On the CTsw and CTLS we use several methods to determine fuel levels for proper pre-flight planning and in-flight management.

On the CTsw in Classic configuration we use the aluminum dipstick as the basic method for checking fuel, with the clear plastic sight gauges as an in-flight back up for determining fuel remaining in the tanks.

On the CTsw Advanced configuration and CTLS with the Dual Dynon glass panel we have three methods, the dipstick, the electronic fuel flow and fuel remaining gauges and the sight gauges.

A comment we have heard was that the dipsticks are hard to read in some light conditions. While it is true that the clear anodized dipsticks can sometimes be hard to read, there are several things one can do to help in seeing the fuel. One is to rotate the dipstick quickly after dipping to get the proper reflection, two is to take a black indelible ink marker (like a Sharpie® or Marks-A-Lot®) and make a stripe down the sides of the stick to show the wetness more easily. One common method used by general aviation pilots is to take a clean wooden stick the same length as the dipstick and use the gauge on the dipstick as a reference to the level shown on the wood.

The clear tube sight gauges located at the wing root allow the pilot to determine fuel remaining while in flight. However, the use of auto fuel darkens the tubes and over time may render them difficult to read. In this situation, you should have the tubes replaced at the next major service interval. If they are dark enough to the point that they are unusable, you must have them replaced before further flight. This recommendation will be further clarified in revisions to the service documents.

The fuel computer on the Dynon equipped CTsw and CTLS provide a third method of determining the fuel remaining, but require that you reset the quantity-on-board value whenever you take on fuel. This is not unlike some much larger aircraft. The reset of the level is quite simple on the D-102 EMS screen, but so simple one can forget to do it. Also, the fuel flow and fuel remaining are approximate and should be used for guidance only and you should be conservative with your in flight planning.

Pilots should always be familiar with the aircraft fuel burn per hour and fuel onboard at the beginning of the flight as a means of backing up any of the fuel gauges.

The CT series have very large fuel tanks and are not typically limited by the amount of fuel allowed in your weight and balance. Don’t let the low fuel burn numbers of the Rotax engine tempt you into an unsafe situation. Thirty minutes reserve fuel is just a few gallons, but the aircraft has a capacity of 34. With the extreme range on the CTsw and CTLS the plane can outlast their pilots.