Originally Posted by
RVDT
N109BC was a 1999 T1 SN 139 - so could even be a CDS "steam gauges" model.
However, as I recall it used the same Warning Unit which contained the fire warning indictor and bottle switches if installed.
Originally Posted by
albatross
Not to second guess their decisions as we do not know how bad they knew the problem was.
Word from local pilots is the problem became apparent prior to the turn-around and a number of open areas would have been in view. The fact the crew let the fire department comm center know they could not respond to the call in the same time frame gives the impression the issue was not initially serious to the crew. The question remains in the local discussion what did the crew see in the cockpit. However, trailing smoke for close to 40+ seconds prior to the boom failure have generated more questions. Once the aircraft hit the roof the pilot and a 2nd medic were able to self- extricate and there are pics and videos of them moving across the roof away from the aircraft until a ladder was provided for them to get down. From what I've heard the answers to those pertinent questions will be forthcoming sooner than later.
Having seen the effects of a thermal runaway on an aircraft battery, I shall be interested to see if this is a contender.
While I don't personally know about this aircraft a number of operators have switched to AGM batteries on 135s in warmer climates. All the ones (30+) I was around in O&G and EMS had AGM installed when completed from the factory. Regardless, all that smoke was fed by something that didn't run out of quantity.