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2 Answers

What does the “CH” and number in the WAAS box on RNAV chart mean?

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Instrument Rating

And why does it matter for the approach?

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2 Answers



  1. John D Collins on Mar 15, 2015

    Each WAAS based approach is assigned a WAAS channel number. To be WAAS based, the approach must have either an LPV or LP procedure included. This number is uniquely assigned to the procedure and can be used as an alternative method of identifying the approach, similar to the way a frequency is used to channel an ILS. On the various WAAS GPS systems I am familiar with, such as the GNS530W, you can select a specific approach by airport identifier then approach runway name or you can simply select the WAAS CH number. In some cases it is quicker to just select the 5 digit number. All this said, this is mostly an academic issue and most pilots don’t know how to use this.

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  2. Drew on Mar 15, 2015

    I’ve never heard this. Thank you.

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