After a skim of the NTSB Preliminary Reports and the comments, I have no doubt engine maintenance was the primary cause of this accident. And that cause lies squarely with the owner / operator of ‘909,’ the Collings Foundation.
The role of the pilot, who was also the maintenance officer (DOM), needs to be more thoroughly examined.
Let’s examine, for a moment, the final cause of the accident events chain: failure to maintain flying speed and altitude, sometimes described as energy management.
Let’s face it … hitting the ALS structures resulted in a loss of control, and a significant departure from the runway center-line. Why so slow, too slow? Why so low? Presumably the pilots knew the correct airspeed to maintain under those circumstances. Were the flaps positioned properly? They may have been… or not. Did the pilot in command (PIC) simply neglect to maintain airspeed in a no-flap configuration?
Sadly, it does appear that the accident was completely within the purview of the PIC / DOM, one way or another…
Was this tragic ending essentially unavoidable, given the loss of two engines on one side? Dunno. Perhaps…