7
$\begingroup$

In a recent news of a Airbus A400M crash, it has the following line -

Sources have told Aviation Week that aircraft MSN23, destined for 
Turkey, featured new software that would trim the fuel tanks, allowing 
the aircraft to fly certain military maneuvers.

I understand what trimming is, but what does it mean to trim the fuel tanks?

$\endgroup$
7
$\begingroup$

Just like normal trimming. However trim the fuel tank use aft fuel tank to achieve the trimming effect. Fuel is pumped between main tank and aft tank to shift CG around to a desire position during flight.

Fuel tank trimming has additional benefit of keeping the airplane in "clean" configuration, creating less drag compare to normal trimming.

$\endgroup$
  • $\begingroup$ What is "clean" configuration of an airplane? $\endgroup$ – Quazi Irfan May 21 '15 at 6:20
  • 1
    $\begingroup$ @iamcreasy: Gears and flaps up; read "clean" as "aerodynamically clean". $\endgroup$ – Peter Kämpf May 21 '15 at 6:24
  • 5
    $\begingroup$ In this context, clean refers NOT to gear/flaps, but to the absence of drag due to trim tabs or drag-generating control forces keeping the aircraft level. In concept, if the tail has to produce lift down because the aircraft is nose-heavy, that's less efficient than if it didn't have to. $\endgroup$ – Ralph J May 21 '15 at 11:30

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.