We take a look at missed approach incidents The following article was published in Transmit, the magazine of the Guild of Air Traffic Control Officers, in February 2020. BALPA has been given exclusive permission to republish it as part of an ongoing awareness campaign between pilots and air traffic controllers. We would like to extend special thanks to GATCO for its continuing support and collaboration in our joint effort to improve safety issues affecting the ATCO and pilot community. The following incidents highlight the need for mutual understanding of procedures between the ATCO and pilot, and to manage each others expectations. Hopefully, this article which is written from an ATCOs perspective will be of interest to the pilot community. here have been a number of missed approach incidents highlighted in various safety discussions recently. This safety update takes a look at a couple of these incidents and the discussions around them. 1. ATCOs issuing different missed approach instructions At a recent Royal Aeronautical Society flight operations group meeting, it was reported that discussions at a previous UK Flight Safety Council meeting had centred on the tendency of ATCOs to issue different missed approach instructions as soon as a go-around is commenced, rather than letting crews follow the published (and coded) procedure. The group also discussed an airprox incident, which occurred when a crew carried out an immediate go-around when they realised they were unstable and they came into proximity with a slower aircraft that had already started its take-off roll. The discussion moved to the wisdom of conducting an immediate goaround instead of warning air traffic control, briefing the other pilot, and then flying the manoeuvre in a more measured manner. One operator insisted that its standard operating procedures were immutable, and that a delay to a go-around could be confused with an attempt to salvage an unstable approach when the flight data monitoring was reviewed; however, others did not agree. There had also been several go-arounds caused by inadvertent activation of TO/GA mode by contact with the thrust levers on Boeing aircraft, which had caused approaches to become unstable: one Boeing 737 operator had eight occurrences in one month. GATCO comment The easy option for crews is to let the FMS follow the programmed published procedure, which reduces the number of last-minute changes in the situation. ATCOs should be aware that SOPs can vary from operator to operator, so should listen with particular care to messages about nonstandard manoeuvres and seek clarification if the content is not completely clear. GATCO is also consulting with IFATCA on this issue. 2. Go-around from unstable approach at Stansted READ MORE RISK CATEGORIES The CHIRP board discussed recent AAIB and UKAB (UK Airprox Board) reports regarding an airprox at Stansted that involved a piggy-back goaround at night. The go-around aircraft was hot-and-high, with little prospect of a stabilised approach when, at around 1,000ft, the somewhat flustered crew initiated a go-around. During the go-around on the published missed approach procedure (MAP), the first officer, who was the pilot flying, became overloaded and the captain took control. However, as the captain attempted to take control, the first officer continued to make control inputs and the resulting CRM issues meant they did not respond to ATCs instruction to turn left now for about a minute. This instruction had been issued to avoid another aircraft that had just got airborne and was departing along the SID. In the event, the other aircraft was subsequently instructed to level off, did so, and was alerted by its TCAS. However, the two aircraft came within 300ft vertically and 80m laterally of each other and the UKAB assessed the risk as category B (see box). In this case, because the missed approach procedure and the standard instrument departure were taking both aircraft in the same direction, there were very good reasons for the ATCO to issue fresh instructions but, along with the CRM breakdown, these instructions contributed to pushing the first officer beyond his capacity. The requirement for go-arounds to be flown using the aircraft autopilot whenever possible is well known and recognised, and the CHIRP board commented that the published MAP should ideally be the one that is most likely to be flown without interruption by ATC. The issue of MAP procedures had also been raised with the CAA in 2014, in light of a previous CHIRP report. In that case, the CAA agreed to encourage airports to publish the MAPs that they expect to be used as a matter of routine. READ MORE RISK CATEGORIES Category A serious risk of collision existed Category B safety of the aircraft compromised Category C no risk of collision Category D insufficient information Category E normal safety standards pertained Ref: UKAB Fact sheet SOPs can vary, so ATCOs should listen with particular care to messages about nonstandard manoeuvres and seek clarification if the content is not completely clear CAA comment After the Stansted incident, the CAA raised an internal safety risk relating to piggy-back missed approaches. These are circumstances where safe separation between a departing aircraft and an arriving aircraft (executing a published missed approach procedure) erodes. The likelihood of these occurrences increases as single runway or closely spaced parallel runway operations intensify. Following the raising of this generic risk within the CAAs regulatory safety management system, the issue was discussed with NATS in mid-2019 and a series of monitoring actions proposed. That work is continuing as we refine an action plan associated with the risk, the first element of which is to identify other aerodromes and air navigation service providers (ANSPs) that present increased likelihood of a piggyback missed approach because of increasing intensity of operations. CHIRP comment The board was heartened that the CAA had agreed further work to look again at MAP procedures, but there are other lessons within the incident that would benefit from further thought by pilots and controllers. For example, having made the decision to go-around when the aircraft was at 1,000ft, was it necessary for the crew to initiate the go-around immediately, rather than pausing a short while? Had they done so, the crew could have taken the opportunity to spend a few seconds to warn ATC first, and to conduct a micro-brief about who would fly the go-around. This would probably have prevented the airprox. Recognising that ATC had very few options in the circumstances, and that an immediate response to the turn left now call was expected, it was also relevant that separation had been reduced in accordance with reduced separation in the vicinity of an airfield (RSVA) procedures, which require the controller to ensure only adequate separation (which is not specifically defined in the RSVA procedures stated in MATS Part 1, Section 1, Chapter 3). However, the go-around crew were on the approach frequency, whereas the departing crew were speaking to the aerodrome controller/departures. There appeared to be a lack of clarity over who was practically ensuring the adequate separation of the two aircraft as a result.
