Standards officials were planning to meet in January to puzzle through a potential problem that has arisen in the introduction of fiber optic avionics systems.
Meeting in Montreal in October, the Airlines Electronic Engineering Committee (AEEC) approved a work request by Airbus and Boeing to consider the impact using fiber optic inserts in conjunction with copper pin inserts in a connector, that could exceed specifications of the ARINC 600 standard for copper wire and connectors.
What the airframers have found, said Dan Martinec, ARINC technical director of industry activities, is that fiber optic termini populating ARINC 600 inserts can exert more force than specified on the low-insertion force connectors described in the standard, with uncertain results. Under ARINC 801, the standard for fiber optic connectors, a terminus requires a certain amount of pressure to ensure a good contact and proper light transmission.
With the use of such inserts, “the force to put a box into a rack is increased,” said Martinec. “There could very well be a tendency of the rack to start flexing, and if there are fiber optic termini in there, that could produce bad results. If the rack starts flexing and the box stays square, the pins are no longer on the [and] that could preclude the needed for proper functioning.”
The problem, if any, has verified, but led to the airframers’ mission of an APIM, or ARINC Initiation/Modification form, a study. The project will be AEEC’s New Installations Subcommittee. An exploratory was planned for January, to connector manufacturer Radiall whose LuxCis fiber optic terminus basis for the ARINC 801 standard. based Radiall recently sold of Jerrik to Conesys Inc.
Two-Year Effort?
“We’re going to invite the fiber optic folks as well as the racking people to take a look at this and see if it is, in fact, a problem, and if we suspect that it is, we’ll probably have about a two-year effort to try to resolve any issues that are identified,” Martinec said. “None of this has been verified, so obviously, it’s going to require some testing on the part of the rack manufacturers, box manufacturers, connector manufacturers. When you plug one of these boxes in, what kind of deflection do we see, what kind of misalignment do we see? Obviously, we need to make sure this is not a problem when we do get these types of equipment that have a large number of fiber optic connectors on them.”
Martinec does not believe an industry assessment of up to two years will delay progress toward implementing fiber optics on airliners, nor will it affect new aircraft like the Boeing 787 Dreamliner, which is making more use of fiber optic connectors. The B787 is scheduled for a first flight in 2007 and to enter service the following year.
“The 787 is going to be using a number of fiber optic connectors, but it’s not going to be at such a level that would cause problem with the racking,” he said. “But as we move toward the future, and fiber optics are found to be more commonplace on airplanes, we could have entire connectors that are composed of fiber optic termini, and if you have 40 or 50 termini, all in one connector, it could very well be a problem.”
The solution might be to strengthen avionics racks, but that could involve a weight penalty. Whatever is decided will likely involve a compromise, Martinec said.
“There could be a trade-off, but as far as slowing anything down, I don’t think so,” he said. “It’s not a connector problem, per se, it’s not a box problem, per se, it’s really the rack. If anything, they may have to put another brace on the back of it. You don’t want to have a basic design have to include patches, you want to make sure that basic design is good enough to stand on it’s own.”
The Montreal conference, meanwhile, advanced the ARINC 800 series of fiber-optic standards. The conference adopted ARINC 807 describing fiber optic technician qualification requirements. The standard provides four levels of qualification ranging from buyer/avionics manager to technician.
Companies
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Air Electro ……………………………………………………………www.airelectro.com
Airtechnics ……………………………………………………….. www.airtechnics.com
American Connector Corp. ………………………………………..www.amccfl.com
Ametek Aerospace ………………………………………………….www.ametek.com
Amphenol Aerospace …………………………..www.amphenol-aerospace.com
Cadillac Cables …………………………………………….www.cadillac-cables.com
Data Bus Products …………………………………… www.databusproducts.com
Device Technologies ……………………………………………. www.devicetec.com
Electro Enterprises …………………………………..www.electroenterprises.com
Electronic Cable Specialists …………………………………..www.ecsdirect.com
EMTEQ ……………………………………………………………………www.emteq.com
Excalibur Systems Inc. …………………………………………..www.mil-1553.com
Glenair …………………………………………………………………… www.glenair.com
HiRel Connectors …………………………………………………….www.hirelco.com
HS Electronics Inc. ………………………………………….www.hselectronics.com
Inertial Airline Services Inc. ………………………………………..www.inertial.com
Intro Corp. ………………………………………………………….. www.introcorp.com
J&K Connectors ……………………………………………..www.jkconnectors.com
Joslyn Sunbank ………………………………………………www.sunbankcorp.com
Marine Air Supply ………………………………………..www.marineairsupply.com
MilesTek Corp. ……………………………………………………… www.milestek.com
Mobile Electronics ………………………………………. www.mobilelectronics.net
Omnetics Connector Corp. ……………………………………www.omnetics.com
PEI Genesis ……………………………………………………….www.peigenesis.com
PIC Wire & Cable ……………………………………………………. www.picwire.com
Radiall-Jerrik ……………………………………………………. www.radialljerrik.com
RIFOCS Corp. ……………………………………………………………www.rifocs.com
RMS Communications ……………………………www.rmscommunications.net
Sabritec ………………………………………………………………..www.sabritec.com
Souriau ………………………………………………………………….www.souriau.com
Spacecraft Components ……………………………………..www.spacecraft.com
Stratos International Inc. ……………………………..www.stratoslightwave.com
Tri-Star Electronics International …………………www.tri-starelectronics.com
Trompeter Electronics ………………………………………….. www.trompeter.com
Tyco Electronics …………………………………………. www.tycoelectronics.com
Wings Electro Sales Co. Inc. …………………….. www.wingselectrosales.com
W.L. Gore & Associates …………………………………………………www.gore.com