As to why they used an f4? Probably a heck of a lot cheaper than a 737 at the time.
It would seem like there are plenty of scrapped 737s available[1] to carry out such a test. I'm too lazy to look up prices on these things, but I'd be very surprised if those were significantly more expensive than a scrapped Phantom.
But it didn't in the video.
As to why they used an f4? Probably a heck of a lot cheaper than a 737 at the time.
It would seem like there are plenty of scrapped 737s available[1] to carry out such a test. I'm too lazy to look up prices on these things, but I'd be very surprised if those were significantly more expensive than a scrapped Phantom.
[1] http://airchive.com/html/scrapped/ardmore-graveyard