Citation X (C750)
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown
Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; Flight Crew FLC Overrode Automation
Human Factors
I was pilot flying as SIC on the arrival. There were a series of published altitudes and speeds plus a NOTAM changing some of those speeds. Approach gave me a descent to 8;000 FT; which I understood to mean unrestricted except for the speeds and I was achieving this using Vertical Speed (VS) mode with the autopilot engaged. I was descending through about 9;500 FT and slowing from 250 to 220 KTS when the Captain began to argue that I should use VNAV instead of VS; despite the fact that I was meeting the speed and altitude restrictions another way. I suggested we could talk about technique and automation on the ground. Suddenly the speed began to increase above 250 KTS and I realized that the Captain had engaged the VNAV without my consent and the Flight Director was commanding a speed of 340 KTS. By the time I recognized this; gone back to VS and deployed speed brakes we had crossed the next fix and exceeded the speed limit of 220 by about 20 KTS. The plane was back on speed shortly after and the remainder of the approach was without incident. This Captain always wanted things done his way; and was particularly fond of using the Vertical Navigation - even when it was inappropriate. I think this situation could have been avoided if the Captain had either: a) left me to continue to meet all clearances and restrictions in the way I was doing; or b) taken the controls and met those same restrictions his way. I suggest that no one should interfere with the flight controls unless there is some breach of safety; not because of differences of technique and certainly not merely to achieve their own way.
CE-750 First Officer; pilot flying an arrival using VS to meet published altitude and speed restrictions; is confronted by the Captain regarding the use of VNAV instead of VS. Captain engaged the VNAV mode without informing the First Officer. First Officer re-engaged VS and landed without further incident.