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Bombardier Regional Jets Subject Of Safety Warning  
User currently offlineLightsaber From United States of America, joined Jan 2005, 13430 posts, RR: 100
Posted (8 years 7 months 4 weeks 7 hours ago) and read 3599 times:
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http://biz.yahoo.com/bizj/060331/1267338.html?.v=2

Quote:
The alarm concerns a particular part which comes in two types, and only one of them is associated with fire hazard, suggesting at least the possibility that many CRJ-200s in service today may not necessarily be affected by the problem.

The NTSB said Thursday there have been six fires in six months aboard CRJ-200 aircraft and issued seven recommendations to the Federal Aviation Administration, four of them classified by the safety board as "urgent."

Gulp!

later in the article

Quote:
The part that is suspected of shorting out is called the 1K4XD contactor. Only a newer version has exhibited this fire problem and is the subject of these recommendations, the NTSB said. An older version of the same part, made with a different material, has been linked to no fires.

Not good news for Bombardier. Some pax already dislike the CRJ's. Time to go back to the old part. I can attest to how important material selection is in aerospace.

Lightsaber


Societies that achieve a critical mass of ideas achieve self sustaining growth; others stagnate.
11 replies: All unread, jump to last
 
User currently offlineA319XFW From , joined Dec 1969, posts, RR:
Reply 1, posted (8 years 7 months 4 weeks 5 hours ago) and read 3505 times:

Quoting Lightsaber (Thread starter):
Not good news for Bombardier. Some pax already dislike the CRJ's. Time to go back to the old part. I can attest to how important material selection is in aerospace.

I would hazard a guess that things like this happens more often than it gets into the press. But 6 times in 6 months does sound quite excessive. Usually things like this should be solved after one or two occurrences.

And you're right - sometimes newer isn't better. New parts, new problems!


User currently offlineCRJ900 From Norway, joined Jun 2004, 2217 posts, RR: 1
Reply 2, posted (8 years 7 months 4 weeks 5 hours ago) and read 3486 times:
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But is it only used on their CRJ200 or does it include the CRJ700 and CRJ900 as well?


Come, fly the prevailing winds with me
User currently offlineHiFi From Brazil, joined Apr 2005, 192 posts, RR: 0
Reply 3, posted (8 years 7 months 4 weeks 4 hours ago) and read 3424 times:

Very interesting case, as Bombardier was not aware that the supplier had changed the material of the contactors, making it vulnerable to moisture-induced short circuits. I've heard of some cases like this, where the supplier assumes that a modification is minor and therefore should not require examination by the a/c manufacturer and the certification authorities. I know EASA is looking deep into this sort of cases.

And an oxygen line passing through the e-bay is a weird solution.. I'm curious to know what kind of constraints led them to decide it would be that way...



Here's the NTSB press release:

************************************************************
NTSB PRESS RELEASE / SAFETY RECOMMENDATION
************************************************************

National Transportation Safety Board
Washington, DC 20594

FOR IMMEDIATE RELEASE: March 30, 2006
SB-06-17

************************************************************
NTSB ISSUES URGENT RECOMMENDATIONS FOLLOWING
SERIES OF FIRES ABOARD BOMBARDIER REGIONAL JETS
(Safety Recommendation A-06-29 through -35)


************************************************************

Washington, D.C. - A series of fires aboard Bombardier CRJ-200 aircraft
has prompted the National Transportation Safety Board to issue seven
recommendations to the Federal Aviation Administration. Four of the
recommendations are classified "Urgent" by the Safety Board.

The recommendations follow seven fires aboard CRJ-200 aircraft,
six of them within the last 6 months. Although none of them has resulted
in loss of life, "the potential exists for an uncontained fire to compromise
the oxygen line, which could develop into an even more critical situation,"
the Board stated in its letter to the FAA. All the fires have involved the
Ultem 2200 surface material of the 1K4XD contactors aboard the planes
(The contactor is a switching device for three-phase AC electrical power
generated by each of the two engine-mounted 30KVA electrical
generators.). Four of the fires resulted in at least temporary loss of all
Electronic Flight Information System (EFIS) displays, preventing the
pilots from using their primary flight instruments and increasing their
workload during an emergency situation.

"The problems identified in the Board's letter must be corrected as
soon as possible," NTSB Acting Chairman Mark V. Rosenker said. "The
potential consequences of these fires can be catastrophic."

The NTSB wants the FAA to require CRJ-200 operators to provide
separation of electrical power sources to prevent the simultaneous loss of
all EFIS displays, require Bombardier to develop a means of protecting
electrical terminals on these contactors from moisture-induced short
circuits, require operators to install that protection once developed, and
require Bombardier immediately to evaluate existing abnormal and
emergency procedures for the CRJ-200 airplane to determine whether they
adequately address these fire hazards. All four of these recommendations
were classified by the Board as urgent.

Safety Board investigators found the cause of these contactor
failures and fires. Various forms of precipitation were present before the
departure of each incident flight and when the main cabin door is open on
the CRJ-200, the forward cabin floor is exposed to the weather. Water on
the floor can then seep into the avionics compartment below, where the
contactor is located. Pulling the main entry door into the closed position
may also result in water draining into the cabin area and subsequently into
the avionics compartment. The Board found that there are two versions of
the 1K4XD contactor approved for the CRJ-200 airplanes; only the newer
version, which uses Ultem 2200 material, has exhibited this fire problem
and is the subject of these recommendations.

Aside from the four urgent recommendations, the other
recommendations contained in the same letter deal with replacement of
these contactors and other components manufactured with Ultem 2200
(polyetherimide) or similar material, and with ensuring the safety from fire
risk for any other electrical components on Bombardier aircraft.

The texts of the recommendations to the FAA are:
o Immediately require operators to provide separation of
electrical power sources in CRJ-200 airplanes to prevent
the potential loss of electronic flight instrument system
displays that may result from contractor failures. (A-06-29)
Urgent

o Require Bombardier to develop a means of protecting
electrical terminals on Tyco Hartman 1K4XD contractors
fitted with Ultem 2200 (polyetherimide) terminal bases
from moisture-induced short circuits. (A-06-30) Urgent

o Once Bombardier has developed a means to protect
electrical terminas on Tyco Hartman 1K4XD contractors
fitted with Ultem 2200 (polyetherimide) terminal bases a
recommended in Safety Recommendation (2), require
operators to install the protection as soon as possible. (A-
06-31) Urgent

o Require Bombardier to expedite the replacement of 1K4XD
contactors on CRJ-200s with contactors that are not
susceptible to short circuit. (A-06-32)

o Require Bombardier to demonstrate the capability of
electrical components to safely tolerate exposure to
moisture or conductive fluids under full electrical load
when such components may be inadvertently exposed to
such conditions. (A-06-33)

o Require all airplane manufactures to determine whether any
electrical components on their aircraft are manufactured
with Ultem 2200 (polyetherimide) or similar material with
arc-tracking characteristics and require removal or
protection of these components to prevent potential fires.
(A-06-34)

o Require Bombardier to immediately evaluate existing
abnormal and emergency procedures for the CRJ-200
airplane to determine whether they adequately address the
fire hazard presented by the failure of the 1K4XD
contractor and provide flight crew with additional guidance
as needed. (A-06-35) Urgent

The full text of the letter may be obtained on the Board's website,
at http://www.ntsb.gov/recs/letters/2006/A06_29_35.pdf



no commercial potential
User currently offlineIlikeyyc From United States of America, joined Dec 2003, 1373 posts, RR: 20
Reply 4, posted (8 years 7 months 4 weeks 4 hours ago) and read 3389 times:

One of these fires happened on one of our aircraft recently, but I believe in our case the aircraft was on the ground at the time. I saw pictures in an internal company email. The electrical contactor is behind CBP-1 and below the floor and, as stated above, gets wet from the pax door being open when it is raining outside. I am actually surprised that the FAA took this long to make these recomendations.


Fighting Absurdity with Absurdity!
User currently offlineLightsaber From United States of America, joined Jan 2005, 13430 posts, RR: 100
Reply 5, posted (8 years 7 months 4 weeks 3 hours ago) and read 3330 times:
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Quoting HiFi (Reply 3):
Very interesting case, as Bombardier was not aware that the supplier had changed the material of the contactors, making it vulnerable to moisture-induced short circuits. I've heard of some cases like this, where the supplier assumes that a modification is minor and therefore should not require examination by the a/c manufacturer and the certification authorities. I know EASA is looking deep into this sort of cases.

Oh man, we had a supplier do that to us to and boy did I get ripped a new one for the problems it caused. Luckily, it was found on the ground during activation and not flight testing... Grrrr... It was changing a metal on the dry side of an o-ring to something that wasn't compatible to the fluid on the other side of the o-ring. Well, the o-ring got scratched by particulate in what was intentionally dirty fluid (but you have to know how a system operates with fluid at the end of its life, don't you?). So the o-ring failed. (No biggie, we went to another material already approved.) But what would have been a 4 hour fix (including required Engineering document changes) was much longer as the component was trashed... Grrr...

Quoting HiFi (Reply 3):
And an oxygen line passing through the e-bay is a weird solution.. I'm curious to know what kind of constraints led them to decide it would be that way...

Me too! I'm a combustion engineer. Any oxygen at high concentration gets my respect.

Quoting HiFi (Reply 3):
the potential exists for an uncontained fire to compromise
the oxygen line, which could develop into an even more critical situation,"

After the TWA 747 with the electrical through the gas tank "incident," I think the FAA is getting more sensitive to these issues. While just an engineering solution, its going to be a headache.

Quoting CRJ900 (Reply 2):
But is it only used on their CRJ200 or does it include the CRJ700 and CRJ900 as well?

Good question. How is the oxygen line routed in those airframes?

Lightsaber



Societies that achieve a critical mass of ideas achieve self sustaining growth; others stagnate.
User currently offlineIlikeyyc From United States of America, joined Dec 2003, 1373 posts, RR: 20
Reply 6, posted (8 years 7 months 4 weeks 3 hours ago) and read 3291 times:

Quoting Lightsaber (Reply 5):
Good question. How is the oxygen line routed in those airframes?

In the 200 the Crew O2 bottle is in the avionics bay, right side of the A/C, just forward of the av-bay door. There is a solid line that runs forward, under the floor to a T fitting that is aft of the flight deck that routs the O2 to the Capt, F/O and observers masks. The capt and Obserer's O2 line runs close to the faulty contactor.

On the 700/900, the Crew O2 bottle is above the floor, behind the wardrobe (you know the F/A station with the Phone). Thats why this only applies to the 200.



Fighting Absurdity with Absurdity!
User currently offlineUAL Bagsmasher From United States of America, joined Sep 1999, 2148 posts, RR: 10
Reply 7, posted (8 years 7 months 4 weeks 2 hours ago) and read 3264 times:

Are they talking about the AC Utility Bus contactors? I ran into a problem with one of those a while back where it was pretty much toast when I got to it.

User currently offlineLightsaber From United States of America, joined Jan 2005, 13430 posts, RR: 100
Reply 8, posted (8 years 7 months 4 weeks 1 hour ago) and read 3185 times:
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Quoting Ilikeyyc (Reply 6):
On the 700/900, the Crew O2 bottle is above the floor, behind the wardrobe (you know the F/A station with the Phone). Thats why this only applies to the 200.

Great information. I love learning these tidbits on a.net!  bigthumbsup 

Lightsaber



Societies that achieve a critical mass of ideas achieve self sustaining growth; others stagnate.
User currently offlineEhrbear From Canada, joined Feb 2006, 34 posts, RR: 0
Reply 9, posted (8 years 7 months 3 weeks 6 days 22 hours ago) and read 3079 times:

I have to wonder what manufacturers consider minor and where the responsibility lies. For example, the material in seat covers cannot be changed offhandedly because of the risk of flammability in an unapproved material. In a past life, I have had to sign off Certificates of Conformity on bearings of all sizes and noted the manufacturers due to the fact that not all of the companies making bearings could actually have a C of C with their product. It baffles me that someone dealing with a product intended for an aviation use wouldn't take a little extra time to consider if the material change might have a negative impact on the product. Yes, even as I write this, I am hearing myself say that the examples of improper products are numerous. Still, I find it maddening.

User currently offlineAeronut From Canada, joined Jan 2006, 138 posts, RR: 0
Reply 10, posted (8 years 7 months 3 weeks 6 days 14 hours ago) and read 2975 times:

Quoting HiFi (Reply 3):
And an oxygen line passing through the e-bay is a weird solution.. I'm curious to know what kind of constraints led them to decide it would be that way...

The biggest constraint an RJ has is it needs to put all of the systems a big jet has in 20% of the space. There isn't any real estate left and maintaining required segregation is tough.


User currently offlineAeronut From Canada, joined Jan 2006, 138 posts, RR: 0
Reply 11, posted (8 years 7 months 3 weeks 6 days 14 hours ago) and read 2956 times:

Quoting Ehrbear (Reply 9):
I have to wonder what manufacturers consider minor and where the responsibility lies. For example, the material in seat covers cannot be changed offhandedly because of the risk of flammability in an unapproved material. In a past life, I have had to sign off Certificates of Conformity on bearings of all sizes and noted the manufacturers due to the fact that not all of the companies making bearings could actually have a C of C with their product. It baffles me that someone dealing with a product intended for an aviation use wouldn't take a little extra time to consider if the material change might have a negative impact on the product. Yes, even as I write this, I am hearing myself say that the examples of improper products are numerous. Still, I find it maddening.

Hey, before we go blaming the vendor, the report states something interesting:

"The Safety Board notes that operators of CRJ-200s have found that the proximity of the avionics compartment to the forward cabin door combined with the lack of a water-tight seal in the floor above this area make it likely that components underneath may occasionally be subjected to moisture. When Tyco Hartman changed the insulator material used on 1K4XD contactors, the company judged it to be interchangeable with the original material in form, fit, and function based on Bombardier-specified requirements for the contactor and did not notify Bombardier of the change. Further, Bombardier’s design specification did not require that the contactor be capable of operating under full electrical load while exposed to moisture or that it be tested to demonstrate this capability."

Had they notified BBD about the changes, chances are the change would have been approved becasue it met the BBD specification. Electrical components in the vicinity of doors and galleys (even under floor) should be required to withstand some form of moisture you would think. These parts are probably used in other places which might not be exposed to moisture as well.


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