Pilot Suffers Electrical Problem | Smart ATC Saves Life

The Handoff Came With Almost No Information

Just after midnight on November 22, 2017, Denver Center called Kansas City Center controller Josh Giles about an aircraft entering his sector with electrical problems. The aircraft was a homebuilt experimental machine, N241BB. When the pilot checked in, the transponder was not working and radar coverage in the area was limited.

The Electrical Failure Spread

The pilot believed the alternator had failed. That single problem had consequences across several systems: the transponder was unavailable, fuel quantity information was unreliable and radio transmissions were intermittent. The pilot initially intended to continue toward New Century AirCenter in Olathe, Kansas, but the situation forced him to look for a closer landing site.

A Radar Picture Wasn't Available

Giles could not rely on a normal radar target to watch the aircraft. He advised the pilot to shut down systems that were not needed for flight and helped identify airports near the aircraft's approximate position. When the pilot could not find Hays Airport, Giles suggested Osborne Airport instead.

A UPS Aircraft Became the Relay

Radio coverage was another obstacle. Giles used a UPS aircraft to relay information between the controller and N241BB. The UPS crew also helped confirm that the runway lights at Osborne were on. Eventually the relay aircraft reported that N241BB had the airport in sight and then that the aircraft had landed safely.

The loss of the transponder created an immediate surveillance problem. With limited radar coverage in the area, Giles did not have a primary radar target he could use to watch the aircraft. The controller therefore had to combine the pilot's reports, approximate position information and help from another aircraft.

The pilot initially wanted to reach New Century AirCenter, but the electrical problem was getting worse and the fuel information was no longer reliable. Giles recommended shutting down equipment that was not necessary for flight, preserving electrical capacity for the systems needed to keep the aircraft airborne and communicate.

The final report from the relay aircraft was the one Giles needed: the aircraft had made it safely onto the ground.

The aircraft's destination changed because the pilot no longer had reliable electrical information. Fuel quantity indications were also affected, which meant the crew could not confidently use the normal fuel displays to decide how much time remained.

The UPS aircraft's assistance was especially important because the emergency aircraft was difficult for the controller to track and had intermittent communications. The relay allowed the controller to keep giving useful instructions even when direct radio coverage was poor.

The final approach was completed only after the relay aircraft confirmed that N241BB had the runway in sight. That confirmation allowed Giles to keep the emergency moving toward a landing despite the lack of a normal transponder return.

OK, well figure it out.

“22, 2017 to advise of an aircraft about to enter Giles’s Prairie Area Sector 66 position, the only thing Giles knew for sure from his ZDV colleague was that the aircraft was having electrical problems.”

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