Many FMS/GPS RNAV units offer an automated solution to  the problem of flying an approach in which the pilot receives  vectors to the final approach course. Once ATC begins  providing vectors to intercept the final approach course, you  should activate the computer’s “vectors-to-final” feature,  which draws a course line along the final approach course.  This feature helps you maintain situational awareness while  being vectored because the assigned heading is clearly seen  in relation to the final approach course. As already noted,  you should monitor carefully to ensure that the FMS/GPS  RNAV unit switches to approach mode within 2 NM of the  final approach fix (FAF). Figure 3-51  shows the vectors-to-final feature. The procedure  required to use the vectors-to-final feature is illustrated in  Figure 3-52. Another briefing technique uses the mnemonic FARS: The most common error made during a GPS/RNAV approach  is to forget to ensure that the approach mode has indeed  engaged prior to beginning a descent to minimums. Routinely  checking for the approach indication 2 NM before the final  approach waypoint not only prevents this type of error, but  also gives you a minute or so to remedy some situations in  which the approach mode has not engaged. Listing several different approach minimums on a single  instrument approach chart introduces the possibility of  another simple type of error: using the wrong approach  minimums. One way to avoid mix‑ups is to verbalize the  equipment being used and type of procedure being flown,  and then search for the approach minimums with these details  in mind. You must be absolutely certain of the certification,  approval, and installed options of the advanced avionics  equipment prior to flight planning. When set to use the vectors-to-final feature, many FMS/ GPS RNAV units automatically set the FAF as the active  waypoint; and set the final approach course as the desired  track to the active waypoint. As with any instrument approach, you should develop and  consistently use a briefing technique to ensure that you  think through all the steps necessary to set up the approach  correctly. One technique uses the mnemonic ICE‑ATM: A common mistake made by pilots when they are learning  to fly vectored approaches without a vectors-to-final feature  is forgetting to set the FMS/GPS RNAV back to sequencing  mode once established on the approach course. This error  prevents the FMS/ GPS RNAV unit from switching to the  approach mode 2 NM prior to the FAF. If you pass the final  approach fix and the computer is still in nonsequencing  mode, the approach mode will be disabled and you must fly  the missed approach, report the missed approach and request  another approach. 3-37 RNG PULL SCAN PUSH ON BRT PROC CRSR MSG OBS ALT NRST CLR ENT D MENU DTK 049 060 TK 9.2nm ECAi LEG Ac t i v t e V e c t o r s ? E L T R O f D T K 0 8 9 ? ENT *CRSR* PROC 1 *CRSR* RNG PULL SCAN PUSH ON BRT PROC CRSR MSG OBS ALT NRST CLR ENT D MENU OBS 089 060 TK 21.5 nm ELTROf OBS APT VOR NDB INT USR ACT NAV 1 FPL SET AUX 9.2 nm Press and choose this option. PROC The GPS/RNAV/FMS automatically sets the final  approach fix as the active waypoint, and automatically  sets the approach course as the desired track.  No mode switching by the pilot is necessary. Common Error: Forgetting To Verify the Approach  Mode Common Error: Using the Wrong Approach  Minimums Common Error: Forgetting To Reengage  Sequencing Mode Prior to Final Approach  Waypoint Awareness: Briefing the Approach Figure 3-52. The vectors-to-final feature. A Altitudes for transition, initial, final, and missed  approach segments T Timing/Distance(s) M Missed approach procedure F Frequencies set and identified A Altitudes for transition, initial, final, and missed  approach segments R Radial (inbound course) noted and set S Special notes (including missed approach procedure) I Identify primary navigation frequency C Course (inbound) set E Entry (direct, teardrop, parallel)