The
Northrop Grumman RQ-4 Global Hawk is a high altitude long endurance (HALE) Intelligence
Reconnaissance Surveillance (ISR) unmanned aerial vehicle (UAV) that was
designed as a potential replacement to the manned version; the U-2 Dragon Lady. The RQ-4 flies at an altitude of
approximately 60,000 feet for more than 32 hours at about 340 knots (Quick, 2009).
The newest version block 40 is equipped with a more advanced
Multi-Platform Radar Technology insertion Program (MP-RTIP) that permits almost
all weather, day or night fully autonomous UAV (Keller,
2012). The original design of
this system was to have it operate completely automated throughout all phases
(start, taxi, takeoff, enroute, landing, taxi and shutdown) of its flight via
the automation software. However
following its inception into the Air Forces inventory, the ability to
manipulate the flight plan was added. A
typical RQ-4 flight consists of two major elements; the Launch Recovery Element
(LRE) and the Mission Control Element (MCE) teams ("Rq-4
global hawk," ). Both of
these teams consist of fully trained and qualified RQ-4 pilots that must
maintain currencies on annual bases, similar to pilots of manned aircraft. The purpose of the LRE is to assist during the
start, taxi, takeoff and landing phases of flight, while the MCE is in charge
of piloting the aircraft ("Rq-4 global
hawk," ). Since the RQ-4 is
designed to be completely automated, it does not have the traditional manual
mode. Rather any alterations required to
the flight path are accomplished through the computer software controlled by
the MCE (Quick, 2009). During the takeoff and landing phase, the LRE
team monitors the flight path and works with the MCE to as needed. Although the route can be altered in flight,
this is not normally practiced as it will alter the sensors targeting
priorities. The landing gear is
retracted automatically once passed 400 feet and again extended automatically
upon approach. In the event the aircraft
loses link, is unresponsive or becomes a possible hazard, the MCE crew is
capable of initiating a self-destruct command.
Once initiated by the flight crew, the system will confirm this command
then execute a vertical stall to pancake into the terrain at approximately the
same location as it was initiated. With
the inability to manipulated the aircraft by conventional means (sick, pedals
and throttles), pilots are limited in their ability to control the aircraft in
a timely manner during the critical phases of flight. This can potentially lead to a safety
incident or accident. This also becomes
a bigger factor as the RQ-4 is further integrated within the evolving National
Airspace System. My recommendation is to
modify the MCE ground control station and aircraft software to permit a more
tactile control.
In
regards to automated takeoff and landing systems on manned aircraft the most
common systems available exist on commercial aircraft. In fact most of the aircraft flying today by
the airlines is fully automated. However
for the purpose of this discussion, the Boeing-777 (B-777) automated system
will be discussed. The B-777 is capable
of landing in zero feet visibility and zero feet cloud deck height safely while
on autopilot; however the minimum altitude in which the aircraft will be flown
in bad weather may vary and in most cases is restricted to 200 feet or higher (Lim, 2008). The
success of this system is made possible do the auto pilot software (autopilot
and flight director system) combined with additional onboard sensors and global
positioning satellites (GPS) that give a constant update to the current
location, altitude, airspeed, etc. Although
the landing phase is automated, the pilot is still required to intervene in
order to reduce speeds as the flaps are selected (Lim,
2008). As the aircraft approached
the threshold of the runway, the automatic system will transition the aircraft
to a landing position (flare), calling out the altitude every 10 feet and
finally at 25 feet above the ground will retard the throttles to the aft or min
position (Lim, 2008). Once on the ground and slowing the automated
system will initiate the auto brakes combined with the pilot’s use of the
reverse thrusters as needed. This
aircraft is also capable of an automated takeoff in which the aircraft will
adjust the throttles to optimal limits, rotate the aircraft at the appropriate
rotational speed and retract the gear once airborne and clear of the runway
environment. Ultimately pilots are responsible
for the constant monitoring of the aircrafts system and instruments and if
needed (from system failure, not operating as intended, etc.) the pilot will
execute an “auto-pilot disengage switch” then manually fly the aircraft. Training in using this system is maintained
as part of the pilot’s annual proficiency.
In regards to safety, recent studies have shown that the transition from
actively flying to monitoring of aircraft systems have caused a deficiency in
flying skills. This is can lead to a
dangerous situation during the critical phases of flight ("Routine hands-on procedures," 2014). In addition, the constant monotony in
monitoring of systems has shown to increase the likelihood of pilot
fatigue. A perfect example of this was
in the 2013 Asian Airlines accident in which the pilot was unable to hand-fly
the B-777 for a landing. My recommendation
is that all pilots are required to fly so many takeoffs and landings per month
manually and that all evaluations check-rides are performed manually.
Reference:
Keller, J. (2012, March 08). Northrop Grumman and Raytheon to
demonstrate MP-RTIP radar system on global hawk block 40 UAV. Retrieved
from http://www.militaryaerospace.com/articles/2012/03/northrop-grumman-and-raytheon-to-demonstrate-mp-rtip-radar-system-on-global-hawk-block-40-uav.html
Lim. (2008, January 07). Executing
a auto landing in a real Boeing 777 as compared to one is a fs 2002..
Retrieved from http://www.askcaptainlim.com/-flight-simulator-pilot-46/636-executing-a-auto-landing-in-a-real-boeing-777-as-compared-to-one-in-a-fs-2002.html
Quick, D. (2009, December 10). Next-gen global hawk hale UAS
completes its first flight. Retrieved from http://www.gizmag.com/block-40-global-hawk-flight/13572/
Routine hands-on procedures will make flights safer. (2014,
January 14). Daily Press.
Retrieved from http://articles.dailypress.com/2014-01-14/news/dp-nws-oped-loh-0115-20140114_1_pilot-fatigue-new-pilots-airline-pilots
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