endpoint for that airway are selected, all waypoints that  occur along the airway are automatically inserted into the  flight plan.  Figure 3-11  shows a navigation unit that allows  airways to be selected. Once a route has been entered into the FMS, the next step  is to review the route to ensure it is the desired route. It is  particularly important to ensure that the programmed route  agrees with the pilot’s clearance, the en route and terminal  area charts, and any bearing, distance, time, and fuel  calculations that have been performed on paper. Using the FMS’s flight planning function to check your  own flight planning calculations is one example of how  advanced cockpit systems can decrease the likelihood  of an error. Alternatively, cross‑check the computer’s  calculations against your own. (Remember the old computer  programmer’s adage, “Garbage in, garbage out (GIGO).”) Every IFR‑capable FMS offers a menu of published  instrument procedures, such as departures, arrivals, and  approaches. When you choose one of these procedures, the  FMS automatically inserts all waypoints included in that  procedure into the flight plan.  Figure 3-12  illustrates how you  might choose an approach procedure using one popular FMS. The convenience of the FMS, especially the “direct to”  feature common to all units, creates the temptation to program  only the first en route waypoint prior to takeoff and then enter  additional waypoints once airborne. Keep in mind, however,  that no matter how skilled you become with the avionics,  programming requires “heads down” time, which reduces  your ability to scan for traffic, monitor engine instruments,  etc. A better strategy is to enter all of the flight data before  you take off. The flight planning page can also be used to review the route  that you entered into the FMS, as illustrated in  Figure 3-13. Be sure to check at least four things when reviewing your  route. Catching Errors: Using the FMS Flight Planning  Function To Cross-Check Calculations Reviewing the Flight Route Entering Procedures Risk: Taking Off Without Entering a Flight Plan BACK EXEC XPND$^{Modify}$ Wpt Arwy Modified KSQL 027 KSQL SUNOL  21.7 027  21.7 No Active Leg DIST BRG 060°   21.7 discontinuity BRG ---   --- FPL n m n m GPS ENR FLAGGED 119.000 121.600 114.10 116.00 1200 A  C  T A  C  T S  B  Y S  B  Y S  B  Y --.- vor BACK V195 V301 V334 SUNOL V195 ECA 50nm ECA SUNOL FPL GPS ENR N FLAGGED 119.000 121.600 114.10 116.00 1200 A  C  T A  C  T S  B  Y S  B  Y S  B  Y --.- vor BACK EXEC XPND$^{Modify}$ Modified KSQL SUNOL  21.7 V195 ECA: TRACY  40.0 SHARR  49.6 ECA 55.0 No Active Leg DIST BRG 060°   21.7 BRG 060°   18.3 BRG 060°   9.6 BRG 049°   5.4 FPL n m n m n m n m GPS ENR FLAGGED 119.000 121.600 114.10 116.00 1200 A  C  T A  C  T S  B  Y S  B  Y S  B  Y --.- vor This FMS allows you to insert  an entire airway into your route. The software performs a  database search for all of the  airways, causing all waypoints  along the airway to be inserted  into the route. Mo di fy Mo d di f fi d ed 11 19 9. 00 0 C The navigation database looks up all of the airways that connect to the previous waypoint in the route. Figure 3-11. Inserting an airway into a flight route. 3-9