A very reasonable precaution. Exactly what I would expect from Israel.
First thing I would do is to check for any backdoor program access to the auto pilot programs, then to install a shunt that can disable the computer if its compromised. I hope also that in the US they provide the Air Marshals with a sizable pressurized oxygen supply, otherwise he would be knocked out as well.
Boeing 777 Airliner
The Boeing 777 is a family of long-range wide-body twin-engine jet airliners developed and manufactured by Boeing Commercial Airplanes. Top speed: 590 mph (950 km/h)
About a 1,000 mile radius should do it!
That would cover all of Egypt, Iraq Jordan, Syria and extend to Iran’s border.
Makes you realize how lucky we are in the USA to have oceans as neighbors for much of our country. Poor Israel, in less than one hour they are very vulnerable from many enemy cities.
Jerusalem to Tehran is 970 miles
Jerusalem to Syria - Damascus 135 miles
Jerusalem to Lebanon - Beirut 146 miles
Jerusalem to Egypt - Cairo 265 miles
Jerusalem to Iraq - Baghdad 547 miles