SoylentNews

Arthur T Knackerbracket [soylentnews.org] writes:

EDITORS: THIS HAS BEEN PRODUCED BY SOFTWARE UNDER DEVELOPMENT - THE CONTENT MAY REQUIRE EXTENSIVE EDITING

https://www.tomshardware.com/tech-industry/us-military-gps-jamming-exercise-suspected-of-contributing-to-civilian-plane-crash-in-new-mexico-medevac-flight-lost-signal-before-flying-into-a-mountain-killing-everyone-onboard [tomshardware.com]

Medevac Flight Lost Signal Before Flying Into A Mountain, Killing Everyone Onboard

While the GPS interference seemingly did not directly cause the crash, it’s apparent that it was the first domino in a chain of events that led to the fatal accident. This raises urgent questions about GPS jamming as reported incidents of GPS interference mount across the world.

This switch meant that the pilots would now primarily fly the plane using instruments in the cockpit instead of looking outside the windows. This is a normal procedure and is what most passenger airliners use during operations. Furthermore, it seems that the pilots have filed for clearance before they took off, as evidenced by their “as filed” clearance to SRR.

Around five minutes after this radio communication, ATC called the military and asked them to stop their GPS jamming activities in the meantime. At 12:07 am, the NTSB said that the Beechcraft’s GPS instruments resumed regular recording. The pilots then called Albuquerque Center a minute after this, saying that they had “a visual on Ruidoso,” the town nearest to SRR, and that they were transitioning to visual flight rules (VFR). This meant that they were moving away from the direct control of the ATC and would navigate and fly using visual cues.

The conditions meant that there was no available illumination to light the ground. It is still unknown what happened next or what the pilots saw (or didn’t see), but the preliminary report says the last recorded information saw the plane climbing from 9,400 feet to 9,823 feet at a ground speed of 150 knots (172 mph). It impacted terrain at about 9,950 feet — some 230 feet below the Capitan Mountains Summit Radio Facility.

Because they could not see that the Capitan Mountains were still between them and their destination, they likely started their descent too early. As soon as the aircraft went below the peak, they would’ve lost visual with the town, and it seemed that the pilots attempted to climb when they realized that there was a massive obstacle in front of them. Unfortunately, it seems that their efforts were too late, especially at their speeds, resulting in a controlled flight into terrain (CFIT) accident.

This was compounded by a high workload and high-stress situation. Landings and take-offs, in normal situations, are already quite hectic in the cockpit, which is why pilots practice the sterile cockpit rule, which avoids extraneous communications, at times like these. The loss of GPS signals also added to their stress, as they initially planned for an RNAV approach towards SRR. While this generally uses a combination of radio signals, it seems that their system primarily relied on GPS, which was inoperative at that time.

Aside from this, ATC also had a higher workload than usual, as they were assisting three other aircraft in the area that have been affected by the military operations. Although the military had temporarily ceased their activities, it seems that the pilots were not aware of this and elected to proceed visually instead of relying on either RNAV or the alternative instrument landing system (ILS).

We still don’t have the NTSB’s final report, so we cannot definitely say what the ultimate cause of the crash. But it seems that if the military wasn’t running a GPS jamming exercise at that time, the flight would have used RNAV from departure all the way to SRR, instead of relying on radar vectors and, ultimately, VFR.

But aside from civilian airliners, many drones, especially those used for long-range attacks, also use GPS. While militaries have been developing new technologies like microwaves [tomshardware.com] and lasers [tomshardware.com] to shoot down these drones, one of the most cost-effective technologies that is readily available today is GPS jamming. It’s probably because of this that Russia has started putting magnetic compasses [tomshardware.com] on some of their drones to help with navigation.

Even though GPS jamming might sound alarming, pilots have been flying around the world for decades, even before it came into widespread use. These include VOR (VHF Omnidirectional Range) beacons that send out signals unaffected by GPS jamming to help pilots determine where they are, ILS, which safely guides pilots towards a runway up to a certain distance, and more.

However, it seems that the sudden loss of GPS caught the pilots of the Beechcraft unaware. This, combined with the lack of visual references, a sudden change of plans from RNAV to ILS approach, and the decision to fly visually, probably led to the crash. The military’s GPS jamming exercise didn’t directly cause the crash, but it was likely the first event in the “Swiss cheese” model that ultimately caused the accident.

Original Submission