Norman
Well-Known Member
This showed up on another list this morning. I thought it might be of interest to some of you guys.
---- Original Message -----
From: Michael Wallace
To: ******@***.***
Cc: mike_1
Sent: Wednesday, February 11, 2004 4:51 AM
Subject: Aircraft Cables
Hello Sir:
In the below statement you wrote that every commercial aircraft flying is equipped with nothing but SS cables and fittings. This statement is only partly true. Yes, the fittings are made from Stainless Steel Type 303SE but most of the cables are Zinc or Zinc & Tin Plated Carbon Steel.
My name is Michael Wallace and I am Vice President of Sales for Loos & Co., Inc. and we are the OEM supplier to just about every commercial aircraft manufacturer in the Western Hemisphere. I'm here at home this morning browsing the internet and stumbled across your statement in the Beech Owners chat room. I realize your statement was from way back in May '03 but I thought I might set the record straight for you.
Our customer list includes Boeing, Douglass, deHaviland, Cessna, Beech, Piper, Gulfstream, Lockheed, Embraer and many other smaller manufacturers. The only ones that use strictly Stainless Steel cables are Gulfstream and Cessna.
The others use 1/8" 7x19 Carbon Steel cables in their primary flight controls. Carbon steel cables provide much greater fatigue life compared to stainless cables. Boeing uses practically no stainless steel cables. They use the Tin over Zinc variety of carbon steel cable in their primary flight control cables.
As far as Aircraft Spruce is concerned, as KenV35A writes below, They pass off foreign manufactured cables as being made to the military specification MIL-W-83420. If you look at the fine print in their catalog, they state that their cables are not QPL certifiable. QPL means "Qualified Products List". It is the list of qualified manufacturers to MIL-W-83420 (The latest revision is titled MIL DTL 83420) that the U.S. Military maintains. There are only 5 companies in the whole world that are on the QPL list and they are all U.S. companies. I'll list them here for you:
Continental Cable - Hinsdale, NH
Loos & Co. - Pomfret, CT
Strandcore - Milton, FL
Strandflex - Oriskany, NY
Wire Rope Corp. - St. Joseph, MO
What Aircraft Spruce pawns off as being "just as good as" to the flying public is in no way representative of true Military Specification wire rope. When Spruces' cables are tested to the criteria in the Mil Spec, they fail miserably. Their intentional mis-representation should be stopped but the FAA has bigger fish to fry. They turn a blind eye to the Sport and Home-Built aviation industry.
Below I've pasted an article from Aviation Today discussing flight control cables.
AC43.13-1B, chpt.7, section 8, lists two types of corrosion-resistant steel for flexible cable use on civil aircraft. Type I, composition B cables, MIL-W-83420 and MIL-C-18375. Goes on to say "is equal
in corrosion resistant and superior in non-magnetic and coefficient of thermal expansion properties. Aircraft Spruce lists MIL-W-83420 as stainless. KenV35A
Inspection: Flight Controls Depend on Quality Cable
By Vicki P. McConnell, Technology Editor
When purchasing wire rope for use as flight-critical aircraft control cable that must meet MIL-DTL 83420, a certificate of conformance is not the same as a certificate of testing. For some years now, the former has been frequently passed off as the latter, according to Michael Wallace, vice president of sales and marketing for cable-manufacturer Loos & Co. This creates confusing or even bogus credentials for aircraft cable that doesn't offer the highest performance properties as manufactured, tested, and supplied by Qualified Producer List (QPL) companies such as Loos & Co. These companies have invested considerable funds to perform mil-spec verification testing of their cable, and go through the requalifying process every two years.
Some large airplanes, such as certain Boeing models, require nearly half a mile of steel aircraft cable, Wallace said. Boeing specification BMS7-265 designates flight-control cable as a QPL item. "This means that replacement of this cable by an MRO facility must be made with cable that comes from a QPL company," he added. Aircraft cable qualified to this mil-spec features 7 X 7 or 7 X 19 construction (referring to 19 wires per strand, 7 strands per cable, or a total of 133 wires working together to deliver optimum performance characteristics). Diameters range from
1/32nd inch up to 3/8ths inch, but typically 1/8th inch is common in flight controls.
"You get what you pay for," Wallace said, "and non-QPL certified cable is always less expensive. In most cases, it is not lubricated and the performance tests have not been performed. Lubrication greatly extends the wear properties of aircraft cable, and all QPL-certified cable is lubricated." Loos & Co. has tested a number of lots of unlubricated non-QPL cable and found significant reductions in the cable's fatigue life. "These products may pass initial breaking strength tests," he said, "but rarely pass the criteria of retaining 50 to 60 percent of breaking strength beyond 30,000 endurance cycles." As a result, the non-QPL cable can fail in a much shorter lifetime.
What tips does Wallace offer MRO facilities that may need to purchase replacement cable? "First, read the OEM's manual to find out if QPL-certified cable is required; most often, it is. Next, obtain the QPL of approved companies from the OEM of the aircraft on which you're installing cable, or use this website,
http://astimage.daps.dla.mil/quicksearch
and download document number 83420."
When ordering from a distributor that doesn't wish to divulge the name of a cable supplier but states it is QPL approved, Wallace said, "beware, especially if the price is significantly lower. Further, if you order from a non-U.S. company directly and it claims to offer mil-spec conformance, realize that is not the same as meeting mil-spec testing requirements or of having QPL approval. To date, the only non-U.S. QPL-approved cable supplier is located in Germany. No matter whom you order cable from, absolutely insist upon seeing the cable manufacturer's certificate of QPL testing to the mil-spec."
The "Rev level" should also be noted, referring to the alphabetical revision letter at the end of the mil-spec number. With regard to MIL-DTL 83420J, an earlier letter designation such as "D" or "E" means the supplier is working with older data. "This doesn't mean the cable isn't QPL-certified," Wallace said, "but it can be a tip-off to dig deeper into your cable supplier and quality verification."
Each QPL certified cable manufacturer is assigned a two-color tracer filament that is embedded within their cable. In working with the Aircraft Cable Control Group, Wallace reported cases of "documentation of non-QPL manufacturers using colors assigned to QPL manufacturers." He advises cable users "to be sure to inspect and verify all the labels, lot numbers, and reel numbers on the cable." He also suggests nraveling a section of cable to verify the cable supplier's identifying tracer colors. "We've seen attempts to counterfeit these," he said. When a supplier is named on a purchase order, there's no harm in telephoning that company to verify that it supplied the cable. (Loos & Co. has been named on purchase orders when it wasn't in fact supplying the cable.)
Wallace also cited
http://www.faa.gov-/avr/spophoto.htm
for providing photos of noted differences between approved and unapproved wire rope.
This issue is relevant for replacement of both commercial and military aircraft cable, because in many cases the OEM specs are the same. Wallace isn't the only voice crying out in the cable quality-control wilderness. A number of investigations regarding bulk wire rope are underway by the U.S. Department of Transportation, U.S. Department of Defense, as well as the Federal Bureau of Investigation, and may eventually result, said Wallace, "in someone going to jail for misrepresenting flight-critical cable as meeting mil-specs."
The term "aircraft cable" is actually a misnomer, in Wallace's opinion: "Very little of the so-called aircraft cable consumed in the United States on an annual basis is actually QPL wire rope. Most of it is what you would find in your local hardware store." It is estimated that less than 2 percent of all "aircraft cable" is in fact QPL material, which makes attention to available safeguards for aircraft cable all the more important.
Pemco Wins Verdict
Pemco Aviation Group has experienced the non-qualified cable problem with some U.S. Air Force KC-135s that it worked on at its Birmingham, Alabama facility. On September 25, Pemco announced that it won a $7.5 million verdict against Certex of Alabama (part of Bridon-American Corporation). Pemco had filed a lawsuit claiming that Certex provided non-conforming aircraft cable, resulting in the grounding of several KC-135s in April 2000. According to Pemco, the KC-135s were refitted with new conforming cable and returned to active service.
_________________________________
---- Original Message -----
From: Michael Wallace
To: ******@***.***
Cc: mike_1
Sent: Wednesday, February 11, 2004 4:51 AM
Subject: Aircraft Cables
Hello Sir:
In the below statement you wrote that every commercial aircraft flying is equipped with nothing but SS cables and fittings. This statement is only partly true. Yes, the fittings are made from Stainless Steel Type 303SE but most of the cables are Zinc or Zinc & Tin Plated Carbon Steel.
My name is Michael Wallace and I am Vice President of Sales for Loos & Co., Inc. and we are the OEM supplier to just about every commercial aircraft manufacturer in the Western Hemisphere. I'm here at home this morning browsing the internet and stumbled across your statement in the Beech Owners chat room. I realize your statement was from way back in May '03 but I thought I might set the record straight for you.
Our customer list includes Boeing, Douglass, deHaviland, Cessna, Beech, Piper, Gulfstream, Lockheed, Embraer and many other smaller manufacturers. The only ones that use strictly Stainless Steel cables are Gulfstream and Cessna.
The others use 1/8" 7x19 Carbon Steel cables in their primary flight controls. Carbon steel cables provide much greater fatigue life compared to stainless cables. Boeing uses practically no stainless steel cables. They use the Tin over Zinc variety of carbon steel cable in their primary flight control cables.
As far as Aircraft Spruce is concerned, as KenV35A writes below, They pass off foreign manufactured cables as being made to the military specification MIL-W-83420. If you look at the fine print in their catalog, they state that their cables are not QPL certifiable. QPL means "Qualified Products List". It is the list of qualified manufacturers to MIL-W-83420 (The latest revision is titled MIL DTL 83420) that the U.S. Military maintains. There are only 5 companies in the whole world that are on the QPL list and they are all U.S. companies. I'll list them here for you:
Continental Cable - Hinsdale, NH
Loos & Co. - Pomfret, CT
Strandcore - Milton, FL
Strandflex - Oriskany, NY
Wire Rope Corp. - St. Joseph, MO
What Aircraft Spruce pawns off as being "just as good as" to the flying public is in no way representative of true Military Specification wire rope. When Spruces' cables are tested to the criteria in the Mil Spec, they fail miserably. Their intentional mis-representation should be stopped but the FAA has bigger fish to fry. They turn a blind eye to the Sport and Home-Built aviation industry.
Below I've pasted an article from Aviation Today discussing flight control cables.
AC43.13-1B, chpt.7, section 8, lists two types of corrosion-resistant steel for flexible cable use on civil aircraft. Type I, composition B cables, MIL-W-83420 and MIL-C-18375. Goes on to say "is equal
in corrosion resistant and superior in non-magnetic and coefficient of thermal expansion properties. Aircraft Spruce lists MIL-W-83420 as stainless. KenV35A
Inspection: Flight Controls Depend on Quality Cable
By Vicki P. McConnell, Technology Editor
When purchasing wire rope for use as flight-critical aircraft control cable that must meet MIL-DTL 83420, a certificate of conformance is not the same as a certificate of testing. For some years now, the former has been frequently passed off as the latter, according to Michael Wallace, vice president of sales and marketing for cable-manufacturer Loos & Co. This creates confusing or even bogus credentials for aircraft cable that doesn't offer the highest performance properties as manufactured, tested, and supplied by Qualified Producer List (QPL) companies such as Loos & Co. These companies have invested considerable funds to perform mil-spec verification testing of their cable, and go through the requalifying process every two years.
Some large airplanes, such as certain Boeing models, require nearly half a mile of steel aircraft cable, Wallace said. Boeing specification BMS7-265 designates flight-control cable as a QPL item. "This means that replacement of this cable by an MRO facility must be made with cable that comes from a QPL company," he added. Aircraft cable qualified to this mil-spec features 7 X 7 or 7 X 19 construction (referring to 19 wires per strand, 7 strands per cable, or a total of 133 wires working together to deliver optimum performance characteristics). Diameters range from
1/32nd inch up to 3/8ths inch, but typically 1/8th inch is common in flight controls.
"You get what you pay for," Wallace said, "and non-QPL certified cable is always less expensive. In most cases, it is not lubricated and the performance tests have not been performed. Lubrication greatly extends the wear properties of aircraft cable, and all QPL-certified cable is lubricated." Loos & Co. has tested a number of lots of unlubricated non-QPL cable and found significant reductions in the cable's fatigue life. "These products may pass initial breaking strength tests," he said, "but rarely pass the criteria of retaining 50 to 60 percent of breaking strength beyond 30,000 endurance cycles." As a result, the non-QPL cable can fail in a much shorter lifetime.
What tips does Wallace offer MRO facilities that may need to purchase replacement cable? "First, read the OEM's manual to find out if QPL-certified cable is required; most often, it is. Next, obtain the QPL of approved companies from the OEM of the aircraft on which you're installing cable, or use this website,
http://astimage.daps.dla.mil/quicksearch
and download document number 83420."
When ordering from a distributor that doesn't wish to divulge the name of a cable supplier but states it is QPL approved, Wallace said, "beware, especially if the price is significantly lower. Further, if you order from a non-U.S. company directly and it claims to offer mil-spec conformance, realize that is not the same as meeting mil-spec testing requirements or of having QPL approval. To date, the only non-U.S. QPL-approved cable supplier is located in Germany. No matter whom you order cable from, absolutely insist upon seeing the cable manufacturer's certificate of QPL testing to the mil-spec."
The "Rev level" should also be noted, referring to the alphabetical revision letter at the end of the mil-spec number. With regard to MIL-DTL 83420J, an earlier letter designation such as "D" or "E" means the supplier is working with older data. "This doesn't mean the cable isn't QPL-certified," Wallace said, "but it can be a tip-off to dig deeper into your cable supplier and quality verification."
Each QPL certified cable manufacturer is assigned a two-color tracer filament that is embedded within their cable. In working with the Aircraft Cable Control Group, Wallace reported cases of "documentation of non-QPL manufacturers using colors assigned to QPL manufacturers." He advises cable users "to be sure to inspect and verify all the labels, lot numbers, and reel numbers on the cable." He also suggests nraveling a section of cable to verify the cable supplier's identifying tracer colors. "We've seen attempts to counterfeit these," he said. When a supplier is named on a purchase order, there's no harm in telephoning that company to verify that it supplied the cable. (Loos & Co. has been named on purchase orders when it wasn't in fact supplying the cable.)
Wallace also cited
http://www.faa.gov-/avr/spophoto.htm
for providing photos of noted differences between approved and unapproved wire rope.
This issue is relevant for replacement of both commercial and military aircraft cable, because in many cases the OEM specs are the same. Wallace isn't the only voice crying out in the cable quality-control wilderness. A number of investigations regarding bulk wire rope are underway by the U.S. Department of Transportation, U.S. Department of Defense, as well as the Federal Bureau of Investigation, and may eventually result, said Wallace, "in someone going to jail for misrepresenting flight-critical cable as meeting mil-specs."
The term "aircraft cable" is actually a misnomer, in Wallace's opinion: "Very little of the so-called aircraft cable consumed in the United States on an annual basis is actually QPL wire rope. Most of it is what you would find in your local hardware store." It is estimated that less than 2 percent of all "aircraft cable" is in fact QPL material, which makes attention to available safeguards for aircraft cable all the more important.
Pemco Wins Verdict
Pemco Aviation Group has experienced the non-qualified cable problem with some U.S. Air Force KC-135s that it worked on at its Birmingham, Alabama facility. On September 25, Pemco announced that it won a $7.5 million verdict against Certex of Alabama (part of Bridon-American Corporation). Pemco had filed a lawsuit claiming that Certex provided non-conforming aircraft cable, resulting in the grounding of several KC-135s in April 2000. According to Pemco, the KC-135s were refitted with new conforming cable and returned to active service.
_________________________________
