AINsight: LOC-I Crashes Highlight Upset Training Value

 - October 24, 2019, 5:59 AM

The June 1, 2009 crash of Air France 447 was a tragedy that put the spotlight on loss of control inflight (LOC-I) accidents, but in no way was it unusual, rare, or unique. That accident is widely considered the watershed moment that finally energized the industry to formalize and even codify formal upset prevention and recovery training (UPRT) for airline pilots. But a decade later, LOC-I accidents remain a leading cause of fatalities in commercial aviation and now evidence points to an increase of these events in business aviation.

In the past two years, two Bombardier Challengers have crashed as the result of inflight upset events. These were the worst two business jet accidents recorded during that period, and in each case the accident profiles were eerily similar to those of Air France 447.      

Air France 447 was a scheduled flight from Rio de Janeiro to Paris that crashed into the South Atlantic Ocean, killing all 228 people on board. The recovery effort to find the wreckage and cockpit voice and flight data recorders took nearly two years.

According to the French Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA) final report, the aircraft, an Airbus A330-200, was in level flight when ice crystals obstructed the pitot tubes, resulting in a momentary “inconsistency” in airspeed indications. This inconsistency in airspeed caused the autopilot to disconnect and the fly-by-wire system to revert to alternate law. In alternate law, many of the flight envelope protections, such as angle of attack or “alpha” protection were not available.

The crew then made inappropriate control inputs that destabilized the flight path. At no point did the crew follow established procedures for the loss of displayed airspeed information. The crew was then late in identifying and correcting the deviation from the flight path and lacked an understanding of the approach to stall. This lack of aircraft state awareness resulted in an aerodynamic stall, and the crew did not make any positive inputs—such as pushing forward on the side stick to unload the aircraft aerodynamically—that would have made it possible to recover from the stall. 

In the case of each recent Challenger accident, both aircraft appear to have stalled at altitude and remained in that condition until impact. Furthermore, each of the respective accident reports points to similarities such as instrument source issues, confusion on the flight deck and a deep stall resulting in an LOC-I accident.  

On March 11, 2018, a Turkish-registered Bombardier Challenger 604 lost control in cruise flight and crashed near Shahr-e Kord, Iran, while en route from Sharjah, UAE, to Istanbul, Turkey. According to the accident report, the aircraft was en route in level flight at FL360 when the crew requested a climb to FL380. Climbing through FL377, the aircraft entered a steep descent and hit the ground.

Flight data and cockpit voice recordings reveal many details of the accident flight. During the climb, a disparity between the two primary airspeed indicators developed. The left airspeed indicator was increasing, while the right airspeed indicator was decreasing. This condition generated an “EFIS COMP MON” warning, which relates to a comparator system that monitors critical flight parameters between the captain and copilot's primary flight displays. As the airspeed indication increased on the captain's side, the overspeed aural warning sounded and both throttles were reduced to idle. Soon afterward, the stall warning and stick-pusher activated.

Confusion on the flight deck prevailed. As the stick-pusher nudged the nose of the aircraft, the captain pulled back on the control column since he believed that the aircraft was overspeeding. This action caused the aircraft to enter a deep aerodynamic stall.

The first officer attempted three times to initiate the EFIS COMP MON non-normal checklist, but each time the captain refused. In this nose-high, stalled condition, both engines flamed out and the aircraft hit the terrain below. Eleven people died—three crewmembers and eight passengers.

On May 5, 2019, a U.S.-registered Challenger 601-3A on a charter flight from Las Vegas to Monterrey, Mexico, lost control in flight and crashed near Monclova, Mexico, killing the three crew crewmembers and 10 passengers. The preliminary accident report provides some similarities to the earlier Challenger LOC-I accident.

After departing Las Vegas, the aircraft climbed to an altitude of FL370. One hour and ten minutes later, the aircraft then climbed to FL390. Five minutes later, the aircraft began a climb to FL410. The last ADS-B data point indicated 40,925 feet before contact with ATC was lost. There was no distress call. Aircraft wreckage recovered from the crash site suggests that the aircraft collided with the ground with very little forward motion. 

The inability to recover from an in-flight upset identifies a serious gap in the knowledge, skills, and training required to prevent or recover from these events. To fill these gaps, operators must provide their pilots with formal UPRT that meets or exceeds current regulatory and industry guidance. In the U.S., all airline pilots must complete UPRT by March 2020 through a mandated extended envelope training program. There are no requirements for Part 91, 91K, or 135 pilots to complete a formal UPRT program. 

LOC-I events based on frequency (the top cause of fatalities) and severity (nearly always fatal) are high risk.

The upset event itself and the subsequent “startle effect” is unique; rarely does a pilot flying a transport-category aircraft experience flight outside of an envelope that is loosely defined as 30-degrees of bank (left or right) and +20/-5 degrees of pitch. Likewise, it is unusual for a pilot flying passengers or cargo to experience a load factor greater than 1.5 Gs or a negative G. An in-flight upset will take a pilot well outside of this comfort zone.

To better experience an integrated UPRT program, I recently visited Aviation Performance Solutions (APS) in Mesa, Arizona. In the U.S. there are very few integrated UPRT programs that offer solid academics, on-aircraft, and simulator training.

The APS program combines nearly three decades of experience to align directly with the latest industry and regulatory guidance to create an integrated approach to overcoming LOC-I as the most effective mitigation tool for pilots. A primary goal of the APS training program is to help students retain the necessary skills to recover from an upset long after graduation.    

Once settled in at Mesa, I was paired with APS v-p of flight operations and standards Clark “Otter” McNeace. He would take me through an abbreviated version of APS’s three-day initial course. Students would typically arrive at APS having completed an interactive computer-based academic course. These academics then would be reinforced throughout the program through comprehensive briefings before and after each flight.

McNeace, like all APS instructors, is a full-time UPRT specialist. The instructor's primary job is to teach and provide students with the tools necessary to recover from LOC-I events and explore all-attitude flight profiles. The academics at APS were solid. Pre- and post-flight briefings are facilitated by instructors using simple, but effective desktop diagrams used to explain key aerodynamic concepts.

One concept emphasized at APS is to train students to be comfortable and proficient recovering within the certified envelope of the aircraft that they normally fly. For most transport category pilots that’s +2.5 Gs to -1.0 Gs (clean).

APS uses two different aircraft types for its “on-aircraft” training. Each aircraft type has a very wide operating envelope to provide a substantial safety margin. The initial aircraft used is an Extra 300L since it’s a +/-10 G capable aircraft. Most of the flying in the Extra is by visual reference.

The benefits of on-aircraft training are the ability to explore all attitudes and the effects of negative and higher positive Gs. A simulator cannot demonstrate negative Gs. As McNeace described, to effectively unload an aircraft, often it will require only -0.5 Gs. Excessive negative Gs (out of the seat) make it difficult to control the aircraft and can harm other occupants that are not belted in tightly. During the demos, experiencing negative Gs were certainly a unicorn experience.     

The other “tool” used for on-aircraft training at APS is a Siai-Marchetti S-211 jet trainer. As configured at APS, the S-211 is equipped with a Garmin avionics suite (including SVS) that is representative of a business jet. Likewise, it’s not only jet-powered and swept-winged, but it is also pressurized and air conditioned. The S-211 is certified for +6/-3 Gs and provides a wide margin of safety, making it a great aircraft to explore high-altitude flight at all attitudes.

Additionally, APS uses a simulator in its UPRT program that is configurable to replicate a turboprop twin (King Air), business jet (Citation Mustang), regional turboprop (ATR), or medium airliner (A320). From my experience, the greatest benefit of this device is to further refine skills, but most importantly practice the CRM elements of UPRT. Effective crew coordination is critical to recover from an in-flight upset; this became apparent while reading the aforementioned accident reports.

Earlier this year, while preparing for a pilot report, I spent time in a simulator with another great instructor, Airbus A220 standards and training manager Captain Pierre Francoeur. In a multicrew environment, Francoeur pointed out that it’s critical to first identify and confirm the scenario, whether it’s an upset (nose-high, nose-low) or instrument failure.

As was the case in the accidents outlined above, each event was recoverable by identifying the instrument failure. Airbus’s recommended practice is for the pilot monitoring to help identify the problem and then announce either “upset nose-high recover” or “upset nose-low recover,” whichever is appropriate.

Any pilot attending an integrated UPRT program will not only learn, practice, and become proficient at recovering from a loss of control situation, but most important will become more aware of the aircraft state and learn to prevent a hazardous scenario from developing in the first place. Additionally, a UPRT program provides a pilot with opportunities to improve upon stick-and-rudder skills. LOC-I accidents are all too common. In the past, the industry has focused on mitigating hazards through better training or technology. 

Pilot, safety expert, consultant and aviation journalist - Kipp Lau writes about flight safety and airmanship for AIN. He can be reached at stuart.lau3@gmail.com