Ground Circuit Problem

Field Technical Supervisor Southwest Airlines Solves Ground Circuit Problem

Field Technical Supervisor at Southwest Airlines

Solves Ground Circuit Problem

I received an email from Matt Couture the Field Technical Supervisor at Southwest Airline on a ground circuit Problem

While conducting an evaluation of the Bartol Mag-Probe to be used at Southwest Airlines Matt Couture developed an effective procedure isolating a ground circuit problem using the Mag-Probe  The procedure is written below.


Good Morning Bob,

That Mag-Probe came in very handy last night!! Here is a copy of the turnover I wrote… Thanks again!!  I will keep up the testing…

This plane just came out of check from MCI.  The CDS had a current fault 31-68861. The GPWS had inflight faults for the #1 terrain relay for 10 legs.  We accessed the R745 in the FWD R/H NWW. I turned on the TERR with the captains EFIS panel and used my mag-probe to see if the relay was powered, it was not. Pulled R745 and checked for power, there was 28vdc. Since I knew the relay was not powered I went after the ground circuit; that is when I hit pay dirt.  The ground circuit was open from the GPWS to the R745 pin 6. I broke down the circuit and found pins 30 and 31 swapped at D40698.  That connector also had two other pins pushed.  It had a fresh label sticker on it, so my guess is that those guys were in it at MCI.  I swapped the pins to the correct location and everything worked.

Best Regards,

Matt Couture

Related Posts

Ground circuit problems do exist.  In the event you suspect a ground circuit problem we recommend using a Bartol Mag-Probe.  Here is another post where another ground circuit problem existed.  Aircraft Technician Saemi walks you through the test in a video recording.  This was the final test before the plane was to be grounded by the FAA permanently.

Mag-Probe Test Keeps Boeing 767 from Being Grounded for Good

Mag Probe – Winning the Race Against Time


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About the Author

Bob Bartol has spent his whole life working with electronics in almost every capacity and spent many hours in Physics classes.

He currently holds 4 U.S. patents and has been making a living off one of the patents “The Bartol Mag-Probe” for over twenty years. Bartol Research’s Mag-Probe now has a global reach and is dramatically reducing trouble shooting downtime anywhere a solenoid valve. relay, or contactor is used.

F111 Air Force Projects – European Flight Competition
January 1968

Bob attended electronics school in the Air Force. Upon graduation he was assigned to a fighter wing in Germany. During his assignment he prepared seven aircraft for European competition. The fighter wings aircraft won the competition.

Bob then returned to the United States and taught advanced radar for two years.

Two years later, he returned to Europe. During this assignment, Air Force headquarters Europe selected Bob to open a Precision Measuring Equipment Laboratory (P.M.E.L) in England. It was the first of its kind in the Air Force.

Upon his return to the United States, Air Force headquarters assigned Bob to Air Force research command in Florida. This was strictly a scientific assignment for research and development.

After three years he moved from Eglin AFB in Florida to Edwards Air Force Base in California where he had direct contact with the National Bureau of Standards and supported research and development aircraft.

During this assignment, he designed a modification for the TF X fighter (F-111). This modification made possible an additional 9800 flying hours per year. The F111 was the first swing wing aircraft in history. General Dynamics completed the modification prior to acceptance by the U.S. Air Force.

Modification of F111 Aircraft
General Dynamics
March 1963

As a result of increasing this flying time Bob Received an award from Edwards Air Force Base for Increasing flying time of the F111 by 9,800 hours per year. The Award was Presented by Colonel Grumbles to TSGT Bob Bartol on June 17, 1963

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