Tag Archives: sonic boom

Awesome photo shows Blue Angels #5 pulling high gs during demo display

This is one of those pictures that don’t need much words.

Taken on Oct 18, the photo in this post features Lt. Cmdr. Mark Tedrow, Blue Angels #5 and Lead Solo with the U.S. Navy Flight Demonstration Squadron, performing aerial acrobatics during the 2015 Kaneohe Bay Air Show and Open House at Marine Corps Base Hawaii.

What makes this image so unique is the condensation cloud that surrounds the wings of Tedrow’s F/A-18 Hornet: even though spectators usually think that such clouds represent a visual manifestation of a “sonic boom”, actually they are the effect of the quick depression on the flight surfaces that brings the water vapour contained in the air at the condensation temperature.

It is a common phenomenon in high-G maneuvers, like those typically performed by Blue Angels #5, when the depression on the upper side of the wing increases (as the lift does); it can be observed even at sea level, when the amount of moisture is significant and air temperature is quite hot.

Image credit: U.S. Navy


Following bomb threat two Italian Typhoon jets perform supersonic scramble to escort Lebanese Airbus 320

Two Italian Eurofighter Typhoon in QRA (Quick Reaction Alert) were scrambled to intercept and escort MEA214 flight that reported a bomb threat aboard.

Two loud sonic booms were heard at around 1.45PM LT in Central Italy as two Italian Air Force Typhoons accelerated to supersonic speed to intercept Middle East Airlines 214 flight, an Airbus 320 from Geneva to Beirut.

The two fighter planes, belonging to the 4° Stormo (Wing) from Grosseto, in QRA (Quick Reaction Alert) service round the clock together with those of the 36° Stormo from Gioia del Colle, were dispatched to intercept the Lebanese plane that, once flying over Bari, in southeastern Italy, radioed the Italian Air Traffic Control the request to land at Rome Fiumicino airport, because of a bomb threat.

The two armed Typhoons intercepted the Airbus 320 T7-MRC and escorted it to landing on runway 16R at Fiumicino airport, then circled at low altitude over the sea near the airport, until security forces surrounded the plane and brought it to an isolated parking slot.

The subsequent inspection did not find any bomb aboard the plane.

The MEA214 route could be tracked on Flightradar24.com as the following screenshot shows.


Image credit: screenshot by FR24.com


Plane Plotter animation shows the moment an F-15E Strike Eagle went supersonic over UK

Here is how an F-15E Strike Eagle from RAF Lakenheath went supersonic over Wales, UK, during air combat training with other aircraft of the 48th Fighter Wing.

Courtesy of Plane Plotter you can now see the F-15E breaking through Mach 1 at an estimate speed of 680MPH (calculated by MLAT – Multi Lateration of Mode-S transponder signals).

Watch AE0000, a spoof hex code for flight previously using callsign “Pyro31”. The aircraft maneuver, accelerates (543 kts is the highest value you can see in the animation) then it “trickled” through supersonic speed.

As the plane made off for the corridor the pilot changed the callsign to “Rumble31” (unfortunate use of such callsign in this case, but quite common during such tactical events).


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U.S. F-15E goes supersonic over UK: ceiling tiles come down in local Supermarket

A sonic boom probably caused by U.S. F-15E Strike Eagles shook homes and businesses in Wales.

The sonic boom that caused several ceiling tiles come down in a supermarket in the Welsh town of Aberystwyth, UK, was caused by U.S. fighter planes.

Indeed, according to the statement issued by the Air Force F-15E Strike Eagle aircraft from RAF Lakenheath had been training in the area when something went wrong.

Initially, the exercise was to be carried out over the sea, but due to the fact that the airspace the exercise was planned in was lost, the jets were directed to RAF military training airspace over the southern part of Wales.

The Strike Eagle which went supersonic broke the “sound barrier” at the altitude of 18,000 feet inadvertently causing the sonic boom.

Here’s  how the last part of the USAFE statement reads:

We offer our sincerest apologies for any disturbance or concern that this may have caused. We continue to emphasise airspeed restrictions in our pre-flight briefings to minimise the possibility of inadvertently breaching the sound barrier.

Supersonic flight over the land is usually forbidden for the military aircraft in normal, peacetime conditions except for specific areas.

In CONUS (Continental US) one of these areas is the HASSC (High Altitude Supersonic Corridor), located in Southern California. HASSC is used for flight testing, and it passes over Edwards Air Force Base. It is not the sole corridor of this type, but it is one of the few controlled by the military.

Most of these are within the FAA jurisdiction.

According to the FAA regulations the controlled airspace extends up to 60,000 feet. Anything flying above may fly at “unlimited speeds.”

There is no risk of noise pollution at these altitudes. Supersonic flights are of course permitted in special conditions, for example in case fighter jets have to intercept hijacked liners.

Jacek Siminski for TheAviationist

Image credit: U.S. Air Force


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Typhoons sonic boom during terrorist hijack alarm causes chaos in UK

At 18.10LT on Thursday Apr. 12 emergency agency telephone switch boards started receiving reports of a large bang or explosion that could be heard all over the southern UK.

It took a couple of hours before the reason for the mysterious bang was made public.

As most countries do, the RAF maintains a number of armed fighter aircraft on alert for air sovereignty and security purposes. The pilots are dismounted but are at a heightened state of readiness and can be airborne within minutes.

Since 9/11 this alert status also includes the possibility of reacting to potential threats from terrorist organisations using civilian aircraft to carry out acts of terror by using the aircraft as weapons of mass destruction.

Image credit: Nicola Ruffino

The Quick Reaction Alert (QRA) pilots are managed by the RAF’s National Air Operations Centre (NAOC), a team of 12/13 members including an Air Defence Wing Commander located somewhere West of London in an underground facility.

The team is charged with air policing of the UK airspace and also areas that come under the NATO umbrella, however, it does not monitor the national sky continuously, a task done by RAF’s Control and Reporting Centres (CRCs). CRCs constantly monitor the UK airspace and work in conjunction with the civilian Air Traffic Control based at Swanwick (Hampshire) and Prestwick (Scotland).

What happens usually when a civilian aircraft starts to raise suspicion that it is acting in a manner that is unusual?

It will first be contacted on the international emergency frequency: 121.5 MHz. Pilots are supposed to monitor this frequency at all times, but sometimes pilots use their second radio to listen to weather reports and other more mundane transmissions.

Therefore they miss this initial contact, prompting the initial investigations on the FPL (Flight Plan) filled by the pilot, the planned route and so on.

If further attempts to contact the aircraft fail, the civilian ATC will contact the CRC who in turn contact NAOC who will probably contemplate a tactical response while the problem within the UK airspace will be possibly notified to other NATO countries.

At this point the QRA pilots may be ordered into their cockpits, power on and be ready for immediate start. When engine are started, interceptors can be airborne in around 3 minutes. If  the aircraft is still not responding to ATC or the airline on “company frequency” the QRA jets will be scrambled, along with a tanker aircraft.

Once airborne all civilian aircraft will be vectored out of the way of the QRA jets en-route to the target.

Whilst trying to contact the suspicious aircraft, the RAF jets will perform a very wide intercept (out of target pilots visual sight) and approach the target from astern (rear) with transponder switched off the mode C o so as not to alert TCAS (Traffic Collision Avoidance System).

As the jets gets to within visual sight of the target the pilots will “shadow” the plane while performing visual checks to see if there is any visual reason for the aircraft not responding (maybe electrical issues).

If there is nothing obvious, the first jet will approach the target on the left hand side and forward of the cockpit so that the flight crew on the target aircraft cannot fail to miss the jet. The jet will then use the international intercept procedure, including visual follow me signals. Obviously, if the target fails to co-operate then things will be taken to the next level which could mean, after some further attempts to contact the plane and to make it comply to the visual instruction, to shoot it down.

[Read also: Air Force One journey on September 11: no escort during the attacks, 11 fighters when the airspace was completely free of airliners]

There is a process where all of the above may not take place so quietly sparking an immediate reaction by the QRA cell, and that is if a pilot enters a certain squawk code into the transponder to indicate that the aircraft, has been hijacked.

That’s what happened on Apr. 12, when a hapless helicopter pilot accidently entered the 7500 squawk code that said he had been hijacked, sparking an immediate reaction by the British Air Defence.

At RAF Coningsby the two Eurofighter Typhoon QRA jets were scrambled immediately, call signs 5KG41 and 5KG42 screamed into the sky in full afterburner, and cleared supersonic. Since it is very unusual for combat plane to fly supersonic at low altitudes one of the fighter pilot was heard on the radio asking to confirm the instruction.

When the cleareance was confirmed the interceptors accelerated trough Mach 1.2. The sonic boom was heard by thousands of people who immediately called the police and fire services to report the unusual loud “bang”. Even the British Geological Survery was contacted to see if the UK had suffered an earthquake.

[Read also: Another supersonic scramble]

By the time the Typhoons were closing in on their target, the helicopter pilot had realized his mistake and had tuned his squawk to the correct code. A bit too late: the interceptors had already caused some concern throughout UK and their supporting tanker had also been in the air to support them.

Once everything checked out, the event which sent the British media into a frenzy, was all over.

Aviation enthusiasts in the UK noted that the VC-10 tanker was still airborne at 21.45LT  a full 3 hours after the intercept and the pair of jets had returned to base at around 21.35LT. The aircraft was also picked up using ADS-B flying circuits off the east coast of the UK over the North Sea. Did they exploit the opportunity to carry out a training mission after being involved in the scramble?

Richard Clements for TheAviationist.com

Image credit: Eurofighter – Geoffrey Lee, Planefocus Ltd