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TCH on approach plate - utility

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Well-known member
Jan 30, 2002
Whats the significange/utitlity of Threshold Crossing Height (TCH) on an approach plate? How is this information useful
It's useful when you fly an airplane where the gear hangs significantly lower than your seat...

We require a minimum 47' TCH so we don't take out any lights...
Example: When a DC-10 crosses the runway threshold, its main gear wheels are only 26 feet from the runway due to its size and angle. Getting a dot off glideslope or flying a Cat II, or III becomes more detremental ...quick.
We used TCH to determine the minimum autopilot disconnect height. For TCH below 47', our minimum autopilot altitude on an approach was 150', but if the approach was conducted to a runway with a TCH above 47', we could go to 100' on the autopilot.

Especially in larger airplanes, where a lot of airplane is behind and below you on the approach, the TCH is important to know.

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