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The Domino Effect of an Infringement

The airspace is essentially divided between Controlled Airspace (Known Traffic Environment) and uncontrolled airspace (Unknown Traffic Environment). This unknown traffic environment, mostly Class G airspace often comes into contact with regulated airspace, particularly around airports which serves Commercial Air Transport operations. The regulated airspace has been put in place to protect passengers and therefore the operations are known or should be known to air traffic control as most commercial operations are planned and the ATCO is not normally surprised by the arrival of the aircraft as they are expecting it!!

An infringing aircraft on the other hand is a surprise as the controller is not expecting it and where no communication can be established with the infringing aircraft the airspace risk increases, this requires the controller to take action with the aircraft they are controlling because the intentions of the infringing aircraft are unknown. The safety nets are increased by using higher separation values, holds and go arounds. The infringing aircraft causes a ‘Loss Of Separation’ (LOS) inside controlled airspace for the Controller, with no height or intention from the infringing aircraft the controller must assume the worst-case scenario.

Your transponder calibration is +/- 185 feet and ATC use +/- 200 feet for level occupancy, so when planning your flight, you should consider what is a sensible distance from the base of controlled airspace for your flight, keeping in mind your transponder might be out of calibration and you may have the wrong pressure setting in the altimeter.

After a LOS event the controller is taken of duty and could face suspension from their job, if in dealing with an infringing aircraft other events occur. Therefore, an infringement could have greater implications for a controller than the GA pilot. But there are things you can do to mitigate against infringing.

  • Make sure you carry out detailed flight planning, study your route, NOTAMS, weather etc.
  • Make sure you understand the airspace you plan to fly in and through. Plan to communicate, use Frequency Monitoring Codes (FMC) where applicable
  • Maintain good situational awareness at all times during the flight
  • If you have a transponder make sure its on with ALT (mode Charlie)
  • If it all goes wrong and you do not know what frequency to use call 121.5 – re-establishing the safety nets as soon as possible.

If you are still relatively new to flying and you are renting a club aircraft show an instructor your planned flight before you set off, as an extra pair of eyes can prevent errors- Using GPS/Moving Maps are great tools to help you navigate BUT before you fly make sure you are fully familiar with all the equipment, GPS, radios and other Navigation Aids particularly which buttons do what.

You do not want to be trying to work out how to use the equipment when you are in flight, particularly if it’s bumpy! Also watch out for confirmation bias, make sure you cross check and confirm what you do – for example many pilots forget to cross check the DI with the compass and end up being out of position.

Finally, the CAA has increased the number of provisional suspensions of pilot’s licenses in respect of Infringements - we all need to do more to make sure that we plan our flights properly. I can recommend the following website and clued up (magazine) as good references for further reading on this subject…..

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