Next time you go flying and you’re landing on a runway equipped with a Precision Approach Path Indicator (PAPI), make your approach to follow the PAPI. Once you’re established on the final approach leg of the traffic pattern take a look around and notice the clearance from any obstructions. The PAPI is set up to provide visual approach information to pilots, including obstacle clearance (ensure there are no A/FD notes or NOTAMs to the contrary).
Typically I teach students to ignore the PAPIs (and formerly VASIs, which are becoming less common these days) because these guidance facilities set you up to land at the touchdown zone on the runway, 1000′ down the runway. Private pilots typically aim for the runway numbers, round out, flare and touch down around the second runway stripe. So I teach students to ignore the PAPI and fly a smooth consistent approach to a touch down at their intended point of landing. However, at night when obstructions are hidden by the ambient darkness, PAPIs and the remaining VASIs provide critical safety information and ensure a nice cushion of protected air below your aircraft.
Once you’ve flown the approach during the day and observed the obstacle clearance afforded by an “on glide slope” approach based on PAPI guidance you can fly confidently at night and follow the PAPI, two white, two red and know you’ll be clear of any obstacles. Since you can see PAPI lights when roughly aligned with the final approach course for a runway almost twenty miles out, you can fly comfortably in the dark, knowing your approach is safe in the darkness.
-Fly Safe, @MTElia1B9