Scotland Helicopter Crash
Discussion
Number two has been observed as being capable of driving the head and tail rotor drive shaft. There has been no mention of the fenestron as yet or any of its connecting parts to the trds.
This is probably due to the fact the tail was detached during impact and thus requires more time to investigate but at the moment loss of fenestron has still to be ruled out.
This is probably due to the fact the tail was detached during impact and thus requires more time to investigate but at the moment loss of fenestron has still to be ruled out.
trashbat said:
That's a little facetious. I took the comment as an acknowledgement that to the untrained observer, a low flying helicopter might sound unusual rather than actually have something amiss.
Don't know if this will help clear it up a bit, a few weeks ago a helicopter (possibly same one?) was circling around the area I stay Blantyre for reasons unknown. I'd say he was circling about 1,500ft which is whit I assume to be normal.Coming back to 2 weeks ago when I came out of the entrance to M & D's my attention was drawn to the helicopter overhead as it was loud & flying what I would say is lower than normal. The way I would describe the sound I heard was loud not deafing but enough to hurt your ear.
Wullie
TheSnitch said:
ninja-lewis said:
TheSnitch said:
The remaining Glasgow tenement buildings are a thing of beauty, although I should imagine they were probably pretty grim back in the day. I think they were usually four storeys high, and to me they have always looked very solidly built things - many of those that remain are of red sandstone construction. It didn't look to me as if much had been done to the roof of the Clutha other than to felt it and make it watertight. It also looked to me that because of that, and the nature of it's wooden structure, the roof had absorbed a lot of the energy of the crash before it collapsed, rather than 'punching' straight through, if that makes any sense?
It was reported at the time that there were in fact three 'roofs'. The original first floor floor with substantial beams, extensive soundproofing and then a further weatherproof roof on top.Crossflow Kid said:
Yep, was aware of that and probably wasn't clear. I meant something going pear-shaped, possibly power turbine related or not (bearing failure?) and the sprag clutch not disengaging fully/correctly, so although the dragging turbine might not stop the head it might slow it enough to bugger up the numbers for an autorotation.
The point, I think, is that gas turbine helicopters don't have a sprag clutch (AFAIK, so don't quote me on that).I would expect, and obviously have never built or designed a helicopter, that if the turbine was dragging sufficiently, the power of the other turbine and the sheer amount of kinetic energy in the rotors would simply break something between the duff turbine and the gearbox. It does seem unlikely that a failure of one engine could cause the rotors to stop and in any case, the pilot ought to have have sufficient warning before this point to get the aircraft on the ground.
You'd hope so anyway.
Hopefully the investigation will find out the most likely cause.
matchmaker said:
I'm surprised it has taken this long.matchmaker said:
Does this mean they found a fault with the one that crashed too? That article doesn't mention whether the Clutha helicopter had or didn't have that fault. Sure we'll hear soon enough though.Super Slo Mo said:
The point, I think, is that gas turbine helicopters don't have a sprag clutch (AFAIK, so don't quote me on that).
I would expect, and obviously have never built or designed a helicopter, that if the turbine was dragging sufficiently, the power of the other turbine and the sheer amount of kinetic energy in the rotors would simply break something between the duff turbine and the gearbox.
Some don't some do, for precisely the scenario described - where the power turbine suffers a problem.I would expect, and obviously have never built or designed a helicopter, that if the turbine was dragging sufficiently, the power of the other turbine and the sheer amount of kinetic energy in the rotors would simply break something between the duff turbine and the gearbox.
I'd agree that a failure on one side shouldn't drag the other side down, hence my suggestion that it may be a combination of minor failures working together. Very unlikely but not impossible.
Seems something else (more obvious) is up though.......
Curious that only Bond have grounded their fleet. Unique in-house maintenance regime perhaps?
Edited by anonymous-user on Thursday 12th December 14:05
I read some info yesterday that seemed to imply that it was only piston engined helis that had the sprag clutch, as turbine ones don't need them. Not that it's a point worth labouring over mind you.
Further reading suggested that the article I read might have been incorrect, that's the FAA for you I guess.
Further reading suggested that the article I read might have been incorrect, that's the FAA for you I guess.
AyBee said:
matchmaker said:
Does this mean they found a fault with the one that crashed too? That article doesn't mention whether the Clutha helicopter had or didn't have that fault. Sure we'll hear soon enough though.
Max_Torque said:
"Grounding", although it's not an official one, is due to a faulty fuel level sensor alarm apparently. Unlikely to be connected to crash, as 95L of fuel were removed from crashed helicopter, suggesting what ever the alarm system reported, there was fuel available to the engines. (not quite clear cut because certain "dynamic flight conditions" can render a quantity of fuel un-usable apparently).
It may well be connected. The report concluded there was fuel in the tanks, which specific tanks the fuel was in it doesn't say. And, fuel being present doesn't mean it was available to the engines.I'm not saying anything other than I find it difficult to draw assumptions without any evidence to base them on.
odyssey2200 said:
Would a faulty sensor stop the available fuel being transferred to where it needed to be?
Possibly. I'm not familiar with the intimate details of the 135's system, but in any aircraft fuel system there can be all sorts of gizmos designed to shut off tanks when they're empty to prevent downstream cavitation of pipes and hoses, or to keep pumps primed and so on.If the system "thinks" the tanks are empty it may well shut them off. Would still seem a little odd that it managed to starve both engines to the point of failure.
StevieBee said:
matchmaker said:
I'm surprised it has taken this long.BBC Article said:
Flights of the EC 135 were suspended briefly after a fault was found on a Bond helicopter operated for North West Air Ambulance.
Bond has said the grounding was not related to the Glasgow crash, and the aircraft were later allowed to return to the air.
Seems pretty empirical - according to Bond it's not related to the Glasgow crash. If it were you would have expected to see NPAS EC135's to be grounded too (if they're the same model/variant etc.)Bond has said the grounding was not related to the Glasgow crash, and the aircraft were later allowed to return to the air.
And I'm curious as to what 'were suspended briefly' means. The syntax suggests that they're flying again?
tenohfive said:
Seems pretty empirical - according to Bond it's not related to the Glasgow crash. If it were you would have expected to see NPAS EC135's to be grounded too (if they're the same model/variant etc.)
And I'm curious as to what 'were suspended briefly' means. The syntax suggests that they're flying again?
It was basically 'don't fly any EC135 until it's fuel sensors have been checked'.And I'm curious as to what 'were suspended briefly' means. The syntax suggests that they're flying again?
Dr Jekyll said:
tenohfive said:
Seems pretty empirical - according to Bond it's not related to the Glasgow crash. If it were you would have expected to see NPAS EC135's to be grounded too (if they're the same model/variant etc.)
And I'm curious as to what 'were suspended briefly' means. The syntax suggests that they're flying again?
It was basically 'don't fly any EC135 until it's fuel sensors have been checked'.And I'm curious as to what 'were suspended briefly' means. The syntax suggests that they're flying again?
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