Sorry JT.
Now, to answer you, I don't 'mean' anything - my whole post is basically asking for a steer as to what might have happened to have caused him to not react quickly enough - surely my post is in plain enough language for anyone to understand that - I'm asking!!
Quite plainly, perhaps he simply didn't expect a
double failure.
For instance is it possible that his hand wasn't on the collective for whatever reason or that the collective was locked with friction or the autopilot was engaged and it takes 1 second to disengage but the RRPM decays in under that time.
His hand
could have possibly been doing something else as the first engine failed, but the collective
shouldn't have been locked by collective friction to that degree. Input to the controls
would override the autopilot and when the second engine went, the hand
should have been on the collective in an instant.
In my machine, if my engine fails (god forbid) I get an engine out tone, I get un commanded yaw and I drop the lever quick. But my machine also allows me something like two seconds in which to do it. Does the EC135 allow such a time frame?
I believe the 206 has higher inertia blades, so I
would imagine the timeframe is a lot shorter. For the 135, entering autorotation is an
immediate action following a double failure.
However, if I had a passenger who panicked and grabbed my arm or I was switching my pitot heat on or changing frequency at the point my engine failed maybe those action could cause me to react more slowly and the RRPM might decay to an un-recoverable point. In this case whilst the manufacturer might consider in a calm cockpit with no other distraction there is traditionally sufficient time to lower the lever there are factors like those I've described that might cause there to be NOT sufficient time to react. It's not rocket science!
I would imagine that most helicopter pilots' motor systems
should have developed enough to be able to get the hand back on the collective immediately, whatever it had been doing at the time.
If there were warning captions illuminated, aural tones, and procedures that he had to follow etc that distracted him, plus pax that might have been talking to him or were panicked causing him to not instantly realise that he'd had a double flame out then he may not have had sufficient (as in humanly possible) time to process the information that his brain was dealing with and consequently not lowered the lever quickly enough.
Mmm, doesn't this suggest that didn't react in time, rather than didn't have sufficient time. When the second engine failed, the time was always there and
could have been used.
None of us were in that cockpit so no one knows what happened but I'm asking for a steer from someone like you who flies twins and understands the systems and processes that might have lead to that.
Quite true, but given the latest report, there are some pretty good leads as to what
could have happened.
Finally, should the fuel transfer switches been on or off, because I don't think that's been answered.
Given that there was 76 kg in the main tank, the transfer pumps
should have still been on, well at least one of them at any given time due to the ac attitude. The supply tanks
should have had 47 & 43 kgs in them and the prime pumps
should have been off. The only reason for the prime pumps to be on in flight,
should be when you get a low fuel pressure warning.
At some point around 22:00 that night (Bothwell task?), when the supply tanks became the only fuel source, the configuration of all the fuel pumps was altered.
However, regardless of the switchology, this doesn't get us away from all the warnings and indications that
should have been there and
should have been actioned upon. I
would have thought that the decrease of supply tank levels down to nothing,
should have risen some back hairs and early action
could have been taken …. if indeed all the warnings and displays were there to take action on!