GASCI Flight Safety message Adapted from an LAA note to GASCo 22nd March 2018 – highly relevant to Irish GA aviators also…
It’s that time of year again, when many LAA members and other pilots ease both their aircraft and our piloting skills out of hibernation.
As a result, in the past month the LAA has been promoting safety advice focussed on two key points:
The first is the quality of the fuel in the aircraft tanks, particularly for those who use Mogas, which in recent years almost without exception contains up to 5% ethanol. It has, since late 2014 been agreed that E5 Mogas can be used in aircraft inspected and approved for the purpose.
One line in the approval is particularly important; “fuel to be fresh”. Mogas is developed to be used every day in a family car and is therefore not as chemically stable as Avgas. If left in a fuel tank for an extended period, such as over the winter, the more active elements evaporate leaving a ‘stale’ remainder. In extreme conditions that can leave you with fuel not even inflammable enough to start the engine. It can also lead to waxy contaminants that could choke carburettors or fuel filters.
There’s an even more serious potential issue for aircraft which use composite materials in fuel tanks or even ‘wet wings’ where the wing skins act as the fuel tank. On some occasions where stale fuel has been left for a long time we’ve seen degradation of the wing itself, as a result of attack by the more volatile fuel vapours as they evaporated. In one extreme case the wings were written off. As a result the LAA has removed the approval for the use of E5 Mogas in ‘wet wing’ Jabiru aircraft.
Another characteristic of Mogas is that fuel companies alter its blend between winter and summer. ‘Winter’ Mogas is designed to be more volatile, which means it’s easier to start your car on a cold morning. However it also makes it more likely to cause a vapour-lock in a fuel system at higher temperatures. Mogas should not be used if the fuel tank temperature is likely to exceed 20 degrees Centigrade, but the use of winter brews on a warm spring day could make a vapour lock more likely.
The second safety message being promoted at this time of year is a focus on pre-flight planning and situational awareness. It has been noted in forums such as the CAA Airspace Infringement Working Group meeting, that each year the number of airspace infringements increases at the start of the flying season.
The theory is that when GA pilots are regaining their currency, situational awareness suffers as too much mental capacity is absorbed in simply flying the aeroplane. In addition, just as with handling skills, navigation suffers with a lack of use.
We’re therefore advocating the “Take 2” campaign created by members of the Manchester and Liverpool airspace user’s group. Its basic premise is simple; don’t fly right up to the edges of the controlled airspace. “Take 2” advocates planning you flight to keep a 2nm lateral gap between yourself and the edge of controlled airspace or planning to fly at least 200 feet above or below any such zone. The “Take 2” advice is easy to remember and could just give a margin to stay legal – and safe!
With Thanks to the LAA & Steve Slater