There are 4 different modes available, these control the how close you need to be to each waypoint for your sector time to be recorded. The mode is selected on the Aircraft Settings form in Flightplan, but it will be automatically reset when you join a race.
So if you were racing in Normal mode and you then join a race in Pro mode, the setting will be changed for you. If you are creating a new race, you’ll want to select your race mode before you go into Cockpit Map to create the race. Mode is tied to the race not the course, so you can have races on the same exact course using Normal, Pro and Fixed modes (for example) but once the race is created, the mode cannot be changed.
Available modes are as follows:
Normal
This is the original Cockpit Map Lap Timer mode. It uses your aircraft actual airspeed in MSFS to calculate how many feet per second you are traveling. It then sets the radius of the waypoint to be the distance traveled in 1 second (in any direction) from the center of the waypoint, rounded up to the nearest hundred. For example, if your aircraft is travelling at 520 feet per second, this will be rounded up to 600 and the waypoint will effectively be a cylinder in space with a diameter of 1,200 feet, centered around the coordinate of the waypoint. It will extend up to the altitude specified for the waypoint or all the way to outer space if the altitude is 0. Some portion of your aircraft must pass through any portion of this cylinder in space for it to count the waypoint.
Pro
Pro mode is simply a variation on Normal mode with no rounding and half the distance. Pro mode also uses your actual airspeed to calculate your airspeed in feet per second, but it does NOT round up to the nearest hundred, but instead sets the diameter of the waypoint to this distance. Using the same example we used for Normal, if you are travelling at 520 feet per second in Pro Mode, the waypoint will be a 520 foot cylinder in space extending up to the altitude specified (if any). Again, some portion of your aircraft must pass through this cylinder in space for the waypoint to be counted.
Fixed Mode
Fixed mode allows you to set a fixed diameter for all waypoints regardless of airspeed, the minimum allowable is 50 feet. Speed is not taken into consideration at all, so a 150 foot fixed distance (for example) will result in 150 foot wide cylinder in space extending up to the specified altitude (if any). It will be the same diameter whether you are travelling at 150 feet per second or 1,500 feet per second.
CAUTION: If you set a very small fixed distance and use a very fast aircraft you could potentially run up against the limits of the reporting system in MSFS (SimConnect) and your processor clock cycles. In theory, if you were travelling at close to Mach 2 and had the distance set to 50 feet, you would only be within the waypoint detection radius for about 1/40th of a second. This may not be enough time for Flightplan to request your aircraft location, receive the information from MSFS and calculate whether you’ve crossed the threshold or not (then do it all over again as your aircraft moves). This process happens very quickly (in just a few milliseconds), but at extreme speeds it’s mathematically possible to basically leapfrog your waypoint between 2 cycles. That said, good luck hitting a 50′ point in space at Mach 2.
Bush Trip
Bush Trip mode is really just an automatic stopwatch feature. You can use it for racing, but it would tend to decrease the competitiveness of the race. Bush trip mode monitors the glass cockpits previous waypoint or the PREV/NEXT waypoints reported by MSFS (if the aircraft lacks a glass cockpit). As soon as the MSFS avionics report that the previous waypoint has changed, the lap timer will consider that waypoint reached. However it will continue to time the sector until you start moving further away from the waypoint.
As long as your are moving toward the waypoint (the distance between you and the waypoint keeps getting smaller) the timer will continue to time. For a perfectly straight flight path over a waypoint, this will mean that the waypoint will trigger approximatly a half mile (typically) from the waypoint, but the timer will continue to time until the exact moment when your aircraft passes over the coordinate and begins moving away from it.
The glass cockpit uses a smoothed flight path to determine when to consider a waypoint reached. This is often half a nautical mile or more from the waypoint (although it can also be very close depending on the angle of the turn. If for some reason the flight plan/glass cockpit doesn’t report the previous waypoint changed by the time you reach a half mile of the waypoint, the Lap Timer will consider the waypoint reached, and begin monitoring your distance to the waypoint so it can determine when to record the time. This way you can get a relatively accurate recording of you leg times as close to the waypoints themselves as possible without having to fly all the way to the waypoint if it’s inefficient. This gives you a realistic comparison of your times enroute against the estimates in the Nav Log.