Ground Cushions Are Not Fair
Dave Jesse on March 27, 2013

Imagine you are a particle of air way up in the atmosphere. An aircraft flies past 100ft above you, and for a moment you duck to let it pass by. This is a happy way of thinking about the local air movements

Inertial Smoothing
Dave Jesse on March 21, 2013

Aircraft height and speed are typically sampled once per second. Sometimes this is not good enough for the question we are trying to answer, for example “what was the vertical speed at the moment of touchdown?”.

Beware of Trolls
Dave Jesse on March 14, 2013

We all get asked to agree to license agreements from time to time, and if you are anything like me, you won’t bother to read all the pages of small print before installing the latest software update. In

Which way to the North Pole?
Dave Jesse on March 7, 2013

So it’s really easy to measure heading. You just get out a compass and it will point North. Easy, eh? But, you’ve guessed it, life is never that easy. Firstly, the compass in an aircraft has to compensate

Data Sharing is Like Playing Tennis
Dave Jesse on February 27, 2013

Last week I had the pleasure of presenting to the European Business Aviation Safety Conference (EBASCON) in Munich. Sadly there was no time to visit the city centre, but it was a joy to meet old friends

Measuring Runway Overrun Risk
Dave Jesse on February 21, 2013

This blog carries on from the previous touchdown measurement and looks at how we can relate touchdown conditions to the likelihood of a runway overrun. When looking to measure the risk of a possible

Computing Touchdown Point
Dave Jesse on February 13, 2013

For safety monitoring we are very interested to know where an aircraft touches down on the runway. There are two problems here, namely knowing where the aircraft is and when it touches the runway. In

Measuring Air Temperature
Dave Jesse on February 6, 2013

OK, it’s really easy. You stick a thermometer out of the side of the aircraft and read what it says. Nothing could be simpler, until you fly through a cloud. I’ll take these two parts – “fly” and

Einstein and Newton Stop on the Runway
Dave Jesse on January 31, 2013

In my last blog I mentioned two different ways of looking at the ability of an aircraft to stop on the runway, and here is a supplement about dimensional analysis of these measures. In dimensional analysis