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Old 8th Dec 2000, 22:56   #1 (permalink)
worn to limits
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Post E.E.C. FADEC.

WITH REFERENCE TO A WRITTEN CAA EXAM QUESTION, COULD ANY HELP AS TO WHAT IS THE DIFFERENCE BETWEEN AN E.E.C AND A FADEC. I KNOW THE FADEC HAS AN EEC INSIDE IT BUT WHAT ELSE DOES IT HAVE. ANY HELP MUCH APPRECIATED.
 
Old 8th Dec 2000, 23:34   #2 (permalink)
SchmiteGoBust
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Talking

I,m not 100% sure about this ,but it may help.
A320's have FADEC which involves no mechanical linkages whatsoever. The whole issue is electronic. It also speaks directly to the flight management systems.
757's have an EEC system. The throttles are still directly linked to the engines and the EEC function is to control a stepper motor in the fuel flow governor to trim fuel requirements more accurately.All auto throttle functions are still fed mechanically into the linkage system.
With a FADEC engine autothrottle is part of the FADEC!!!!
Hope this is of some use.
 
Old 9th Dec 2000, 00:10   #3 (permalink)
spannersatcx
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Red face

Also the RR uses FAFC full authority fuel control!!
 
Old 9th Dec 2000, 01:08   #4 (permalink)
jetfueldrinker
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Spanners, which RR uses fadec? The RB211 that I know and despise has, as stated earlier, an EEC which trims fuel requirements electronically through sensors, but there is still a throttle cable likned to the FCU. With FADEC there is no mechanicle linkage, but the back up is a dual channel system.
 
Old 9th Dec 2000, 02:34   #5 (permalink)
worn to limits
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THE RB211 524 G/H FITTED TO THE 747 400 HAVE THE FAFC. IS THIS THE SAME AS THE FADEC. IN WHICH CASE IT APPEARS THE DIFFERENCE BETWEEN THE EEC AND THE FADEC IS THE ABSCENCE OF ANY MECHANICAL LINKAGES.
 
Old 9th Dec 2000, 02:45   #6 (permalink)
gas path
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The 534H has a FAFC with no mechanical link to the FMU.
The GE90 has an EEC with no mechanical link to the HMU.
The Trent has an EEC with no mechanical link to the FMU.
The CF6-80 has an ECU with no mechanical link to the HMU.

The FADEC is made up of sub systems, the EEC being one of them and the others, things like:-
dedicated alternator, discretes (sensors), solenoids, torque motors, VSV/VBV/TCC and protection.
"Closed loop engine control" !!



[This message has been edited by gas path (edited 08 December 2000).]
 
Old 9th Dec 2000, 14:14   #7 (permalink)
spannersatcx
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jetfueldrinker, as stated by gaspath, the 747-400 with RB211-524-g/ht has an FAFC, with no mechanical linkage to the PAG (pump and govenor) also the TLA is sent via potentiometers on the bottom of the throttles. My interpretation of FADEC is that it appears to be a generic term, in that the whole eng control system is electronic i.e fuel control,bleeds etc, whereas the RR still has pneumatic/mechanical VIGV's and that not all engines are controlled entirely electronically as the 'FADEC' system suggests. I'll have to read up to be more precise in what is and isn't controlled electronically.

[This message has been edited by spannersatcx (edited 11 December 2000).]
 
Old 12th Dec 2000, 15:03   #8 (permalink)
near enuf is good enuf
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Just for info:

Just the 75's with RB211's fitted are EEC controlled.
A few are fitted with PW 2000's which are full FADEC.

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Old 12th Dec 2000, 18:36   #9 (permalink)
offshoreigor
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Cool

Hope this explains it:

The primary customers for Control Systems FADECs are GE Aircraft Engines and CFM International. The company also supplies FADECs for use on military aircraft.

So what does a FADEC do, exactly? Simply put, it’s a “black box” of computer circuits and sensors that tell the engine what to do and then make sure everything is working properly.

The FADEC constantly monitors things such as engine rotation, fuel flow, air pressure and temperature. It also is programmed to carry out sophisticated engine diagnostics, so it can notify the flight crew of any significant problems or include information about lesser problems in the reports it prepares for maintenance crews.

“Essentially, the engine controls itself,” McGlynn explains. “The pilot communicates electronically with the FADEC, telling it the thrust level he or she wants, and the FADEC computer figures out how to get there. The pilot has no direct mechanical control of the engine.”

Without FADEC, the flight crew would have to continually monitor engine gauges and “trim” the throttle to maintain a constant thrust level.

With FADEC, the workload of the flight crew is reduced and engines can achieve better performance and operate more efficiently, thereby minimizing stress on engine components and maximizing fuel efficiency.

Because of their crucial role on an aircraft — and because they ride on the engine, not in a protected electronics bay — FADECs are designed to be extremely robust. They can endure temperatures from 60 degrees below zero to 200 degrees above, and they have redundant systems to protect against failure.

But even the most effectively designed system can’t guarantee reliability and quality. That’s up to the people who produce the system. In this case, those people are the FADEC commercial team at the Control Systems facility in Fort Wayne, Ind.

“Our operators on the floor are 100 percent focused on producing the highest quality product possible,” says Sam Stokes, who until recently was program manager for commercial FADECs. “They understand how this product is used and that even with backup systems it is flight critical. There’s a tremendous amount of teamwork between the operators who do the assembly work and the product and process engineers. Sometimes you look out on the floor and you can’t tell which is which.”

The FADEC team members, like employees on other product teams at the Fort Wayne facility, are cross-trained to work in cells, so that each FADEC unit is finished before the next one is started. It’s a form of “lean manufacturing” that allows problems to be discovered and fixed quickly before multiple units are in production and each one would have to be reworked.

The lean manufacturing process has been one of several improvements that have helped Control Systems reduce the price of its FADEC line of products by 25 percent since 1996.

The facility also uses a quality analysis process called “six sigma” in which the teams aren’t satisfied when products are merely within a particular specification range, but rather they require that their products are centered within the range.

The Fort Wayne facility’s attention to quality has earned it ISO9001 certification and the state of Indiana’s quality improvement award for three years running.

In addition, the facility has been selected as one of three Lockheed Martin companies employing LM21 Best Practices for quality, to be used as a quality benchmark throughout the Corporation.

Even with its record of success, the FADEC team never stops striving to improve. Every six months, it conducts reliability reviews with customers. Field data is carefully scrutinized for trends and potential areas for improvement.

Also, the rare incidents of in-flight shutdowns are fully and aggressively investigated. (A jet airliner can fly on one engine, so a single engine shutting down is not by itself catastrophic.)

“Much of the FADECs’ reliability is simply paying attention to detail,” says John Faulks, FADEC product support manager. “We listen carefully to our customer, and we base all of our ongoing engineering development and corrective action plans on what those forums are telling us.”

Improving FADEC, both the products and the production, is a constant process at Control Systems. Upgrading systems to meet the lifecycle requirements of the engines they control is challenging, Faulks notes, as certain FADEC components go out of production and need to be replaced.

In addition, Control Systems has set a goal to reduce FADEC production costs by another 30 percent through redesign and simplification.

All of these efforts will almost certainly go unnoticed by the average airline passenger who glances casually out of a cabin window at the housing of a GE engine.

But as the aircraft takes off with its FADEC in control of that engine — something that happens every 17 seconds somewhere in the world — the employees at Control Systems will have the satisfaction of knowing they have done everything possible to ensure a smooth flight.

Cheers, OffshoreIgor

 
Old 13th Dec 2000, 04:51   #10 (permalink)
worn to limits
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Thanks everyone for your help. It makes sense now.
 
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