AS332L2 Ditching off Shetland: 23rd August 2013

[KiwiNedNZ]

Double Bogey - Thanks and so basically CFITW is a real possibility based on the sequence of events.

[HeliComparator]

KNZ. I'm not saying it was CFITW, just that it has not yet been ruled out with the info we have. A manually flown approach, wx on minima, decide to slow down so reduce collective, nose up a bit, get distracted, next time you look the aircraft is doing 20kts with high ROD that you can't manage to arrest before the surface. Something like that. Even though it sounds unlikely, unfortunately these things do happen, look at the LAX accident recently. All that is pure speculation obviously.

The report mentions 2 miles (not 3) and they would (should) be at 710' at 2 miles on the lLS DME but its a non-precision approach so could be higher or lower.

Bondu - true!

[HeliComparator]

DB's example is of course biased towards the 225 because such a chain of events cannot happen in the 225 - it would automatically go into 4 axis as the speed bled below 65kts, and then increase the collective to stabilise the situation

[KiwiNedNZ]

HC - Thanks and didnt take it that you were saying CFITW - just asking that with those sequence of events it includes CFITW rather than rules it out. Either way I hope they find out the cause sooner rather than later so you can all get back to doing what you do best.

[Deux Cent Vingt Cinq]

I would say that the choice of language - and the decision to include reference to the IAS - strongly hint at what DB/HC are suggesting.

[212man]

I would say that the choice of language - and the decision to include reference to the IAS - strongly hint at what DB/HC are suggesting

It could explain the lack of a 'mayday' call.

[Tractor_Driver]

All speculative.

However, if true, would vindicate the 'no mixed mode' policy I mentioned in post #632. A modern aircraft, coupled 4 axis/3 cue would prevent this, hypothetical, event.

All the more reason to get the highly capable 225 back into service ASAP.

[HeliComparator]

Or even a 225 coupled in 3 axis / 2cue. Although why anyone would want to fly it like that I don't know. Are you feeling a little unwell, TD?

[Hummingfrog]

HC

Interesting theory of how the autopilot can trap you and initiate a chain of events that can rapidly get out of control!! Does this not emphasise my point of there now being a disconnect between "piloting" and "systems management".

You can be excellent at setting up and using the autopilot to its best but if it has properties that can basically stop the a/c flying, as DB explained, and your hand flying skills are not refreshed enough to recognise and then correct the displacement from safe flight you are in trouble fairly rapidly

If you were used to hand flying you would see the system is not doing what it should and manually remedy it before it went too far! I flew the SAR Seaking with a simplex let down to auto hover - a very good piece of kit but on still flat calm nights it sometimes needed watching carefully with encouragement to help it along!! This was easy as I also had to demonstrate, to the trainers, that I could fly the profile manually.

Weren't there instances in the early days of the Airbus where pilots were saying "what is the a/c doing now" as some part of the autopilot took over without them realising!

HF

[Mark Six]

In the AS332 does ALT hold disengage once the IAS drops below a certain threshold?

[HeliComparator]

HF - you could either ban all automation, but that would put us back into the accident regimes of yesteryear, or ensure that your crews are fully aware of its behaviour under different conditions, know the pitfalls and have well thought-out SOPs for its use. I prefer the latter approach. Also its a good idea to have automation where the pitfalls are plugged, such as in the 225.

But in this case IF, (and its a big IF) it was as we describe, the fault was a failure to monitor, not an inability to fly.

[Agaricus bisporus]

This is all very well but let's not lose sight of the technique you'd use if something broke and you had to ditch NOW!

You'd lower the collective, raise the nose and slow down as you descended...

Exactly the same indications, descent and reducing airspeed.

I really don't see that anything can be gleaned or inferred form the press elease but those two basic facts.

[DOUBLE BOGEY]

In the EC225, flown 3 axis coupled, the flight envelope is fully, and I mean FULLY protected. Inadvertent reduction of airspeed or descent to RADALT 150 feet, results in an immediate automatic reversion to 4 axis coupled and captures safe flight parameters.

These are called Hidden Protections based on the concept that if the EC225 is operated correctly, to a logical safe set of SOPs then in theory the crew will never experience these protections.

Of course we provide 28.5 x 2 = 57 hours of Type Rating Training in SIM and AC to provide the pilot with a comprehensive and fully formed model of how the AFCS, the FADEC and the Display system integrate to support the crew. We believe this is just about enough to get all the messages across and prepare the crew for safe EC225 operations.

I do not know how this compares with the average NS TR on L2 and EC225.

[DOUBLE BOGEY]

Agaricus, the AAIB have full access to the crew. if something broke and caused the reduction of airspeed the AAIB bulletin would have been worded very differently!!

DB

[HeliComparator]

AB you may be right, but it just seems odd that there is no mention at all of any technical malfunction, even in the most general terms.

[HeliComparator]

DB when I did my EC225 differences course in the aircraft at Marignane (pre-sim days), I seem to recall doing 5 hrs (L2 to 225) and my colleagues did 8 hrs (L to 225). We were tough in those days!

Anyway, glad to see that EC have improved that. We do something similar for a differences or type rating + OC course now that we have the Sim.

Although I have to say, it might be better to do a shorter course, put the guys on line for a bit, then do more after say 3 months. Although all the ground is well covered on such courses, I'm not sure how much is retained by a pilot for whom its all very new.

[Hummingfrog]

HC

I am not against good automation in any way - it is obviously the safest way to make an approach in marginal conditions. The 225 seems to be an excellent machine for this and well trained crews will cope with "outages" if the system has a fault.

My point is the disconnect between "systems management" and "piloting".

the fault was a failure to monitor, not an inability to fly.

I disagree with your comment - the fault was failure to manage the system - including monitoring the ASI and AH and when the system showed failure modes - low air speed etc the "piloting" skills should have taken over to increase airspeed and probably power. If this had been done then "piloting" skills would have saved the day.

By definition if a serviceable a/c crashes the pilot has failed to fly it safely.

HF

[DOUBLE BOGEY]

HC I hear you and There is merit in all you say. Retention is an issue but more relevant I think is the continuance of concept and procedures....onto the line. We teach and advocate 4 axis coupled whenever it is appropriate and there is no other compelling reason not to do so.

Of course this accident is an L2 and it works and behaves differently.

DB

[Tractor_Driver]

HC,

I am in the peak of health, thank you.

I do not choose my company car. The S92 is a very good aircraft and has some advantages over others but I don't believe that I have ever said anything disparaging about the 225.

[marcr]

225 / L2

All speculation. But another unhelpful difference between the "variants".....
Weather near minima. You've reduced to Vy 3 axis on a shallow run in to the Missed Approach Point. MDA plus 50' captures. You notice the airspeed dropping off, select IAS and beep forward to accelerate back to Vy+. Whether 3 or 4 axis and even with increased power/collective applied the L2 will most likely "dive" or "descend rapidly" to recover/increase airspeed. (Even if GA mode is selected.) IMC at 300+ feet. Not much room or time to recognise, react and recover.

The 225 has a lot going for it.

Thoughts to all concerned.