I've only got a 400 hrs PPL(A) (lapsed since 2006) and of that an hour was in an R22 a few years ago, so just about irrelevant experience, so......PPL(H)s and pros, is there a single thing that the person in the LH seat could have done that would have resulted in the pilot not "catching" the problem quickly enough? (Excluding airframe break-up).

I am just wondering whether one of the PAX did something in error?

Years ago there was an Arrow accident (i've got about 250 hours on that type) where they think a passenger inadvertantly pulled the control yoke full deflection and the pilot reacted in the opposite way which broke the wing off (well that was one theory).

Curious to know if it may have been similar (but different) that happened here.

And RIP to all those affected, terrible tragedy.

It takes like 18 lbs of pressure to break the rivit and pop the floats. Not an easy thing to do without intent,...and that's provided they armed them before takeoff.

I'm sure there could be, and there are precedents in other RW accidents, such as the FlyNYON AS350 accident in The New York East River.

Churning through so many random people at the controls of a light helicopter seems a recipe for disaster sooner or later; the typical formal student I think will have more reverence for the controls and risk involved.

It certainly is, i remember doing six 20 minute back-to-back trial lessons once, and it occured to me, from a safety perspective, that it wasn't ideal

I'm also fixed wing, so have been trying to get my head around this mast bumping concept... and done a fair bit of reading. Like you, I started with this idea of the rotor blades moving relative to the fuselage, but now I think this is wrong?

Experienced helo pilots please pull this to pieces:

1. Robbo's (and some other types) use a "semi-rigid" rotor system. The benefits are lighter rotor blades, since the blade roots are free to hinge as they wish, and so the inner portion of the blade does not have be designed to take large bending moments.
2. While shutdown the rotor blades do rest on stops, however, once rotor RPM rises, the blades rise by centrifugal force from the stops.
3. The whole rotor assembly is free to tilt (teeter), but easier if you think of it as the spinning rotor produces lift, and the fuselage is hanging by gravity below it.
4. The cyclic controls blade pitch, which "flies" the rotor disc in roll and pitch. Seems an error to think they are controlling the fuselage attitude, just as the rotors roll and pitch the fuselage follows along "hanging" below the rotors according to local gravity.
5. This is all fine under +ve 'g'.

However, at low/zero/negative 'g', this concept of 'hanging' below the rotor is lost. The cyclic can control the rotor's pitch and roll, but the fuselage will pitch/roll in an unpredictable way. As an ATSB report put it from an FAA publication "and the pilot has lost control of fuselage attitude but may not immediately realize it". There seems a typical Robbo consequence:

1. The tail rotor is producing sideways thrust from below the rotor plane, leading to the fuselage rolling right.
2. The pilot, seeing the roll right of the fuselage, instinctively applies left cyclic.
3. The right rolling fuselage and left rolling rotor plane quickly exceed design limits and the inboard end of the blades hits the rotor shaft = mast bumping.

In essence, once mast bumping occurs it (likely? always?) leads to significant failures e.g. pitch links. The divergent attitudes of the rotor and fuselage can lead to rotor strikes e.g. on tail or often the forward left side of the fuselage.

I assume the basics of the design prevent simple ways of stopping this... except educating pilots to avoid low/negative g, and gentle aft stick to add 'g' if it occurs.

Put forward in trying to understand 'mast bumping' and not being suggested in any way related to this accident.

I do wonder if this incident will result in the CAA taking more on an interest in the flight training world and the subject of passengers in the back/quick turnaround short lessons

After a R-66 crash the ATSB put out a good video on the mast bump phenomenon, animation of the relevant bits starts around 2:57:

RIP to all 3 of them

I met Simon a few times at Blackbushe while he was flying G-OCLV and what a lovely guy, great loss to the industry.

Have bumped in to the company a few times down at Lydd and Redhill and the teams and pilots there have been fantastic too, they have an AOC so not sure some of these comments on AOC loopholes are right. If the operation was anything like Blackbushe they had a mix of lessons and pleasure flying and pre-booked, and pretty sure they had weights in advance so knew what was coming up next.

Really hope the guy in hospital pulls through and the families and friends of those who passed can have some answers.

Quite possibly. After all, one of their key aims, taken from their website is "Protecting consumers and the public". As I said a few posts ago, I think the wider issue of public-carrying flight operations at unlicensed aerodromes needs to be looked at.

And what difference does the airfields licensed status have to the outcome of this accident? The accident occurred off airfield.

Public carrying flights frequently take off from unlicensed airfields and private sites regularly in the helicopter charter world all whilst being conducted under an AOC. As another poster has already mentioned, flying training can and does take place at unlicensed airfields across the UK Whether a site is licensed or not does not have any bearing on a flights ability to be carried out safely. It will not change the fact that 3 people tragically lost their lives.

ditching is a very specific subject in the regulation and is not the same requirements as those generally used in emergency floats on part 27 aircraft. I’m not aware of many folks certifying for ditching under part 27.801

More commonly the ditching requirements in 29.801 are needed for transport category aircraft flying more than 50nm offshore.

I hope, that following this accident, the CAA tightens the legislation around ‘trial lessons’ and pleasure flying. Flying lessons should only ever be 1 to 1 up until solo flight. A minimum of 30 minutes of briefing before flight by the instructor should be normally required too.
There is a lot to take onboard at the beginning and carrying other ‘students’ is totally unnecessary (and a distraction) other than for cost. Pleasure flying, unless at an organised event, can be sporadic and therefore expensive if it’s being done properly.
This (unfortunately) seems like a Commercial Air Transport flight rather than any sort of lesson with proper pre-flight instruction. With dual controls fitted, any front seat ‘student’ could cause a problem very quickly without time to recover the situation

Good luck with that when instructor are paid a pittance, and only when the engine starts

If you're flying a Robby a pre-flight breifing on the controls and pitfalls of a light, low inertia, semi rigid, helicopter is required, before you are allowed to even touch the controls. Its called Awareness Training, and ends with a required endorsement in your logbook.

there is no requirement for this in the UK

Well, its required in the country the helicopter was designed, built, and certified. Seems irresponsible for other countries using that helicopter to not also require it.

other countries are less litigious!

It’s possibly insensitive but it’s true. It applies to aviation accident across the whole industry - that’s why CRM was introduced by airlines/regulators decades ago. It’s even more true for road accidents - probably closer to 99%!

He posts here so may well expand on his comments.

The average student only remembers the first few minutes and the last few, so most of a 30 minute briefing will be forgotten. It's called a BRIEFing for a good reason. It's not the same as a formal classroom lesson.