Visual air navigation siting

✍ Scribed by Xiaosong Xiao; Scott Litsheim

• Publisher: Institute for Transportation Inc.
• Year: 2006
• Tongue: English
• Weight: 269 KB
• Volume: 40
• Category: Article
• ISSN: 0197-6729
• DOI: 10.1002/atr.5670400305

✦ Synopsis

The principle of a Precision Approach Path Indicator (PAPI) System is to provide the pilot with an on-slope signal and guide the aircraft down to the runway safely. Threshold Crossing Height (TCH) related to PAPI siting ensures that aircraft have a certain landing gear clearance over the runway threshold. Therefore, it is an important parameter in PAPI siting. In this paper, the factors related to PAPI siting are addressed and the determinations of the TCHs for PAPI and ILS (Instrument Landing System) are discussed. Most importantly, two approaches to calculate the eye-to-wheel height are proposed and a procedure to quickly check a PAPI siting also developed. The results show that the angle on which a TCH is based affects the NAVAIDS siting, and that any calculation of TCH should be based on the lowest angle in order to maintain the acceptable minimum wheel-to-threshold (WTH) height of 10 feet.