Originally Posted by
NAROBS
Isn't this machine declared on FR as having mode S which is spec'd to transmit every 25 ft change inaltitude and won't the French Primary radar be tracking everything that moves within 25 miles of Cap de la Hague nucleur asset ?
The question of whether it was equipped with Mode S ELS/EHS (25' altitude resolution) or simply Mode C (100') is largely immaterial. As a 35-year-old privately-owned aircraft it almost certainly didn't have ADS-B, which means that it would only have transmitted altitude when interrogated by ground radar.