Originally Posted by Sidestick n Rudder
Yup, been shown this 'clever trick' by some morons early in my career, when flying for a somewhat shady charter operator. However, it's not clever and, in fact, not legal. If you re-dispatch in the air (which the above in-fact is), you are still supposed to have alternate, final reserve AND contingency fuel for the remainder of the flight.
Properly done, re-dispatch can save a couple of kg's and possibly prevent a fuel stop on the way, but it is not a license to operate without adequate reserves...
@Sidestick... You don't appear to understand the concept of using an en-route alternate to reduce contingency (or statistical contingency) fuel.
It is not a shady practice and is written into most EASA Ops Manuals. The entire amount of Contingency fuel may be used at the Captain's discretion any time after dispatch.