Wood Burners and Banked Turns
Dave Jesse on November 27, 2019

This is, I have to admit, a blog only tangentially related to aviation, but I came across a mathematical jollity which I just had to share. Woodburner My brother-in-law lives in a cottage in Devon, and wanted to fit a second stove to keep his house warmer. The chimney goes up from the stove, through […]


Those of you who have the memory of an elephant will recall that in 2016 we discussed superframes and the superframe counter. While the true aficionados of this blog will go and view G-ACDC, the normal reader could probably do with a brief summary of this topic.     Superframe Recap Parameters that vary slowly […]

When Do You Stop?
Dave Jesse on July 22, 2019

It sounds like a simple question, but sometimes the task seems to grow while the target moves further from your grasp. Here is a tale of one such case which illustrates how hard it can be to decide when to stop working on a problem. An Undefined Error One of our customers raised a support […]

Runway Marking Quiz Results
Dave Jesse on June 11, 2019

OK, I have to admit to a little subterfuge.  I wanted to ask a question which I thought might be a little embarrassing and so, rather than ask the tricky question straight out, I hid it inside a quiz.  For all those who took part in our recent runway marking quiz, I thank you for […]

Dave’s Runway Marking Quiz
Dave Jesse on May 7, 2019

Flight Data Services are interested to understand where pilots aim to land when flying a visual approach.  Of course, visual cues are not recorded on the Flight Data Recorder – how could they be?!  Please take part in our little quiz and when you send in your answer, we will return a more detailed explanation […]

Monitoring TCAS Resolution Advisory Alerts
Dave Jesse on April 25, 2019

It’s been some time since I last posted on this blog. There are some weak excuses (lots of work to get the TCAS RAs working correctly, busy running a business) and some strong excuses (three weeks holiday on a narrowboat, son’s wedding etc.). Anyhow, I’m back on the blogging trail and I can tell you […]

A crisis of confidence (intervals)
Charles Newey on June 14, 2018

Lately I’ve taken to exploring some of the aggregated event statistics that we have on file at Flight Data Services — and as a side project, I was using my knowledge of statistics to develop a fairly straightforward anomaly detection algorithm. My first approach was to compute the daily average of a particular key point […]

Traffic Collision Avoidance System (TCAS)
Dave Jesse on June 6, 2018

The TCAS system is designed to avoid traffic collisions between two aircraft. At first a Traffic Advisory (TA) warning is given to alert the crews of approaching aircraft. Then, if the separation continues to reduce the two aircraft exchange position, direction and speed information and, in a clever piece of negotiation, agree which aircraft needs […]


The Simple Question It’s a simple question, and for today’s ditty I am only going to consider aircraft where the maintenance manual limitation is expressed in normal acceleration units (g). There are a number of aircraft (Embraer types and BAE 146 for example) which express hard landing criteria in vertical speed at touchdown, and this […]

Self-Healing Aircraft
Dave Jesse on March 29, 2018

Sounds impossible? Well by now, dear reader, you should be ready for the unexpected. In today’s blog I shall reverse the natural order of things, turn the arrow of entropy back to front and disprove the second law of thermodynamics. I am going to show you two graphs from the same flight and demonstrate a […]

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