For planning purposes, what is the highest usable altitude for an IFR flight on V573 from the HOT VORTAC to the TXK VORTAC?

The highest usable altitude for an IFR flight on V573 from the HOT VORTAC to the TXK VORTAC is determined by the National Flight Data Center charts and the altitude structure in relation to the minimum enroute altitudes (MEAs) and any airspace restrictions.

For this particular route, the MEA at the segment in question would typically be established to ensure terrain and obstacle clearance while allowing for adequate communication and navigation performance. Altitude planning for IFR flights often follows certain rules, including the inclusion of a buffer for reliable navigation signals and required obstacle clearance.

In this case, the highest usable altitude on the route is set at 16,000 feet MSL, which provides an effective upper limit for flight planning, taking into account both safety and operational considerations. It ensures that pilots remain within a safe altitude range, allowing for compliance with regulations while minimizing the risk of flying too close to terrain or obstacles.

While lower altitudes may exist along the route, they would not provide the same level of safety or flexibility in flight operations, making 16,000 feet the viable choice for planning purposes.