I work on complex numbers. Let Q \subset \PP^4 be a quartic threefold that contains a double line l. I want to compute the normal sheaf of l in Q, and I seem to find only two possible cases, i.e.

O_l(-1) \oplus O_l and O_l(-2)\oplus O_l(1)

can someone tell me which is the right one? There should be some paper by Iskovskikh about that but I am not able to find a copy of that.