Human Factors Incident Reporting — Page 319, Lesson 514

I want to walk you through a new chapter now — Human Factors Incident Reporting. This is a critical part of your training because it shows you real-world examples of how human factors, which we've been studying in theory, actually play out in the cockpit. The book uses reports from a system called CHIRP — that stands for the Confidential Human Factors Incident Reporting Programme. It's a voluntary, confidential reporting system where pilots and other aviation professionals can submit reports about incidents they've been involved in, without fear of punishment. The goal is to learn from these mistakes and improve safety across the industry. Let's start with CHIRP Report 10, which is titled "Cockpit Design." In this report, a crew is taxiing out from dispersal — that means they've left the parking area and are moving toward the runway. They've reached the point in their checklist for "Flap Selection." The captain confirmed that the flaps should go to the takeoff setting, so the first officer — the person speaking in the report — put his left hand down, grasped the knob, and pushed downward. But the travel of that knob felt remarkably smooth, so he looked down and found he had actually closed the No. 2 HP cock — that's the High Pressure cock, which is a fuel shutoff valve for engine number two. By pushing that lever, he shut the engine down. The key point here is that the top of the flap lever and the HP cock are immediately next to each other. The design of the cockpit placed two controls with very different functions — one for configuring the wing for takeoff, the other for shutting down an engine — right beside each other, with similar shape and feel. The pilot's expectation and muscle memory led him to the wrong lever. The report notes that this was only a small incident and not much more than highly embarrassing, but it might have been different if they had been on the approach — meaning if this confusion happened during a critical phase of flight like landing, the consequences could have been far more serious. Now let's move to CHIRP Report 11, titled "Automated Controls." This report describes a situation where throughout the descent, the entire crew assumed the Auto Throttle System — abbreviated ATS — was engaged. The Auto Throttle System is the automation that controls engine thrust to maintain a selected speed. Although they all checked that the correct speeds were set "in the window" — that refers to the speed reference display where you dial in target speeds — they ALL missed the fact that the ATS was not actually engaged. Here's what happened next: they captured the Localizer — that's the lateral guidance beam for the instrument landing system — and were levelling off at 4,500 feet to capture the Glideslope, which is the vertical guidance beam that brings you down to the runway. During this transition, the speed was allowed, inadvertently, to drop 10 to 15 knots BELOW MIN SPEED — that's below the minimum speed for the current configuration, meaning they were approaching a stall. On noticing the speed, the pilot applied maximum thrust and prevented the aircraft from stalling. The reporter adds that he knows of two other similar cases concerning different crews, told to him confidentially. His conclusion is important: it's apparent that crews rely rather heavily on the autothrottle system, and it only takes the assumption that ATS is engaged, combined with a distraction on the flight deck, to set up a potentially dangerous situation. This is a classic example of automation dependency and expectation bias — you see what you expect to see, and you miss the critical indication that the automation isn't actually doing its job. Finally, let's look at CHIRP Report 13, titled "Flying and Health." This one is cut off, but we get the beginning. On the climb to FL80 — that's Flight Level 80, or 8,000 feet pressure altitude — the pilot suddenly started to feel unwell, with stomach pains and an urgent desire to defecate. It soon became obvious that he was suffering from an attack of diarrhoea. The report notes that to divert back to the departure airport to go to the toilet would have incurred serious commercial penalties and, no doubt, very little sympathy from the company. This highlights a real dilemma: a physiological need that can be distracting and even incapacitating, versus the commercial pressure to continue the flight. It's a reminder that human performance is affected by basic bodily functions, and that pilots need to consider whether they are fit to fly before and during a flight.