fuel imbalance
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fuel imbalance
Hello,
Would someone please explain to me (in a simple way) how an 'exceedence of a fuel balance limitation' affect the structural life of the airframe and landing gear? The FCTM also says "Lateral control is not significantly affected when operating with fuel beyond normal balance limits".
thanks
Would someone please explain to me (in a simple way) how an 'exceedence of a fuel balance limitation' affect the structural life of the airframe and landing gear? The FCTM also says "Lateral control is not significantly affected when operating with fuel beyond normal balance limits".
thanks
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You didn't specify what aircraft or any details, but fuel loading by tank concerns not only aircraft control but wing bending moment. Fuel load may be attached to structural and operational limitations, such as being limited to certain speed ranges at certain altitudes, at certain fuel states or with certain tanks filled or not filled. One may be required to maintain a greater fuel difference outboard than in, in some aircraft, for wing bending moment purposes. Some of these restrictions won't necessarily affect aircraft control, but will affect the stresses places on the airframe (specifically the spar, and associated load-bearing structure).
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thanks for your reply SNS3Guppy
Sorry for not mentioning the a/c type, I'm talking about Boeing 737-800.
From your answer I understood that an out of limit fuel imbalance could cause the wing/tank that has the low fuel might bend. However I am still not sure if this will happen with the center tank fuel is empty. (in the 737 we use fuel from the center tank fuel first untill it becomes zero). Also I still do not understand how this could affect the landing gear?
Sorry for not mentioning the a/c type, I'm talking about Boeing 737-800.
From your answer I understood that an out of limit fuel imbalance could cause the wing/tank that has the low fuel might bend. However I am still not sure if this will happen with the center tank fuel is empty. (in the 737 we use fuel from the center tank fuel first untill it becomes zero). Also I still do not understand how this could affect the landing gear?
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From your answer I understood that an out of limit fuel imbalance could cause the wing/tank that has the low fuel might bend. However I am still not sure if this will happen with the center tank fuel is empty. (in the 737 we use fuel from the center tank fuel first untill it becomes zero). Also I still do not understand how this could affect the landing gear?
2. The LG situation is similar. LG is designed for certain impact speeds for certain masses sat at the top of the gear. Simplistically, each main gear is assumed to carry a certain % of the landing weight - more than 50%, to account for small imbalances and the like. But if you have a lot more fuel in one wing than the other, even if your overall weight and touchdown conditions are "in limits", the gear under the heavy wing is seeing a lot more load than normal. Hence possible gear issues. (If you took the extereme and had one wing full and one empty, your aircraft is probably under max landing weight - but the gear under the heavy wing is seeing conditions akin to a MTOW overweight landing)