Return to Base (RTB)

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Returns to Base (RTBs)  are essential for flight safety.  While it's understandable to be concerned about being onboard a helicopter which has 'technical issues', the reasons for RTBs are often more mundane than it seems.

Return to Base

An RTB occurs when a helicopter crew chooses to return the helicopter to the airport without completing the intended journey.  This is a precautionary measure and in the majority of cases it is due to minor technical issues. 

Pilots follow detailed procedures to determine the safest and most practical action.  Once the aircraft has returned to the hangar, it can be inspected by engineers and remedied with the parts and equipment that are available, if required. 

By contrast, if a similar technical issue is identified on a commercial flight from Aberdeen to Heathrow, there is engineering support at both ends of the flight.  When flying offshore there are only engineers at one end so the safest and most practical thing to do is return to the airport, rather than flying to the installation and potentially having to shutdown offshore.  Helicopters cannot be fully inspected offshore, as there is a limited range of engineering expertise and equipment available.

What causes an RTB?

Most RTBs are caused by indicators from the aircraft’s safety systems.  These systems have numerous back-up systems and the cause of an RTB is often related to a back-up system.  The vast majority of RTBs are precautionary and are done to ensure the continued safety of passengers and crew.  The reason for an RTB may not be immediately known.  Pilots and engineers must download and process large amounts of information and data before the reason for an indicator can be understood. 

RTB Classifications

There are a number of reasons why a helicopter may not complete its planned journey:

RTB:  the crew have followed standard precautionary procedures and have returned to base so that the aircraft can be inspected by engineers.

Pan Call:  the crew have followed standard precautionary procedures and have returned to base, requesting priority to land.  The airport, following their own procedures, will put the emergency services on standby as a precaution.   

Mayday:  the crew have issued a Mayday alert and must land the aircraft immediately.   

Step Change works with the three helicopter operators in Aberdeen to ensure the workforce receive information about RTBs that are reported in the media.  Visit the Helicopter News section of the website to read about recent occurances. 

Download the RTB Factsheet for more information.