CANPA calculator


Staff member
I just built a CANPA calculator you can use to calculate the non-precision constant angle descent for non-precision approaches:

It is linked on the bottom of the Flight Planning page.

The calculator uses Javascript so you don't need to reload the page to have it work. This lets you open it on the ground and have that URL work without the internet later.

If you have Javascript disabled, a "Refresh" button is visible to reload the page with your new data. This does require an internet connection.

These are some resources for you:
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Staff member
I expanded the calculator so it now calculates KTAS, Density Altitude and Pressure Altitude and added the wind component to calculate a ground speed in knots...even if the IAS is MPH.

This is the current weather at KLXV (Leadville) using the RNAV (GPS) RWY 16 approach from SKKID at 13000 to TALUE at 11440

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Staff member

This is a 6-minute walkthrough video I made

I think the calculator is looking pretty good now. Here's what it does:

- Popup a choice of local airports to examine
- This pops up a window to select an airport. The list shows the distance from KCOS, field elevation and airport name and ICAO identifier
- Link to information about an airport in the database
- Gets the current METAR and displays it on the page
- A "decoded" link appears to see the decoded METAR information
- Field elevation is automatically pulled in with links to add +50, +100 and +500 to the field elevation (clicking the same link adds another +50, +100 or +500 feet)
- Temperature, altimeter settings and wind speed and direction relative to the runway heading calculate:
-- True Airspeed in knots
-- Headwind/Tailwind component
-- Crosswind component
-- Density Altitude
-- Pressure Altitude
- Final approach ground speed in knots is calculated
- Distance and altitude to lose are input by the user
-- This calculates a descent angle and a descent rate in feet per minute

Let me know what you think.