Go Back  PPRuNe Forums > Aircrew Forums > Military Aviation
Reload this Page >

Chinook - Still Hitting Back 3 (Merged)

Wikiposts
Search
Military Aviation A forum for the professionals who fly military hardware. Also for the backroom boys and girls who support the flying and maintain the equipment, and without whom nothing would ever leave the ground. All armies, navies and air forces of the world equally welcome here.

Chinook - Still Hitting Back 3 (Merged)

Thread Tools
 
Search this Thread
 
Old 22nd Feb 2010, 10:47
  #6201 (permalink)  
Just a numbered other
 
Join Date: Feb 2000
Location: Earth
Age: 72
Posts: 1,169
Received 0 Likes on 0 Posts
fish

And with a Sea Level temperature of 9 Deg C, the crew would be working on a 'rule of thumb' freezing level of about 4500'

The pathetic so called icing clearance for the Mk2 was 4 Degrees, to be expected at 2500'.

IFR was not an option, and contrary to CAZ's assertion that Flight in accordance with IFR would be required in the vicinity of the Mull ( I know he is only quoting the BOI report), low level VFR along the coast was easily achievable.

Why no turn was made to follow that plan will never be known beyond any doubt whatsoever.
Arkroyal is offline  
Old 22nd Feb 2010, 15:32
  #6202 (permalink)  
 
Join Date: Feb 2003
Location: uk
Posts: 3,225
Received 172 Likes on 65 Posts
The pathetic so called icing clearance for the Mk2 was 4 Degrees,
Not forgetting that, due to an administrative cock up, the Release to Service at the time of the accident made no mention whatsoever of Icing Clearance.
tucumseh is offline  
Old 22nd Feb 2010, 21:16
  #6203 (permalink)  
 
Join Date: Mar 2005
Location: Falmouth
Posts: 1,651
Likes: 0
Received 0 Likes on 0 Posts
IFR was not an option
If IFR was not an option then what options were available to the crew? Should they have remained VMC if they knew that they couldn't fly IFR ?
vecvechookattack is offline  
Old 22nd Feb 2010, 21:38
  #6204 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
vecve - I think you missed my #6240? Could you have a look?
BOAC is offline  
Old 22nd Feb 2010, 21:58
  #6205 (permalink)  
 
Join Date: Jan 2010
Location: High Wycombe UK
Posts: 52
Likes: 0
Received 0 Likes on 0 Posts
New Look.....

Thankyou to all responses to my # 6155 , # 6181 , # 6220 and # 6225....mainly concerning theSuperTANS..

..the inescapable fact remains that the RNS252 from the crash , had both the GPS and Doppler 'plots' initialized to the location of a grass field about halfway between Aldergrove and the town of Antrim ........
IF this is where the flight departed from ? then it would be correct.............
But as it departed from Aldergrove......surely this is wrong , and has to be either........
a fault on the equipment.....
or a mistake by somebody ....
or a third possibility....it was intentional......ie.. known and accepted......

....any astute navigator would realise that an offset applied to navigation equipment would effectively move all the waypoints in a certain direction.............in this case the offset moved waypoint 'A' out to open sea away from the coast and the lighthouse......

..the remaining waypoints were less affected as it only changed the distance to run ....
..If they had stuck to the Doppler source this strategy would have guided them on a safer course.........as this was the last time the doppler source was initialised.........

GPS on the other hand , by its very nature will attempt to constantly update its positon if allowed......

I am more than a little suprised that no-one has pointed this out before , given the high level of scrutiny applied to the altitude data by many people..?? !!!!!??!!!!!.......

In the analysis of any problem , it is important to assess ALL the data which is available not just the bits
that interest oneself , or those which are more easily understood owing to one's background and training .

Any enquiry can only be as good as the persons on the board or panel.......if they fail to ask pertinent
questions or call expert witnesses or if they back down over any sort of confrontation , they will never hear the complete story.........

The data recovered from the RNS252 was valid and readable , any corruption would have been obvious . The fact that it only gives a limited picture does not make it less valid........only less useful ...........

The Doppler settings were found to be correct for flight over water.......
..but the less reliable GPS source (in those days )was selected.....????
Pilot error maybe , but not GN....
Robin Clark is offline  
Old 23rd Feb 2010, 07:34
  #6206 (permalink)  
 
Join Date: Mar 2003
Location: England
Posts: 286
Likes: 0
Received 0 Likes on 0 Posts
@Robin

the less reliable GPS source (in those days )
Could you expand on this for my education?

@Brian

A follow up question arising from the Racal report, kindly supplied by tucumseh. I had not appreciated that the GPS unit was a separate box from the Supertans. Was it ever examined to see what, if any, internal data it held separate from that fed into the Supertans memory?

I ask this because even quite early, admittedly self contained, GPS units maintained track logs and data to help with re-initialisation. Presumably Trimble would have to have been involved.

EG
ExGrunt is offline  
Old 23rd Feb 2010, 08:53
  #6207 (permalink)  
 
Join Date: Aug 2009
Location: Aylesbury
Age: 58
Posts: 378
Likes: 0
Received 0 Likes on 0 Posts
New info published by Computer Weekly re FADEC

Chaps,

I presume you've seen these?

EDS report on 'dangerous' Chinook software published for the first time - 22/02/2010 - Computer Weekly

What was the 'dangerous' flaw in safety-critical Chinook system? - 22/02/2010 - Computer Weekly
Jabba_TG12 is offline  
Old 23rd Feb 2010, 09:15
  #6208 (permalink)  
 
Join Date: Feb 2003
Location: uk
Posts: 3,225
Received 172 Likes on 65 Posts
Or, as MoD would say, "This is nothing new (but we decided to withold it from all inquiries in case they asked awkward questions of CA and ACAS)".

Looking forward to these inquiries being completed at last.
tucumseh is offline  
Old 23rd Feb 2010, 22:49
  #6209 (permalink)  
 
Join Date: Feb 2003
Location: uk
Posts: 3,225
Received 172 Likes on 65 Posts
Exgrunt


I had not appreciated that the GPS unit was a separate box from the Supertans. Was it ever examined to see what, if any, internal data it held separate from that fed into the Supertans memory?
You have identified a strange weakness in the investigation (or perhaps not so strange, given the political imperative).


The AAIB report makes no mention whatsoever of the GPS. (Remember that the RTS informed aircrew that GPS Initial Operating Capability had not yet been declared by the US DoD, and warned them that the “Error” message was “meaningless”).

In discussing the RNS252 SuperTANS, the AAIB said this;
“The ON/OFF switch was found at OFF, and an absence of substantial damage to the lift-toggle type switch, including its ramp mechanism, together with ground fire sooting patterns suggested that this had been the setting at impact. However, subsequent examination and memory read-out by Racal reportedly clearly showed that the unit had been operating until impact and it appeared that the switch position had in fact been altered by the effects of the crash”.

Thereafter, the AAIB simply refers the reader to the Racal report, as if it is comprehensive, factual, valid and verified - when they obviously doubt all of this.


Now, any reasonable reader would twitch violently at the above paragraph. Nobody would dispute the AAIB has vast experience in such matters and the author (Mr Cable) makes it quite clear he thinks the switch was OFF at impact; and his scepticism about the Racal conclusion is clear. He must have examined hundreds, if not thousands, of such fire damaged switches in his career, and could be relied upon to come to the correct conclusion. Clearly, there was a conflict to be resolved. Equally clearly, the MoD party line was that Racal’s report took precedence.


One obvious question is not asked. Does setting the switch to OFF actually power down the unit completely, or does it “simply” remove indications but continue to calculate away in the background? This standby mode is a common concept. Could it indicate an attempt at resetting? If so, it could mean the crew switched off the RNS252 – we already know they were told not to rely on it and did not trust it. We also know that they had only just returned to flying a Mk2, and the respective Releases to Service did not complement each other. That is, the meaningless “Error” warning was not in the Mk1 RTS. From a Human factors viewpoint, they'd be thinking "Both aircraft have the same kit, which version do I believe?".


The worst part is this. Based on the Racal report into the remnants of the RNS252, the MoD concluded, ludicrously, that this meant the entire Nav System was both accurate and serviceable. There is no mention of other sub-systems being tested; except the Rad Alt Tx/Rx which, as we know, was found to be both faulty and defective. (And due to the paucity of testing info and equipment, vital power interrupt tests were not possible). Nor is there any mention of the quite important fact that many systems were not cleared for use in the first place. For example, the AAIB report simply says the VOR/ILS was “ON”, but no-one has ever addressed the fact it was not cleared for use. Why were these anomalies never challenged or investigated by the BoI? Answer - Because CA and ACAS, and their subordinates, simply could not afford to allow any investigation to go there, revealing the fabrication that was the Release to Service. But now it HAS been revealed.


My conclusion is that the technical investigations were limited and disjointed - something John Blakeley has said for years. The AAIB acted within their remit, but one can easily read between the lines and see they were acting in isolation, without vital information. For example, they made no mention of the classified equipment that was on board, which a BoI witness declined to give details of and was omitted from the RTS; yet it could be vital in an EMI sense. On RNS252, Racal were allowed to dream up an unvalidated and unverified method of extracting and analysing data from the RNS252: to be fair to them though, they said nothing outrageous, merely claiming that their simple calculator/indicator worked. It was MoD who made the false claims. The Reviewing Officers? They, of course, determined immediately that the aircraft was both serviceable and airworthy; when manifestly it was neither.
tucumseh is offline  
Old 24th Feb 2010, 11:51
  #6210 (permalink)  
 
Join Date: Aug 2006
Location: West Sussex
Age: 82
Posts: 4,764
Received 228 Likes on 71 Posts
tucumseh:
The AAIB acted within their remit, but one can easily read between the lines and see they were acting in isolation,
“The ON/OFF switch was found at OFF, and an absence of substantial damage to the lift-toggle type switch, including its ramp mechanism, together with ground fire sooting patterns suggested that this had been the setting at impact. However, subsequent examination and memory read-out by Racal reportedly clearly showed that the unit had been operating until impact and it appeared that the switch position had in fact been altered by the effects of the crash”.
Seeing as the AAIB's very experienced inspector said that the RNS252 was switched off at impact and the BoI decided otherwise, the isolation of which you speak could not be made clearer. But then he was investigating an aircraft accident (within the AAIB remit) and it becomes ever more obvious that the BoI was not.
Chugalug2 is offline  
Old 24th Feb 2010, 12:17
  #6211 (permalink)  
 
Join Date: Dec 1998
Location: Sutton Surrey England
Posts: 12
Likes: 0
Received 0 Likes on 0 Posts
Strong points from tucumseh. I've read the AAIB report a few times and am often struck by the way the AAIB distances itself from the Racal report. Yet the case against the pilots, as put by the air marshals and the MoD, pivots on it.
Tony Collins is offline  
Old 1st Mar 2010, 08:48
  #6212 (permalink)  
 
Join Date: Jan 2010
Location: High Wycombe UK
Posts: 52
Likes: 0
Received 0 Likes on 0 Posts
New Look.....

..and catching up with some responses...

Beagle...
Yes they were flying by Lat/Long to WGS84 but the unit had an option to use local grid info which in this case was the Irish grid....but the actual
differences were only a few feet....

ExGrunt...
A quick refresh on GPS , derived from earlier experiments using satellites ,
and culminating in the aid we now know and love.?...... a few years earlier
in 1986 the GPS coverage was really poor , the round the world flight by
Voyager only had use of GPS for about 1/3 of the record breaking flight .
They had to rely on Omega ........incidentally the same year Racal
announced the SuperTANS......
Only earlier in 1994 had the full set of satellites been completed , the last
two of the 24 having been launched in March I think , but later that
year two of them were giving problems and had to be switched to use an
alternate frequency of operation.....but for some time after they had to
constantly tweak the orbits to get them all syncronized .....
....so 1994 was still early days in terms of
developing a stable product.......

Tucumseh....
I thought it was only the use of GPS which they had been warned against , in Doppler mode the SuperTANS should have behaved much as
the TANS fitted to MK1 Chinook surely ????.....

The data extraction technique used by Racal may not have been a normal
maintenance or repair procedure , but had probably been used before in
design and development , and maybe on the assembly/test line too ........
They were carefull not to try and power up the damaged RNS252 as a
complete unit , but added an external battery to the memory card before
unplugging it . By inserting the card into a know good unit and powering
up in test mode they were sure to preserve the data , by not allowing
the unit to initialise itself .
The only clever bit as far as I can see was transcribing the 8000
characters from what was usually machine code (hexadecimal code....a
mixture of numbers 0-9 and letters A-F) into English so we could read
it ......each pair of characters translates to a real number or letter
or space,hyphen whatever......
Doing it by hand manually would take forever and it sounds like they wrote
a program to do it.....

Jayteeto
As you have used this equipment , perhaps you can confirm that the
accepted initialisation procedure came to be something like , power
up , then wait for the GPS to find satellites , then check that the position
given was accurate , if not ...give it longer to sort itself out......then
when you are confident that it is good , load the location into the
Doppler/DR before the A/C moves .........??????....

In this way any automatic initialisation which the box is programmed to do
on power up becomes irrelevant.?
..but this was the first SuperTANS in NI..we are given to believe that
there was a low level of confidence and understanding of the box at that
time......what could the crew have done , or thought they had done to
give them a safe margin passing the Mull.....???????...

Another point which keeps appearing.......they would never have turned
onto the heading to track towards waypoint 'B' at that time....as it would
entail overflying high ground , with the same arguments about
icing limitations....
..anyone who mentions that has obviously never looked at a map of the
region.....
Their only course under vfr had to be navigating at low level between the
many islands and then turning to follow the Great Glen .....

..and another thing , I can find no mention of Turnberry VOR in any
discussion or report....??.
.. this would have been their nearest VOR as they approached the
Mull.....and a DME check would have confirmed their East/West position.
...but , 34 NM West of the old airfield would have given them a safe
clearance...
..whereas 34NM DME from the VOR would have taken them into the
Mull....as the VOR is inland on a hill... .
A very basic mistake maybe , but I do not know exactly what charts they
had to work from....

rgds Robin....

Last edited by Robin Clark; 1st Mar 2010 at 09:02.
Robin Clark is offline  
Old 1st Mar 2010, 10:01
  #6213 (permalink)  
 
Join Date: Jun 2006
Location: uk
Posts: 463
Received 4 Likes on 2 Posts
The RNS 252 fitted to the Mk 2 was identical to the Mk 1, more than likely the same piece of hardware as they were delivered to the factory. They were fitted for Op Granby and after 3 years in service, were well understood by the crews.

Your description of the initialisation procedure is correct.

Use of VOR in low level navigation would be unusual, at 34 nm reception would have been difficult at hts below 300'.
chinook240 is offline  
Old 1st Mar 2010, 11:41
  #6214 (permalink)  
 
Join Date: Jun 2007
Location: Detroit MI
Age: 66
Posts: 1,460
Likes: 0
Received 0 Likes on 0 Posts
The only clever bit as far as I can see was transcribing the 8000
characters from what was usually machine code (hexadecimal code....a
mixture of numbers 0-9 and letters A-F) into English so we could read
it ......each pair of characters translates to a real number or letter
or space,hyphen whatever......
Doing it by hand manually would take forever and it sounds like they wrote
a program to do it.....
It's not that clever. Hex(adecimal), has been ubiquitous in programming since the beginning of virtual time. Dumping Hex to Decimal character set equivalents is simplicity itself and there are a million programs out there that can do it. You will also find people who can read the Hex and translate to the Decimal character equivalent in their heads. It's not that difficult for real geeks...
Airborne Aircrew is offline  
Old 1st Mar 2010, 13:02
  #6215 (permalink)  
 
Join Date: Jan 2010
Location: High Wycombe UK
Posts: 52
Likes: 0
Received 0 Likes on 0 Posts
New Look.......

Chinook240
Good point about the VOR , just assumed it would have good range over water...........so I checked , the VOR antenna is 600 feet asl......so it has
line of sight to an object in/on the water at 30.24NM and an a/c at 300' has line of sight up to 51.3NM before the curvature of the earth gets in the way........how it would behave in practice probably depends on all sorts of things.....but I think it should have worked....
rgds..
Robin Clark is offline  
Old 1st Mar 2010, 13:24
  #6216 (permalink)  
 
Join Date: Aug 2000
Location: Liverpool based Geordie, so calm down, calm down kidda!!
Age: 60
Posts: 2,051
Likes: 0
Received 17 Likes on 6 Posts
Initialisation was correct and very accurate, it was not the first unit. We had been using it on Puma for years and loved the kit.
jayteeto is offline  
Old 1st Mar 2010, 14:14
  #6217 (permalink)  
 
Join Date: Feb 2003
Location: uk
Posts: 3,225
Received 172 Likes on 65 Posts
The same GPS/TANS was operated in the Mk1 under Service Deviation.

My point was that the installed performance apparently differed because there was a warning to regard "Error" indications as "meaningless" in the Mk2, but no equivalent warning in the Mk1. But, the indication MUST mean something, which tends to confirm Boscombe's position that the aircraft's performance had not been established accurately enought to warrant a CA Release recommendaton - so they didn't give one.

MoD then lied about this, claiming Boscombe HAD recommended CAR. As ever, follow the lies, MoD's weaknesses are exposed and the truth emerges.
tucumseh is offline  
Old 1st Mar 2010, 14:21
  #6218 (permalink)  
 
Join Date: Jun 2006
Location: uk
Posts: 463
Received 4 Likes on 2 Posts
the installed performance apparently differed because there was a warning to regard "Error" indications as "meaningless" in the Mk2, but no equivalent warning in the Mk1
If there was a difference in performance we operators didn't experience it.

an a/c at 300' has line of sight up to 51.3NM
While not entirely relevant to the accident, Turnberry VOR would not have been the beacon of choice as it was on the extreme edge of performance, and more importantly, not on the planned route.
chinook240 is offline  
Old 1st Mar 2010, 14:28
  #6219 (permalink)  
 
Join Date: Feb 2003
Location: uk
Posts: 3,225
Received 172 Likes on 65 Posts
Sorry, I should have added that the Mk1 Service Deviation had no equivalent in Mk2, therefore the installation must either have been cover mod'd or, if it remained exactly the same, the RAF didn't get round to issuing a new SD. Neither GPS or TANS is mentioned in the list of Mk2 mods.

Of course, if one were to believe Adam Ingram, the above is academic as the Mk2s were new build, so could not have inherited any legacy configuration control problems from the Mk1. But, he lied and we don't believe him.

CDP (Walmsley) admitted this to the HCDC in 1999 when acknowledging the Chinook suffered from configuration problems. And AD/HP1 said it had significant systems integration problems. All this adds up to an immature and unmaintained build standard which, in turn, largely invalidates any safety case; meaning the decision to sign both the CAR and RTS was deeply, some would say criminally, flawed. Both documents are fabrications as they deliberately misrepresent the facts. This is beyond gross negligence.
tucumseh is offline  
Old 10th Mar 2010, 20:24
  #6220 (permalink)  
 
Join Date: Mar 2000
Location: u.k.
Posts: 39
Received 0 Likes on 0 Posts
Just Culture

Hello Brian, I don't think I've posted since early thread (I) days (drawing attention to that magnificent and highly relevant book "Impact Erebus") but I have followed your endeavours, not least because, in a previous life, I operated a similar performance (fixed-wing) a/c in that theatre and environment, indeed I flew a number of the bereaved to MAC on early anniversaries of this tragedy. Anyway, enough of me:

Are you movers and shakers as struck as I am by the contrast between the MoD's ostrich-like intransigence in this case and the RAF's current Chief of Staff (Operations), AVM Garwood's clarion call in his forward to on-line Air Clues 2.0 (q.v.)
" JC is about treating those involved in incidents and accidents in a transparently fair and consistent manner, whilst ensuring that all factors which lead to an incident, be they individual or organizational, are recognised and taken into account" (my italics).

Sadly I'm far too remote nowadays to 'do' anything about it but an introduction of the Left Hand to the Right Hand within the greater MoD would seem to be appropriate, any ideas anyone?l
twinboom is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.