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An introduction to decision making and flight route selection

Posted By Elena Psyllou, 20 December 2018

by Elena Psyllou


Every day we make thousands decisions; some are unconscious and others need extra effort. For instance, on my way to work, every morning I get on the Bakerloo line, change at Embankment and get off at South Kensington. But when the service suffers from severe delays, that is when I need to change my route and find the shortest and most comfortable journey to my destination.

Decision theory has gathered interest across disciplines from economics to engineering and social science. In aviation, there have been studies into the decision making of pilots. Models were then developed in an attempt to improve the design of the systems that are routinely used whilst promoting awareness across individuals of the complexity of human cognitive activity. Models like FOR-DEC and SAFE (read more here) have been used in pilot’s training and they outline the main steps of the decision making which are seek information, assess the options, make a decision, take the action.

Moving beyond such simplified versions, extensive research has been conducted in order to better understand the rationale behind the decisions and elicit the contribution of key factors such the expertise, the conditions decisions are made and the quality of information.
Research in naturalistic decision making has shown that expertise plays a key role in responding to critical situations where time is limited or information is uncertain and unavailable. Aviation and evacuation of buildings are great examples of such challenging environments in which critical decisions need to be made in a speedy manner and be of an appropriate nature.

In the 90s Gary Klein developed such a naturalistic decision making model, known as the Recognition Primed Decision (RPD) model that describes how experienced individuals make decisions in time-pressured situations where they are not able to generate and assess a range of options. The model was developed based on fire-fighters and pilots. Individuals use their expertise to find a satisfactory decision/action rather than that which is the best. They start this dynamic decision making by assessing the situation based on patterns of cues. This situational awareness activates mental models and action scripts that the individual has available from prior experience. Under such conditions, a successful decision relies on a correct assessment of the current situation, an adequate utilisation of cues, effective evaluation measures and of course, the experience of the individual.

The RPD model shows that the analytical approach of evaluating every possible course of action in order to reach the best course of action is time consuming and in safety critical industries like aviation, delays can be catastrophic. There are various ways that expertise is transformed to be easily retrieved. Research in pilot decision making (such as O'Hare et al. 2009, and Hunter et al. 2009), pilots code their previous experience into rules and cases and they retrieve those during their decision making. Rules are conditions that need to be met, for example, select a route that is straight, direct and above the minimum safe altitude. Cases are representations of events that they have previously experienced, for instance, the weather changes fast along a certain route and a diversion is needed.

Traditionally, pilots use paper charts to select the route and do the calculations for weather adjustments and fuel. Today, apps on our smartphones and tablets tell them the fastest and most direct route and with limited mental effort needed by the pilot. Similarly, route planner apps for urban travel such as CityMapper and Google maps suggest routes based on a series of computations by their algorithms. The apps not only show the flight path but they also present the trip duration and other relevant information. Nevertheless, the user who can be a pilot, a pedestrian, a motorist, remains the person that makes the decision which route to take and at what time.

Research conducted with recreational pilots and the use of route planning apps for air travel in the UK, Norway and Finland at Imperial College revealed four types of uses of these apps:

1. “YES MAN” The pilot accepts the suggested straight direct route and will make modifications in-flight, if needed, i.e. tactic decision making. A previous plan saved on the app might be used.
2. “HOLD ON A MINUTE” The pilot inspects the route and make any adjustments that will make the flight more pleasant, more cost effective and safer using rules and cases pre-flight
3. “ASSIST” The pilot uses the app to seek information, make a few calculations, e.g. regarding the weather, or see previous flight routes that are saved on the app
4. “TRUST ME” The pilot does not use the app and relies on his/her ability to remember and seek support from other sources.

It was further revealed that the pilots use the app differently based on the features of the route. In particular, for routes that are frequently used, pilots do not necessarily study every parameter (YES MAN or ASSIST) whilst routes that are flown for the first time, more time will be spent to review the airspace and weather (HOLD ON A MINUTE). Individual factors also affect the decision making and the use of the apps. In particular, pilots who want to encounter the latest weather update will do further modifications in-flight instead of pre-flight. Such en-route decision can also lead to issues such as loss of situation awareness in that pilots fail to holistically comprehend the situation in such dynamic conditions aviation operations and can lead to loss of situation awareness.

Similarities on how the route is selected using the apps are expected between pilots and any type of commuter. Sometimes we rely on the app especially if we are strangers in the area and other times we select routes we drove before. Next time you use the route planner app, as a pedestrian, a driver or pilot, think of how they contribute to your decision on what direction to follow and identify yourself which of the four types of users you are.

Tags:  Decision Making  Flight Route Selection  GANG  General Aviation  Navigation  Pilot 

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Note of meeting of the International Maritime Organization Maritime Safety Committee IMO MSC100

Posted By Kim Fisher, 11 December 2018

Note of meeting of the International Maritime Organization Maritime Safety Committee IMO MSC100 – 3 to 7 December 2018

by Kim Fisher

This was a 5 day meeting of the Maritime Safety Committee under the chairmanship of Mr Bradley Groves (Australia) because the previous meeting this year had been an 8 day meeting in June. Since this was the 100th meeting, and also coinciding with the 70th anniversary of IMO, the opportunity was taken to hold some special events. A seminar was held on the first afternoon and Her Royal Highness Princes Anne was invited to address the meeting on the Wednesday,

The seminar dealt with the technology progression of maritime autonomous ships, the human element and smart marine ecosystems. Some impressive film was shown of a ferry making a totally autonomous voyage, berth to berth. These special events together with a long report from Ukraine on the issue of the capture by Russian forces of Ukrainian naval vessels somewhat restricted the time available for the meeting which consequently became rather rushed.

The substantive issue at the meeting concerned a regulatory scoping exercise for the use of Maritime Autonomous Surface Ships (MASS). The previous meeting had set up a correspondence group to move the work forward and a report was available which showed just how complex the issue was. A Working Group at the meeting produced a simplified report and the work will now continue as a web based exercise for the next meeting. Since there is only one MSC meeting next year, a special 5 day intersessional meeting has been arranged for later in the year.

Another Working Group discussed the issue of safety measures for non-SOLAS ships operating in polar waters as an extension to the Polar Code but was not able to make much progress.

Much of the rest of the meeting concerned ship construction standards. New work items were agreed for the use of emergency personal radio devices in multiple casualty situations and for a revision of ECDIS guidelines for good practice.

At the end of the meeting the retirement was announced of Jo Angelo of the USA.

The next meeting of MSC is scheduled to take place from 5 to 14 June 2019. The intersessional meeting on MASS is scheduled to take place from 2 to 6 September 2019. A meeting of the subcommittee on navigation, communication, search and rescue (NCSR) is scheduled for 14 to 25 January 2019.

Tags:  IMO  International Maritime Organization  maritime  safety 

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An iPad Nightmare

Posted By David Broughton, 28 August 2018


Fly/Sail is always the most-fun weekend of the year, and this year it was going to be at Solent Airport and the Hornet Services Sailing Club, Gosport. A handful of fliers and sailors gather at Saturday lunchtime, with the sailors being flown around the local area in the afternoon and then, after a very sociable evening, the sailors accommodating the fliers overnight and taking them for a sail the next morning. All head homewards with huge grins after Sunday lunch.

But, flying from Conington, Peterborough, meant that I had a good hour’s flight to Solent, having to pass by Luton and Heathrow airports amongst a handful of other restricted areas. The aircraft I was to hire was a beautiful-looking and modernised Piper PA-28, with drooping wingtips. I had previously looked carefully at its navigation fit: it had a couple of VOR receivers and an elderly GPS with no graphics.


So I bit the bullet and decided that, as an almost-octogenarian, I would treat myself to an iPad and navigation software. I needed one with GPS, so checked with the experts at the Mac store in Cambridge – yes, all new iPads have GPS they confirmed. I decided to buy it on offer from the largest department store in Cambridge, whose expert also confirmed that the iPad 6th Generation 32GB for £319 ‘has GPS’.

I had also had an offer of free SkyDemon for a month, so I took that up; it works well on the iPad but, sadly, not on my Mac desk- or lap-tops. So I put the track (Conington-Cranfield-Woodley NDB-Solent) directly into the iPad; it was incredibly easy to do and let me play with height to avoid airspace infringements. As well as a very usable chart, it produced an excellent flight-plan, complete with many useful frequencies, for viewing or printing.


By now I had been to AeroExpo and bought a smart knee-pad from Pooley’s to hold the iPad. So, to convince myself that all was working, I tried it in the car, with my wife driving of course. But as soon as I went into SkyDemon navigate mode, I received a warning that I could only undertake a 30-minute flight under the free trial. Wow, thank goodness I had given it a try – had I only read the instructions with the trial I would have known that. But the navigation in the car seemed to work well; the aircraft symbol tracked us around and aligned itself with heading. So I paid £12 for a month of trial that would allow SkyDemon to work as a useful navigator.

On the Saturday morning, with the aircraft full of fuel and overnight kit, we taxied out at Conington. My co-pilot was a lapsed PPL who, between take-off and landing, was happy to hold height and heading, allowing me to devote time to the iPad strapped to my knee. As soon as we headed south, I opened-up the iPad on my knee – to be greeted with the message ‘Current Location Not Available’. The beast obviously had no intention of navigating, so I threw it onto the back seat and scrambled for my chart and printed pilot-log. Thankfully, I had prepared a 250k chart with the track and timing marks and the flight continued as an unexpected and sweaty map-reading exercise. Thankfully, we made it to Solent with no infringements, thanks in part to a very helpful Farnborough Lower Airspace Radar Service (LARS).

It turns out that the iPad that I had bought, in spite of assurances from Mac and department store staff, has no GPS (or any other GNSS). I can only assume that it worked during my car trial by using the car’s Bluetooth and inbuilt navigation. I spoke to a handful of fliers at Solent, who confirmed what I had just discovered about my iPad; a couple showed me their small Bluetooth GNSS receivers which, at around £90, had resolved the problem for them completely by pairing with the iPad and allowing it to navigate.

So a lesson or two learnt: make sure that free software trials fully do what you need; don’t glibly believe what sales staff assure you about iPads; and, most importantly, ensure that you have a properly-prepared paper chart and hard-copy flight-plan at your fingertips... and brush-up by reading the Institute’s booklet on ‘Infringement Avoidance’.

Tags:  Aircraft  Fly/Sail  GPS  Navigation Software 

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Who’s a Hero? Three WW2 Special Operations Part Three

Posted By Keith Hope-Lang, 21 August 2018

Airborne Arctic Support


Operational area from Sullom Voe.

Both Germany and Britain needed to install Arctic weather stations to assist operations on the convoy route to Murmansk. Desolate Spitzbergen, lying almost 80N, was an ideal location for Met observations. In early 1942 the Luftwaffe established a Met station on Spitzbergen. The Allies identified some German radio traffic so they sent a raiding party of 60 Norwegians in an ice breaker and a sealer to land in a nearby fjord. The two ships were seen whilst unloading and destroyed by 4 Focke-Wulf Kondors leaving the landing party scattered across the ice. In the ensuing silence the RAF was tasked with finding out what had happened to the landing party.


RAF Catalina. Photo credit RAF Seletar.

The Consolidated Catalina was an amphibian; only 11 were delivered to the RAF and their primary role was recce and convoy protection. One task was to monitor the edge of the ice pack and for this a flight of Catalinas was based at Sullom Voe in the Shetlands and the northern most airfield in Britain.

Crew of P for Peter. Seated left to right co pilot Ronnie Martin, pilot Tim Healey and navigator Scho Schofield; standing wireless operators, flight engineers and a rigger. Photo credit Schofield. Catalina P for Peter was prepared for the flight. It was commanded by Fl Lt Tim Healey with 2nd pilot Ronald Martin, navigator Scho Schofield, 3 wireless operators, 2 flight engineers and a rigger.


The flight would be between Sullom Voe at the tip of the Shetlands and the Spitzbergen archipelago about 1000 miles north midway between Greenland and Russia. This was in an aircraft that had no heating; the crew wore sheepskin Irvin suit, several layers of woollens, fur lined boots and 3 pairs of gloves.
At 11.23hr on 25 May 1942 P for Peter slipped her mooring and flew at 600ft under 10/10 low stratus. The wind was SE so they set a course of 042deg and held the same course for the next 8 hours. In that time the wind varied between 10 and 32 knots and the magnetic variation between 13 and 6degW so the track made good altered by up to 13deg. As a further complication the RAF charts ran out at 71deg N after which the Admiralty charts were used with, of course, a different scale.

At intervals low cloud forced them down to 400ft and they met occasional fog patches to sea level. After 4hr flying a quick sun sight through thinning cloud put them 5 miles from their DR. After 10hr of flying they made their first landfall when the radar showed Bear Island at 35 miles on the starboard bow. After 2 further hours they sighted the south tip of Spitzbergen.

Flying at 700ft they had stratus at 1500ft in which they would hide if attacked. They passed up the W coast with precipitous cliffs and the peaks chopped off by stratus cloud. There was no visible German activity where they expected to find it.

Two survivors waving to Catalina. Photo credit Schofield.

They then backtracked and suddenly saw up a side fjord a long channel through the ice. There were a few huts but a man stood by one with an Aldis lamp and a second man waved his arms..

1) Survivor: ‘Ships sunk, nothing saved, survivors here, Germans in next bay, help essential’
2) Catalina: ‘Ok, will organise help. God bless’
3) Survivor: ‘Some survivors and wounded here’

By now the Catalina had been in the area for 1hr30 and burning fuel. So, at 14 hours into the flight, the Catalina set course for home via Jan Mayen Island. They flew under 10/10 stratus and the sea ice below became solid. For 30min the temperature stayed below zero and they met freezing fog; the Catalina staggered along managing 85kt at 300ft. Five hours after starting back the Catalina was again flying over clear water. At 14.27hr the Catalina landed at Sullom Voe and cut engines. The engines had worked non stop for 27 hours and 10 minutes.


On 28 May the same aircraft and crew made an over-flight and dropped medical supplies, warm clothing and some luxuries for morale.
On 31may: they flew with arms and ammunition but after 10 hours had to turn back after meeting a snowstorm. On 6 Jun the same aircraft and crew returned and landed in the fjord. They delivered 24 rifles, 3000 rounds and a 2 gallon jar rum. They collected 6 wounded Norwegians.

Who’s a hero?

My Chambers Twentieth Century Dictionary, New Mid Century Version 1952, says a hero is ‘A man of distinguished bravery’. You will note the date as1952; the dictionary was a school prize given me in my formative years and my idea of bravery has not changed since.
So my heroes are the freighter crews trading with Sweden: for their repeated operation of small boats in the winter N Seas when faced with standing patrols, radar stations and destroyers deployed on the Norwegian and Danish shores, minefields and hostile command of the air.
My heroes are also the Mosquito crews for repeated operations over the entire war of small unarmed aircraft in challenging weather with only speed as their defence.

Finally, of course, are the heroic Catalina crews supporting Spitzbergen operations: for their repeated flights of 24 hour duration in the extreme cold of an unheated aircraft, invariably adverse weather usually with solid stratus at 1500ft and occurrences of frozen fog.

By PK Hope-Lang

Acknowledgements for this three-part series: 
Ralph Barker, 1976. ‘The Blockade Busters’. Chatto & Windus, London.
Norman Malayney, who had served in Vietnam with the 12th Tactical Fighter Wing, had a great interest in the BOAC Mosquitos and had interviewed all the crew that he could find. 
Alan S Milward, “Could Sweden have stopped the Second World War?,” The Scandinavian Economic History Review, vol. XV, 1967, 127‐138.
Ernest Schofield and Roy Conyers Nesbitt, 1987. ‘Arctic Airmen’. History Press, Stroud.
Jeff White of The Old Tautonians Associatio

Tags:  airborne  ww2 

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Who’s a Hero? Three WW2 Special Operations Part Two

Posted By PK Hope-Lang , 15 August 2018

Airborne Blockade Running


No. 9621 de Havilland DH98 Mosquito FB Mk IV (G-AGFV) owned by BOAC.
Between 1943 and the end of the war civilian registered Mosquitos were operated by BOAC as transport aircraft on a regular route over the North Sea between Leuchars in Scotland and Stockholm in neutral Sweden. To ensure that the flights did not violate Sweden's neutrality the aircraft were unarmed, carried civilian markings and were operated by crews who were "civilian employees" of BOAC. In the bomb bay the outgoing loads were mail, newspapers and magazines to counter propaganda; the return loads were ball bearings.

Bomb-bay used as passenger compartment.

On several occasions important passengers were carried, locked in the bomb-bay with a supply of refreshments, reading material and oxygen. One such notable passenger was the nuclear physicist Niels Bohr who was evacuated from Stockholm in 1943. The flight almost ended in tragedy since Bohr did not don his oxygen equipment as instructed and passed out. He would have died had the pilot not guessed from Bohr's lack of response to intercom that he had lost consciousness. The pilot descended to a lower altitude for the remainder of the flight; Bohr's comment on landing was that he had slept like a baby for the entire flight.


Track between Leuchars and Gothenberg.

The flight described here was made by Capt White and Radio Officer Gaffney on the night of 28 Aug 1944. White/Gaffney left Leuchars for Stockholm in Mosquito G-AGKR and they were followed by two more Mosquitoes, Longden/Miller in G-AGKO and Carroll/Weir in G-AGGC.

When they approached the Swedish Grebbestad radio beacon, just short of Norway, the weather turned bad; it was the worst they had ever encountered on this route. They flew into storm clouds with lashing rain, strong winds and turbulence and they had about 60 degrees drift on track to approach the beacon. They changed course to the south for Gothenburg and so strong was the tail wind that they sighted the airfield beacon almost immediately. The airfield was experiencing a blustering gale with driving rain.

Whilst loading the aircraft the crews consulted the Gothenburg Met officer on the prospect of returning to Leuchars. White/Gaffney decided to return to Leuchars although their artificial horizon was unserviceable and Longden/Miller decided to follow. Carroll/Weir decided not to go any further.

White/Gaffney took-off for Leuchars and Longden/Miller followed fifteen minutes later. Longden decided to fly through the Skagerrak at 10,000ft instead of the usual 20,000 feet. However on reaching the Grebbestad radio beacon they were surprised to find the weather had cleared. Longden eased back and climbed to 20,000 feet; their flight time from out had been 3hr 8min but the return flight only took 2hr 30min.

When Longden/Miller landed at Leuchars they were surprised not to see White/Gaffney. Longden/Miller waited in the flying control room for news until they knew White/Gaffney would have run out of fuel. They then went to their lodgings. 

What happened? 

Likely return track

Next day Miller, who had navigated Longden, went to the RAF radar centre who had reported an unusual plot of an unidentified aircraft approaching the north coast of Scotland from the direction of Norway but well north of the normal Mosquito track. Before reaching the Scottish coast just north of Aberdeen, the aircraft had altered course 45deg to starboard and headed for Wick. It disappeared from the plot about three-quarters of the way there about the time White’s Mosquito would have run out of fuel. It seemed quite incredible that White’s aircraft would have been so far off course and heading on a north-westerly track.

The Swedish airline ABA was agent both for BOAC and Deutsche Luft Hansa DLH. The BOAC representative unofficially asked ABA to ask DLH to ask Luftwaffe HQ in Oslo if they had shot down White’s Mosquito. Very quickly came the reply that Luftwaffe had not taken any action that night but the same night the Luftwaffe station at Lister, on the southern tip of Norway, reported hearing an aircraft flying westwards very high in bad weather. The time of the report seems to indicate that it was White’s Mosquito.

Miller later said, in an interview just before he died, that he thought the White/Gaffney Mosquito flew as if it had no nav-aids. This would be the case if they had lost electrical power. The battery had a nominal endurance of 30 minutes but Miller said that in his experience the battery would not power the radio for more than 5-10 minutes; the aircraft would then lose the artificial horizon and the ability to take radio bearings. The instrument lights would probably fail within the half hour and the compass would then only be readable with a torch.

Miller thought that, when north of Rattray Head, they may have expected to be in sight of Scotland. Seeing nothing they presumably thought they were way south of track so altered course northwards. It looks as if the Mosquito missed Scotland altogether, ran out of fuel and crashed in the North Sea.

By PK Hope-Lang

Acknowledgements for this three-part series:
Ralph Barker, 1976. ‘The Blockade Busters’. Chatto & Windus, London.
Norman Malayney, who had served in Vietnam with the 12th Tactical Fighter Wing, had a great interest in the BOAC Mosquitos and had interviewed all the crew that he could find.
Alan S Milward, “Could Sweden have stopped the Second World War?,” The Scandinavian Economic History Review, vol. XV, 1967, 127‐138.
Ernest Schofield and Roy Conyers Nesbitt, 1987. ‘Arctic Airmen’. History Press, Stroud.
Jeff White of The Old Tautonians Association

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