Many of you reading this are already shaking your head and rolling your eyes, because you have had first-hand experience dealing with fuel leaks on older corporate jet aircraft during pre-buy inspections. This particular issue can represent the most costly, time consuming, and frustrating aspect of the inspection.
Why “older” aircraft? Well, it’s not that “newer” aircraft are immune to fuel leaks, but that their fuel systems have been subjected to far less stress brought on by a number of factors, some within an operator’s control and some that are not, such as gravity. Differing and more modern design and manufacturing processes also factor into lower risk and more economical maintenance of fuel leaks on newer aircraft.
From the aircraft operator/owner’s perspective, the revelation of fuel leaks during a pre-buy can often be alarming and unsettling since they are not often noted during the actual operation of the aircraft. Leaks are generally insidious, developing slowly and often only reproducible under certain and somewhat aggravated circumstances. One of these circumstances is a dedicated and extended time-based static fuel leak check common among comprehensive pre-buy work scopes. Corporate jet aircraft do not generally sit for extended periods of time with full fuel, and they are not generally scrutinized by a qualified technician following such event, but this is exactly what happens during a pre-buy, often leading to the identification of discrepancies.
This is just the beginning, as the next steps are to classify the leaks, determine the resolutions through troubleshooting, and making the necessary repairs with subsequent leak checks to confirm the completion of the repairs. Trying to explain this process to an owner/operator can be very difficult and it is critical to arm oneself with all available information and develop a plan to manage the repairs so that no one is surprised by the final repair invoice. Along with the aircraft manufacturers, there are a number of companies specializing in corporate jet fuel systems, principally fuel leak repairs.