The Level Best Campaign

Click here if you have problems playing the Levelbust 2 DVD
(now out of stock, but you can view the video here
courtesy of Scott International Procedures)

Latest updates June 2010 here

A message from Peter Riley, outgoing Level Bust Working Group Lead here

The Scale of the Problem:
NATS figures for Level Busts & Losses of Separation
2004 to end of June 2010
Click to enlarge


Source: NATS Division of Safety
SSE Explanation here

The bars represent reported Level Busts – this is not the whole story.

The only statistics we are sure we capture correctly are the Level Busts which cause a loss of separation.

We estimate that the number of reported Level Busts represents approximately 30% of the actual number of Level Busts

During this campaign, we would like to see:

  • An INCREASE in the proportion of level busts which are reported, we want all events to be reported because we need to understand the full scale of the problem

  • Level Busts resulting in a loss of separation DECREASE

You will find articles and posters, which you are welcome to use, as well as other information on Level Busts and tips on how to avoid them.

If you have a comment about Level Busts, or about this campaign, please e-mail us on the feedback form: every piece of information, comment, or experience is very useful to us. We are especially interested in which sector of the aviation industry you are employed in. Please use the drop down box on the feedback page to indicate this. Also, if you'd like to be informed when this website is updated please tick the box on the feedback form.


A message from Peter Riley, Level Bust Working Group Lead:

I thought it an appropriate time to update you on the current situation with regards to level busts, not least because of the change of ownership that is being completed as I hand over the Workstream Lead to Paul Hodgson, who has been an able deputy during my tenure in charge and who will continue to be, I am sure, an excellent focal point for the continuing activities of this workstream.  This will leave me more time to provide support to NSL.

Since my last update in December there has been an overall fall in level bust reports with the rolling total falling to 383 for the 12 month period, a drop from the 450 rolling total which has characterised the last year or so.  However, this fall in reports should be balanced against decreasing traffic levels and a slight increase in the number of reported losses of separation.  There is still much work to be done!  Indeed since the last update there have been a further 2 SSE2 s reported on the Ocean and two other SSE3s, one of which was due to altimeter setting error, a noticeably more significant factor in level busts over the winter period.  Indeed altimeter setting error has now overtaken Correct Pilot Readback followed by Incorrect Action as the primary level bust causal factor in 2009.  Business aviation aircraft continue to account for anything between a quarter and a third of our level busts on a monthly basis.

So what we have been doing about it most recently?

For awareness and education we have continued to send out level bust performance data to 45 or so individual operators. This data compares the performance of the operator with that of the average operator over a one year and three year period. It also indicates the operator’s position within a league table.  The data is very much appreciated by the airlines and often used as a key performance indicator by them.

For some operators we have sent out trend analysis of causal factors, type, level, position etc to help identify any peculiarities associated with particular fleets or bases.

Also, as a result of such data analysis, the Regulator has written to the National Supervisory Authority of two foreign operators highlighting poor level bust performance. Whilst business aviation remains a very hard sector on which to target awareness material effectively, we have been able to provide a remote screen cast and telephone question and answer session to the North American Business Aviation International Conference held recently in San Diego, and working with partners within the NATS and SRG, a Safety Day aimed at Business Aviation operators at Swanwick and set piece presentations to the British Business and General Aviation Association and Royal Aeronautical Society.

The article previously produced for AeroSafety World and reported in my last update has also been promulgated recently in Focus.  The article and the screen cast are available on the Operational Safety Website and this website. Much time was spent early this year making the case for retention of the phraseology for climbing aircraft above the SID as laid down in ATSIN 119, with the original ICAO-aligned proposal having been deferred subject to review in the Summer.

With regards to technology and airspace development, I can report some progress.

Notwithstanding the previously reported cancellation of the Midland Airspace Project it has been confirmed that it is the intention to continue with the initiative to raise the Transition Altitude in the Manchester and Birmingham areas to 6000ft in line with DAP policy; however, this is unlikely to be realised until the radar QNH conversion area can be adapted appropriately and after the move of Manchester Area Control Center (MACC) to New Prestwick Centre (PC).

An Investment Proposal has been made for a tool for use in Swanwick ATS Investigations which will use Mode S downlinked Barometric Pressure Setting and Mode S Selected Flight Level together to identify erroneous altimeter setting error. The Investment Proposal is being progressed for build packaging within NODE.

A workshop was held to define NATS position with regards to the raising of the Transition Altitude above 6000ft. The workshop recognised the potential advantages of moving to a higher transition altitude as part of an ECAC state wide solution, and this position would be reflected back to the DfT.  Moreover, a further workshop held recently to assess hazards associated with PRNAV SIDs that transitioned from an altitude to a flight level recognised that, with the need for both altimeters to monitor the same datum, it would not be acceptable for PRNAV SIDs to have a step at an altitude where the SID ended at a flight level. Additionally where there was a turn based on an altitude after the initial acceleration / clean up point, it was also not acceptable for the SID to end at a flight level.  As a consequence some of the trial PRNAV SIDs are being reconsidered.

I guess that is it from me – and over to Paul.  I would like to thank everybody who has helped and contributed to the activities of the Level Bust Workstream during the last couple of years and who has helped keep this item on the agenda.  Thank you, I trust you will continue to provide Paul with the same level of support.


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