tappers dad Keep digging I too wouold be interested to know, one thing is for sure all the civi's won't touch it with a barge pole.

Found this item for those interested in aircraft and wiring, toddbabe as you can see a few civi's have/do use kapton:

http://www.vision.net.au/~apaterson/...wire_types.htm

http://www.publications.parliament.u...t/91209w01.htm

Exrigger: Many thanks for that information. I have read the Hansard statement many times, and it is clear that the spokesman states that Nimrod carries PVC/Nylon wiring not Kapton. My feeling is that although that was the case when Nimrod entered service, Kapton wiring has been used for additional equipment fits such as Yellowgate. My basic question simply begs a yes/no answer from avionics at 1st line.

By the way, I note from your 2nd reference that whilst Kapton wiring is considered to be very dangerous, PVC/Nylon is regarded as dangerous and is subject to aging and has a low operating temperature. It is not used by the USAF

DV

Mad Mark said
I have personally been told by senior figures at Kinloss that no mayday call was made by the crew of XV230. A call was made that was described as something else (name escapes me now) but it was some sort of priority call to report a problem but not a mayday call.

I have no intention of adding further to the speculation around the incident just wanted to clarify that one point.

A "Pan" call

DV

That's it a 'pan call'.

Oh look another politician interested in Nimrods.

NIMRODS FUEL-LEAK FIGURES SHOCK
The Ministry of Defence confirmed yesterday that 25 fuel leaks had been reported in the six months to March 31 this year.
These latest figures will heighten concerns about the safety of the aircraft which has been in service with the RAF for more than 35 years.
Last night, Moray MSP Richard Lochhead said: "Clearly this is alarming and reinforces the anxiety of service personnel and their families who are awaiting the final conclusions of the on-going investigations into the Nimrod tragedy.

Although the RAF board of inquiry into last September's crash has still to publish its findings, a fuel leak is thought to have led to the catastrophic fire and explosion which brought down the aircraft.
http://www.pressandjournal.co.uk/dis...=sidebarsearch

Nimrods exceeded planned flying hours for 2 years before fatal crash
 

RE: scotsman article

No. of hours / year is not necessarily related to safety - so it is extremely misleading of this article to imply that it is.

Its a bit like saying I planned to drive 10,000 miles this year in my car, but actually did 12,000.

Is the person who wrote this a complete muppet, or am I missing something?

James Kirkup, is switched on, he works out of Westminster and has written several articles about lack of equipment, overstretch etc, but I don't think he has specialist knowledge of aviation matters.

He is a good guy though, I have had several chats with him, why not give him a call and set him straight. I have his number somewhere.

Nimrod Flying Hours
 

Sorry JFZ, I think James Kirkup is making a valid point. If you examine all the available data (from 1997) you will find that prior to 2004 "achieved" and "planned" are roughly the same. It is only during the last 3 years that the overflying has taken place. I understand your point about running a car, but if I had a 39 year old car I would not be flogging it to death at the end of it's life.

"It is only during the last 3 years that the overflying has taken place."

And with less assets, both air and groundcrew :ugh:

NLH. By overflying I mean "achieved" is greater than "planned". This does not mean that more flying was carried out in last 3 years than in the previous years. In fact number of hours flown last year was about 30% down on what it was 4 years ago.

I'm guessing that you would not have cut the number of people looking after it either.

Len G: You are correct. As machines get older you have to spend more on spares and support crews, and we haven't done that.

Am I also right in thinking that the intervals between scheduled servicings was increased again recently. The major cycle was changed from 2000 to 2400 flying hours in the late 80's or early 90's. What's the interval now ?

S_H

I did hear that since the crash the intervals between scheduled servicings was increased . However whether they are major servicing or routine ones that have increased I don't know.

Kapton Wiring
 

I see there are no takers yet for my original posting. It should be an simple question for any current avionics guys out there. "Does the Yellowgate system use Kapton wiring?"

If there are problems posting a reply, then please email me.

DV

Come on Pontius Navigator I am sure you either know the answer to DV's question RE Kapton WIring or know someone else that does?

TD, sorry, I am a navigator and an historian and had never heard of Kapton wiring until it was raised here.

As you no doubt know, the wiring was manufactured by DuPont. You will also have seen it was used in the Harrier GR5. How did it get into the GR5?

The only reference to Kapton wiring my addled brain can come up with - ISTR an incident involving a Harrier accident in which a Kapton wiring fire may have been involved. I don't have any details and I don't have access to mil docs any more.

It's a vague memory, I'm afraid, but it did lead to controversy at the time about the use of this cabling in other [commercial] aircraft, maybe even to the extent of replacing it fleetwide...

I believe the Tornado was (is?) still full of the stuff, due mainly to it weighing less and being less bulky than just about any other type of insulation then available. I remember attending an early Q course were the carbon arc tracking video was shown. I am sure several losses were attributed to this. The footage looked to be quite old even then.

Has kapton got anything to do with Nimrod? I don't know, but I'm fairly certain that civil fleets spent a lot of effort in getting the stuff removed.

The ESM system incorporates Kapton wiring.

AC Ovee, who is the manufacturer?

AC Ovee: Thank you, you are an ace. That explains why the CB's should not be reset if they trip in flight.

DV

DV from what I read, the Kapton sheath acts as a conductor and bypasses the CBs, that was the nub of the problem.

"Somewhat concerned" questions from an aircrew bod:

1. Scheduled servicing intervals - have they increased? [I keep remembering the Air Alaska MD incident]. Why did they increase?

2. Re the YG system & Kapton wiring - is this why the CB issue is so important re Pod overheating or Fan failures?

Kapton
 

Well, for what it's worth I think Kapton wiring installations** that have been properly designed, correctly installed AND maintained are ok. However when added "ad hoc" to airframes as "short term modifications" that then are still flying some 20+ years (in some cases) later it does call into question the integrity of the engineering processes that STILL call for these mods to be left in the airframes.

Re the YG system & Kapton wiring - is this why the CB issue is so important re Pod overheating or Fan failures?..

..Basically after the topcoat becomes damaged the kapton degrades as an insulator until it "flashes over" and basically becomes a conductor liberating a lot of energy as heat (<3000C). It also can support the current demands of the consumer units thus not providing the crew with any type of system failure as a warning whilst it can have the very sneaky practice of not tripping cb's due to the short duration of the flashovers. It can also spread ALONG a harness.


**No I wouldn't call the battery/avionics compartment of your average Tornado such a suitable installation/zone.


Mojo

Mojo
http://www.iasa.com.au/folders/Safet...RAFKapton.html
It is worth emphasizing that polyimide wiring was implicated as a contributing factor in the loss of two Tornados.
Furthermore, numerous ground fires have been recorded as a result of damage to this type of wiring. Laboratory tests have shown that the power of the Carbon Arc not only can destroy wiring looms, but can severely damage structures.
Without doubt, complacency cannot be allowed to creep in when handling polyimide wiring. It is no longer a ‘fit and forget’ component or a suitable place for hanging your torch in confined areas. To maintain our aircraft in an airworthy condition, it is essential that cables be continually inspected, cleaned and re-cleated. It should be noted that this form of inspection and maintenance will be with us for some time as Harrier GR5, Sentry AEW and Tristar all contain a polyimide construction of cable that is even more susceptible to carbon arc tracking than Tornado wiring.

The attitude towards resetting any tripped CBs in flight changed radically in the civil airline world after the Swissair crash near Halifax.

For example, although it is sometime permitted to pull and reset certain specific CBs to 'reboot' some systems, it is never acceptable to reset a tripped CB in flight in most modern airliners.

On the military large aircraft program in which I'm involved, I asked whether a 'once only' reset of a CB was acceptable in flight. The answer from the OEM was an emphatic "NO!"

What is the current RAF teaching?

Hi Beagle,
Current policy on most types is to allow one reset/replacement of a CB or fuse, where it is known that the wiring is not Kapton. Even if it is Kapton, if the reason for the CB trip is known by the crew, ie a power surge or interrupt throughout the jet or a switch pigs, and it is safe to do so, then it can and should be reset. We have a job to do.

Tappers Dad,

Following your link above I am not sure how it arrived at the fact that Kapton wiring was implicated in the crash of two Tornadoes. It could be sloppy writing but this statement occurs for the first time in the conclusion. Conventionally mention of the Tornado should be made in the body first.

However I am pasting some extracts from web searches.

The first shows that Kapton wiring was fitted to the Boeing Harrier GR5.
The second, from Hansard, refers to two incidents of electrical fires on GR5s. I suspect this is pre-labour spin and it is possible these were accidents or, in other words, crashes. The final extract refers to Harrier crashes.

I don't doubt the accuracy of your quote; I doubt the accuracy of your source.

<<The BAE Systems/Boeing Harrier II (GR5, GR7, and GR9 series) is a second generation vertical/short takeoff and landing (V/STOL) jet aircraft used by the Royal Air Force (RAF) and, since 2006, the Royal Navy. It was developed from the earlier Hawker Siddeley Harrier and is very closely related to the US built AV-8B Harrier II. Both are primarily used for light attack or multi-role tasks, and are often operated from small aircraft carriers.

Pasted from <http://en.wikipedia.org/wiki/BAE_Harrier_II>

<<Pasted from <http://www.publications.parliament.uk/pa/cm199900/cmhansrd/vo991213/text/91213w07.htm>


13 Dec 1999 : Column: 24W
Mrs. Dunwoody: To ask the Secretary of State for Defence how many military aircraft have been grounded as a result of advice on the safety of Kapton wiring. [100925]

Mr. Spellar: None. However, following two instances of electrical fires on RAF Harrier aircraft in 1991, the Harrier GR5 and GR7 fleets were restricted to operational flying only for a short period. Subsequent investigation showed that the fires had occurred as a result of the mis-routeing of wires. Modifications were subsequently introduced to improve the electrical installation.

Kapton - the aromatic polyimide wiring insulation around the wire strands - has no place, he says, in passenger-carrying aircraft. He says that the main reason is that, in an electrical short, the wiring insulation chars to a conductive carbon residue and ignites like a dynamite fuse, affecting the whole wiring bundle (and therefore many disassociated systems).

<<Pasted from <http://www.vision.net.au/~apaterson/aviation/kapton_mangold.htm>

Although the United States Navy has banned Kapton and the insulation is no longer used by Boeing since 1992, the world's largest planemaker Airbus Industrie continue to use a version of it in their new planes. Even though the British CAA (Civil Aviation Authority) has forbidden the use of Kapton insulation in new aircraft designs, a loophole allows it to be used in current designs.

Despite ample warning about its dangers, the Royal Air Force took delivery of Kapton-wired Harrier GR5s. Two crashed because of the wire before the RAF embarked on a program to modify the use of Kapton in all the vulnerable parts of their planes.

British Airways admit they use Kapton widely in their aircraft, but that its use meets the requirements of regulatory authorities. Panorama understands, however, that British Airways was warned of the dangers of Kapton insulation and did make its concerns known to Boeing, its principal supplier. BA has declined to confirm or deny this.

Kapton insulation (a DuPont trade name, although their patent has now expired and they are no longer the sole manufacturers) seemed to be the dream wire insulation for commercial and military fleets in the 1970s and '80s. Wiring is like a plane's blood vessels, and the average big jet carries up to 250 kilometres of it. When the giant aircraft manufacturers were looking for something extremely light, tough and flame resistant they settled for Dupont's Kapton. Boeing, McDonnell Douglas, Lockheed and later Airbus Industrie all installed it in good faith in their models during the '70s and '80s. Today, 40 per cent of all planes still carry Kapton-insulated wiring.

Pasted from <http://www.vision.net.au/~apaterson/aviation/kapton_mangold.htm>

Yeah...........
 

contributing factor in the loss of two Tornados

What were the other factors? Hot air leaks? Hyd fuel leaks? Titanium fires?

Mojo.

Despite ample warning about its dangers, the Royal Air Force took delivery of Kapton-wired Harrier GR5s. Two crashed because of the wire before the RAF embarked on a program to modify the use of Kapton in all the vulnerable parts of their planes.

The mod's called KT in generic terms, all harriers still have a % of Kapton left installed no mind whatever MOD/BAe say, back end of a modern Harrier is not a pretty sight.

MoJo

According to Jeremy Vine at the end of this evenings 'Panorama' [28/05/07]
Next weeks [04/06/07] is all about the 'Nimrod Problems'.

Not wanting to sound too negative here, but giving the absolutely appalling standard of reporting on Panorama this year, I wouldn't get too excited. The wi-fi episode was utterly, utterly biased and showed little or no understanding of the technical issues. http://www.badscience.net/?p=418

Panorama has turned to dog poo
 

Yes it HAS gone down the soundbite route, probably easier to produce and costs less, that presenter, Vine is it?; sounds good on the radio but if you take a step back and look at the structure of the program it's the old "we think this so it must be right" scenario again from bliars broadcasting corporation.

mojocvh

I think this Panorama programme will be one that Mr Blair et al won't like one bit.

Mojo
Agreed, it's become the Jeremy Vine video show. It's all sound and light and fury, all about the surface froth and no digging down to the real substance of the subject as used to happen. I suppose that takes time, effort, talent and money.

So now we pre judge a TV program as`well as the BOI