Pilot Navigation, a mix of instinct and information – By Marcus Bicknell
Please enjoy this article by Marcus Bicknell who is a pilot in his own right but was also trained by his father, who flew reconnaissance missions all over the Content in Mosquitoes during the war, without any navigational aids, of course.
This article is really interesting as, for me, this tells you how a good pilot operates but what he is talking about must also tell us about how animals navigate too.
Situational Awareness. A Holistic Approach to Navigation
We were flying at 5000 feet approaching Weston Super Mare from the east in a single engined Mooney. My Mooney. 1989. My rather proud dad, 71 years old and fresh from taking up his instructor licence after a gap of 40 years, was waxing lyrical in the right seat. “ We used to swing round the lighthouse at Weston-super-Mare if the sortie over Germany had been at all boring.” It took me a moment to digest this remark. My dad used to fly Mosquitoes in World War II. Yup, Wing Commander Nigel Bicknell DSO DFC was with 1409 Met Flight, part of Bomber Command and commonly known as Pampa, based at Wyton near Cambridge. I looked at the map afterwards to see that Weston-super-Mare was about 160 miles away from Wyton so what dad was saying was that after risking their lives under enemy anti-aircraft fire for 3 hours to take photographs of bomb raids or weather conditions over the continent, they would just “swing round” another 300 miles. However, at the Mosquito’s speed of up to 300mph this would only add about an hour to their trip and could be considered a jolly. Was their RAF base going to give them some navigation aid out of the Bristol Channel and back again? I don’t think so. He just went flying. The map, the compass, and the sun in his eyes.
It got me thinking about the sort of skills he had. How much of navigation is what you learn in ground school and how much is seat-of-the-pants? When Nigel was giving me instructions of the PPL IMC rating, for flying on instruments in the clouds, we were based at Compton Abbas near Shaftesbury and flying a Club Cessna 150. Returning from a navigation exercise round Southampton I was aware that we were stuck in a thick cloud layer with no sight of the ground. Compton Abbas, where we had to land, has no navigation aids. “Just continue on the 280 radial from SAM for 35 nautical miles on the DME and I think you’ll find the cloud will be broken up and we can turn back to Compton Abbas from the west.” That’s what we did. That’s what happened. What in Nigel’s brain could have told him that the cloud would break up to the west of the field? Experience. He had seen it before. He’d noted it on the way out and stored away in memory. He just knew.
This was a pilot of great experience. He had flown 4000 hours in the war in over 50 different types of aircraft and more than half of those hours over enemy territory with no navigational aids except the occasional OBOE to test. In his photo album during his time with Pampa is a beautiful photograph of the Argentiere glacier from 30,000 feet. You can see it at http://www.marcusbicknell.co.uk/nigel/. The entry in his logbook for 12th October 1944 reads “Pampa: Avallon-Chamonix-Aosta-Le Puy” with F/L Dale, his regular observer, 4 hours 45 minutes in the air. That means they undertook a single aircraft mission over enemy territory to come back with photos and reports of the cloud formations and other weather indicators to help Bomber Command decide on that night’s bombing missions. With no navigation aids they flew at the top of a piston-engined aircraft’s envelope across Holland, Belgium, the Rhone Valley, the French Alps over the Mont Blanc where this photo was taken (among many on the mission) then west over the Massif Central, north to Paris and back to Cambridge. By following the map. By assessing compass headings and prevailing winds. By timing their legs and their turning points. By checking what they saw with what they expected to see. And home for tea.
Of course this was inspirational for a young pilot. I lapped it up. Some aspects of technical skills and the use of the brain and sense organs for perception are surely hereditary. Intuition. Seat of the pants. How does it all fit together?
In ground school we start by learning visual navigation techniques, that is, using reference points on the map to establish a position plus the compass, the aircraft’s speed, wind speed and wind direction to establish the next course and to verify the next waypoint. If you are not certain what the wind speed and direction are, then there are techniques which help you anticipate being blown off course. The most significant is the use of a clearly-visible line roughly at right angles to your course such as a coast, a river or a railway line. If you arrive at that line and you are not certain of your position you can turn left or right on the line until you can identify the waypoint (a town, an airfield) or another feature from which you can establish your position.
As soon as a pilot is in the air, a multitude of other senses and inputs come into play. With the map on your lap and your eyes out of the cockpit windshield, a whole world of space and time opens up. For the unwary these free dimensions are dangerous. Disorientation, confusion, incorrect map reading, forgetting the time, forgetting to synchronise the direction indication to the compass… all can get a pilot into deep trouble. As has been frequently documented, the escalation of a variety of small errors can lead to fatal consequences.
For those with a good grounding in the techniques and some confidence in their own instincts, navigation is a fine art giving great satisfaction. The human brain excels at storing away peripheral information. We just have to retrieve it and put it to use. What sort of information?
Whatever the forecast said, what is the wind now? Point to where the wind is coming from on the ground and you can be 90% certain that at altitude it will be coming from 30° to the right. How strong is the wind as you get into the plane? How much fuel did you put in? Without even writing it on your log, have you retained what the endurance will be before you run out? What did the national weather map look like? Where is the depression (more often than not over the Irish Sea heading towards Scotland)? The wind runs anti-clockwise round a depression, so your brain has logged how the wind direction might change during a long flight. When you flew over that other airfield, what direction was the windsock pointing? When you saw the stubble burning on a cornfield which direction was the smoke blowing? With what you know of the wind, should you be turning home when your tank is half empty, or much earlier? Is the aircraft bumping about in turbulence more now than it was half an hour ago? What are the typical weather conditions in the area you are flying? Are there physical features like sea or mountains which can influence wind and precipitation?
All these indicators about the weather can be very useful when the brain is trying to assess later in the flight what the position is and what the best course of action is.
Situational awareness is an animal skill vital to an office worker crossing the station concourse, to a driver going round a roundabout and, crucially, to a pilot. In addition to your navigation and the weather there are other factors in your “situation” of which you must be “aware”. This is not just about what is in your peripheral vision (but that helps). This is about the human’s organs’ ability to compute from multiple sources or data, in real time.
- The ears. What are you learning from the engine note (and from an unexpected change in the engine note)? What is the sound of the airstream telling you about the speed and attitude of the aircraft? Is the sound of the aircraft correct for the power selected (or are your wings icing up and causing potentially fatal lack of lift and drag?). What did you hear another pilot say on the R/T about something out of order? Is the aircraft balanced, i.e. is the rudder input balanced with roll in the turn…. Whoops, what’s that got to do with the ears. Well, the ears are the body’s principal balance organs, and they will tell you if the body is upright and if your weight is acting vertically through the body. Learn this feeling now because it will save your life when flying on instruments only.
- The nose. What are you learning from an unusual smell? I worked hard at being conscious of smells and establishing in my mind what smell was engine oil dripping from a pipe union onto the exhaust as against the ozone and plastic smell of an electric wire shorting.
- The eyes. Are your eyes scanning (as was drummed into you by your instructor) for converging traffic ahead, the engine gauges, your horizontal situation indicator, the navigational instruments, the clock? And if you are scanning them okay are you actually processing this information and drawing conclusions? Part of this input process is instinctive (a motor memory) and part is conscious, i.e. I must look at data differently from time to time in order to notice a trend. Is the fuel gauge going down at the rate I expect? Do Ts and Ps correspond with the throttle position and altitude? Are you able to assess what’s on the map and what you see on the ground at the same time as continuing the vital scans? Which leads to…
- The brain. How is your CPU working? Yes, each of us has a central processing unit (don’t get me started on Thuring and the birth of computers and artificial intelligence) which has to poll the myriad of input signals, assess their importance, compute the required solution and instruct the hands (often) what to do next. How does your body react to stress? Are you hands sweating right now? Have you trained yourself, or had help, to prioritize tasks when there is not enough time to do them all? This skill can save lives whether it’s decision-making when running short of fuel or when preparing for an approach to an unknown airport in bad conditions.
- The memory. That’s part of the brain, isn’t it? How much am I remembering about flight conditions I learnt in advance, about features I saw on the map when I planned the flight last night? How much of what I am retrieving from memory is conscious and how much is subliminal?
- The magnet. Just kidding. Humans don’t have a magnet. Or do we?
- The sextant and the theodolite. Well, the mid fuselage gunners of big bombers used to take fixes from the stars, so, yes, it’s a possible input.
I am certain that situational awareness required for safe flying to visual rules depends on every single one of these factors and many more too. We depend on a holistic approach to situation awareness, i.e. the ability to see the whole picture at any one time.
When the pilot has mastered flying to visual rules, i.e. out of the cloud, it’s time to start learning how to use electronic aids such as non-directional beacon, the radials of a VOR, the distance to a DME. Even with the use of instrumentation in the aircraft the wind has a significant effect and the aircraft’s heading must be adjusted to those conditions to be able to follow the required track. The advent of GPS in light aircraft has taken a big burden off the pilot because it is now very difficult to get lost.
However, situational awareness is just as important when flying on instruments. I was privileged to progress from an ordinary Private Pilot’s Licence to a PPL with Instrument Rating and a state-of-the-art high altitude tourer, in my case the Piper Malibu 350, 200 knots at 25,000 feet. But a VOR and ILS approach to a foreign airport in instrument conditions and some wind can be very disorientating. What is it about intuition, or the seat of the pants, that tells you where you are in relation to the green and purple lines on your Garmin? How much is intuition, or mechanical assessment of the dials in front of you, experience or speedy brain computation guiding your reactions? The skilled pilot knows his or her position, speed, heading, track, next turning point and all the factors described in this article, knows all these factors, all at the same time, and is processing them into calm, safe navigation. A poorly trained pilot without recent experience of seat of the pants flying will sooner or later lose control of his aircraft. Air France 447 from Rio to Paris in 2009 is a classic case in point; just one instrument (the pitot, air speed indicator) faulty and the pilots went to pieces. They spent over 15 minutes pulling the nose of the aircraft up instead of pushing the stick forward. The aircraft was in a deep stall and 228 people died.
The most exciting part of my instrument flying training was “unusual positions”. In the cloud or with the screens up, I, the pilot, cannot see out. The instructor tells me to release the controls and hide my eyes. He throws the aircraft around to disorient me. He might choose to knock the throttle off, trim the tailplane for a climb, throw the aircraft into a left turn. Incipient stall. “You have control”. In a panic I open my eyes and grab the yoke. Check engine speed, listen for the engine note, listen for the airstream, throttle setting, HSI, climb indicator, turn indicator, any other input of use. Then apply the corrections to get back to level flight. Wow, sweaty palms!
So, the answer is not “instinct”. In the many dimensions of flight, man’s seat of the pants instinct can be dangerous. It can lead to the wrong conclusions – “pull the stick to stop the aircraft descending”. But I do think that regular flying in conditions where all the techniques mentioned here are deployed, refined, processed and acted upon is the safest way to keep a pilot sharp. Situational awareness is not a technique which can be taught in ground school. Situational awareness is not just awareness of what’s in your peripheral vision. It is the permanent refreshing of the pilot’s ability to process information from a multitude of different sources and acting on the right conclusions.
23 March 2015