CHIRP commends the reporter for their open and honest account of this event. It takes integrity and professionalism to share experiences that could easily be kept private, and doing so contributes significantly to the learning and safety of the wider aviation community. This is precisely the kind of valuable reporting we aim to encourage at CHIRP. In many ways the candid report speaks for itself. The reporter identifies that they were concentrating on a demanding phase of the flight, ie the landing, became distracted and just didn’t hear (or fully process) comms between the airliner and ATC. Listening whilst anticipating something specific (in the reporter’s case to be told to land) can, owing to confirmation bias (in this case a mention of a light aircraft), lead to the brain hearing what it’s expecting to hear.

It’s possible that the reporter felt that they were a lower priority than the airliner, leading to expectation bias and implicitly receiving the corresponding message. The problem seems to have been compounded by a reduction in capacity owing to focus on another task ie landing. To their credit, throughout finals and the landing, the reporter did absolutely the right thing in prioritising flying the aircraft.

It’s worth remembering that if you’ve missed an ATC call, partially heard something, or are just not sure what was said, rather than assuming it’s ok or hoping it wasn’t relevant to you, then requesting a “say again” never harms; it’s better to be safe than sorry. The reporter did particularly well to identify on go around that something wasn’t right, then calmly and systematically work through the possible causes, finally correcting the mistake without rushing and potentially compounding the error. Sometimes unexpected things happen in flying; working through the issue and always remembering to Aviate, Navigate, Communicate will lead to a better outcome. Then debrief yourself afterwards when you’re on the ground and assess what went wrong, how you dealt with it, what you did well and what could have been done better. There are invariably lessons to be learned; maybe consider reporting to CHIRP so that others can benefit from the experience too.

In general, it’s also worth highlighting that ATC are very unlikely to call for a touch-and-go to be converted to a full landing once an aircraft is on final, unless there is some sort of emergency. For safety reasons, ATC try to avoid issuing changes of instructions to pilots during high-workload activity. Finally, for unusual operations eg in this case an airfield in controlled airspace and with regular airline training traffic, some thorough Threat Error Management and having a plan for potential eventualities is always a good idea.

This report addresses two separate but related issues. It’s a valuable contribution, bringing attention to two minor events that might have been overlooked but instead sparked important and lively discussion about aspects of air traffic services and human factors in aviation safety.

Issue 1 – Similar callsigns equally abbreviated causes confusion

The controller’s handling of the situation certainly seems to have been lacking in some respects. Firstly, if there are multiple callsigns on frequency with the same final two letters then, to mitigate confusion, the controller should immediately revert to full callsign and advise pilots that similar callsigns are on frequency. Therefore, it wasn’t unreasonable for the reporter’s candidate to request clarification, especially since he hadn’t heard the entire message. CHIRP always advocates the use of “say again” or similar if there is any doubt. It’s not safe or sensible for a controller to assume that a pilot will ignore calls for their callsign just because the call isn’t strictly relevant to the service they’re receiving. Overall, an unnecessary level of ambiguity ensued owing to this mistake and, as the reporter identifies, safety margins were reduced by superfluous R/T.

The second area where the controller wasn’t overly helpful was in the tone and manner of their response to the candidate’s question. Even if the controller had been in the right, such a brusque response seems at best unconstructive and could even have unsettled the pilot, especially if they were under pressure or with a high workload, leading to distraction and impacting safety. An angry or even curt approach on the R/T will never improve matters. For pilots and controllers alike, patience, courtesy and consideration, no matter how frustrating the situation or pressure of workload, should always be the overriding consideration on the radio.

Notwithstanding the above, CHIRP does have a degree of sympathy with ATC. Farnborough is a notoriously busy airspace with the same controller often running several frequencies at once. It’s useful if pilots can be aware that when receiving a service from Farnborough, an additional level of vigilance may help controllers manage a challenging task. In this circumstance, controller workload is unknown; but if it was particularly high then they may not have had the bandwidth to realise there were similar callsigns on frequency. We understand that this would not be uncommon with Farnborough. Similar callsigns can be difficult to pick up and are sometimes only noticed when a controller gets an ‘odd’ response to a transmission or a reply from a different voice to what their brain is expecting. Even if the controller had realised, in the heat of the moment it was probably better to call the traffic than not. At worst, this leads to two aircraft looking out, which is better than none if there is the chance of an imminent conflict. The controller’s subsequent response may well have been indicative of someone under considerable pressure with multiple inputs who just didn’t have the capacity to explain the full picture. Nonetheless, as a rule of thumb, pilots and controllers can usually save time by sticking to standard phraseology and not reacting/escalating on the airwaves. Although everyone must achieve a minimum standard to qualify them to participate in aviation, competence and quality will vary with both controllers and GA pilots. Humans, by their very nature are not perfect and changing circumstances affect performance, so ‘cutting some slack’ both ways is the best approach and working together as a team to achieve a more effective, enjoyable and ultimately, safer, day out.

As an aside, regarding the level of information provided, the controller is correct that calling traffic is not a feature of the Basic Service and indeed controllers are not even required to monitor such flights. However, controllers should give Traffic Information about general aerial activity and will do so when they perceive a definite risk of collision exists, so it is not uncommon to hear this practice. Indeed, the controller has a ‘duty of care’ and cannot let a collision occur if they’ve noted a conflict on the radar screen, therefore some kind of deconfliction action should be taken where possible. CAP 774, para 2.5-2.9 provides further information. Alternatively, for general, easily accessible, refence material covering the different air traffic services available to GA pilots, try these:

• The Skyway Code https://www.caa.co.uk/publication/download/16112
• CAA Safety Sense leaflet SS22, Radiotelephony, https://www.caa.co.uk/media/vfybdggv/safetysense22-radiotelephony.pdf.

Issue 2 – Limitations of a Traffic Service

To clarify a pilot’s responsibility under a Traffic Service – pilots are required to advise the controller of altitude changes under a Traffic Service as noted in CAP774 ‘UK FIS’ Chapter 3 ‘Traffic Service’ Para 3.11 ‘Levels’ which states:

Unless safety is likely to be compromised, a pilot shall not change level or level band without first advising and obtaining a response from the controller, as the aircraft may be co-ordinated against other airspace users without recourse to the pilot.

Although CAP774 para 3.11 does allow for pilots to request a block to operate within, this is at the discretion of the controller, who may not have the capacity to provide such a service or may be aware of other aircraft that prevent the allocation of a block. This was communicated to the reporter, who was grateful for the update and responded.

Response from Reporter: I have to admit to a slight misunderstanding of the pilot responsibility in terms of level changes under a traffic service so that’s definitely one I can pass onto my students. I don’t often operate under a traffic service as it generally isn’t that suitable for instructional flights for exactly the reasons I believe the other pilot then changed service.

While the controller’s message was technically correct, their tone came across as abrupt and unhelpful. As in the earlier example, they may have been under pressure owing to traffic levels, but being antagonistic on the radio rarely helps and can unsettle less experienced pilots, potentially affecting their performance. This report highlights the importance of staying constructive on the radio and remembering that pilot skill levels vary widely in general aviation—something controllers should always keep in mind.

As with the previous issue from this report, there was also some sympathy for the controller. Non-face-to-face communication is particularly prone to misinterpretation and it’s unclear whether the Farnborough controller was indeed ‘snippy’ or it was a case of the reporter interpreting it as such. Either way, some consideration for controller workload, especially in busy airspace like Farnborough, can help with a smoother service. By all means ask for a block but expect to be advised “unable due workload” or “reduced traffic information due controller workload” and have another plan (such as downgrade to a Basic Service, which is what the pilot did here). In quieter parts of the country, it’s much more reasonable to expect to be able to operate in a block whilst receiving a Traffic Service, but with Farnborough, especially at busy times of day, it’s highly unlikely that any controller would have the capacity to accommodate such a request. As with so many reports to CHIRP, this highlights the importance of being aware of and making allowance for the situation of others in the wider team. Everyone remembering the ‘3 Cs’ will go a long way to safer skies – Caution, Courtesy and Consideration.

Finally, although not specifically germane to this report, did you know that there are recourse options if airspace access doesn’t work out as hoped.  It’s frustrating — you plan a route, note the frequencies you need, refresh your RT wordage, get well into the flight, request a transit through a piece of controlled airspace and are refused entry. What do you do? Ideally you fall back on Plan B and continue outside that piece of airspace. But what about after landing? Do you simply shrug your shoulders, or perhaps complain to a few friends, and then forget about it? While some pilots do follow up a refusal to try to find out why they were denied access, many others don’t which is a pity because there’s a straightforward system to record these denials and, importantly, this provides data for the CAA to use to help improve airspace access for all. It’s called the UK Airspace Access or Refusal of ATS Report Form and is designed to highlight airspace refusal issues that can be resolved so that others might in future get the access you were denied. If you haven’t yet come across it, it’s an online form (technically known as FCS 1522 – UK Airspace Access or Refusal of ATS Report) that lets the CAA know you were denied access, refused an air traffic service, or type of service you wanted. Read more about it in this edition of Clued Up – GA Update.

The airfield concerned is a CAA licensed aerodrome with Air Ground radio only.

This report highlights just how easily expectation bias and task focus can influence decision-making even before getting airborne, especially in a busy, high-workload environment. The reporter had formed a mental ground picture, based on the NOTAM and their expectation. This was reinforced by the other visible aircraft and led to an understandable but incorrect assumption about where aircraft could be expected to route. Combined with the reporter’s strong focus on airborne traffic and finding a precious gap to depart, this created a blind spot to the radio transmission which would have provided vital spatial awareness. This report also highlights the importance of careful reading and interpretation of NOTAMs; on this occasion, was the runway out of use for all operations including taxying, or was it just unavailable for take-off and landing?

In aviation, it’s easy to make assumptions and become fixated on one element of the task, especially when there’s a high workload and pressure, real or perceived. In this case, it was uncertainty about squeezing into a busy circuit and the knowledge of aircraft queuing behind. The key takeaways are: how quickly situations can change and how it is easy to miss a vital piece of information when attention has been prioritised elsewhere.

Fortunately, the reporter made a timely R/T call to announce their intentions; thus, the unfolding hazardous situation was picked up by another waiting pilot, who spoke up and saved the day. What a great example of successful teamwork and therefore the incident being just chalked up to a ‘near miss’. This radio intervention prevented a potential runway incursion and underlines the value of good communication and mutual vigilance, particularly at airfields with only an Air Ground service where pilots carry more responsibility for situational awareness and separation.

The reporter did an excellent job of analysing the human factors at play here, even if they were a little hard on themselves. We all make mistakes, but what and how we learn from them is a measure of our calibre as aviators. We commend the reporter for their honesty and willingness to share this experience. Rather than brush it off, they reflected, identified where assumptions had crept in, and recognised how their attention had narrowed. This kind of insight is exactly what helps others avoid similar situations. It’s a valuable reminder that, even at familiar airfields, staying alert to the big picture and expecting the unexpected is essential to safe operations.

This was an honest and insightful report. The reporter has candidly identified the causes of the problem and some nodal points where, in hindsight, different decisions could have been made. This rather fraught experience will almost certainly have permanently altered their skydiving behaviour.

For our skydiving readers, there is a detailed explanation of the equipment factors that led to the incident and additional specialist considerations at https://chirp.co.uk/hot-topic/skydiving-special/. In summary for non-skydiving aviators, one of the drawstring tabs had been able to come free and tangle in a ‘cascade’ (where two lines attached to the parachute are fused into a single line halfway down to the parachutist). This is a known but infrequent cause of malfunctions. While it is disappointing that the reporter has received no direct response to their email to the manufacturer, it is of note that the manufacturer is currently advertising this make of canopy as having ‘continuous Dacron lines’ (i.e. no cascades) and a ‘snag resistant collapsible slider’ so that ‘cascade related malfunctions are impossible’. It appears that the technical issue may have now been addressed.

CHIRP has a deal of sympathy for the reporter since jettisoning a main parachute which appears mostly open takes a degree of resolve, particularly if it looks as if it may improve shortly. It is easy to keep on trying to sort it out well past decision altitude, or even to forget about decision altitude, and then find one is also too low to cutaway and there is no easy way out. So, by ‘decision height’, the jumper should be sure that the canopy is large, rectangular and undamaged with lines that are clear, untangled and undamaged and that the canopy is fully controllable with turns in each direction and normal flare response to using the brakes. The controllability check is an essential part of a canopy check, which should follow immediately after ensuring there is no risk of collision with other canopies. If the canopy is flared for the first time at 20 feet above the ground, it is too late to do anything if it stalls or collapses (except for attempting a good landing roll if possible).

The reporter states that when their canopy collapsed near to ground level, they were thrown onto their back. They expressed the view that they may have broken their legs if they had attempted a PLF (parachute landing fall – a technique which spreads the impact across multiple body areas and reduces the risk of injury). The CHIRP skydiving members were of the unanimous view that a PLF remains the best way of reducing the risk of serious injury during a hard landing, even if a lower leg injury may occasionally be the price of avoiding a spinal, chest or head injury.

For a safe jump, the jumper will need to have a clear plan in their head long before walking out to the aircraft. The plan will include choreography of all jumpers to ensure clear airspace in time to deploy at an altitude which gives them an open and controllable canopy at or above their minimum opening height. They must have a clearly defined decision height in their head and be resolute that they will commit to emergency procedures if their canopy and lines do not look normal and behave normally by that height. The jumper must be resolute that any attempt to clear a problem will be interspersed with frequent altitude checks and will not go past decision altitude. Finally, they must have a clear minimum cutaway altitude since low cutaways may be fatal or life altering. Exact decision altitudes and minimum cutaway altitudes are determined by many considerations including exact type of equipment, Automatic Activation Device settings, local geography, jumper experience and currency. Student skydivers under training must do exactly as instructed. Licensed skydivers who are not clear about these altitudes should discuss with an advanced instructor before manifesting for their next jump. Any skydiver will benefit from regularly practising emergency drills in a suspended harness. Many drop zones run a safety day each Spring, providing supervised simple and complex emergency drills for any skydiver who wishes it.