Automation in aviation alleviates some of
the workload on pilots and aircrew in operating the aircraft. Automated control systems capable of handling
take-offs and landings can assist aviators during some of the most demanding phases
of flight. Aircraft carrier operations
are some of the most demanding tasks for aviators. Automated take-offs and landings from carrier
decks significantly contribute to reducing the burden on naval aviators. However, the automated system is still a
mechanical and electrical device and subject to failures. A manual control options must still be
present for these contingencies.
The Boeing F/A-18E/F Super Hornet
multi-role fighter aircraft is equipped with the Automated Carrier Landing
System (ACLS). Schrum (2007) writes that
the aircraft flight control computers continuously receive discrete commands from
the aircraft carrier landing system that in turn actuate the aircraft flight
controls in order to establish and maintain an on glideslope / on azimuth
flight profile to touchdown (p. 1). The
shipboard equipment comprising the ACLS is designated the AN/SPN-46(V3). The system consists of a precision tracking
radar, a ship motion sensor, and a high speed general purpose computer (Schrum,
2007, p. 5). Schrum (2007) writes that
the ACLS significantly aids naval aviators in recovering on board the carrier,
particularly when the pilot is stressed and fatigued from long, demanding
missions, when poor weather has developed, or both. The automated system can save lives, preserve
aircraft, and aid in smoother tactical carrier operations (p. 31-32).
Equipment “wear and tear” affects
reliability of ACLS components over time and presents the primary weakness in
the system. Preventative maintenance and
periodic certifications are required to sustain operations (Schrum, 2007, p.
33). Another weakness is that excessive
motion of the carrier in high seas may render the ACLS unable to perform a safe
landing (Schrum, 2007, p. 34).
Established procedures and continuous monitoring of the ACLS by the
pilot, carrier personnel, and aircraft itself are employed to maximize safety
of landings. If any component in this
system determines that a safe approach cannot be made, the pilot expediently
alerted and manual control is asserted (Schrum, 2007, p. 31-32). Schrum (2007) also recommends increased use
of the ACLS to increase proficiency and promotion of a culture accepting of and
recognizing the benefits of automation to increase confidence in the system (p.
43-44).
The Northrop Grumman X-47B Unmanned Combat
Air System (UCAS) is a prototype unmanned aircraft built to test suitability
for aircraft carrier and naval aviation operations. The X-47B operates largely autonomously. Human operators set the aircraft’s
destinations and the UCAS’ control system flies the aircraft to the specified
location (Dillow, 2013). The X-47B
program preceded the planned successor to the ACLS, the Joint Precision
Approach and Landing System (JPALS), and conducted carrier landings using ACLS
(Freedberg, 2014). The UCAS uses three
navigation computers for redundancy and to check each other for anomalies. During one of the landing trials, the control
system detected a fault, aborted the UCAS’ approach, flew a holding pattern
over the carrier, informed the human operators, and awaited further
instructions. The controllers ultimately
directed the aircraft to divert to a land base for recovery (Hillis,
2013). Dillow (2013) writes that the
aircraft never makes a decision itself that operators haven't preprogrammed it
to make, so the humans always know exactly what it is doing and always maintain
the power to change what it is doing.
Although the X-47B was never intended for operational service,
cybersecurity is a vulnerability for successors, such as the planned Unmanned
Carrier-Launched Airborne Surveillance and Strike (UCLASS) aircraft. The command, control, and communication (C3)
links for an unmanned combat aircraft must be secure and robust to ensure
control over the platform (Dillow, 2013).
The level of automation in the X-47B during
take-off and landing is appropriate for these delicate phases of flight. Latency in C3 links means that, during manual
remote control, there is a slight delay in a pilot’s control inputs and the
aircraft’s response. Given the
importance of accurate, timely corrections in carrier landings and take-offs, a
lag in control response would be very difficult to deal with (X-47B Historic
Drone Carrier Landing, 2013). However,
in the event of a complete failure of the redundant navigation computers and a
lack of divert bases on shore, a backup manual control system must be
available. Mounting this system on the
ship would reduce the latency in the C3 link as much as possible.
The advances in automation systems will
make aircraft carrier take-offs and landings easier for manned and unmanned
aircraft. However, automation systems
are still mechanical and electrical devices that can fail. A manual control system must be available for
these contingencies and humans must maintain the skills to effective use these
controls.
Dillow, C. (2013, July 5). What the X-47B Reveals About the Future of
Autonomous Flight. Popular Science. Retrieved from http://www.popsci.com/technology/article/2013-05/five-things-you-need-know-about-x-47b-and-coming-era-autonomous-flight
Freedberg Jr, S. (2014, August 17). X-47B Drone & Manned F-18 Take Off &
Land Together In
Historic Test. Breaking Defense. Retrieved
from http://breakingdefense.com/2014/08/ x-47b-drone-manned-f-18-take-off-land-together-in-historic-test/
Hillis, A. (2013, July 12). UCAS Carrier Landing Divert a Window Into Its
Automation.
Aviation Week. Retrieved from http://aviationweek.com/blog/ucas-carrier-landing-divert-window-its-automation
Schrum, B. (2007).
F/A-18A-D Hornet Current and Future
Utilization of Mode I Automatic
Carrier Landings
(Masters Dissertation). Retrieved from http://trace.tennessee.edu/
cgi/viewcontent.cgi?article=1356&context=utk_gradthes
X-47B Historic Drone Carrier Landing
[Video File]. Retrieved from
https://www.youtube.com/watch?v=kw3m7bqrQ64
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