Threshold crossing height (TCH)

Definitions

• The theoretical height above the runway threshold at which the aircraft’s glideslope antenna would be if the aircraft maintained the trajectory established by the mean ILS glideslope or MLS glidepath.
• The theoretical height above the runway threshold at which the aircraft’s glide slope antenna would be if the aircraft maintains the trajectory established by the mean ILS glide slope or MLS glide path.

References

• Instrument Flying Handbook, Federal Aviation Administration, 2014
• Pilot's Handbook of Aeronautical Knowledge, Federal Aviation Administration, 2023