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Fly On Track Radar Replay #1

You can view a real radar replay of infringement here if you have Windows Media player.... but before you do, read the following to understand what you are seeing.... and remember, not one passenger or aircraft was ever endangered in this incident... the whole sequence that you will see is simply a classic example of standard safety measures in action because an 'G.A. Infringer' enters into Heathrow Class 'A' Airspace. When you play the radar replay, (button at the bottom of this page), you will see the DISRUPTION caused by an unknown aircraft entering the Heathrow CTR from the North. OK, we know many of you will go and play the clip right now, but when you've viewed it, please come back and read about what is happening and even WHY, below.

You may need to replay the sequence more than once, there is so much happening. To help you identify him, the infringer will be highlighted with a white circle. Note he is squawking 7000, the general conspicuity code, but he is not revealing his altitude which should be shown where the three dashes --- are. To understand the data on the commercial aircraft, pause the replay and look at any green '*' which represents a aircraft approaching or leaving Heathrow. The ones on the last stages of their descent inbound will have a green number, representing the altitude in HUNDREDS of feet (so '43' represents 4300'),and a green 'LL' representing Heathrow (ICAO code EGLL). The orange/brown number trailing some flights is the altitude that the aircraft is descending to at this stage. So a '43' with an orange/brown '40' trailing it shows the aircraft passing 4300' on the way to 4000'.

As the infringer moves South towards the well spaced commercial traffic lined up for landing on 09L at Heathrow, the controller, unable to contact the infringer, has no option but to break off two aircraft from final approach to a runway... That's why controllers are there... they enforce safety by taking action. That's why controlled airspace is there... to give a defined 'known environment' to protect commercial flights. If anything 'unknown' enters that environment, then set procedures ENSURE that safety is not compromised, and the casualties are 'time' and 'cost' (and perhaps patience if you were a passenger on board with a tight transfer, or a train to catch, or just wanting to get home after a long day). If you are interested in direct costs, think of each minute of extra flight time suffered by the aircraft broken off approach and re-sequenced into such as busy stream as being in the order of £100 per minute and you won't be far wrong.

Whilst the real incident shown here was not a 'safety' problem due to the diligence of the controllers and their processes, the most likely incident that could lead to safety problems would be an infringer without 'Mode C' breaking into controlled airspace from below or above - for example climbing into the LTMA from below either not transponding, or simply forgetting to turn the transponder to 'ALT'. Always use Mode C if you have it. What do you do if you suddenly realise you are in Controlled Airspace? Call the controller as quickly as possible, as you can then quickly become 'known traffic' and other flights might not need to be diverted once you are identified and the situation is being resolved. If you do not know who to call, don't wait for things to get worse, use 121.5 Mhz, tell them your problem, and the situation will start to improve for everyone.

So, have a look at this incident by clicking on the radar head button below. Note how the commercials are first arrested in their descent and then broken away for resequencing. This has to happen when unknown traffic in the same airspace gets within 5 miles or 5000'. Why did it happen? - the infringer, heading for White Waltham (seen on the western edge of the CTR) but intending to route around the airspace reported accidentally was heading 202° instead of 222° as planned. As a consequence he misidentified Amersham and subsequently mistook Beaconsfield for High Wycombe. Finally, well inside Heathrow CTR he recognised Maidenhead and turned to exit the CTR as quickly as possible - too late to prevent delays to two commercials!

Click on the image on the left to launch the radar clip. It is currently only available in 'wmv' format, therefore Windows Media Player should be used. Many thanks to all at NATS who have gone out of their way to make the public viewing of this clip possible. A different infringement and analysis will appear monthly - until they stop!

The latest radar replay (#7) shows an aircraft starting in the Manchester Low Level Corridor then infringing the CTR with the controllers breaking off approaches ahead of it.

The latest radar replay (#6) shows a small aircraft slowly transiting Stansted CTR.

Radar replay (#5) shows an aircraft not noticing the lowered airspace ahead near Compton VOR and breaking in at altitude.

Radar replay (#4) shows a student lost and crossing the Luton CTR and extended runway centre line.

This radar replay (#3) shows disruption caused by a short infringement into a layer of the LTMA over Sussex, eventually descending to the correct altitude but not early enough.

This radar replay (#2) shows a problem caused by a pilot NOT squawking Mode C and then getting lost eventually turning up close to the extended centreline of Stansted in the CTA. Due to the lack of Mode C the controller didn't know he was in the CTA.

The original radar replay (#1) shows the disruption caused when a pilot makes a navigation mistake and enters the Heathrow CTR and heads down towards final approach without realising it (at first!)