Kapton® wire in older Bells.

[Gimble]

At least two operators that I know of have rewired an entire aircraft due to the predominant presence of Kapton looming.
Is it a problem? Or did those operators waist their money getting their aircraft rewired.
I recall an issue with 737s as well.
What is the problem with this wire.

[sprocket]

My observations with kapton, is that the insulation on this wire does deteriorate (cracking and peeling), particularly with age and exposure to the elements.
I have not heard of any serious problems on Bells apart from the odd annoying rectification at inconvenient times.

Regular inspection of the wire in the higher risk zones is usually successful in keeping any problems at bay.

Re-wiring is a big job, but if the heli is having a re-furb at the same time it probably would be worth doing it.

[Screwed™]

What is the problem with this wire. We have been told that the CHC aircraft that is being supplied to NSW Health is full of it.
Gimble, it that the best that you can come up with? Sheeze....:ugh:

[Clarence]

Gimble

Are you a journalist, do you have a relative that is a journalist or are you just fishing?
As a CHC insider I will refute the claim. NSP has little, if any, Kapton wiring in it. The machine is more that 20 years old and it has had just about every part on it changed, rewired or modified. The claim by the uniformed and malicious few that the thing is full of kapton is a load of crap; a sad attempt to discredit CHC and NSP in particular. Even if it was full to the brim of Kapton, it has not burst into flames yet, so I think it will survive until July.
Yes, some operators have spent a fortune getting their aircraft rewired. One operator spent a reported $1,000,000 getting their aircraft rewired when the normal cost is about $250,000; that's what happens when you have more money that sense.
NSP has given five different operators an unequaled record of service. It was the first 412 in Australia to do EMS and SAR and the way the old girl is going it will probably be the last!

[Gomer Pylot]

Our mechanics call it 'crap-tan' wire. It does cause problems sometimes, but they're generally annoying, such as high-resistance shorts, and take time to trouble-shoot, not dangerous. Bell isn't the only maker who used it - I think the Sikorskys have it also.

This Oz soap opera is becoming tiresome. I've never heard so much whining, on both sides, about any issue anywhere. :mad:

[NickLappos]

Gomer is right, Sikorsky used Kapton for the S-76 until about S/N 80 or so. Kapton is lighter, but more brittle, and must not be bent sharply. Special strain relief connectors are used to help it last.

It is approved, and it works, but it takes more care, and has more problems. It has very good high temp capabilities, and is used extensively in many industrial applications. Ariane 5 has it extensively!

http://www.dupont.com/kapton/

[IHL]

If you would like an interesting read on Kapton Wiring and Arc Tracking check out:
http://members.aol.com/papcecst/index.html

[NickLappos]

IHL,

That site is an example of how well and poorly the web works. The techncian who wrote the site (not an engineer, and certainly not looking at the problem as an engineer might) was on a rampage, and certainly did not try to be balanced.

There is much to be learned from that site, but the sky is not falling!

[IHL]

Nick :
I have flown early model S76 and Bell helicopters that used Kapton wiring. I have not experienced any bad outcomes from Kapton wires. The maintenance technicians [engineers] used to complain about Kapton wiring and said it was crap [Crapton] because of its brittleness and it would frequently break with helicopter associated vibrations.

Transport Canada recognizes the hazard of resetting trip circuit breakers regardless of the type of wiring used and has put out a policy letter on the subject.
In part:
“Historically, crew members, maintenance personnel, and aircraft ground servicing personnel, (e.g., aircraft cleaners, aircraft fuelers, and baggage loading personnel) have viewed the resetting of a tripped CB as a relatively common occurrence in operations. Generally, resetting a tripped CB is met with no adverse results.
However, there are occasions where smoke, burned wires, electrical odors, arcing, and loss of related aircraft systems have been reported as a result of resetting tripped CBs. Aircraft manufacturers normally provide guidance in the AFM, MM, and aircraft servicing manuals that enables crew members, maintenance personnel, and aircraft ground servicing personnel to perform their tasks with a high degree of safety.
There is a widely held view that one reset of any tripped CB is acceptable. Locating and eliminating any associated fault is required prior to considering resetting any CB remembering that both high and low ampere CBs could readily ignite a fire.
Transport Canada provided information on this issue in the Aviation Safety Letter 1/2001 titled "The Deliberate Weak Link in the Electrical Chain" which clearly recommends that organizations develop and incorporate a comprehensive policy on CB. The Aeronautical Information Publication (AIP) Canada section AIR 4.11 Circuit Breakers and Alerting Devices also provides guidance on this subject. “

http://www.tc.gc.ca/CivilAviation/commerce/policy/PL161.htm

[NickLappos]

Wise words, IHL.