Sonic booms over Munich

Last week, at around midday on Monday (27.Sep.2004), more than 12 people independently reported hearing a frighteningly loud explosion in Munich. The noise was heard all over from Berg-am-Laim to Schwabing to Allach. Nobody seems to know for sure what the cause of this noise was. The general consenus, however, is that it was a military aircraft's sonic boom. ...

[img]http://www.toytowngermany.com/munich/sonicboom.jpg[/img]
A fighter aircraft as it breaks the sound barrier

Only a sonic boom can be heard so loudly over such a large area. If the noise was from an explosion (eg. a bomb, or an accident) it would not only have been more localised, but it would also surely have been reported in the press.

A sonic boom is caused when an object travels through the air faster than the speed of sound (around 1200 km/h). Two objects which commonly do this are military aircraft and meteorites. The loud bang heard in Munich last week was most likely caused by an aircraft. Before the mid-1980's sonic booms were commonly heard throughout Germany. Nowadays there are rules and regulations designed to prevent them.

[img]http://www.toytowngermany.com/munich/sonicscience.jpg[/img]

Aircraft may only break the sound barrier Monday to Friday, 8am to 8pm, and not during the midday 'quiet hour' from 12.30pm to 2pm. Also, the sound barrier may only be broken at an altitude between 10.8 and 15 thousand meters. At this height the sonic boom is usually unnoticably faint by the time it reaches ground level.

Exceptions to these rules are made when an aircraft is being scrambled for emergency military purposes. With the increasing threat of terrorism, military jets are being scrambled more frequently nowadays than before. For example, on Thursday last week an Airbus with 118 passengers onboard was flying from Berlin to London when a bomb threat was made against the aircraft. Two F-16 fighters were scambled to escort the Airbus to a safe landing in Amsterdam.

It is possible that fighters from an airbase near Munich were similarly scrambled last Monday. Alternatively the pilots could simply have been breaking the law. Jets from the Lagerlechfeld airbase near Augsburg are notorious for causing sonic booms in the area. And the new Eurofighter is currently being test flown out of Manching Airbase near Ingolstadt, 40km north of Munich. Maybe one of the test pilots had drifted off course?

Whatever the exact cause on Monday, this isn't the first time such a noise has triggered speculation on the internet. Archived away in Google groups is a long discussion about a similar loud bang heard in Munich on 26th June 2003. And Wednesday last week there was a report of a sonic boom across the eifel region on the German/Belgian border.

The German word for a sonic boom is Überschallknall.

If you live out in the west of Munich around the Furstenfeldbruck area you will hear sonic booms almost on a daily basis from the jets that fly in and out of the military airbase nearby - nothing new !!!!

Not all of us are country bumpkins. Oooh Aghrrr!

Tornados used to train regularly where I was. Fantastic things if you ask me. 200 ft off the ground and bombing it along.

Hi all,

Whist working on a roof in Heimhaussen, one of these Pesky fighter planes broke the sound barrier... the house shook, and I needed a clean pair of Boxer shorts... ;o)

G

Working out in the sticks 50k north of Mü these massive booms shake my office a couple of times a week.. hard to believe they are from a small vehicle passing overhead!

Hey Wurzel, define "country bumkins" ? oohh aargghhh !!!

We heard it in Haar. We were walking our dogs, Jerry & Indy before heading into town to set up the buffet at the Bondi. Indy has angst for alles and headed home dragging me along behind her.

Some 20 years ago I visited some relatives in south germany. There were no military airport close by, but during nice weather there were jets in the air constantly. US jets in pursuit coming in low over a mountain, flying down the into the valley chasing each other, doing some minor dogfighting right over the middle of this small town, and then skimming the treetops while climbing up the pretty steep big mountain next to that place.

Another time we were having lunch sitting on the balcony, the house being located halfway up a hill about 250 meters high. Suddenly 2 jets flew by through this narrow valley barely 500 meters wide, we were about the same level with the pilots (they couldn't have gone much deeper due to electric lines being there. While they weren't supersonic (otherwise the whole town would have needed new windows) the noise still shellshocked you pretty bad, making you physically sick, unable to think for several seconds with ears ringing, and unable to even move your hands to protect your ears.

Another time I was on the marketplace (this must have been several years earlier) when a F104 came in low. I heard an awful noise, looked up and could literally count the rivets on that jet right over me. The F104 was the deadliest plane ever built for western military pilots, 30% or so of them went down since they only had one engine.

Soon afterwards the German air force bought several vehicles with radar, video cameras, automatic target trackers for them and some other gear to identify and punish those pilots that violated the rules, and this shit eventually stopped, but only after a Canadian(?) jet crashed into one of the hills right next to a farm, about 5km away from that place I stayed at.