News & commentary about aerial firefighting, air tankers, and helicopters

A Lockheed Stalker XE Unmanned Aerial System aircraft crashed as it was attempting to land after completing a mission to detect heat and map the perimeters of wildfires in southwest New Mexico.

It occurred August 7, 2019 about 26 miles west-northwest of Truth or Consequences, New Mexico.

The cause, according to a brief preliminary report, was an incorrect altitude of the landing area obtained from “a new GPS out of the box.”

Below is an excerpt from the report about the accident:

“The Type 2 UAS was ordered for a number of fires in and around the XXX Wilderness on the XXX of the XXX National Forest. The mission was to detect any heat remaining on the fires, map their perimeters, and provide imagery to local fire managers. The day before the mishap, a flight was conducted on a fire that went smoothly. On the second day, a similar mission was planned over a different fire. A thorough safety and operational briefing took place prior to launch with all members of the mission. The only difference in this mission and the previous day’s was the location of the fire and the placement of the launch area. The UAS flew over the fire for just over an hour collecting data before the Pilot in Charge (PIC) began the procedures for landing.

“On final and while flying on an automated flight plan, the UAS aggressively changed its angle of attack and pitched down. The UAS impacted the ground at this angle one-quarter of a mile from the intended landing zone. The fuselage, leading edges of the wings, and tail boom all sustained significant damage leading to the aircraft being deemed not airworthy. The angle of attack change is normal for this aircraft on approach to its landing zone.

“The crash was due to an incorrect input into the Ground Control Station (GCS) of the landing zone elevation. This elevation was gained from a new GPS out of the box. The input into the GCS was 5915 and the actual elevation of the landing zone is 6280. This incorrect input made the aircraft believe that it was over 300 feet higher and continue with this angle of attack prior to leveling off for landing.”

The Lockheed XE was first introduced in 2006. The latest models can fly up to eight hours with a propane fuel cell or up to four hours with a battery option at a cruise speed of 35 mph. It can be launched with a bungee cord, a catapult, or by using a recently developed optional vertical takeoff and landing kit.

In 2015 Lockheed demonstrated how the Stalker XE can provide data and a precise geolocation to an unmanned K-MAX cargo helicopter, which conducted water drops to slow the spread of a fire.

In October Lockheed Martin demonstrated for wildland fire officials in the Boise area the use of a remotely-piloted K-MAX helicopter for dropping water on a simulated fire and delivering externally-carried cargo. Now the company is developing a system that uses a small drone to work with the K-MAX to communicate with Air Traffic Control in real time.

Below is the text of a news release.

“Lockheed Martin demonstrated its ability to integrate unmanned aircraft system (UAS) operations into the National Airspace System (NAS) using its prototype UAS Traffic Management (UTM) capabilities, the company said in a Dec. 2 release.

During the demonstration on Nov. 18, the Stalker XE UAS provided data and a precise geolocation to the unmanned K-MAX cargo helicopter, which conducted water drops to extinguish a fire, while the UTM tracked the UAS operations and communicated with Air Traffic Control in real time.

“This demonstration represents the path forward for flying UAS in the NAS using Flight Service-based UTM capabilities to extend the technology and systems that air traffic controllers know and understand,” Paul Engola, vice president, Transportation & Financial Solutions, said in the release. “We were able to successfully modify the existing K-MAX and Stalker XE ground control software to connect to the UTM services and conduct the firefighting mission.”

For more than 80 years, manned aircraft have supported firefighting missions during daylight hours. Because unmanned K-MAX can fly day and night, in all weather, its insertion into firefighting operations offers the potential to triple the amount of time ground firefighters can receive aerial support.

The Stalker XE UAS worked in tandem with K-MAX to identify hot spots and fire intensity with its electro-optical, infrared camera. Its stable, high definition imaging capabilities enable day and night operations. Powered by a ruggedized solid oxide fuel cell, Stalker XE achieves more than eight hours of flight endurance.”

Thanks and a tip of the hat go out to Chris.

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