Applemacmaster:
We work for the same Company I belive and I can assure your information regarding fuel savings isn't correct. The actual fuel savings will vary due to weight and pilot technique. In fact there is actually no single figure for the A320 family. The values vary with the speed, which varies with each engine/aircraft/weight combination plus the engine characteristics (TI vs. non-TI) etc. You can be assured, however, that the average montly saving due to CONF 3 comes close to 10 times the TRIP fuel requirements from SSH to LGW - small numbers add up when you fly 1,100 flights/day.
On the Airbus there has never been a requirement to have a minimum thrust setting on the approach, the aircraft certification standards (FAR – Part 25) ensure that the thrust achieved after 8 seconds from power application (starting from flight/approach idle) allows a minimum climb gradient of 3.2 % for go-around.
The issue of tailstrikes on the A321 decreases when using CONF 3 instead of CONF FULL. This behavior can be explained when looking carefully at the lift surfaces. The A321 has doubleslotted fowler flaps, instead of single slotted flaps on the A319 and A320. Most tailstrikes occur due to aircraft mishandling.
Have a good summer.