Re: Fuel-imbalance

Date:         30 Mar 99 01:53:45 
From:         gdlpilot@aol.com (GDLPILOT)
Organization: AOL http://www.aol.com
References:   1
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Good question - and rather unusual since it is normally given as a
single value.

However, I would guess that since the ability to maintain good lateral
control is the determining factor, and since the amount of lateral
'force' available is a fuction of airspeed, the condition is most
critical at low airspeeds since aileron effect will be less at low
speeds.  It is probably a case that since the minimum operating
airspeeds increase with aircraft weight - consequently, the amount of
aileron effect at the minimum speed is greater, at a greater weight.
Therefore, the maximum allowable imbalance increases.

Another way to look at it, is that the imbalance is really a function of
airspeed since that determines aileron effectiveness.  The higher the
speed, the more imbalance you can handle.  If you get very low airspeeds
- such as you would have at light weight conditions - you reach have
reduced aileron authority and cannot support as high an imbalance.