None of that applies here. Range at 35,000 feet for primary radar systems is over 100NM (~190km). It was a clear night over open ocean using a country's prima

None of that applies here. Range at 35,000 feet for primary radar systems is over 100NM (~190km). It was a clear night over open ocean using a country's primary early warning and defense mechanism situated along the coast. The US located the cargo door that departed from UA 811 in 1983 using radar analysis to find the part. They could see a 6meter piece of metal fall from the aircraft at 25,000 feet. 100km off shore.