"At 500ft? on lift off??"
Didn't both the B-47 and the B-52 have attitude issues on take off?
And somewhere I've still go a copy of the first ed. of "handling the Big Jets" where people are being warned (in the '70's still
) to pay serious attention to attitude
With all the add-ons I'd be amazed if it flew like a 707 TBH