Announcing iBulldog

Our newest free app, iBulldog, is now live. This is a niche application for owners/operators of Scottish Aviation Bulldog aircraft, enabling you to calculate the Fatigue Index ('FI') for your airframe.


The Fatigue Index ('FI') determines the available life remaining in the Bulldog airframe. It is calculated from measurements of acceleration obtained from the 'Fatigue Meter' instrument, recorded after each flight. In the UK, for continued air-worthiness under CAA rules, each Bulldog owner/operator is obliged to send the readings each year to DeHavilland Support Limited (DHSL) who compute the revised life-remaining, according to formulae devised by British Aerospace (formerly, Scottish Aviation) during the full-scale fatigue life tests conducted as part of the original certification of the aircraft in the 1970s. 


Our iBulldog app gives you the ability to assess the Fatigue Index at any time within a given year, i.e., before the next official evaluation by DHSL. The results are accurate to within 4 decimal places of the DHSL  calculations. By enabling you to predict (approximate) FI consumption (for a given set of assumed FI readings), the app helps you to assess, a priori, the relative effects on lifetime of, for example, aerobatics versus circuits & landings, or steep-turns/air-racing versus gentle aeros. Armed with this information, you can fine-tune your flying profile accordingly.