Flight Operations

Pre-Flight

After breakfast at the most convenient truck stop ...

The tracking and recovery coordinator will disperse the personnel at his disposal to best cover the predicted landing zone.

This zone may vary in size due to the confidence level of the prediction. The dispersal may also vary depending on available personnel. When we have a very small tracking and recovery contingent a fairly tight circle around the landing zone will be established. If we have a big crew, a second circle further out may be established to minimize the necessity of moving tracking and recovery team members around during the flight.

During Flight

With today's modern APRS position reporting systems aboard all balloons, the tracking and recovery coordinator has the leeway to skip collecting many "test" bearings in favor of constantly refining the distribution of his "troops".

As the balloon flight progresses the real-time track of the balloon is compared with the preflight prediction. This process can help reveal any trends as to where the balloon may actually touchdown. Should a significant variation start to develop between the prediction and reality, the Tracking and Recover coordinator will move his people into positions better located to deal with the new touchdown location.

During each flight a very strong attempt to do several RDF bearings on the balloon is made. If the balloon is following the predicted path closely, then the teams are settled in their final tracking positions for much of the flight and generating these bearings is no problem. If the balloon is diverging from its expected path then the T&R coordinator will be shuffling folks around more and bearings may be harder to obtain. It usually revolves around the number of trackers. If there is a large tracking group an attempt to leap frog trackers is made leaving some trackers setup to take bearings while others move into more optimal positions. That scenario is somewhat rare. If the tracking and recovery team is small, then, your expertise is taken for granted, your practice is put in abeyance and you are all directed to move into a more optimal position to track the balloon during its final descent to touchdown.

Just Before Landing

Regardless of GPS/APRS reliability, it is always the goal of the Tracking and Recovery coordinator to have his crews properly positioned during the final descent so that they may take bearings that will triangulate nicely and give an accurate position report of the balloon.

It takes approximately 40 minutes for a payload train to make the descent from 95,000 ft ASL to the ground here in Colorado (5000 ASL more or less). This means there isn't much time to drive anywhere AND find the ideal site at that new location to DF from after the burst. That is why most of the repositioning is done or at least initiated prior to burst. It is hoped that you are moving towards your final bearing taking position or even at it when the balloon bursts.

From that position you should have a clear view of the horizon in the direction you expect the balloon to land. You should be clear of RDF problems if possible (metal fences, buildings, towers, power lines, etc.) so you may provide the most accurate bearings possible

The T&R coordinator may ask for several bearings during the descent if he has a balloon following its flight path closely and all trackers are in their final positions for much of the descent. On the other hand, you may arrive at your final bearing taking position minutes before landing.

The MOST IMPORTANT BEARING is the final LOS bearing. We what that bearing most of all. It represents the balloon at its closest approach to the ground prior to touchdown. With 2 excellent or 3 pretty good bearings we can usually get to within visual range of the payload system. If not visual we will be close enough to "hear" the radio systems aboard the payload train.

Once it is agreed by a consensus of the tracking and recovery teams that the balloon has landed (multiple stations lose the signal) the T&R coordinator will ask if anyone can still hear any of the payload systems. If someone has a good copy on one of these systems, we have at least one active bearing we can use to attempt to find the balloon should things start to get problematic during the recovery attempt. So, that station is sometimes asked to remain at that position and maintain a monitoring of that signal. If we have a very light turnout of tracking and recovery teams we might just take a GPS reading of that location from that station so we can return to it later if need be, and then that station is released to move in the direction of his bearing to attempt to track down the payload.

When the touchdown location has been positively determined the Recovery Procedures come into effect.