Even if in the F-104 age there were many scrambles, I remember that only a few times the interceptor “broke” the sound barrier during the mission. Even in the post 911 period, until 2004, under highened security measures, the QRA (Quick Reaction Alert) aircraft rarely performed supersonic interceptions (or at least the went through Mach 1 above the sea and were not heard from the people on the ground).
In the last year at least three times the fighter scrambled to intercept a “zombie” performed a supersonic acceleration causing a loud sonic boom that was heard by the population.
The last occurrence was on Oct 8 when 2 F-16 of the 37° Stormo based in Trapani were scrambled at 07.18 LT from the COFA/CAOC5 to intercept an unknown aircraft flying without the FPL (Flight Plan).
The Vipers on alert took off in 6 minutes and were vectored to intercept the unknown aircraft that despite being identified by the ATC (Air Traffic Control) had provided unclear information and had decided to change its routing after being informed of the imminent interception by the Italian Air Defense. At around 40.000 feet above the Gulf of Naples the two F-16 went supersonic. At 07.45LT the 2 F-16 ADF reached the Byelorussian Ilyushin 76, flying from Sebha, Libya, to Linz, Austria, between Foggia and Napoli, and escorted it until it exited the Italian airspace, above the Adriatic, North of the Tremiti Islands.
On Sept. 16, two F-2000 of the 4° Stormo, based in Grosseto, had departed at 18.45LT to intercept a Czech Boeing 737 from Tunis to Praha, that had lost the radio contact with the ATC flying abeam Rome. During the initial phase of the interception the two Eurofighter accelerated above Mach 1 causing a sonic boom that was heard from many miles away. The two fighters did not complete the mission since the civilian aircraft was able to establish the contact with the ACC and the F-2000 were cleared to RTB (Return To Base).
On May 30, two F-16s belonging to the 37° Stormo of Trapani were scrambled to intercept the Lufthansa flight LH8619T, that was flying from Milan Linate to Athinai, and at 08.29 LT lost the radio contact with Padova ATC. The QRA flight of Southern Italy was immediately scrambled to intercept and escort the civilian A300 and two armed “Vipers”, just after take off, were cleared to accelerate to supersonic speed in order to reach the “zombie” in the shortest time possible. The consequent shock wave caused a loud “bang” that was heard from the ground.
The two fighters were cruising above Mach 1, when the Lufthansa flight was able to establish the radio contact with “Brindisi Control”, and they were ordered to “skip it”, to slow down to subsonic speed and RTB. The F-16s made a fuel stop to Gioia del Colle before proceeding to Trapani.
As I have already explained here, unlike it happened in the past, when there were many bases sharing the QRA duties in Northern and Southern Italy (at the end of the ’80s they were: Istrana, Cameri, Rimini, Grosseto, Grazzanise, Gioia del Colle, Trapani and Sigonella, where a cell was deployed on rotation) the current Italian Air Defense set up foresees two QRA (Norther and Southern), each made of a flight of 2 fighters ready for departure in 15 minutes: 2 fighters in either Grosseto (9° Gruppo, equipped with the F-2000 Typhoon) or Cervia (23° Gruppo, equipped with the F-16ADF); and 2 aircraft in Trapani (where two Squadrons share the alert shifts, the 10° and 18° Gruppo).
It is normal that to intercept a “zombie” asap, possibly departing from an airbase far away (in more than 3-5 minutes like the F-104 was able to do), the fighters are compelled to fly supersonic. Since both Cervia and Trapani are going to cease their QRA shifts with the expiration of the Peace Caesar programme, from 2010 – 2011 there will only be two Eurofighter MOBs (Main Operating Bases) fulfilling the Air Defense duties with the Typhoon: Grosseto (9° Gruppo and 20 OCU) and Gioia del Colle (12° and 10° Gruppo).
So, the situation is not going to change in the near future. Actually, it was not completely different before, since there were always 2 bases with QRA cells (one in the North and one in the South with another two in 2 hours stand by alert) and it could happen that a flight of F-104 from Grazzanise had to intercept a Tu-16 above the Adriatic Sea. However, there were many other airbases distributed on the peninsula: it often happened that the alert one was also near (or the nearest) to the “zombie”, thus interception took place in short time and without the need of supersonic accelerations.