Electrical Failure Leads to a Fatal Crash

Flight context

N571JM departed Phoenix Deer Valley Airport on 17 July 2017 for a business flight toward Santa Ana. The recently purchased high-performance experimental aircraft had a known electrical problem that had already appeared on a previous flight. About 25 minutes after departure, the pilot told ATC that the electrical system was not charging and requested a diversion to Falcon Field, where the aircraft's maintenance facility was located.

The problem was not simply that the aircraft lost electrical power. The critical issue was what happened after the warning appeared. The pilot continued toward the diversion airport while electrical reserves declined, eventually lost transponder and radio capability and then attempted to complete the arrival with a degraded system.

The critical sequence

The electrical warning was an early decision point. The pilot knew the charging system was not working and expected that radio communications could be lost. A conservative response would have been to land as soon as practical rather than continue a long diversion while consuming battery power.

The aircraft's electrical degradation eventually affected the transponder and radio. The pilot then used a low pass as a way for the tower to confirm that the landing gear appeared down. That was an understandable adaptation to a communications problem, but it placed additional workload on an already compromised arrival.

The final accident was a loss of airspeed during maneuvering. The pilot was distracted by the electrical failure and did not maintain sufficient airspeed while maneuvering for landing. The NTSB found that the airplane exceeded its critical angle of attack and entered a stall/spin.

Evidence from the aircraft and downloaded devices allowed investigators to reconstruct the sequence. The NTSB also reviewed the pilot's use of a phone and the extent to which troubleshooting and distraction competed with aircraft control.

ATC decisions during the event

ATC provided a diversion and then worked with the aircraft as communications became less reliable. Radar data was particularly important because it continued to show the aircraft's movement after the electrical system began to fail. The case illustrates the difference between an ATC clearance and actual aircraft capability: once electrical power became insufficient, the controller could no longer depend on normal transponder and radio performance.

Investigation and aftermath

The NTSB determined that the pilot failed to maintain adequate airspeed while maneuvering for landing, resulting in a critical angle-of-attack exceedance and stall/spin. Contributing factors were the electrical-system failure, distraction caused by that failure and failure to follow emergency procedures. The investigation's recorder and device evidence provided an unusually detailed picture of the final flight.

The electrical problem did not by itself explain the final impact. The NTSB's reconstruction shows that the aircraft remained airborne long enough for the pilot to divert and conduct the landing-gear verification pass. The decisive loss of control occurred during the subsequent manoeuvre. That distinction is supported by the radar track and the sequence of airspeed and altitude changes, and it prevents the accident from being reduced to a simple 'electrical failure caused the crash' explanation.

The accident record also distinguishes the electrical failure from the pilot's final control inputs. The aircraft was still controllable during the earlier diversion and low pass, but the subsequent turn required the pilot to maintain airspeed and altitude while configuring for landing. The radar-derived flight path shows that this margin disappeared during the manoeuvre immediately before the stall.

What the record establishes

The NTSB evidence establishes an electrical-system problem followed by a difficult approach sequence. The aircraft's charging/electrical condition deteriorated, and the pilot conducted a low pass so the landing gear could be checked visually. Radar then showed the aircraft making a steep left turn while manoeuvring to downwind. During that manoeuvre, airspeed decreased until the aircraft stalled and entered a spin, with the accident occurring at about 16:51 MST. The sequence matters because the loss of control occurred during the post-low-pass manoeuvring phase rather than being the immediate result of the low pass itself.

What the sequence shows

N571JM demonstrates that a technical problem can become a control problem without any additional mechanical failure. The aircraft still had enough performance to reach the airport, but the electrical failure changed the pilot's workload and attention. Once the pilot was maneuvering at low altitude, the margin available to recover from a stall was essentially gone.

• Land promptly after a known electrical-system failure when practical.

• Do not let troubleshooting displace airspeed and aircraft control.

• Use emergency procedures before improvising around a degraded system.

• Treat low passes and non-standard approaches as additional workload.

• Maintain a safe airspeed margin during every phase of an emergency landing.

Accident facts

Sources

• Original ATC recording