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The Great Tennessee Air Show 2025 After Action Report

June 6-8

Weather

Rain threatened all day on Friday during practice but never hit until just before we left at 1530. Saturday was overcast throughout the day with rain in the area. Rain prevented the Blues from flying. Sundays weather was much better. Highs in the low 80s and mostly sunny with some clouds. Ceiling at 6000'. Wind 15 gusting to 20MPH was the norm on Sunday.

General Notes

Most everything was successful. We were at the airport Friday during practice as well as Saturday and Sunday during the show. The RV (see below) was a huge asset and should be utilized in the future. An APRS digipeater/igate was set up in the RV. Communication was established between East Ops and West Ops utilizing the portable repeater setup on the West side. Our side (east) of the airport used simplex and had very few issues communicating.

It should be noted that traffic takes approximately two hours to clear the parking lot once the show ends. We waited in the RV both Saturday and Sunday for two hours before leaving. There were no traffic delays when we left.

Failures

My YAAC setup would not show Don, KW4DTW, location on the map. He utilized his phone and the APRS_fi app on Sunday. I could see his location on aprs.fi but it would not show on the YAAC map. It did show in the station list but no coordinates were available.

Don, W4WWF, was unable to see the APRS objects that I created on his Pinpoint APRS map. The objects were showing up on the radios and on aprs.fi. An educated guess is some sort of filter issue in the software.

This was overcome but some APRS radios were not showing objects. Need to be certain that no one is filtering out APRS objects in the settings of their rig. Once the filters were corrected, objects were shown.

We did not know that we should monitor the show radios for potential traffic originating from other show personnel. Next year, East Ops should monitor the show radios for traffic that can then be relayed to the guys driving the carts.

There were two occasions that HT batteries were depleted before the end of the day. It happened to one operator on Saturday and another on Sunday. Neither recognized their radio was off for 30ish minutes or so. Recommend everyone swapping batteries at lunch regardless of battery life remaining.

A minor issues was observed where the PL tone for the simplex channel was not programmed into an HT. Be sure to follow the 205! Should the 205 be updated to remove the PL tones on simplex frequencies?

Radios

How many did we need? ALL OF THEM! The Icom 705 was used as the APRS rig and was connected to the X1 Carbon laptop. The Retevis RA89 was programmed for our main and backup simplex frequencies. The D75 served as a backup digipeater that wasn't used. It was used to communicate with West Ops though the portable repeater. The D74 was carried on person when I left the RV. The VX6 was used to monitor weather on Friday and Saturday. On Sunday it was used to listen to the air boss. The FT2 was loaned out. The UV-Pro was available but not loaned out.

The 705, RA89, and X1 was powered from the RV house batteries. The D75 was powered with a portable Anker battery bank. There was enough power in the battery bank to run the D75 all weekend. The other HTs ran on their batteries and were recharged each night.

APRS

An APRS digi/igate was set up in the RV and we had a good path to both the Short Mountain and Gallatin digipeaters. APRS was used to track the golf carts as well as marking all important spots with APRS objects. This proved to be a vital resource as I could see everyone’s location on the YAAC map and know exactly where everyone was located.

APRS objects were created for the west side operations before arriving on site. This was possible because the majority of their stations were located at street crossroads. The objects on the east side of the airport had to be created Friday during practice as there is nothing to reference these points on the YAAC map. Mark, KD4EYF, drove a golf cart to each location on Friday. He then sent out a beacon which was received in YAAC. He would relay the landmark where he was located and an APRS object would be placed on the map. All of the objects were exported from YAAC at the end of Friday so they could be imported on Saturday and Sunday.

It is VITAL that the digipeater be configured to only respond the WIDE1-1 traffic. This will allow for digipeating everyone on site but not digipeating anything sent from high level digipeaters in the area.

Don, W4WWF, set up a digipeater on the west side of the airport as well. He had issues with the filter in the Pinpoint APRS app and was unable to see the APRS objects. Otherwise his digipeater seemed to be functioning correctly and we were able to pass APRS messages between our stations.

There was a total of 27 APRS objects created for this event. These objects were all imported into YAAC at one time creating a bit of RF saturation temporarily. In the future, objects should be imported into YAAC in stages (7-8 at a time) and a 5ish minute window should be observed before the next set of objects is imported. This would eliminate all of the objects being transmitted in a very short window and creating RF saturation.

The crowd exceeded 12K people at the show. There were reports of people not being able to use the cell phone at times due to network saturation. Don, W4WWF, and I both had a Starlink on our RVs and had no issues with network connectivity. I used 12GB of data over the entire weekend. Most of this usage was pulling radar images on Friday and Saturday. We had the potential to experience no or slow connections if we had relied on cell phone data plans.

RV

My RV was delivered to the airport on Thursday morning. Since there is no commercial power available, it ran on the house batteries all day Thursday and Thursday night. There is a total of 200Ah of battery capacity available on the RV. When we arrived at 0930 on Friday morning the batteries were at 80%. Mark’s, KD4EYF, generator was used to power the RV during the day. The house batteries were used to power the RV overnight. The lowest battery level witnessed was on Sunday morning when the battery bank was depleted by 50%. With partly sunny conditions on Sunday and the generator being ran, the batteries were at 90% when I got home Sunday evening.

Generator

The generator used ~10 gallons of fuel over the 3 days of operation. We had to use Marks 3 way splitter that converts his 30A style plug to standard household 110V and my 110->30A plug adapter for the RV because the two 30A plugs were different styles of connectors.

Winlink was available and checked regularly over the weekend but was not used. I chose to run Winlink over telnet since Starlink was providing good internet connectivity. It is worth noting that regular email was used a few times between myself and Don at the west side operations.

Antennas

The TN07 29’ green mast was used at my RV. A N9TAX roll up jpole and an Ed Fong jpole were both used on the same mast. One for voice and the other for APRS. The APRS antenna was hung just below the voice antenna on the same mast. A small rubber duck antenna was all that was needed on the D75 running on low power to reach the portable repeater. A signal stick antenna was used on the D74 when I was out of the RV.

https://aviationweather.gov/data/metar/?decoded=1&ids=KMQY&hours=24

Thing to consider in the future

  • Phone numbers of key personnel
  • Local Police Phone Number (Not 911)
  • Everyone should set up WiFi calling in advance
  • Custom APRS group specific to the air show*
  • Custom APRS frequency specific to the air show**

*A custom group would make it possible to send a group message to everyone at once without alerting anyone else in the area. For 2025 bulletins were used to announce over APRS when the box was activated/deactivated. As of mid 2025 custom groups are not possible with the VGC and UV-Pro china radios.

**While everything worked with APRS there is a lot of traffic on .390 due to the fact that my digi was hearing both the Gallatin and Short Mountain high level digipeaters.

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