Feasibility Assessment of Unmanned Aerial Systems for Precision Approach Path Indicator Inspections: a Cost-Effective and Sustainable Alternative

ABSTRACT The use of unmanned aerial platforms has increasingly been demanded in various applications. Among these, in-flight inspection stands out, traditionally conducted by aircraft equipped with various sensors to verify the performance requirements of ground-installed navigation aids, as well as air navigation procedures for operational and airworthiness purposes. In-flight inspection is costly in terms of time, qualified personnel, necessary equipment, flight hours, and operational impact on the inspected aerodrome. In this context, the use of unmanned aerial systems (UAS) emerges as a potentially cost-effective alternative, with the potential to significantly reduce the costs associated with the in-flight inspection of navigation aids. This work presents the methodology and results of in-flight inspection of the precision approach path indicator (PAPI) using UAS. The results presented are selected from over a dozen field campaigns, wherein inspection procedures were adapted to replace conventional aircraft with UAS. The results were compared to traditional inspections performed by the conventional aircraft crewed with professional flight inspectors. The findings indicate a strong similarity between the UAS methodology and conventional inspection, suggesting that UAS could partially or completely replace conventional inspections, significantly reducing the time, costs, and impact of inspections carried out by conventional aircraft.