LHR Flight Path Angle Calculator is a simple app to help pilots comply with London Heathrow airports Constant Descent Arrival procedures for noise abatement. In order to minimize noise, aircraft are required to fly a constant descent prior to intercepting the final approach course 3° glide slope.
This app allows pilots to quickly and easily make three inputs: their current altitude, the altitude LHR ATC has cleared them to descend to, and the distance to touchdown given to them by LHR ATC. The app will then display the Flight Path Angle for a constant descent to intercept a 3° glide slope at the cleared altitude, and the pilots can then set the Flight Path Angle in their aircrafts mode control panel.
It is recommended that pilots set an FPA in the mode control panel 0.2° less than the FPA calculated by the app, in order to account for variance in LHR ATCs distance-to-touchdown number.