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BOI into the 2012 Tornado Collision over the Moray Firth

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BOI into the 2012 Tornado Collision over the Moray Firth

Old 12th Jan 2014, 22:41
  #141 (permalink)  
 
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I know that the GR4 is fitted with Mode S transponders and that these have hex codes allocated for the transponders ID, that these transponders can be linked to an ACAS system and information exchanged between them.

So is it a case here that this part of the GR4 avonics upgrade was only the transponder and therefore the chance to fit some sort of CWS was missed at the time?

If so I think we missing a safety milestone in doing so.
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Old 13th Jan 2014, 07:48
  #142 (permalink)  
 
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My point was that, as with BoIs, the Coroner can only work with the evidence placed before him. And that is DV's point. MoD have a nasty habit of destroying or withholding evidence; or just denying it exists in the first place.

However, in the case I mentioned, the Coroner acted appallingly towards the families, one father in particular. He was a "temp", necessary because of the sheer number of inquests. He did not have a stenographer, due to financial cutbacks, so had to take all the notes himself in longhand. As a result, the proceedings were disjointed and shambolic.

He would not allow questions relating to the three main contributory factors noted by the BoI. He refused to reconcile vastly different witness statements. Time after time he put up with witnesses refusing to answer the question, or offering a wholly unrelated reply.

Most witnesses were patently unsuitable for the questions, and he constantly said "We'll get back to that later" or "Write to me with the answer". Not once did he ever return to get the answer, and both MoD and Coroner's Office confirm that no submissions with the answers were made after the inquest.

Justice was not seen to be done. What was discussed at the 3.5 day inquest could have been finished in a day. Contrast this with Ft Lt Cunningham's inquest, planned to last 3 weeks.

Mr Walker did a fine job on Nimrod. The Government's response? Set up a Committee to look at how to curb his enthusiasm for the truth. A lesser known fact.... The MP representing the family (above) and who had asked Minister some leading questions (MoD actually told the truth in one reply, but this merely exposed the fact they had lied to the original investigators) was placed on this committee, meaning he was not permitted to ask any further questions on related matters. A very effective gag, and stopped awkward questions in their tracks. The more I look at this case, the more it looks far worse than any other.
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Old 13th Jan 2014, 09:07
  #143 (permalink)  
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Clicker

Seeing as successful Tornado CWS flight trials were concluded in 1997, it would have been much better to have installed a CWS during the GR1 upgrade to GR4.

Which avionic upgrade are you talking about?

DV
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Old 13th Jan 2014, 16:13
  #144 (permalink)  
 
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DV,

I'm presumed that there was an upgrade from the GR1 to GR4 as Mode S was fitted.

I'm not in the service so just my assumption that a chance may have gone begging.
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Old 27th Jan 2014, 19:54
  #145 (permalink)  
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I understand that Bond Helicopters have fitted Honeywell TCAS II to their Super Puma helicopters. It took them six months including flight trials and certification etc. MoD plan on installing Honeywell TCAS II to the Tornado GR4 aircraft, and so far it has taken them six years.

http://aerospace.honeywell.com/~/med...Bond_TCAS.ashx

As a retired aircraft engineer who has been involved in engineering new fits and and carrying out flight trials testing I believe that the Bond time frame is the more realistic, if there is the will.

DV
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Old 17th Feb 2014, 12:48
  #146 (permalink)  
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I wonder if this event features in the SI,

Tornado collision: Warning system was ?cancelled? - The Scotsman


DV
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Old 17th Feb 2014, 13:14
  #147 (permalink)  
 
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I wonder if this event features in the SI,
I'm completely confused as to what the MAA does. The Red Arrows thread is a litany of incompetence and failure to act. They seem to have no power over the procurers in DE&S or operators. Yet the last SDSR was delayed by them insisting on some elements of the Nimrod review being funded. BZ. Which only shows someone thought it a good idea not to fund them, which is pretty frightening. They need to be "open and honest".
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Old 18th Feb 2014, 08:44
  #148 (permalink)  
 
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DV you are correct but TCAS 2 is only fitted to the L2 variant.
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Old 25th Feb 2014, 18:40
  #149 (permalink)  
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Has MOD gone completely mad?

Angus Robertson: To ask the Secretary of State for Defence what audible warning the Honeywell Traffic Collision Avoidance System II will give in an imminent collision scenario. [187988]

Mr Dunne: As two suitably-equipped aircraft approach one another, their crews will hear the words, ‘traffic, traffic', If there is a risk of collision the Honeywell Traffic Collision Avoidance System II will direct the crews to manoeuvre to avoid a collision and they will subsequently hear either the instruction: ‘climb, climb now,' or alternatively, ‘descend, descend now.' Once the aircraft have achieved safe separation, the crews will hear the words ‘level off'.
So we have two Tornadoes closing around 14nms/min at 500ft, and one gets "climb, climb now", and the other poor sod gets "descend, descend now". This is the very reason why AAIB advised in 1994 that TCAS was unsuitable because "It resolves conflictions by advising manoeuvers in the vertical plane and this would be inappropriate at low level"

So we have waited 20 years for MOD to select a piece of equipment that they were advised against using in 1994.

DV
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Old 25th Feb 2014, 18:59
  #150 (permalink)  
 
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So we have two Tornadoes closing around 14nms/min at 500ft, and one gets "climb, climb now", and the other poor sod gets "descend, descend now". This is the very reason why AAIB advised in 1994 that TCAS was unsuitable because "It resolves conflictions by advising manoeuvers in the vertical plane and this would be inappropriate at low level"
Given the rate that a Tornado can climb at low level, does it matter if the other cannot descend much?
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Old 25th Feb 2014, 19:13
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Come on then DV, propose a better solution. Years were wasted trying to develop a gold-plated bespoke CWS for fast jets.

Just because the AAIB wrote something doesn't make it gospel, especially not when it's 20 years old. Anyone familiar with TCAS II knows that 'Descend' instructions are inhibited below 1000 feet as measured on the radar altimeter, so the lower aircraft in a proximity situation will only receive the advisory call "Traffic, traffic". This will cue the pilots' eyes immediately to the TCAS display, where they will see a plan view showing where to look out for the offending aircraft and hopefully allow them to duck under it.

Meanwhile the higher aircraft will get a "Climb, climb" resolution advisory, because these are not inhibited by low heights. So by following the instructions, the collision will be broken, even if both aircraft are hoofing around at 100 feet. TCAS II is a cooperative system, so if both aircraft are at exactly the same altitude, the system will still make a decision to tell one of the aircraft to climb.

Of course the problem of confliction with non-transponding aircraft will continue post installation of TCAS II. Have you got any bright ideas of how to deal with that, DV? Perhaps Tornado should be fitted with FLARM? There's a nice spot for a COTS unit on the glareshield, it should block the view out of the windscreen nicely.... get in touch with the PT, I'm sure they'd appreciate your guidance.
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Old 25th Feb 2014, 19:26
  #152 (permalink)  
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Just because the AAIB wrote something doesn't make it gospel, especially not when it's 20 years old
MOD accepted this advice at the time and funded a CWS programme for fast jets.

Years were wasted trying to develop a gold-plated bespoke CWS for fast jets.
I understand that flight trials were concluded in 1997 for a fast jet system. MOD decided at that time to procure the CWS with a planned in service date of 2004; hence the statement in the 1998 SDR.

DV

Last edited by Distant Voice; 25th Feb 2014 at 19:53.
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Old 25th Feb 2014, 20:05
  #153 (permalink)  
 
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Easy Street


All this TCAS stuff is long after my time, so a genuine question - one that arose during the Mull of Kintyre debate.

'Descend' instructions are inhibited below 1000 feet as measured on the radar altimeter

Taken literally, that could mean you have a rock face 1000' in front of you, with your huff and puff altimeter saying, say, 3000'. In other words, most Radar Altimeters measure the RANGE to the nearest fixed object within the beam pattern. The word "altimeter" can be misleading. So, for example, when the Chinook hit the hill at (800'?), the RadAlt indicated zero, or as near as dammit. Have I got this wrong? I remember this on MoK because the various reports seemed at times to confuse barometric with radar. (I've deliberately not mentioned Radio Altimeters!) Thanks.
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Old 25th Feb 2014, 22:53
  #154 (permalink)  
 
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tuc,

You have got me doubting whether I should have said 'radar' or 'radio' altimeter, so I shall stick to 'radalt'!

I don't know what beamwidth a rotary-wing aircraft's radalt would typically have, but the scenario you describe would certainly be possible with the radalts fitted to fast jets. The beamwidth of older ones was about 90° to ensure that they stayed locked on at moderate bank and pitch angles, and they returned the "height" reading from the shortest range return. This was noticeable when flying parallel to vertical cliff walls, when it was possible to get a return from the side at small bank angles. To address your specific scenario, someone flying into a hillside in level flight would see constant barometric altitude, while the radalt progressively decreased to zero.

There are some newfangled 'covert' radalts, designed to be better in tight EMCON. Whether these have a narrow beamwidth, electronically steered to the vertical axis, I know not. If they did, it might be possible to fly into a vertical cliff wall while getting a height reading from the valley floor.

Back on topic, TCAS II believes whatever radalt input it gets when deciding whether to screen out "descend" instructions. They didn't account for covert radalts or valley flying when drawing up the spec! The cooperative decision on vertical deconfliction is taken with reference to barometric altitude at 1013.2hPa, as fed to the transponder, so there should be no chance of undulating terrain compromising the integrity of the instructions (only exception being where the 'low' aircraft is forced to climb by terrain, in which case the 'high' aircraft should get an 'increase climb' instruction). It's worth remembering also that GPWS warnings have primacy over TCAS instructions, even in civvie airliner land; rest assured that system designers had actually considered the possibility that vertically-based deconfliction instructions near the ground might carry their own risks...

TCAS II is not ideal for fast jets but it is better than nothing, which following the failure of the bespoke programme (which I had always understood to be much later than 1997; I thought 2004...) was the only alternative. Even in situations where its deconfliction instructions are inhibited, it will cue aircrew to look in the right place when squawking traffic approaches. It probably would have saved 3 lives in 2012. Let's see what the SI has to say over MoD taking 10 years to actually get round to fitting it.....
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Old 26th Feb 2014, 06:47
  #155 (permalink)  
 
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Thanks Easy Street. Far more up to date than me. Always ask someone who knows!
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Old 26th Feb 2014, 20:28
  #156 (permalink)  
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which following the failure of the bespoke programme (which I had always understood to be much later than 1997; I thought 2004...
It is documented that the initial trials were commenced in 1994, and concluded in 1997. MoD then decided to procure the system with an in sevice date of 2004. This "bespoke" system was persued because of the percieved problems with TCAS, as I indicated in my ealier post. It now seems that we are back to the 1994 position.

The whole thing was summed up by the DG MAA in 2010 when he reported "Incremental mitigation of this chronic risk, which has a high 'societal concern' factor, has suffered protracted delays over successive PRs since the 1998 SDR.

I am not against the TCAS system, it is just that if it is OK to install it now, why not 20 years ago; the basic system has not changed that much.

Let's see if the SI contains this information.

DV
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Old 26th Feb 2014, 22:32
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I am not against the TCAS system, it is just that if it is OK to install it now, why not 20 years ago; the basic system has not changed that much.

Let's see if the SI contains this information.
No need to wait for the SI on that one. This was merely another symptom of the illness diagnosed by Bernard Gray before he became CDM, namely the institutionalised gold-plating of requirements, under-estimation of technical risk as a means of securing funding when pursuing novel programmes, and a systematic refusal to contemplate the off-the-shelf 80% solution. TCAS was only adopted when there was literally no other option - and judging by the time taken to get it into service, I wouldn't be surprised to see evidence of a rear-guard action by the gold-platers....
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Old 26th Feb 2014, 22:49
  #158 (permalink)  
 
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Maybe a few areas of misunderstanding about radalt. I was about to try to explain in my own words, but then found the following. Sorry, I have no idea what language this was written in, but it explains some very important priciples about radalt and what it actually measures - notwithstanding East Street points about beamwith.

The transmitted pulse reaches the surface first on a small point. As the pulse advances, the illuminated area grows rapidly from a point to a disk, as does the returned power. The reflecting area depends on the beamwidth of the antenna. The energy from the center of the main beam has to travel the shorter path than the energy from the edges. An annulus is formed and the geometry is such that the annulus area remains constant as the diameter increases. The returned signal strength, which depends on the reflecting area, grows rapidly until the annulus is formed, remains constant until the growing annulus reaches the edge of the radar beam, where it starts to diminish.
It's not just a simple measurement of distance from Tx/Rx to the nearest object.
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Old 27th Feb 2014, 11:11
  #159 (permalink)  
 
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It is the dim and distant past but I do not recall TCAS trials in the mid 90s but do remember GPWS being trialled, I think on the SAOEU GR1 at Boscombe. It was being aligned with a [email protected] IN competition to replace the old mechanical system.
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Old 1st Mar 2014, 15:45
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TART Report

Does anyone have a copy of the Tornado Airworthiness Review Teams (TART) report, dated circa 1996? MoD appears to have lost all their copies.

Please PM me if you have.

DV
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