Fatal Cirrus SR-22 CFIT in Las Vegas

They were level at 6,500 feet on a Visual Flight Rules (VFR) flight plan in radar contact with air traffic control (ATC). After being vectored around Nellis Air Force Base, they were north of the city, expecting a practice instrument landing system (ILS) approach and landing at North Las Vegas.

Approach control: "N7GA, turn left heading two seven zero."

N7GA: "Two seven zero, seven gulf alpha."

Approach control: "N7GA, altitude your discretion."

N7GA: "Seven gulf alpha."

ATC was busy for a while with other traffic, including a Medivac aircraft and a flight of four F-35 fighter jets departing Nellis Air Force Base.

N7GA: "We're getting a low-altitude alert for N7GA, we gotta turn left."

Approach control: "N7GA, turn left heading two five zero."

N7GA: "Two five zero, N7GA."

The Cirrus was low over the mountain ranges immediately north of Las Vegas. It was a completely clear night over the desert, with no clouds and unlimited visibility, and it was dark, with no moonlight. The pilot was flying VFR, talking to ATC but choosing his own cruising altitude. Using a landline, the approach controller's assistant arranged a handoff for the Cirrus with North Las Vegas Tower, then the controller called on the radio to give the pilot the tower frequency.

Approach control: "N7GA, Nellis."

Approach control: "N7GA, Nellis approach, reply not received if you hear me [unintelligible]. N7GA, radar contact lost."

Approach control: "N7GA, Nellis
approach."

On a landline, Nellis Tower called the assisting controller. "Hey, did you guys get an ELT on one two one point five?" They were asking the radar controller if they had heard an emergency locator transmitter (ELT) broadcasting on the emergency frequency, 121.5 MHz. Approach control replied, "We did." The tower had more bad news: "Okay, ’cause we're looking at, like, I don't know, a flare out towards Gass Peak-ish, and now it looks like a fire over there." 

The Cirrus had crashed into the mountain. A Las Vegas Metropolitan Police Department helicopter quickly arrived on scene and determined the crash was "not survivable." No rescue efforts were made. Crews would not reach the rugged location until the next morning. The wreckage was found about 400 feet below Gass Peak's highest elevation. It was close to its last recorded radar return, still at an altitude of 6,500 feet, the same altitude it had been cruising at since entering the Las Vegas area. All three people onboard died in the impact.

After the accident, the National Transportation Safety Board (NTSB) examined the fire-damaged airframe and engine, finding "no evidence of any preexisting mechanical malfunction that would have precluded normal operation." In the March 2022 final accident report, it determined the probable cause to be "the pilot's failure to maintain clearance from terrain during cruise flight in dark night conditions." While that's literally true, did he know the mountain was ahead of him? What was the "altitude alert" that ATC relayed, and shouldn't the controller have warned the pilot of impending danger?

These types of crashes are called Controlled Flight Into Terrain, or CFIT (pronounced "see-fit"). A perfectly good airplane, under pilot control, impacts the ground. The terrain you descend into, or the terrain that's rising up to meet you, isn't visible until it's too late to change your flight path to escape impact. It's a serious issue when flying in the clouds, but it also happens in clear skies, typically on a dark night.

For VFR pilots, most of the time, we look out the window and can simply use our eyes to stay above the terrain. But there are exceptions. Sometimes a visual illusion can fool us. And flying over unlit mountains on a dark night requires special vigilance. With no moon and no lights on the ground, what in the day are obvious, grand peaks can look like black lakes. The most specular rocks can be truly invisible from the cockpit. At the time of the accident, the sun was more than 12 degrees below the horizon, and the moon was more than 37 degrees below the horizon. So, did the pilot know Gass Peak was even there?

I'm sure the pilot was familiar with the terrain to the north of Las Vegas. The mountains are clearly apparent during the day from the northern suburbs. He had lived in Las Vegas for a long time, retiring in 2015. Even more noteworthy is that he had retired from a career as an FAA air traffic controller at the McCarran (now Harry Reid) International Airport (KLAS). He had 440 hours of flight time over more than 10 years of flying, with about 123 hours in his Cirrus SR-22. This wasn't a case of a transient pilot unaware of the local geography.

Moreover, the terrain is clearly marked on sectional maps and found in electronic databases. The pilot's penultimate transmission, 22 seconds before the last radar return---"we're getting a low altitude alert!we gotta turn left"---shows he was using some type of electronic device in the cockpit. The plane didn't have a radar altimeter, but the pilot did have a Pro Plus subscription for the ForeFlight app on an iPad. Its hazard advisor feature requires GPS information, and we don't know what GPS source the pilot was using. Ultimately, the NTSB was unable to determine the source of the alert and noted, "It's likely that the pilot did not have sufficient time to maneuver to avoid terrain." More sophisticated sensors feeding ForeFlight may have given him more warning. It's also unknown what kind of terrain awareness display the pilot had available to him in the panel-mount avionics, but it's hard to imagine he didn't have some visual reference of the rising terrain ahead. 

Controlled flight into terrain (CFIT) accidents look like an altitude problem. But that's not really true. CFIT accidents are often a situational awareness or positional problem. We believe our altitude is good---because we're not where we think we are, or we're not aware of the terrain immediately surrounding us. This pilot knew his altitude (6,500 feet), and he knew the altitude of Gass Peak (6,900 feet), and he probably knew all the higher safe IFR altitudes from his time as an air traffic controller. It's possible he didn't know Gass Peak was ahead of him. He may have thought he was well south of the mountain range.

ATC had taken the flight well to the north, but just before the crash, it was heading due west at 6,500 feet, where they would have had a great view of the bright lights of Las Vegas to their left. And if the pilot thought he was over the flatlands between the edge of the suburbs and the start of the Gass Peak foothills, 6,500 feet would be a good altitude. Maybe he was preparing for the practice ILS. Maybe being in radar contact reduced his concerns about altitude and position. He might have assumed that the controller was looking out for him, but ATC has few obligations to monitor or alert pilots of VFR flights to potential terrain conflicts. 

The air traffic control instrument flying rules (IFR) minimum vectoring altitude (MVA) over Gass Peak is 8,000 feet. One of the advantages of VFR flying is going lower and more direct than prescribed IFR routes, and we rely on clearing terrain visually. But still, shouldn't the controller have warned the pilot of the mountains ahead? The controller's manual, FAA order JO 7110.65Y, Air Traffic Control, says:

"Issue a safety alert to an aircraft if you are aware the aircraft is in a position/altitude that, in your judgment, places it in unsafe proximity to terrain, obstructions or other aircraft. Once the pilot informs you action is being taken to resolve the situation, you may discontinue the issuance of further alerts. !The issuance of a safety alert is a first priority."

In a written statement, The U.S. Air Force controller said, "Although the MVA in the area is 8,000 MSL, I did not believe that the aircraft was at an unsafe altitude because regulations dictate that MVAs in mountainous areas are 2,000 feet above the highest obstacle." The NTSB did not interview the controllers or further examine the safety aspects of this statement or the radar services provided.

The NTSB did note that choosing safe altitudes is ultimately the responsibility of the pilot. The Aeronautical Information Manual (AIM) is clear that when receiving terminal radar services while VFR, "these services are not to be interpreted as relieving pilots of their responsibilities to!maintain appropriate terrain and obstruction clearance."

Flying VFR over unlit mountains at night requires knowing the altitude of the terrain. But knowing the altitude of the peaks isn't enough. You have to know exactly where you are in relation to those peaks. The lights of the Strip are an amazing sight from the air, but as pilots, we have to know what's hiding in the darkness ahead. 

VFR At Night

Do you want to read more After the Accident columns? Check out "Black-Hole Illusion Leads to Fatal Piper PA-32 Crash" here.