Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 40; Flight Crew Total 10100; Flight Crew Type 500
Situational Awareness; Workload; Confusion
Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Flight Crew FLC Overrode Automation
Human Factors; Aircraft
On departure we were executing the LADYJ FOUR (RNAV) departure. Climbing through 10;000 our FMS began to accelerate beyond 250 knots around OROSZ Intersection as programmed in the FMS. The LADYJ departure indicates that 250 knots shall be maintained until advised by ATC. We briefed this and were aware of it; however; the way the information is presented is not on the pictorial of the chart and I believe it leaves a significant gap for error; because the flight crew must either assume that the Controller will issue normal speed; or the flight crew must constantly ask for normal speed with subsequent controllers. Also; all aircraft are programmed to accelerate to climb speed above 10;000 feet which requires a non-standard method of selecting manual speed versus having the MCDU command speed appropriate to the airspace and configuration of the aircraft. Selecting manual speed could result in a low speed event in the subsequent climb. Just passing OROSZ the Controller issued normal speed; and I believe this was a non-event. On further research this departure is mentioned as a poorly designed departure and I would hazard to guess there are numerous safety reports on it.
Air carrier First Officer reported the FMS began to accelerate beyond 250 knots above 10;000 feet while on the LADYJ FOUR (RNAV) even though the programmed SID requires 250 knots until advised by ATC.