RAW, it _looks_ like any unit that uses VTOL or WiGE movement during its turn should get the +1 TMM mod for airborne movement, even if it lands at the end of it turn (or started the turn landed).
This doesn't seem controversial but somebody on the CGL Discord has a different reading of the rules.
The rules in question all come from Total Warfare 10th Ed PDF:
A unit using VTOL movement is considered airborne and therefore is
harder to hit (see the Attack Modifiers Table, p. 117).
(pg 54)
As with jumping and VTOL movement, a unit using WiGE move-
ment is harder to hit, but finds it more difficult to make an attack (see Combat, starting on p. 98).
(pg 55)
• F: Flak. When used against a unit that presently has an Altitude or Elevation, or that expended any VTOL or WiGE MP or
Thrust Points that turn (even if it landed at the end of that Movement Phase), apply a –2 to-hit modifier in addition to any
other modifiers such weapons might convey. However, flak conveys no bonus above low altitude.
(pg 114)
(note the explicit mention of "**even if it landed at the end of that Movement Phase**")
And from the attack modifiers table:
Movement:
...
Jumped/Airborne (non-aerospace units) +1 additional
(pg 117)
The key phrase seems to be "considered airborne".
Nowhere does it say that landing, or starting or ending a turn landed, removes this bonus (or the -2 to-hit modifier of Flak).
However, not getting the Airborne movement bonus is an _emergent_ effect of starting and ending the turn landed _if_ the unit does not expend VTOL or WiGE movement points.
I should note, currently MegaMek implements VTOL and WiGE movement as receiving the +1 TMM mod even if they land at the end of movement.
The opposing position is that anything that lands at any point in its movement is "landed" and therefore not "airborne"; this appears to be directly contradicted by the Flak entry above, but they are adamant.
