Police helicopter crashes onto Glasgow pub

[SilsoeSid]

Can someone from the West Midlands tell us when the checks were carried out and what those checks actually were please.

[SASless]

It is beginning to sound as though some sort of message(s) was sent to the Command Post.....wonder what information was passed?

[Winch-control]

Given we are in the 21st century, is it not to be considered unacceptable, that the authorities, given to them power to investigate, cannot with all the evidence laid in front of them come up with an answer as to the cause?

I would suggest 7 days, 10 at the most is adequate. If the AIB need 12 months plus to resolve the reasons for any accident/incident I would suggest they are sadly very lacking, and not fit for service.

Possibly they are financially capped, short of personnel, these issues must be resolved.

It is not acceptable in this day and age that an incident is not resolved within a very short space of time.

[SASless]

The Gears of the Bureaucracy grind slowly.....but very thoroughly!

It takes a while for all the technical examinations and other forensics to be completed, results considered, and reports written. Just compiling the witness statements will be a time consuming process.

The 332 Crash which had both crew members survive....is still under investigation.....so you should not think this one is going to be done any quicker.

I hate to think how complicated the crash sketch and diagram will be....that alone is a huge undertaking.

The AAIB does good work.

[jayteeto]

Sid, you are a little tinker!

[xlsky]

Given we are in the 21st century

just that the physical and chemical substances we humans inclusive our brains are made from hasn't changed at all since the last 21 centuries and even much longer. So what do you expect?

The investigators will take the time they need for any statement they are willing to make public, be it 1 week or 1 month or one year or even longer.

It's incredible amazing to see the impatience and utterly unprofessional wild speculations here, even sometimes from apparently experienced pilots. Are these 'pilots' fit to fly?

[Thomas coupling]

Would current ec 135 drivers dispel this following (ridiculous) idea of mine please as it sounds too far fetched to be true. But I need to air it:
When I first flew the 135, I remember an issue with the rotor brake "chattering". The pads occasionally touched the brake disc. It wasn't a big thing at the time and moves were made to sort it.
Question then: IF the rotor brake was applied in flight (either inadvertently or on purpose) would it be man enough to initiate the following scenario (or would it be too small a system to slow the rotors in flight such that it was merely a severe embarrassment):

Rotor brake pressure applied - Nr begins to decay slightly, Drags Nf down causing the engine(s) to stall/surge. [Eye witnesses report popping and spitting] Pilot sees and hears this but (obviously) doesn't connect it with a rotor brake problem - he sees it as an engine(s) problem. So he tries to identify the source but the noise(s) and (slight) drop in Nr troubles him to the extent that his best course of action is to remove the stalling engines. So he sets himself up for an auto and chops the throttles (all of this has taken seconds to decide and all the time the engines are popping and surging). He chops the throttles but the rotor head now much more easily slows down as the rotor brake has no engine resistance fighting against it. Engines are off, Rotors are stopping??????

[Hughes500]

TC
Not a 135 pilot but that scenario has just sent a shiver down my spine

[DOUBLE BOGEY]

TC , I think your scenario would result in a fire, developing very quickly.

[Non-PC Plod]

TC,

I have not flown the T2, but I am guessing its not an automated rotor brake. In which case, surely you are going to have to physically apply any rotor brake pressure. (Not something you can do inadvertently). "Chattering pads" with no pressure behind them are surely not going to dent the Nr.

[choppereng]

There have been no additional checks instigated as a result from this accident.
I have read all the speculation on here and here I my thoughts on some of the 'ideas'
1. Both engines flaming out- very unlikely. However if I'm led to believe the sortie times are correct they would have been extremely close to running out of fuel
2. MGB failure- very unlikely. If the MGB had had a failure or seized it would be in the bottom of the Clyde and the aircraft spread across a big area
3. TR drive failure- possibly. If the TRDS had failed the drive shaft cowling would be completely trashed. Looking at the pics this seems fully intact. Trust me I've seen the results of driveshafts letting go. It's messy. If it had failed further up the drivetrain then this would be harder to see from the pics. So a maybe.
4. Fin cracking -Very unlikely. The new ASB was instigated after one modified ring frame was found to have a small crack. This would take ages to propagate. Anyway this aircraft I would think by its age would have the big carbon fibre patch modification and not be subject to the ASB.
5. Tail rotor hub failure- very unlikely. Looking at the pics although the hub and stators are detached this is a result of the fin striking the roof on landing. If you look at the blades six are still attached. The four missing would be again as a result of the impact on the roof.
6. Reports of he blades not turning. My experience of night time ops is that blades are extremely hard to see at night and if his side strobes were on this has the effect of 'stopping the blades'
7. Engines popping.- could be engine surge. Again my experience of surge is of a popping/banging sound. What could cause this is the engines shutting down with power still being pulled in.
8. Lack of damage to blades- hard one to quantify. All I can bring to this is that they made a landing on the roof and managed to shut the rotors quickly with the brake. The aircraft then fell through the roof under its weight. They only thing that I can't get my head round is how they died. All I can suggest it the roof timbers etc came through into the cabin and killed them??

So in conclusion. We don't know. What we do know is that this is one of the safest aircraft out there and none have crashed due to a catastrophic mechanical failure. And before you say...the Japanese one was due to somebody mistakenly thinking the thread was left hand and not right hand and weakening the rod.
I would and have flown on testing recently with no worries at all.

[choppereng]

TC.
When we fit new pads to the rotor brake we have bed them in. This entails then brake being pulled on with rotors turning. Trust me. With rotors at max chat there would be no significant drop in NR. He would get a caption on his CAD 'ROTOR BRAKE'. And if the lever had been pulled...very unlikely..... It would be released again. The brake can not inadvertently come on in flight. Discount this idea. The brakes on the 135 are, to coin a phrase, a bag of crap. I wouldn't fit them to my bike.

[jayteeto]

I have 2500 hours on 135s, I have never encountered rotor brake pad chattering. I do know someone who started with the rotor brake still on and the rotors ran up as normal, the engines being stronger than the brake. No fire.
Not saying the theory is wrong, no-one can rule anything out.
I have flown 135 since this crash and remain confident in my aircraft

[choppereng]

Here here Jayteeto!

[Fortyodd2]

ChopperEng, TC and others,
Sid is correct, since October 2nd, West Mids do not have their own aircraft.
And I would also like to know what these checks were, what was checked and who carried them out? Certainly nothing recorded in our tech log.
TC, the only "rotor brakes coming on" scenarios I can think of were 2 x early EH101/Merlin and a Lynx in Germany which was, fortunately, on the ground - the crewman involved is one of my pilots. All resulted in a fire.

[ShyTorque]

Choppereng, but on the other hand, I've seen an aircraft that had suffered an inflight T/R drive shaft coupling failure. From the outside there was nothing to see. The flector pack sheared but the shafts themselves stayed relatively intact.

Has it been proved that the all damage to the tail end was caused completely by contact with the roof? I'm not aware that this has actually been properly established.

[Winch-control]

Let's just jump in and be completely direct.

There is no apparent mechanical problem with this incident. If there was the a/c would be grounded.

What emergency call was made by the rear crew?

Why then, did a perfectly serviceable help land where it did?

[RVDT]

Rotor Brake -

A lever in the cockpit forward of the overhead panel attached to the centre windscreen frame.

It has a latch to hold it in the OFF position and ON position. When on it is fairly obvious.

Manually actuates via a bowden cable to a master cylinder and reservoir.
There is a "damper" spring in series to avoid too much pressure being applied.

The calliper is free to move for and aft in the direction of rotation slightly and is held
in one direction by a spring. On application the calliper moves in the direction of rotation against the spring and activates a micro-switch to bring up on CAD - ROTOR BRK.

On activation at =50% NR with engines OFF it should stop the rotor in ~ 45 seconds.

All looks like it was stolen off a Malaguti Scooter and made by Brembo.

If on in flight it would certainly get hot. The lever hanging down in your face and the CAD Caption would be a giveaway.

Noticeable NR change or Q increase - doubtful.

[Mechta]

Winch-Control wrote:

Given we are in the 21st century, is it not to be considered unacceptable, that the authorities, given to them power to investigate, cannot with all the evidence laid in front of them come up with an answer as to the cause?

I would suggest 7 days, 10 at the most is adequate. If the AIB need 12 months plus to resolve the reasons for any accident/incident I would suggest they are sadly very lacking, and not fit for service.

Possibly they are financially capped, short of personnel, these issues must be resolved.

It is not acceptable in this day and age that an incident is not resolved within a very short space of time.

Getting to the root cause of an accident, particularly one of this nature, in which none of the crew survived, is a slow laborious task if the job is to be done thoroughly. Most of the possible causes postulated in this thread will need to be discussed, investigated and ruled out. That could involve microscope analysis of the crash components (and others from similar aircraft), checking of manufacturing and maintenance records. Given the number of critical components in a helicopter, many of these investigations will prove to be dead ends, although they must be ruled out for the avoidance of doubt. Some tests may require test rigs to be built to allow accelerated lifing of components. The rigs and the subsequent tests all take time. With the reliance of software in the control loop of modern aircraft, pages & pages of code may need testing and analysis. Spacecraft have been lost for the sake of one mistyped character.

It must also be borne in mind that the AAIB does not have a team of highly skilled experts sitting idle waiting for an accident to give them something to do. Any investigation around the world which has a UK involvement, either through location of the accident, place of manufacture, place of registry, or nationality of the victims could be drawing on the time of essential staff.

That the AAIB manage to get a report out in a year, is an achievement in itself and a credit to them given the work involved.

According to Wikipedia, AAIB has 49 employees. Given their workload and output, I'm inclined to agree with Winch-Control's third paragraph.

[choppereng]

Apologies fortyodd2. What meant was there is an aircraft operating within the West Mids area
And I can quite categorically say that that this aircraft has had no extraordinary checks carried out on it....