I’m surprised at the attitude some pilots express regarding safe fuel margins. There seems to be a attitude that the regulations provide for safe fuel levels in some parts of the industry. They promulgate the minimum for safe operation and should be a starting point for any fuel calculation and not the target. If everything goes well, then the minimums will be enough. Get allocated a cruise level two down from planned, or do a 100nm weather deviation, then the contingency is gone and now there is no margin for the unexpected, such as the weather at destination being worse than forecast.
A good example of how it can go wrong is the CIAIC report on the incident at Alicante in May 2010 where a RYR aircraft landed at its alternate with less than reserve fuel. It gives useful insight into the mind-set of the RYR pilot workforce. The crew were both quite young, but not inexperienced. Their experience as detailed in the report suggests that they had flown most of their careers with RYR and had developed their operational philosophy within the constraints of that system. This is probably why the crew elected not to carry any additional fuel above the 5% contingency despite planning to arrive at an airfield with a fairly good likelihood of less than optimal weather. The commander elected not to carry the 300kg allowed by the company without explanation. However, they had a little extra on arrival – they were slightly lighter and having not used the contingency, were slightly up on fuel. This may have led them into complacency.
The result was that after the first go-around, the crew had a little spare fuel, but not enough for what they then attempted. They obviously felt pressure to make the second approach. The RYR criteria for dropping the alternate aren’t known to us, but if they exist and were available to this crew, they very unwisely decided to make this second attempt to land. However, they did have the sense to abort that attempt early and opt for the diversion.
But their fuel state gave them no breathing room and the details from the report suggest they were now under a great deal of stress and made errors.
Just taking the 300kg would have given them enough time to feel comfortable, albeit only about eight minutes flying time. An additional 600kg would have given them enough fuel to try the second approach safely. The net result of the decision to take no extra was a declared emergency and RYR operations being put under the spotlight - again!
I will leave the individual to decide whether this fuel decision was sensible, but I can honestly say that I would have taken more - quite a bit more. A quick rule of thumb calculation reveals that 300kg would have cost about US$30 to carry at today’s price. If the margins at RYR are that tight, then I could accept that there is a good reason. But looking at their results for last year, it’s clear to me they are putting profit ahead of safety.
It appears that some pilots feel it’s OK to routinely operate like this – but I’m not one of them. Saving that $30 (none of which will go into my pocket) would not be my priority.