Hi
Ledhead27:
Always a good discussion topic but, as others have already indicated, you seem to be stuck without much specific information. That may be deliberate on the part of your instructor, so you have to look at a range of cases.
Like
kenparry, I'm confident that the term "tanking" in your assignment refers to "tankering" fuel, i.e., an arrival at Munich (your choice) with considerably more than the normal reserves. That's usually only done, of course, if the fuel price (or maybe availability) at the original departure airfield is better than at the first destination (Munich). It may or may not leave enough fuel for the second sector without topping-up.
If it's purely a fuel-price differential, the first criterion in deciding to tanker (or not) will be the length of the sector, on the basis that it costs fuel to carry extra fuel. During the sudden fuel crisis of 1973, my company's (VC10) flight ops dept quickly produced a graph of cost-differential versus flight time, and a list of prices at all the airfields on our network. Problem was: the fuel prices were being frequently renegotiated by our hard-pressed, one-man, fuel-purchasing department!
The other thing affected by the flight time, of course, is the temperature of the fuel on arrival. During the cruise, the fuel temperatures fall steadily, and the smaller tanks tend to get colder quicker. On my last fleet, the A320, we had a rule of thumb that if the flight time exceeded a certain value (might have been 1:15, but I forget),
AND high humidity with freezing temperature was expected at the first destination, we would normally not tanker fuel.
High humidity at the first destination during the turnround can be a spoiler if you are not going to need to de-ice the whole airframe for other reasons (sleet, snow, or air frost). However, as
Jonty says, on some types like the A320 you may be able to accept 3 mm of frost on the BOTTOM of the wing tanks (not the top) for departure. So provided none of the wing tanks is full, you may get away with it. The problem on many types (including the A320) is that the small outboard tanks will normally be scheduled as full (for wing-bending relief) until the inboard tanks are at a low state (which is unlikely in this case). So in high humidity the wing skin above the outers may develop frost even on the landing and taxiing in.
(In the early days on the A320, as wing-bending relief was not an issue at lower weights, we used to preempt that top-skin frost forming by transferring the fuel from the outers to the inners at top-of-descent. But it involved tripping and resetting CBs in the cockpit, so it may no longer be acceptable as an SOP.
)
Finally, speaking generally, the effect of the extra weight on landing performance must be taken into account, as
B737900er has already said. In your case, it seems unlikely to be a problem on Munich2's long runways.
My choice? Don't live in Bavaria, but a
constant temperature of -15C sounds like anti-cyclonic gloom, and snow seems unlikely. High humidity first thing in the morning is normally associated with clear skies that have caused a considerable fall in temperature. So you might be lucky in this case; otherwise be prepared to join the queue for the (eco-friendly) de-icing facility on departure. You can't win 'em all!
