So why is a story about flying weaved into a risk management blog you might ask?....For the skeptics among us who cant quite make the connection between managing risk and flying, the 2008 FAA Instrument flying Handbook (pages 1-17 and 1-18) truly read like a risk management manual! Only what we know as MMM (Measure, Manage, Monitor) the FAA calls PPP (Perceive, Process, Perform).
Even the FAA's PPP process continuum map looks eerily similar to the circular MMM process maps so familiar to risk managers....
One major error in the skies may be one's last, but there are many ways to avoid that one mistake. The PPP approach is designed for that purpose, as is the more sophisticated DECIDE model below:
Now the story...
I have a flying license but I am a novice. Let's get that out of the way. With 190 hours on the clock, I have now actually figured out that I am neither the Red Baron nor do I know everything ever written about flying. But I am careful. What happened this summer in Maryland over the Chesapeake Bay started as really scary, and ended up being yet another lesson in applying consistent principles to assessing risk.
It was a fine late summers day. With calculated fuel burn after a long flight (long by the meagre standards of the minuscule 3/4 ton Diamond DA 20) requiring 18 gallons to refill the tanks to overflowing after landing (note here the capacity is 24 gallons which means I arrive with 6 gallons or 50 minutes of flight time in reserve), the fuel truck is called after a day of fun and apparently safe flying.
As the refuellers flow meter passes, 18, then 19, then 20 gallons delivered, my smug self satisfied demeanour is replaced by horror in knowing that not only was I wrong about the amount of fuel remaining, but that I nearly went for an unscheduled swim, having spent the last 20 minutes of flight over water. Overall 22.5 gallons were loaded on boar, suggesting around 15 minutes of flying time remaining - the sort of 'Oops' moment that gets airline pilots fired, and keeps the FAA 'enthralled'.
But how come such an egregious mistake....i am getting a little long in the tooth but not so old that I cant do simple math to figure out fuel burn in what amounts to no more than an aerial Moped (a nice one, but still no F15!). The math was correct; I should have had 6 gallons remaining, but the evidence suggested otherwise.
The fuel tank was the size it was supposed to be in the books, the fuel burn was accurate, and everything else checked out (ie fuel measure before and after flight, engine performance etc.). Three weeks of self doubt and mild paranoia passed before the inconsistency was resolved. It was accomplished using a PPP analysis of all the components of the flight and the clue to the resolution is as follows:
The DA 20 is a low wing aircraft.....
$20 to the first person who solves the mystery before we reveal the answer in 2 weeks time!
Quite simple. Cross flow was not in the off position. Therefore whilst fueling on one side the fuel went to the other wing. When topped off and capped the fuel went over to the other side. About 4.5 gallons. Topped off other side and therefore tanks not fully topped off.ReplyDelete