Fatal Twin-Engine Aircraft Crash Following single Engine Failure

Fatal Twin-Engine Aircraft Crash Following Single-Engine Failure: What Happened to Cessna 335 N79HP in Fort Lauderdale?

The Cessna 335 had been airborne for only a few minutes when the emergency began. Shortly after departing Fort Lauderdale Executive Airport on December 1, 2018, white smoke appeared behind the left engine. The crew reported a fire and a loss of power, then turned back toward the airport. The airplane was only a few hundred feet above the ground, leaving almost no margin for correcting the problem.

The controller cleared the flight to land on any runway. But the Cessna could not maintain its climb. Radar and onboard GPS data later showed the airplane descending as it maneuvered back toward the airport. At about 1:27 p.m., it struck the roof of a building in an industrial area, hit the ground and came to rest inside another structure. A post-impact fire destroyed most of the aircraft.

The pilot and pilot-rated passenger were killed. One person inside the building suffered minor injuries, while people at a nearby therapy center were able to evacuate. The accident initially appeared to be a straightforward engine-fire emergency gone wrong. The NTSB investigation ultimately revealed a more complicated chain: the airplane was not considered airworthy, the left engine suffered a partial loss of power caused by detonation, and the left propeller remained unfeathered during the emergency. According to the NTSB, those decisions and mechanical conditions combined to leave the aircraft without enough performance to climb.

The Emergency Begins After Takeoff

N79HP, a Cessna 335, departed Runway 9 at Fort Lauderdale Executive Airport for a personal repositioning flight to Hilliard Airpark in Florida. The weather was visual, with winds from 150 degrees at 18 knots and gusts to 23 knots.

The flight had been instructed to fly straight out. Shortly after departure, the controller became concerned about the airplane's low altitude and asked whether it was flying low along the shoreline. Around the same time, the crew reported a problem with the left engine.

The recorded ATC sequence is brief but important. The crew initially reported a fire in the left engine and said they were turning back. The controller cleared the aircraft to land on any runway and asked whether assistance was needed. Moments later, the crew reported a sink-rate problem.

That exchange illustrates how quickly the situation deteriorated. The aircraft was not dealing with an engine problem at cruise altitude, where the crew could normally spend time identifying the failed engine, securing it, configuring the aircraft and establishing a single-engine climb. This emergency began immediately after takeoff, at low altitude and with the aircraft still close to the airport.

NTSB radar and GPS data showed the airplane first tracking north, then west, while altitude and groundspeed decreased. At one point it was about 301 feet above mean sea level and moving at approximately 110 knots. The final recorded groundspeed was about 67 knots. The airplane never regained the altitude needed to safely complete the return. (NTSB Data)

Smoke From the Left Engine

Video recorded during the departure provided investigators with an important clue. As the Cessna passed the departure end of the runway, white smoke could be seen trailing from the left engine.

Witnesses later described the airplane as descending in a nose-low attitude. One witness reported hearing what sounded like high engine power and did not hear obvious sputtering. Another security video showed the aircraft shortly before impact with white mist trailing behind it.

The investigation found that the left engine had suffered detonation damage to several pistons. The damaged engine components allowed crankcase pressure to increase, and the rod-oil gauge and cap assembly was no longer attached. Investigators concluded that oil could escape the engine and contact hot exhaust or turbocharger components, producing the smoke seen before the crash. (Accidents App)

This distinction matters. The crew perceived the event as an engine fire, but the evidence did not establish a conventional uncontrollable engine fire before impact. The visible smoke was associated with the damaged left engine and escaping oil. The actual mechanical problem was a partial loss of engine power caused by detonation.

Why One Engine Was Not Enough

A twin-engine airplane is not automatically capable of climbing after one engine loses power. Performance depends on aircraft weight, configuration, altitude, airspeed, engine power, propeller drag and how quickly the failed propeller is feathered.

The Cessna 335's approved one-engine-inoperative performance chart provided a useful comparison. Under the conditions present during the accident, the airplane was expected to climb at about 360 feet per minute with the failed engine's propeller feathered. But the same performance chart required a 400-foot-per-minute deduction for a windmilling propeller. (NTSB Data)

That difference was critical.

The left propeller was not feathered during the accident sequence. The NTSB's examination found no evidence that a pre-impact failure of the propeller or propeller governor prevented feathering. Ground-mark analysis indicated that at impact the left propeller was rotating at approximately 900 rpm, while the right propeller was turning at about 2,700 rpm. (NTSB Data)

In other words, the airplane was carrying substantial aerodynamic drag on the side of the damaged engine while trying to climb or return to the airport. Instead of converting the failed engine's propeller into a low-drag configuration, the propeller continued to rotate.

The NTSB concluded that this left the airplane with negative climb performance. Had the propeller been feathered promptly, investigators determined that a positive rate of climb likely could have been achieved. (NTSB)

The accident therefore was not simply a case of an engine stopping. The surviving engine was still producing power. The problem was that the aircraft's overall performance, at that altitude and configuration, was overwhelmed by the combination of partial power loss and propeller drag.

The Airplane Had a Troubling Maintenance History

The most significant finding in the investigation extended well beyond the few minutes of flight.

The Cessna had a documented history of maintenance problems before the accident. An annual-type inspection in July 2018 did not approve the airplane for return to service. The owner later applied twice for an FAA special flight permit that would have allowed the aircraft to be repositioned, but the requests were not approved. (NTSB Data)

An FAA ramp inspection identified several discrepancies, including an observation that the left engine mounts appeared to be sagging. A later maintenance facility began another inspection but stopped after more than 100 discrepancies were identified, nine of them involving the left engine.

The airplane continued to undergo work during the following months, but problems remained. During engine runs in November, a large oil leak was found in the left engine compartment. Other discrepancies included problems with the right engine's power output, and the left turbocharger subsequently failed. The turbocharger was replaced shortly before the accident, but the mechanic reportedly considered the replacement unit to be in worse condition than the component it replaced. (Accidents App)

The NTSB found no documentation showing that all of the known discrepancies had been corrected. On the morning of the accident, the pilot performed additional engine runs and worked around the engines with tools. Investigators could not determine exactly what maintenance work was performed that day.

The sequence is important because the airplane had not simply developed an unexpected defect during an otherwise routine flight. Investigators found multiple warnings that the aircraft was not ready to fly.

The NTSB ultimately concluded that the airplane's condition was clearly unairworthy and that the pilot's desire to move it, amid mounting parking and travel costs, likely influenced the decision to depart. (NTSB Data)

Earlier Warning Signs

The investigation also uncovered an earlier flight that demonstrated how difficult the airplane could be to operate when its engines were not producing full power.

About nine months before the accident, another pilot flew the Cessna to Fort Lauderdale after it had been sitting for years. Just after rotation, the left engine's rpm dropped significantly. The airplane's climb performance was poor, and the pilot described the situation as concerning. After reaching a low altitude, the pilot adjusted the right engine and observed some improvement in the left engine's operation.

After landing, that pilot told the people responsible for the airplane not to fly it because he considered it unsafe. (Accidents App)

That warning was followed by months of maintenance problems, repeated attempts to obtain a ferry permit and inspections that identified extensive discrepancies.

The accident pilot also had a relevant training history. A flight instructor who had flown with him in a Cessna 310R several months before the accident reported that he had simulated unexpected zero-thrust conditions twice. On both occasions, the pilot misidentified the affected engine and applied incorrect rudder input. The instructor recommended additional training before the pilot operated the accident airplane. (Accidents App)

These details do not mean the pilot's earlier performance directly caused the accident. They do, however, show why engine-failure recognition, directional control and propeller management are critical skills in light twins.

The Final Turn

The aircraft's final moments were shaped by altitude, airspeed and the geometry of the attempted return.

After reporting the left-engine emergency, the crew turned toward Fort Lauderdale Executive. Radar data showed the airplane descending while maneuvering. It crossed above buildings while continuing toward the airport, but the aircraft was losing both altitude and speed.

The Cessna eventually clipped the roof of a building about 17 feet 6 inches above ground level. Ground scars and wreckage distribution indicated a descending impact path. The airplane then struck the ground and continued into a building, where the post-impact fire became intense. (NTSB Data)

News coverage from the day of the accident described the crash scene as a building fire in an industrial area and reported that a therapy facility serving children with autism occupied part of the complex. Several children and staff members were inside at the time. Staff evacuated them after the crash, and one person inside the building suffered minor injuries. The two people aboard the aircraft did not survive. (7News Miami)

That part of the story is important because the accident had consequences beyond the aircraft itself. The flight path ended in a populated areadjacent to the airport, but the building's occupants were able to escape.

What the NTSB Concluded

After examining the engines, propellers, flight controls, maintenance records, ATC communications, radar and GPS data, the NTSB identified several links in the accident chain.

The left engine experienced a partial power loss caused by detonation. The pilot continued the flight in an airplane that investigators determined was unairworthy. During the emergency, the left propeller was not feathered. The resulting drag prevented the airplane from achieving the performance that would have been available with the propeller feathered.

The NTSB's probable-cause statement is:

“The pilot's improper decision to fly the unairworthy airplane and his failure to feather the left propeller following a partial loss of power from the left engine after takeoff. Also causal was the partial loss of power to the left engine due to detonation.”

— National Transportation Safety Board, Accident No. ERA19FA060. (NTSB Data)

Accident Facts

The NTSB docket contains 27 investigation items, including FAA records, maintenance information, ATC material and other investigative documents. (NTSB Data)

The Broader Aviation Safety Lesson

The Fort Lauderdale Cessna 335 crash is a clear example of why a twin-engine aircraft should never be treated as if an engine failure automatically guarantees a safe outcome.

A single-engine failure creates asymmetric thrust and additional drag, and the available performance can disappear rapidly when the aircraft is low, slow, heavy or improperly configured. Prompt identification of the failed engine, directional control, maintaining the correct airspeed and timely propeller feathering can determine whether the aircraft climbs away or continues toward the ground. The NTSB has specifically highlighted delayed feathering in partial-power-loss events because a windmilling propeller can create enough drag to compromise control and climb performance. (NTSB)

Just as important, the accident demonstrates that risk management begins before takeoff. In this case, the engine problem was only the immediate trigger. The deeper safety issue was the decision to launch an airplane with a documented history of unresolved discrepancies after attempts to obtain authorization to reposition it had failed.

For pilots of light twins, the lesson is straightforward: an engine failure is an emergency, but the emergency does not begin when the engine quits. It begins with preparation, aircraft airworthiness, training, configuration and the discipline to reject a flight when the airplane is not ready.

The Cessna 335 had a second engine, an airport nearby and a controller ready to help. What it did not have was enough performance margin once the damaged engine was producing less power and its propeller remained unfeathered. That combination turned a potentially manageable engine emergency into a fatal loss of flight performance.

Sources

• https://data.ntsb.gov/Docket?NTSBNumber=ERA19FA060