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-   -   Police helicopter crashes onto Glasgow pub (https://www.pprune.org/rotorheads/528850-police-helicopter-crashes-onto-glasgow-pub.html)

IB4138 30th Nov 2013 17:21

The :mad: at the BBC News are at it again.

They have shown a picture of the helicopter involved today, "AO" and said "a helicopter similar to this one".

Do these people not do their research or have brains before opening their mouths?

G-CPTN 30th Nov 2013 17:26


the deadweight of the airframe, and the C of G with heavy transmission on top might have started to turn the aircraft inverted before impact?
At least one eyewitness reported the aircraft tumbling end over end as it fell from altitude.

SawMan 30th Nov 2013 17:27

Not a pilot here but a builder so I'm limiting my comments to that. It is not uncommon for a structure to fail in stages, especially when the initial stress has caused large-scale structural damage to adjacent stressed members. In this case just the reverberation from the band's amplified sound or from dancers in rhythm could have caused just enough vibratrion to make the rest of the structure fail as shear forces were aggravated or displaced parts shifted. And if wood was involved, it often delaminates relatively slowly as opposed to snapping in two, even without additional stress loading being applied. It could have been failing slowly even without any other aggravating input after the initial settling under the strain. Of course the structure was never designed to accept this load so it seems to have done very well and performed admirably and normally. Having nothing else to add that's it for me in this thread.

LFT 30th Nov 2013 17:42

A local SBS user reported that his last contact was 22:21:49 at 725ft.

staplefordheli 30th Nov 2013 17:47


Armchair_Ace
Patronising, sarcastic, condescending & downright rude
staplefordheli,:rolleyes: Rolling eyes at an eye-witness report. Were you there?
All: This is a public forum and non-flyers are just as entitled to comment as much as some of the "expert-never put a foot wrong- know-it-all" pilots on here. There are some extremely well written comments on this site that are a pleasure to read & then there are the patronising, sarcastic, condescending & downright rude smart-a55es who, quite frankly, just show themselves up
Not sure why you have singled out my post in particular which was one of the first on this thread as the event unfolded.

The emocon was more to do with the fact the media were using the witness reports of backfiring noise as being a misfiring and failing engine as the cause akin to a R44 or R22 with Lycoming Piston engine . Not a twin engine turboshaft. Flameouts can pop and bang but not like that unless the core of the turbine was breaking up. but that would still have left an active engine to run on save for damage to control components and hydraulics probably leading to a fire

It was more likely the noise described to have been a mechanical noise associated with parts of the main transmission breaking apart so It wasn't aimed at the ley witnesses in any way who wouldn't know if it was powered by turbine piston or even electric rare earth motors

As for some of the other comments on this thread, each to their own
There is place on here for everyone however outlandish their views after an accident such as this and you cannot stop some folks who may not agree with your views posting. However I dont agree with some being shot down by others for having those views

For now with the 3 crew confirmed dead along with members of the public I am just leaving it up to the AAIB who I have every confidence will expediently publish what they find

arica 30th Nov 2013 17:56

low rotor rpm
 
the result seems to be similar to the 2008 crash of an ec135 of the Hungarian Air Ambulance - low rotor rpm in autorotation. The cause at that time could not be found out clearly - might have been a mismatch during emergency procedure after FADEC-induced engine out of one of the engines in low altitude.

dmanton300 30th Nov 2013 17:56


Originally Posted by CharlieOneSix (Post 8181018)
Do Police helicopters downlink video/sound at all times to their control room or do they only do that when on a tasking? Just thinking there could possibly be a lot of useful information to the AAIB there.

In my experience as a PC dealing with the helicopter, the downlink is only used when selected, it doesn't operate at all times. There is an aerial that deploys below the aircraft (at least the MD902 my force had when I was in). This was left down upon landing several times causing damage and downtime for the downlink. FCR would normally request it's usage, it wasn't automatic.

Lon More 30th Nov 2013 18:01


At least one eyewitness reported the aircraft tumbling end over end as it fell from altitude.
That would be the editor from the Sun on a nearby multi-storey car park?
Possibly in a flat spin?

Lurker2500 30th Nov 2013 18:03

I am not a professional pilot by any stretch, but a long time lurker - over the years I've learned a lot of interesting stuff!

But I am a Glaswegian. The junction that the Clutha sits on is larger by some measure than the Clutha's roof, is relatively quiet at that time of night due to the bus lane and being relatively far away from the real nightlife.

A view of it is here. Would a pilot really choose to land on this roof if they had a choice in the matter? Moreover, the buildings in that block aren't exactly known for their structural integrity, which any local can vouch for.

But regardless I'm sure the AAIB will get to the bottom of it. This is a really sad event for the crew and the casualties on the ground - no one should have to go to work (or for a night out, for the matter) and not come back.

ShyTorque 30th Nov 2013 18:13


Flameouts can pop and bang but not like that unless the core of the turbine was breaking up.
Don't forget that the turbine engines of a very rapidly yawing aircraft can suffer a compressor surge or stall, due to airflow disturbances across the intake. A symptom of which is a popping noise.

Obviously, part of the AAIB investigation will look at the whole picture and part of that will be to check the fenestron tail rotor drive.

skadi 30th Nov 2013 18:27


Don't forget that the turbine engines of a very rapidly yawing aircraft can suffer a compressor surge or stall, due to airflow disturbances across the intake.
But the engine intakes on the 135 are way inside the airframe, so that I think a yaw movement would have nearly no influence.

pitofrost 30th Nov 2013 18:36

In a force control room (FCR) close to me, the down link is only requested when on a task. The crew sometimes leave it on when transiting but not normally. The down link images are not recorded in the FCR either, recordings are stored on a hard drive in the aircraft itself. The microwave antenna is is hinged down below the skids when needed and needs to be raised for landing.

John Farley 30th Nov 2013 18:40

zorab64

Thank you for your post.

Have a good day tomorrow

Lonewolf_50 30th Nov 2013 18:42

This is a thought only, and has to do solely with reports of little damage to the main rotor blades in this accident:

If one pulls "early' on an autorotation, and ends up -- lo and behold -- above desired spot with a bit of extra altitude, would not the blades be mostly out of inertia as one makes contact with whatever is below one at the bottom?

That is one way to explain general lack of damage to main rotor blades, I think.

Please correct me if I am making a meal of that thought.

EDIT:

Question for clarification: is EC135 high inertia rotor system or low inertia?

Rushed Approach 30th Nov 2013 18:46

Surely the idea that a chopper pilot would choose to land on the roof of a building when he could land on the ground, even a busy junction, is somewhat strange? Cars and pedestrians would be likely to have at least some chance of getting out of the way, whereas those in a building would not, not to mention the added danger to the crew if the roof gave way.

Also surely the C of G of this craft would mean it stays upright when the blades are seized?

uksatcomuk 30th Nov 2013 18:56


A local SBS user reported that his last contact was 22:21:49 at 725ft.
Network shows last contact 75 feet 2224

Armchair_Ace 30th Nov 2013 18:56

Tragedy & Emoticons
 
Thank you staplefordheli for taking the time to reply to my frustrated rant.
Your post on this thread about a dreadful accident, to be honest, really wound me up. To me it came across as "non-pilots, what do they know" & is an attitude that exists on & spoils this forum. Yours was simply the straw that broke the camel's back & I would have used any other had I come across them today. You seem to have a good knowledge of helicopter workings & your explanation of the bangs was very informative - much more useful than rolling eyes!

RotorRPM 30th Nov 2013 19:00

zorab64 Fenestron....
 
zorab64, just curious as to your understanding of the fenestron being intact... There is a decent angle of the tail boom with horizontal stabilisers sticking up in the air, you can also see the fenestron hub with a few blades attached, no shroud or other blades remaining. My understanding would be it's not quite intact...

Big Duke 6 30th Nov 2013 19:14

Judging from the google earth picture of the pub above, if he had to do an emergency landing at night while having a large work load the roof top might not be to dissimilar looking from the road or a small parking lot.
It's a flat felt roof, with no lights and it's low level right beside the junction.

piesupper 30th Nov 2013 19:15

Further to Lurkers contribution, the Clutha building was originally a multi-storey that was partially demolished. This is seen in many places across the city where clearance has taken place leaving the ground-floor pub as the only remnant of a block of tenaments. Hence the walls are pretty substantial but the roof is much newer and flimsier than the apparent age of the building would suggest. No surprise that it couldn't hold a 3ton chopper even if an attempted autorotation had removed most of the energy.
Given the variety of more benign landing spots available - King St car park, the Briggait Broomielaw Stockwell St intersection, Clydeside Walkway and the Clyde itself, I'd go along with the supposition that the pilot flared out of the autorotation too early and landed on the pub, not the intersection.

Doesn't explain eyewitness statements about tumbling end over end though.


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