The transient flowfield over a delta wing during pitch-up motions to v
ery large angles of attack was investigated. Emphasis was directed at
the growth and the eventual breakdown of the leading-edge vortices. De
lta wing models were tested in a wind tunnel at Reynolds numbers of or
der 10(5). The flowfield along the trailing edge was mapped out via a
seven-hole probe designed, constructed, and calibrated to generate tim
e-resolved information. Instantaneous surface pressure measurements we
re also obtained. Earlier qualitative evidence of hysteresis in the de
velopment of the flow was confirmed. Moreover, the present data indica
te significant differences of vorticity content between the steady and
the unsteady motions, for reduced frequencies as low as 0.01.