Aircraft speed and weight at cruise.

Date:         16 Oct 97 00:44:13 
From:         jf mezei <"[non-spam]jfmezei"@videotron.ca>
Organization: VTL
Followups:    1 2 3 4 5 6 7
Next article
View raw article
  or MIME structure

Sorry if this is very basic:

Correct me if assumptions as wrong:

-A wing generates a lift value which is proportional to the air speed.

-The force of the lift should always equal the weight of the aircraft
 otherwise the plane would either climb or drop.

-The weight of an aircraft changes as fuel is exhausted during cruise.

QUESTION:

Assuming a LAX-SYD flight with no winds. Towards the end of the flights
when the plane is much lighter, doesn't the lift provided by the wings
exceed by quite a bit the lighter weight of the aircraft ?

Is this change so trivial that it is not an issue, or do pilots take
this into consideration (reducing speed to reduce lift or what ?) ????

If speed is adjusted to match the lift with the weight of the aircraft,
how does this affect airline schedules  where cargo loads may influence
the time it takes for the airctaft to get to destination ?

Would a fully loaded plane not travel faster then a same plane but
lightly loaded ?