they went from a positive 4,000 FPM climb to a negative 15,000 FPM in about 6 seconds.
Is that true? That would mean almost 20ms^-2 AVERAGE accelaration i.e. -2g
EDIT: 737 seems to have a limit of -1g with the flaps down. And acceleration of 2 engines at full thrust on empty plane is only 0.58g