Check out the legal version of this requirement of the FAR.
During taxi, flight attendants required by this section must remain at their duty stations with safety belts and shoulder harnesses fastened except to perform duties related to the safety of the airplane and its occupants.
What about the Galley?
While most flight attendant adhere to this requirement, unfortunately some (more
often “Galley FAs”) are accomplishing duties not related to safety during taxi. This message is not about
picking
 on the “Galleys.”  
After all, they are the miracle workers of the kitchen. Instead, the focus is to raise awareness that accomplishing non-safety duties during this period is risky. Here’s why.
After all, they are the miracle workers of the kitchen. Instead, the focus is to raise awareness that accomplishing non-safety duties during this period is risky. Here’s why.
Physics-101
 While
 the aircraft is whisking along towards the departure runway, you (along
with any other unsecured items) are being held in place by simple laws 
of gravity. Should the flight deck crew make a sudden stop, the laws of 
inertia quickly trump gravity -- thus placing you (and those loose 
items) in a precarious situation. In fact, the
more distance from any fixed object (galley wall/surface), the greater 
the risk for severe injury.  What about those unsecured items 
(inserts/carts/rack of glasses)?  Applying the aircraft brakes “firmly” 
will result in those items very quickly on the floor
-- even worse, possibly striking you!  Look at it this way….,
While
 the aircraft is whisking along towards the departure runway, you (along
with any other unsecured items) are being held in place by simple laws 
of gravity. Should the flight deck crew make a sudden stop, the laws of 
inertia quickly trump gravity -- thus placing you (and those loose 
items) in a precarious situation. In fact, the
more distance from any fixed object (galley wall/surface), the greater 
the risk for severe injury.  What about those unsecured items 
(inserts/carts/rack of glasses)?  Applying the aircraft brakes “firmly” 
will result in those items very quickly on the floor
-- even worse, possibly striking you!  Look at it this way….,
·        Greater
Distance/Speed = Greater Inertia = Harder Impact
Don’t think it happens?  Guess again because in 2013 (for one airline) over 25 flight attendants
were seriously injured due to surface movement accidents.  Sadly,
most were avoidable had these flight attendants been seated and buckled-up.
 Let’s Talk $$
But more importantly,
you could be injured. Please
 don’t chance your personal
safety. During taxi, all flight attendants not performing safety related
 duties must be in their jumpseats (focused on cabin safety) with 
lapbelt and shoulder harnesses fastened.
Opening wine bottles, linen lining inserts, tray unwrapping, and all the other
fabulous things you do for our customers can wait.  On the other hand, your personal safety
can never wait; it
must always be #1.
 


