Wizofoz, the IAS cannot cannot remain the same. Here is Milt's quote
“For the high performance aircraft climbing vertically at constant IAS the thrust has to be equal to the weight PLUS the drag!!”
If the thrust is equal to weight plus drag, then there is no excess thrust to accelerate the aircraft. Because to keep the same ias, then the TAS would have to increase. It is, of course, climbing up, into less dense air.
My post was to suggest that instead of “IAS”, that the use of “TAS” would be correct for Milt's post.
In Milt’s case, I believe the thrust would have to be greater than the weight plus the drag, in order to accelerate and keep the same IAS. Again, his applies to Milt's scenario.
Hawk