He told you how to do it, you just have to implement it...
Assuming anim 44 is falling neutral, anim 45 is falling forward and anim 46 is falling back, with anims 47,48 and 49 being landing neutral, forward and backwards respectfully, then:
;---------------------------------------------------------------------------
; Jump Land
;---------------------------------------------------------------------------
[Statedef 52]
type = S
physics = S
ctrl = 0
[State 0, ChangeAnim]
type = ChangeAnim
trigger1 = time = 0
value = ifelse(anim = 44,47,ifelse(anim = 45,48,49))
[State 52, 1]
type = VelSet
trigger1 = Time = 0
y = 0
[State 52, 2]
type = PosSet
trigger1 = Time = 0
y = 0
[State 52]
type = Turn
trigger1 = P2dist X < -30
[State 52, 3]
type = CtrlSet
trigger1 = Time = 1
value = 1
[state 1051, land explod]
type = helper
trigger1 = time = 0 & numhelper(8010) = 0
name = "land explod"
id = 77010
stateno = 77010
postype = p1
pos = 0,0
sprpriority = -1
bindtime = 1
ownpal = 1
ignorehitpause = 1
persistent = 0
[State 52, End]
type = ChangeState
trigger1 = AnimTime = 0
value = 0
ctrl = 1.
Specifically, I took the normal common1 statedef 52, removed the anim at the top and added:
[State 0, ChangeAnim]
type = ChangeAnim
trigger1 = time = 0
value = ifelse(anim = 44,47,ifelse(anim = 45,48,49))
I tested it myself, it works.