Kudos to the Supplier

I enjoyed reading in the January Editor’s Note (page 4) Capt. Bill Watts’ remarks concerning standardization for the future cockpit. The example sited, steam gauges on a glass display, is exactly why our software tools are in such high demand with avionics display developers.

While Capt. Watts was correct in giving credit to Boeing for being innovative in meeting a customer’s requirements, credit should also be given to the avionics display supplier. Without the innovation and future thinking of avionics display suppliers, Boeing would not have been able to provide Southwest Airlines with an acceptable solution. Moreover, Boeing would probably have lost the sale.

Flexible standardization is what software is all about. The avionics display suppliers are the real heroes in this example.

William A. Veitch
Program Development Manger
Virtual Prototypes Inc.

Cockpit, Databus Interest

I would like to provide a little constructive feedback on your January issue.

First, let me say I thought the article "Faster Databus: The Holy Grail" by Charlotte Adams was informative.

Second, I believe you have a real winner with the new feature "Cockpit Profile." I plan to save a copy of each cockpit and think many others will do the same.

I would like to request that you print the cockpit pages on a heavier stock (ideally glossy) such as the paper used for the cover or pages 3, 4, 45 and 46 of this issue.

Greg Tenerowicz

Editorial: Thanks for your comments. You certainly will see more "Cockpit Profile" photos and your suggestion of a heavier stock is one to be taken into consideration.

In Favor of PED Testing

GREAT article in Avionics Magazine (January 2000, page 41). I enjoyed "Potential Perils of PEDs."

I am an EMC engineer with 30 years experience in both box level and system design in military platforms and a frequent flyer. This column by Walter Shawlee 2 highlights a real problem that I have worried about several times. The solution (to require PEDs that have "reduced emissions in any band of potential interference") should be carried a bit further, however, as it is more stringent than may be necessary for safety. The extremely low specification level you suggest, should be limited to the frequencies that an aircraft uses, all the radio operational bands.

I like your test method, as PEDs are battery operated and ungrounded to the aircraft frame. This is a fast, repeatable, go/no-go test. If your test method is adopted and a test sample passes, it should be clearly marked as "Aircraft Safe" so the flight crew need not make the decision as to whether it is allowed or not allowed to operate on board a commercial flight. The equipment may be more expensive because of the added testing and design, but the consumer would have to make that decision at the time of purchase.

The manufactures that want their equipment to pass this test would have to plan their clock frequencies and operational circuits so their fundamental and harmonic frequencies fall outside these aircraft bands. This would not be difficult.

John Flinn

Now I’m a Believer

I really enjoyed your December 1999 Avionics System Design column in Avionics Magazine, "Why Do the Wings Dip When I Hit Play?" about electronic items and "in-flight" disruption.

Being in the Avionics/Electrical Test Group (all aspects: bench, flight, ground, development and now environmental, with some EMI) here at Sikorsky Aircraft since 1985, I’ve often "pooh-poohed" those stewardess warnings to turn off laptops and cell phones before flight and was surprised at the "simple test" results you presented.

Thanks for the info, I look forward to future articles on this subject and I’ll stop laughing at those warnings!

James F. Gagliardi
Sikorsky Aircraft
Avionics/Electrical (Qualification)

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