January 13, 1997

Dear Mr Lacagnina,

I found your article "Tricked by a Transient" very interesting, and appreciate the quick fax response. Not being a pilot, it was very informative to me as to what degree a pilot, in any emergency situation is expected to second guess his instruments, diagnose the problem, analyze the situation and implement the correct use of his available resources to insure the safe handling of his aircraft, and to do it all in a matter of a few seconds. Too bad the maintenance crews aren't as gifted.

Walter Shawlee, in various articles for Avionics Magazine has talked about some of the reasons why flight crews have difficulty in correctly handling emergency situations. He cites too many systems, too many modes of operation, non-intuitive user interfaces on the equipment, unfamiliar backup systems with a lack of operator manuals and often no training on them.

While it seems that the "Series of Errors" syndrome may be a common underlying contributor to several crashes, the one thing that keeps getting overlooked is the fact that the equipment failed or falsely failed, thereby setting off the "series of errors".

When a system failure is the result of intermittent connectivity problems such as shorting or open wires, connectors, solder joints, relays or sensors then that failure is probably preventable and is the result of poor maintenance and improper testing.

Avionics systems engineers and maintenance managers seem to think that irregardless of what happens with malfunctioning equipment, redundant/backup systems or the pilot, will always get the aircraft back on the ground safely. They and the FAA believe that while intermittent avionics cause numerous emergency landings, they are not a contributing factor to any crashes. They believe that a crash is just an emergency handled badly.

We don't claim to be safety experts, but it just seems strange that in nearly all discussions of safety the "Errors" are always attributed to the pilot and none to the maintenance practices that totally ignore the safety risks associated with intermittent avionics equipment. With 40-60 percent of all pilot reported equipment failures going unrepaired ("No Fault Found") we believe it might be time for someone to do a "Series of Errors" article concerning avionics maintenance.

With this view in mind, please take a look at the enclosed literature and the letters that detail our concerns with avionics testing and safety issues. Hopefully you will find something that your readers can use to make flying safer. 

Please keep up the good work and if we can be of any assistance please call.

Thank you,