From the NTSB 2nd Press Conference:
The Captain of the aircraft had 7,300 hours on the B-17 - the highest of any pilot employed on the 16 x B-17 registered in the USA. He was also the Safety Officer for the Collings Foundation.
The aircraft hit about 30 x approach light breakaway poles up to 1000 feet out from the threshold.
A number of statements have been made on
[email protected] that one or two engines were being worked on immediately prior to take-off (19:48 in video).