There was much wincing and frowning at BAUA's mid-November meeting, as the 50-strong audience - many of them pilots - watched on a radar plot display just how easily one aircraft might become entangled in the flight path of another. As conversation between the relevant pilot and air traffic controller becomes ever more frantic, a miss is avoided by a mere half-mile fraction and the audience is left to heave a sigh of relief.\rAs the air hostess on one of the aircraft put it: "I saw the registration on the other plane's nose-wheel cowling, that's how close it was."\rNational Air Traffic Services says that, during the time period spanning October 96 - September 99, 1,107 level busts were reported to the CAA in the UK. However, while there are 400 reports of level busts a year, evidence from safety departments from major operators and anecdotal evidence, suggests that there are actually over 1,000 level busts in the UK per annum. In the last three years, there have been 170 losses of separation caused by level busts.\rSo what is a level bust? David Essen, 'On the Level' project coordinator later told us: "A level bust is a deviation of more than 300 feet, which needs to be reported." Not quite so serious is an 'almost bust', which he defined as "a developing situation where a level bust was prevented by sharp eyes or a prompt at the last minute." \rDebbie Westley, NATS HQ, initiated the level busts seminar, which took place at Inflite's The Jet Centre, Stansted Airport, with the pronouncement that "we are here to have a discussion, not to preach at you". Indeed she was quickly backed up by Mike Edwards, NATS ATC Investigation, who spends much of his time talking to flight operations staff about level bust scenarios. \r"We want to encourage informal exchange of information" he said. "If an incident was ATC error we will put our hand up and explain what happened. If it was pilot error we would like you to investigate and tell us the results so that we can create feedback loops to the crew and controller involved and flight safety lessons can be learnt. Flight safety is our highest priority and all conversations are in confidence. Information gained is used to amend ATC and Flight Deck procedures."\rThe daily existence of level busts was first brought to NATS attention in 1989 when radar studies showed that some incidents were not being reported. The detective agent NATS employs to find out about level bust incidents is known as Separation Monitoring Function (SMF). Westley explained that SMF records all incidents where the separation achieved is less than 66 per cent of the proscribed standard separation. \rSMF was introduced as a management tool to monitor NATS' performance. It is entirely reactive and is invisible to the controller. SMF quickly showed incidents, including level busts, that were not being picked up the Mandatory Occurrence Reporting (MOR) scheme. NATS and the CAA now positively encourage reporting of all incidents, so that most level busts that are reported are done so voluntarily. \rSo what has NATS been doing to combat level busts? As a leading member of the CAA's Level Bust Working Group, in addition to producing videos, leaflets, and making presentations to controllers and pilots, NATS has even produced a league table of the safest operators and worst offenders. Not wishing to add insult to injury, Westley said the table is not presently published but operators can find out that they are 17th in a table of 87, for example. Operators are taking a keen interest in this as it is seen as very commercially sensitive. Some of the operators near the bottom of the table - i.e. some of the worst offenders - are Executive AOC holders.\rAdditionally, an Awareness Campaign is being run by the Safety Regulation Group of the CAA.\rFeedback from operators, said Westley, has centred around suggestions that their workload is reduced by having one transition altitude for Europe; by employing higher SID levels; and by having user-friendly charts. However nothing, said Westley, would be achieved unless there is a joint approach across the industry to take action. "If we cannot cure the problem," she said "we will have to reduce the effect, which means increasing separation, which in turn means reducing capacity. This is bad for our business and bad for yours."\rTo begin his presentation, Mike Edwards took a look at those he deemed primarily responsible for level busts. He did not have to look far. "The large majority are not caused by air traffic control," he told us, "but pilots." Indeed, we were told, 94 per cent of level busts are entirely pilot error.\rLevel bust types are wide and varied but highlighted at the top of the NATS hit-list, in 22 per cent of the cases, is 'exceeding SID altitude on departure'. In half as many cases, said Edwards, level busts were caused by a failure to correctly set the altimeter and in seven per cent of the instances, the ATC was found to have missed erroneous feedback. \rInterestingly, commented Edwards, this area is now considered in the US to be a 100 per cent pilot error situation (the precedent having been set in a US court). Nonetheless, he said, "we don't view it this way", adding that a solution rather than blame was of far more importance. \rIn 18 per cent of the level bust cases, a verdict of 'unknown causes' has been recorded by NATS as it is "very difficult to get feedback from some single aircraft operators".\rThe results for private executive transport or general aviation, said Edwards, were less than encouraging. "General Aviation provides NATS with four per cent of the business but 24 per cent of the incidents, so you are giving us six times as many problems as you should be," he remonstrated.\rThe majority of GA level busts are by aircraft registered in the USA or Caribbean. With reference to the types of aircraft involved in the incidents, 28 were Falcons, 26 Citations, 18 Gulfstreams but at the bottom, only 11 were Learjets, "Why Learjets have had less than half as many level busts as Falcons," said Edwards, "we do not know."\rAfter a break for coffee, Steve Sharp, CAA Safety Regulation Group, took to the floor with a look at the problem areas which surround level busts. Firstly he highlighted Standard Operating Procedures (SOPs). There were three main reasons why he could see that SOPs were not being carried out as they should be: Flightdeck procedures are not being followed or they are being rushed; poor RT phraseology/aviation English - "Don't be ambiguous, cut down on pleasantries" - and read-back/hear-back.\rSecondly he brought our attention to Standard Instrument Departures (SIDs), for which he said, unclear plates were creating ambiguities and the design of routings themselves were reducing flyability. He said: "Charts need to be designed to make the vital bits of information more clear.\r"The design of routes has been dictated by noise considerations, and could be rethought to take advantage of modern engine performance and FMS capabilities."\rFinally we were asked to think about how level busts are perceived by pilots and controllers. "I would suggest," said Sharp, "as a pilot, if you get away with it, you might think of it as a non-event. At the current time, ATC sees it as far more of a problem than pilots do. That's not right."\rOne reason level busts were not being reported, Sharp suggested, was because every report of an incident is a threat to business. "Who wants to have 25 MORs (mandatory occurrence reports) involving their pilots?" he queried, "but, although no one does, incident reporting is symptomatic of a healthy safety culture, so some MORs should be seen as a positive indication that safety is taken seriously by the operator.However, to avoid the scenario altogether, he offered, "if in doubt, check on the R/T".\rOne way in which level busts are being tackled is via the confidential 'On The Level' project, currently being conducted by Captains David Essen and Mike Nash. Throwing down the gauntlet, Essen said: "This is a pilot's problem and if it needs fixing, pilots need to fix it." By way of reassurance to any doubters, he added: "We have no political allegiance in this."\rEssen introduced us to the idea that the current reporting system is inadequate. MORs, he said, gave the basic details only and described simply what had occurred but not why. \rThe 'On the Level' project has been running for 18 months and concerns UK-registered aircraft only. Essen and Nash expect to have received 500 reports by Christmas 1999 and will be publishing their findings in full in the new year. Those they highlighted at the BAUA meeting include:\rSIDs
* Pilot interpreted clearance, "this is the only time you get clearance that you don't read back and is a major, major problem"
* First Stop Altitude (FSA) bust
* High workload situation
* Complex chart position, "I'm not making a sales pitch here but Jeppesen has come up with an amendment which is far easier to read and Racal (Airrad) has also been very responsive, changing the colours of its charts to ease reading and improve safety".\rSIDs suggestions
* more current pilot involvement in SID construction
* simplify chart portrayal
* give prominence to FSA
* include FSA with initial clearance, "a cracking suggestion," said Essen
* automatic frequency change after take-off
* standardise SIDs to finish at an altitude\rIn an open forum session, members of the audience suggested various ideas that would help reduce level busts, for example:
* record rates of climb
* eradicate SIDs altogether
* speed restriction
* SID clearance earlier
* install Datalink, "we're using an antiquated system that simply can't go further"
* RT loading
* RTF discipline
* No stepped climb SIDs\rNATS undertook to take some of these suggestions forward and report their progress back to BAUA.\rBusiness aircraft operators are encouraged to discuss any flight safety incident with NATS and can contact Mike Edwards by telephone on 01895 423 157, or by fax on 01895 423 934.