Peer Review On Aviation
· Read and reply to at least two of your classmates’ postings and a peer review at least 300 words per review.
Peer review #1
Flight 1549 will forever be remembered as the “Miracle on the Hudson” (Atkins, 2010). On January 15th, 2009, an A320 landed in New York’s Hudson River due to a dual engine failure caused by geese. Captain Sullenberger and the flight crew’s rapid and accurate responses led to zero injuries and an undamaged airframe (Atkins). Flight 1549 is a great example to explore on a deeper basis for the future of autonomy.
The Airbus A320 utilized on Flight 1549 had numerous autonomous controls, such as autopilot and autothrottle but nothing capable of calculating a safe emergency landing. Although the aircraft was equipped with an advanced avionics systems, it reverted to the pilot making the crucial decision of how to safely proceed (Atkins, 2010). The avionics system knew all the critical information, such as terrain, airspeed, obstacles, wind, and airport coordinates but could not autonomously land safely at an airport (Langewiesche, 2009). With all this data in hand, the system’s job was to simply provide input to the pilot, leaving the pilot to output the critical decision of where to land.
Although Flight 1549 was not equipped with a system that could safely emergency land autonomously, Atkins describes an adaptive flight planning automation aid with the potential to identify emergency landing plans in under a second. Additionally, this system would communicate efficiently the plan and state of aircraft to Air Traffic Control (Atkins, 2009). As technology grows and the demand for autonomous systems increases, more learning will come. In order for unmanned aerial systems (UAS) to safely integrate into the National Airspace, many scenarios, some of which can not even be imagined at the moment, will need to be thought of and incorporated into the design.
In the case of Flight 1549, Captain Sullenberger and his flight crew brought expertise and composure to a situation that could have led to potential fatalities. In manned aircraft, pilots bring senses, gut feelings, and most importantly prior knowledge to the operation. An autonomous system relies solely on input from the other aircraft systems. In a UAS, if these other systems were to fail it could lead to potential fatalities. On the other hand, Flight 1549 could have had a very different ending if another pilot and crew were on board. Unmanned and manned each have their advantages and disadvantages. In the end, the best thing that can be done is to learn from one another and work to improve.
Atkins, E.Emergency landing automation aids: An evaluation inspired by US airways flight 1549. (2010) doi:10.2514/6.2010-3381
W. Langewiesche, Fly by Wire: The Geese, the Glide, the Miracle on the Hudson, Farrar, Staus, and Giroux, New York, 2009.
Peer Review #2
There are many examples in aviation history of pilot intervention averting catastrophe, but the most timely and profound is the “miracle on the Hudson.” The miracle was the skill, experience, calmly executed, and perfect judgment of Captain Chesley “Sully” Sullenberger, aboard the A320. The A320 is a “fly-by-wire” airplane, which means that pilot control inputs on the side-sticks are processed by flight control computers that then send electrical signals to the hydraulic actuators that move the pitch and roll flight control surfaces – the pilots do not directly control the plane’s movement. The A320 fly-by-wire design incorporates flight envelope protections; the flight computers are designed to prevent exceedance of the safe flight envelope in the pitch-and-roll axes when in “normal law,” which is the normal operating mode of the airplane’s electronic flight control system (NTSB, 2009). Normal law is one of three sets of control laws (the other two control laws are “alternate law” and “direct law”), which are provided according to the status of the computers, peripherals, and hydraulic generation. The airplane cannot be stalled in normal law. According to the Airbus Flight Crew Training Manual, control law is the “relationship between the pilot’s input on the side-stick, and the aircraft’s response,” which determines the handling characteristics of the aircraft (NTSB, 2009).
Automation, however, does not eliminate errors. Rather, it changes the nature of the errors that are made, and it makes possible new kinds of errors. The paradox of cockpit automation is that it can lower the pilot’s workload in phases of flight when the workload is already low, and it can increase the workload when the workload is already high. What automation does not account for, however, is human delay – recognizing and diagnosing the problem, weighing possible remedial options, and ultimately selecting a plan of action. Humans’ mental state, fatigue, stress, or other internal factors also influence their decision-making process; this is what humans bring into the situation (Wachter, 2015). In a series of emergency simulations run after the incident from Airbus’s headquarters in Toulouse, France, test pilots were able to safely land the aircraft at La Guardia airport if they initiated their approach immediately. The NTSB, however, ultimately rejected these simulations as reflections on Captain Sullenberger’s performance by noting that they failed to “account for real-world considerations such as time delay between the human crew’s perception and reaction (Sandberg, 2016).
As the integration of UAS into the NAS becomes as reality, automation will continue to evolve along with it, however, I believe humans will continue to play an integral role in their operation – even if that means passively monitoring systems and intervening whenever deemed appropriately. While automation may be reliable and alleviate workload, there are still cases where it may experience failure – that is when humans will need to intervene.
NTSB. (2009). Loss of Thrust in Both Engines After Encountering a Flock of Birds and Subsequent Ditching on the Hudson River US Airways Flight 1549. Retrieved from https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR1003.pdf
Sandberg. (2016). Automation algorithms could provide safe landings for disabled aircraft. Michigan Engineering. Retrieved from https://news.engin.umich.edu/2016/09/automation-algorithms-safe-landings
Wachter, B. (2015). My Interview with Capt. Sully Sullenberger: On Aviation, Medicine, and Technology. Retrieved from https://thehospitalleader.org/my-interview-with-capt-sully- sullenberger-on-aviation-medicine-and-technology/