: Gulfstream G650 Captain reported that the FMS caused a crossing restriction not to be met; requiring the autopilot to be disengaged and the remainder of the arrival was flown manually.

Narrative: The airplane FMS decided to leave 13;000 feet while in VNAV mode before reaching the crossing restriction point ZZZZZ at 13;000 [feet]. The next crossing restriction would be ZZZZZ1 at 11;000 feet and 250 Knots. The airplane would have attempted to violate that restriction as well if we had not intervened; by disengaging the autopilot and manually flying the arrival at the proper altitudes. So technically; we flew below one crossing restriction by a couple of hundred feet; but made the rest [by] hand flying the aircraft.This flight leg originated at ZZZ; and was on a quick turn from ZZZ1 and then back to ZZZ1. So the airplane was never completely shut down after arriving in ZZZ. There are over 3;000 software fixes for the FMS in the works from Honeywell; but the release date keeps getting pushed back. In addition there are flight control issues that recently resulted in changes to the Aircraft Flight Manual. 15 emergency procedures involving flight controls were revised to state that the airplane should be landed as soon as possible if a flight control message was displayed on the EICAS. For the Gulfstream; that means at the nearest airport that has an approach if one is required; and a runway that the aircraft can be stopped on.There was also an issue recently with the rudder that has restricted the entire G650 fleet to 250 KIAS until the rudder is modified with a trailing edge strip.Clearly; Gulfstream does not have a handle on their new fly-by-wire technology; their revised FMS software; and the aerodynamics of their Flagship high speed long range aircraft.Many of the changes Gulfstream implemented were driven by the FAA demanding that Gulfstream could not continue to build on their old Type Certificate designs; but to start with a clean sheet designs. If we had shut the airplane down on the ground; to a black aircraft; then restarted; the FMS issues probably [would] not have happened. We will do that on every leg from now on.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1718861
Time
Date	202001
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Make Model Name	Gulfstream G650
Operating Under FAR Part	Part 91
Flight Phase	Descent
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Flight Instructor Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 200 Flight Crew Total 30000 Flight Crew Type 1000
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Altitude Overshoot Deviation - Altitude Crossing Restriction Not Met Deviation - Procedural Published Material / Policy Deviation - Procedural Clearance

Gulfstream G650 captain reported that the FMS caused a crossing restriction not to be met; requiring the autopilot to be disengaged and the remainder of the arrival was flown manually.