Dropping Drinks on your Toe
Dave Jesse on February 12, 2018

..or the link between TCAS and apples…     Recently my Safety Manager, Capt Herb Feller, asked if an aircraft carried out a Traffic Collision Avoidance System (TCAS) avoidance manoeuvre, and a loose drinks trolley ran down the aisle, what would be the force when it hit something or someone? As an engineer, it seemed […]

Red Eggs
Dave Jesse on February 8, 2018

Welcome back, dear reader. I hope you had a happy holiday and wish you a fruitful New Year. In a few months’ time it will be Easter and some of our Greek friends will be celebrating with eggs coloured deep red like this one.     He’s getting old and slightly crazy, you may think, […]

Who Flies the Aeroplane?
Dave Jesse on January 4, 2018

Looking Back The origins of the Flight Data Monitoring (FDM) process date back over twenty years and are enshrined in ICAO regulations. One of these states that “A flight data analysis programme shall be non-punitive and contain adequate safeguards to protect the source(s) of the data.” This need for data security has been implemented in […]

You Can’t Have a Binary KPV
Dave Jesse on December 8, 2017

  A long time ago I explained that our analysis of flight data is based upon the concept of a Key Point Value, where an aspect of a flight is reduced to a single number. For example,  the airspeed at takeoff or the maximum angle of bank during a flight. These are analogue measurements, that […]

Women Pilots
Dave Jesse on December 1, 2017

  A “just for fun” blog – nothing mentally challenging this time! Portsmouth Guildhall Every month I help our local scout group to raise funds through a jumble sale. I run the book stall, selling second hand books for a few pence each. At the last sale someone had brought in some old local newspapers, […]

Computing Charts
Dave Jesse on November 16, 2017

Well, it seems an age since I last blogged – somehow work gets in the way. I’ll have to complain to the boss about that one day. Anyway, we recently had a case where we needed to convert a chart into an algorithm, and I thought I’d give you the recipe I have used for […]


This was one of the more interesting discoveries of the last few weeks, and I thought that it would make a fun post for Flight Data Community. As a part of my role as a Data Scientist, it is one of my responsibilities to ensure that the data we record and monitor is of high […]

Does an Aircraft Fly or Travel?
Dave Jesse on November 2, 2017

Today I was asked what the difference is between the Distance Flown and the Distance Travelled. Like so many things in life it seems obvious if you know the answer, but confusing if not.   An Extreme Example I will explain this by referring back to a time when I was working at Bristow Helicopters, […]

From Autocorrelation to Fourier
Dave Jesse on September 12, 2017

Just for fun Here is a little interlude to get back to helicopter accidents – and do some more tricky maths in the process. Autocorrelation Here are two combs from the previous blog, which was about autocorrelation. You will recall that we compared one comb with another to see how good the match was.   […]