411A:
Briefing had nothing to do with this accident...incorrect programming of the FMS, and a hurried rapid descent most certainly did.
If they had briefed the arrival/approach they would have realized that they already had the IAF for the VOR approach to RWY 19 - TULUA VOR programmed into the FMS and were flying direct to it at the time they accepted the offer of a straight in approach. Because they hadn't briefed
any arrival/approach they were not situationally aware enough to realize this and confused the approach clearance they were given, leading the captain to select direct CALI VOR in the FMS, which action erased the TULUA waypoint. He then compounded the error by activating the wrong waypoint in the FMS thinking he was inserting ROZO, the FAF for the cleared approach. The aircraft responded by turning off the approach track toward the mountain peaks and the rest is history.
How long does it take to switch to HDG mode or disconnect the autopilot and take over manually and stop an inappropriate turn?