Case Analysis Tool Effectiveness

The work carried out over these weeks provided me with a broad overview of the human factors issues relating to unmanned aircraft systems. This case analysis provides me a systematic approach to narrow down to a significant topic that is worth discussing. In addition, the peer reviews helped in significant ways to provide different perspective at times and can help to enhance the content and focus of the topic through the various related issues and their alternative solutions. With my capstone project nearing, this tool will provide a foundation to be able to build a justifiable case for the project, which will most likely be related to UAS.

In terms of career, I anticipate and am confident that UAS will eventually be a common sight as the cars we see on the roads today. The technology will certainly proliferate further to create new directly and indirectly related jobs and responsibilities for this sunrise industry, along with its associated issues and problems as it matures. This case analysis approach will in many ways contribute to such future scenario for the betterment of future research studies by aiding how these problems are to be approached, and why certain solutions are necessary for stakeholders, which can be done in a concise, objective and holistic manner. In my area of work, I do occasionally have some time to engage in research to address practical issues related to common engineering problems, including those of unmanned systems. 

Where the topics of discussions are concerned, there was quite a lot of interaction with every student proposing ideas and solutions within the same topic. There are numerous learning points in the midst of these discussions and the activities promote the eventual narrowing down of the discussion to several interesting and main coherent thoughts as well as differing ideas. Finally, the human factors involved in UAS today might be better represented by producing a mind-map that collates related issues, designs, mitigation and future research to aid in depict all discussion points into one overall picture to make it more interesting and promote knowledge sharing (Zipp, Maher, & D’Antoni, 2015). 

Reference

Zipp, G. P., Maher, C., & D'Antoni, A. V. (2015). Mind mapping: Teaching and learning strategy for physical therapy curricula. Journal of Physical Therapy Education, 29(1), 43.

 

Operational Risk Management

Introduction
The integration process of unmanned aircraft systems (UAS) into the national airspace system (NAS) has been occasionally hampered by incidents and accidents around the world, indicating that more work needs to be done to ensure operational safety. The risks associated with the operation of UAS are real and has to be properly managed. The Raven RQ-11 is a small lightweight unmanned aircraft system (sUAS), designed for rapid deployment and high mobility for both military and commercial applications (Aerovironment, 2016). Being unmanned, the aircraft can be used for conducting intelligence, surveillance and reconnaissance missions over hostile areas without being too intrusive with the aid of video sensors (Aerovironment, 2016). It is capable of autonomous and manual operation and can be conveniently launched by hand without any need for prepared take-off and landing strip.

For any UAS operation, it is good to perform risks assessments to provide the UAS operator a straightforward idea of what to expect before deciding and committing to the actual operation, and allow safety and management of real-time information needed to continually review and monitor operational safety (Barnhart, 2012). The operational risk management is a decision-making tool to systematically help identify operational risks and benefits and determine which course of action are suitable to be taken for any given situation (FAA, 2000).
 

Preliminary Hazard List/Analysis (PHL/A)
According to FAA (2000), a hazard is “any real or potential condition that can cause degradation, injury, illness, death or damage to or loss of equipment or property. For the preliminary hazard analysis, several hazards have been identified during the flight stage as shown in Table 1 under appendix, which is based on the template from Barnhart (2012, p. 125). Other operational stage can also be prepared separately. Hazards for planning stage can include tall trees and mountains, electrical cables, rough terrain for landing, etc. Staging hazards can include electrical shocks during set-up and launch stage hazards can include engine failure, personnel injury during hand launching. The risk level is based on MIL-STD-882D/E in the appendix section of Barnhart (2012). The higher the number for risk level, the lower the risk.
 

Operational Hazard Review and Analysis
According to FAA (2000), risk is defined as probability and severity of accident or loss from exposure to hazards. In order to have continuous evaluation of hazards and provide the feedback necessary to determine the effectiveness of the mitigating actions, an operational hazard review and analysis (OHR&A) is to be performed after PHL/A. According to Barnhart (2012), the main difference between PHL/A and OHR&A is in the action review column, as shown in Table 2 under appendix section. A review is to be carried out on the mitigating actions and annotated in the review to indicate their effectiveness to lower risks.
 

Operational Risk Management Worksheet
Table 3 in appendix shows the operational risk assessment worksheet is meant to be a decision-making tool as discussed previously to ascertain the GO/NO GO status of the UAS flight. The worksheet can be filled up by crew members prior to flight. Left column of the matrix shows the conditions for evaluation and points are allocated to each condition status. Once the form is filled, the total of the scores will determine the risk levels of the mission. The higher the score, the higher the risk. Depending on the risk score and what the mission entails, the approver will endorse on the worksheet to indicate that the risk assessment was carried out with due diligence and sound supervision.
 

Conclusion
Operational risk management is a useful tool to evaluate the risks involved in Raven RQ-11 operations. Based on recommendations from FAA in the ORM 6-step process, there is a need to capture lessons learnt for both positive and negative ones so that they may be part of similar future ORMs. There is no one-size-fits-all approach in ORM and the methods for risk management are dependent on individual methods and experience levels (FAA, 2000).

References
Aerovironment (2016). Raven RQ-11 A/B. Retrieved from http://www.avinc.com/images/uploads/product_docs/Raven_Datasheet_v1.1.pdf

Barnhart, R. K. (2012). Introduction to unmanned aircraft systems. Boca Raton: Taylor & Francis.

FAA (2000). FAA System Safety Handbook, Chapter 15: Operational Risk Management. Retrieved from https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/risk_management/ss_handbook/media/Chap15_1200.pdf

Automatic Takeoff and Landing

Introduction
Automatic take-off and landing systems have been in existent for many years and their usefulness have been well documented since the introduction of this technology. There are three main phases in a typical automatic flight system. They are take-off, navigation and landing with each of them using different control laws and methods (Stojcsics & Molnar, 2013). Automated systems are used to relieve the workload of pilots, especially during critical phases of flights such as take-off and landing. Approximately 50% of all UAS accidents are attributed to human factors, with a significant portion occurring in the landing phase because of the difficulty to control the UAS under adverse weather conditions with limited situational awareness (You et al, 2012).

Automation in manned and unmanned aircraft take-off and landing
The total reliance on automation in both manned and unmanned aircraft has been widely debated. A classic example where an automated system might not be able to perform better than humans is the case of the Hudson River landing of US Airways Flight 1549 in 2009 where the pilot thought out of the box and chose to land on water, saving everyone on board the aircraft. However, if this was the case of an unmanned aircraft, having a remote human intervention might not be the best way to offset the rigidity of automation (Atkins, 2012). Automatic take-off and landing technology in both manned and unmanned aircraft systems are quite similar in a way that both systems largely make use of global positioning system (GPS) and the instrument landing system (ILS) for landing. In manned aircraft, automation has reduced cockpit flight crew from five to just pilot and co-pilot today, whose jobs are also significantly simplified.
 
Boeing 737
According to Richards (2012), most manned commercial aircraft pilots still prefer to manually perform take-off and landing, despite knowing that the automatic system available onboard is fully capable of such tasks. The Boeing 737 has two-autopilot, fail-passive system capable of category IIIA operations (Cohen et al., 1995). As like most other aircraft systems, the autopilot has redundancies incorporated to mitigate the risks of any system failure. Boeing 737 is able to have automatic flight by making use of its auto-throttle system that automatically varies the engine power from start-up to take-off through climb, cruise, descent and landing using avionics such as its flight control computer and flight management computer. However, the automatic flight can also be disengaged when certain events take place, such as loss of electrical or hydraulic power, inertia reference system failure, or the manual override activation by pilot using the autopilot disengage switch (Smartcockpit.com, n.d.). In this way, there is always an avenue for the flight crew to manually control the aircraft when necessary.
 
Global Hawk
The Global Hawk is a fully autonomous UAS which has the capability to automatically take-off and land without human intervention. The aircraft will follow a computer controlled flight plan throughout its flight unless there is a need for manual override due to system malfunction or any other emergencies. Since it is a high altitude and long endurance (HALE) UAS, it makes sense to automate the take-offs and landings due to the known data-link control latency present in any long range operations. The aircraft performs its autonomous take-offs and landings using its ground based launch and recovery element (LRE). The precise altitude and speed information is provided by high precision GPS for flight control. Within the aircraft, it has an inertia navigation unit which augments the GPS for automatic point to point navigation (Lee, 2009). The Global Hawk ‘pings’ the ground stations to maintain communications. If it determines that communication is lost, it will go into some form of self-diagnostic mode, using a back-up radio, checking circuit breakers, and finally flying itself through a serious of known waypoints to land itself with GPS and radar if all else fails (Ross, 2011).
   
According to You et al. (2012), most of today’s UAS incorporate level 2 automation where attitude stabilization and guided navigation technology are good enough. However, the Defense Advanced Research Projects Agency (DARPA) has recommended to have all future UASs use level 3 automation where the conventional workload on pilots such as take-off, landing, reconnaissance, ground attack missions can be reduced to allow pilots to concentrate on higher priority tasks (as cited in You et al., 2012, p. 1).
 
Recommendation and Conclusion
Having automation capabilities for all flight phases of both manned and unmanned aircraft systems has many advantages. The level of automation required for each of these systems will depend on their roles and mission requirements. In manned aircraft, appropriate automation has been proven to reduce the workload of pilots, but at the same time, it can also lead to complacency and skill erosion (Drappier, 2012). For unmanned aircraft, automation has been reported to have led to boredom and degraded vigilance while reducing workload (Cummings, Gao, & Thornburg, 2016).

In conclusion, there is always a need for a human to have oversight over the incorporated autonomous system regardless of automation levels and to intervene when required. This is because it is practically impossible for any designer to anticipate all scenarios encountered by the aircraft such as unexpected traffic, onboard system failures, or any erroneous and conflicted data, and cater accurate counteractions during the aircraft design phase. There will still be conditions that will render such automatic systems inappropriate.

References
Akins, E.M. (2012). Certifiable autonomous flight management for unmanned aircraft systems. The Bridge on Frontiers of Engineering, 40(4), 35-43. Retrieved from https://www.nae.edu/Publications/Bridge/37526/37584.aspx

Cohen, C. E., Cobb, H. S., Lawrence, D. G., Pervan, B. S., Powell, J. D., Parkinson, B. W.. . SWIDER, R. J. (1995). Autolanding a 737 using GPS integrity beacons. Navigation, 42(3), 466-486. doi:10.1002/j.2161-4296.1995.tb01901.x

Cummings, M. L., Gao, F., & Thornburg, K. M. (2016). Boredom in the workplace: A new look at an old problem. Human Factors, 58(2), 279. doi:10.1177/0018720815609503

Drappier, J. (2012). The erosion of manual flying skills. Retrieved from http://halldale.com/files/halldale/attachments/Drappier_0.pdf

Lee, T.W. (2009). Military technologies of the world. Westport : Praeger Security International.

Ross, P.E. (2011, November 29). When will we have unmanned commercial airliners? Retrieved from http://spectrum.ieee.org/aerospace/aviation/when-will-we-have-unmanned-commercial-airliners

Richard, J. (2012, November 2). How often are commercial flights landed using autopilot?  Retrieved from https://www.quora.com/How-often-are-commercial-flights-landed-using-autopilot

Stojcsics, D., & Molnár, A. (2014). Autonomous Takeoff and Landing Control for Small Size Unmanned Aerial Vehicles. Computing and Informatics, 32(6). Retrieved from http://www.cai.sk/ojs/index.php/cai/article/view/992/609

Smartcockpit.com (n.d.). Boeing 737 systems review: Automatic flight. Retrieved from http://www.smartcockpit.com/docs/B737-Automatic_Flight_Systems_Summary.pdf

You, D. I., Jung, Y. D., Cho, S. W., Shin, H. M., Lee, S. H., & Shim, D. H.A guidance and control law design for precision automatic take-off and landing of fixed-wing UAVs. AIAA Guidance, Navigation and Control Conference. () doi:10.2514/6.2012-4674

Shift Work Schedule

Introduction
Due to the need to provide non-stop continuous armed, intelligence, surveillance and reconnaissance (ISR) functions in conflict zone operations, the squadron operating the MQ-1B medium altitude, long endurance (MALE) UASs has to implement shift work for its UAS crews. However, it has been well documented that shift work often lead to human factor health concerns such as sleep loss, circadian disruption and subsequent fatigue, accompanied by degraded job performance and increased risk for human errors (Thompson, 2006). UAS pilots have been reported to work an average of 900 hours a year, compared to only 250 hours a year for manned fighter aircraft pilots (Hennigan, 2015). Therefore, there is a need to design good shift systems for UAS crews to minimize the adverse associated human factors effects such as fatigue, stress and other sleep disorders.
 
Existing shift work schedule and its issues
The UAS squadron’s existing shift work schedule is supported by 4 teams of UAS crews that work continuously for six days in a single shift followed by two days off as shown in Table 1 below. The shifts for each team follow a clockwise (forward) rotating cycle from day to swing and then to night shift. Unfortunately, extreme fatigue with complaints of inadequate sleep has been reported by the crew operating according to the schedule. The continuous 6 nights of work is detrimental to the well-being of crews. Sallinen and Kecklund (2010) reported that severe sleepiness in night shifts was due to the daytime oriented circadian rhythm of alertness that made sleeping or resting difficult and also hard to stay alert at night, and that 28% of night shift workers involuntarily dozed off and slept during 40 minutes of the shift. The rotation from day, evening and night shifts forces the crew to adjust their body functions to duty periods which can result in a progressive phase shift of circadian rhythms across the successive night shifts (Costa, 2003). In addition, working 6 or more consecutive shifts and more than 35 hours per week has been found to aggravate complaints of awakening and a higher need to recovery (Van de Ven et al., 2016). The current shift system requires the crew to work approximately 51 hours per week on 6 consecutive days on a single shift. Thus it is much longer than a typical U.S. worker work week of 34.4 hours (Snyder & Jones, 2015). However, Viitasalo et al. asserted that this 3-shifts forward rotating schedule is still better than backward rotating ones (as cited in Sallinen and Keckund, 2010, p. 130).

Table 1
Existing squadron shift schedule

Recommended shift work schedule and its benefits
Based on the report by Kundi (2010), there should not be more than three night shifts in a row for a good shift schedule. In another separate article by Burgess (2007), it is recommended that 3 day shifts, 3 evening shifts (swing), 3 night shifts, and 3 recuperating days off be implemented to have 24/7 coverage of duties. It was also asserted that 8-hour, clockwise rotating shifts are preferred. The recommended shift schedule, as shown in Table 2 below, features a 3-shift clockwise (forward) rotating shift system that provides coverage for daily 24/7 operations. Each team is only required to work in a single shift for consecutive 3 days in a clockwise (forward) rotating manner. Although the total number of working hours per week is about the same as the existing schedule, and every team has to work 9 consecutive days before getting a break, the new schedule allows the much needed rest of 3 days after every 3 consecutive night shifts.

Table 2
Recommended new shift schedule

   

Conclusion
It remains an important focus to continue to design effective shift systems for UAS crews that requires 24/7 operations to mitigate any negative human factor issues during work. The recommended new schedule provides the necessary operational coverage with the same number of crew and working hours. However, it provides the added benefit of allowing adequate crew rest after consecutive night shifts to reduce fatigue and prevent other problems from any disruption of human circadian rhythm. It is assumed during design that UAS crews are relatively young and the crew numbers are fixed. However, these are also valid considerations when designing shift work schedules for other organizations with a more dynamic workforce age and manning numbers.

References
Burgess, P. A. (2007). Optimal Shift Duration and Sequence: Recommended Approach for Short-Term Emergency Response Activations for Public Health and Emergency Management. American Journal of Public Health, 97(Suppl 1), S88–S92. http://doi.org/10.2105/AJPH.2005.078782

Costa, G. (2003). Shift work and occupational medicine: an overview. Occupational medicine, 53(2), 83-88.

Hennigan, W.J. (2015, November 9). Air Force struggles to add drone pilots and address fatigue and stress. Los Angeles Times. Retrieved from http://www.latimes.com/nation/la-na-drone-pilot-crisis-20151109-story.html

Kundi, M. (2003). Ergonomic criteria for the evaluation of shift schedules. Theoretical Issues in Ergonomics Science, 4(3), 302-318. doi:10.1080/14639220210158907

Sallinen, M., & Kecklund, G. (2010). Shift work, sleep, and sleepiness — differences between shift schedules and systems. Scandinavian Journal of Work, Environment & Health, 36(2), 121-133. doi:10.5271/sjweh.2900

Snyder, B., & Jones, S. (2015, November 11). Americans work hard, but people in these 15 countries work longer hours. Fortune. Retrieved from http://fortune.com/2015/11/11/chart-work-week-oecd/

Thompson, W. T., Lopez, N., Hickey, P., DaLuz, C., Caldwell, J. L., Tvaryanas, A. P., & HUMAN SYSTEMS WING (311TH) BROOKS AFB TX. (2006). Effects of shift work and sustained operations: Operator performance in remotely piloted aircraft (OP-REPAIR)

Van de Ven, Hardy A, Brouwer, S., Koolhaas, W., Goudswaard, A., de Looze, M. P., Kecklund, G.. . van der Klink, Jac J.L. (2016). Associations between shift schedule characteristics with sleep, need for recovery, health and performance measures for regular (semi-)continuous 3-shift systems. Applied Ergonomics, 56, 203-212. doi:10.1016/j.apergo.2016.04.004

UAS Beyond Line of Sight Operations

Introduction
The RQ-4 Global Hawk is a high altitude, long endurance (HALE) and fully autonomous unmanned aircraft system (UAS) that is optimized to support intelligence, surveillance and reconnaissance (ISR) missions. Equipped with multi-intelligence payload, it is commonly used by the military to collect essential imagery and intelligence data for war theatre commanders in order to support ground units (USAF, 2014). At the same time, it incorporates capabilities that are ideal for meteorological applications. The prime contractor for this UAS is Northrop Grumman Corporation and various developments of Global Hawk systems have evolved over the years that feed a block build approach (Kinzig & Brown, 2010).
 
System Infrastructure and Sensors
The Global Hawk UAS comprises the unmanned aircraft, sensor payloads, communications data links, launch and recovery element (LRE), mission control element (MCE), support element and trained personnel to operate the UAS. The MCE includes a shelter measuring 8ftx8ftx24ft and provides the management of aircraft and its sensors. The element has personnel that provide command and control, mission planning, imagery quality control, and communication functions with data up-and-down links to the UA directly and via Ku satellite and UHF satellite systems. The LRE is housed in an 8ftx8ftx10ft shelter and handles the loading of the autonomous flight mission plan into the UA and monitoring the operation of the aircraft during its take-offs and landings (Northrop Grumman, n.d.). By having separable elements, the MCE and LRE can be operated in different geographical locations, with the MCE deployable with the supported command’s primary exploitation site (Gatlin, 2003). The UAS is able to utilize direct line of sight (LOS) communications with the ground station via a common data link as well as a beyond line of sight (BLOS) communication channel using Ku band satellite communication (SATCOM). The integrated sensor suite on board the Global Hawk includes an X-band synthetic aperture radar, electro-optical and infrared sensor system that is able to provide wide area search coverage of 40,000 square nautical miles a day (Airforce-technology, n.d.).

Benefits and Challenges
According to Northrop Grumman (2012), the deployed crew for the Global Hawk is significantly smaller than other UASs due to its unmanned capabilities, mission and flight management system and technical sophistication of the system. Once the mission parameters are entered into the Global Hawk, it has the ability to taxi, take off, fly the mission, and land autonomously. As the name of the UAS implies, Global Hawks, with its LOS and BLOS control capabilities, are well suited to be deployed anywhere globally due to its high endurance capability. At the same time, its ability to operate at altitudes above 60,000 feet ensures its survivability in hostile airspace (Airforce-technology, n.d.).
Naftel (2011) highlighted that mission planning for unmanned aircraft is more laborious compared to mission planning for manned aircraft. In the case of Global Hawk, it is required for the whole team to develop procedures covering pre-flight, flight, and post-flight, along with mission rehearsals and simulations prior to actual flight (Naftel, 2011). As reported by Rogoway (2014), Global Hawk struggles to keep up with the 55-year old Lockheed U2 in that it cannot fly through bad weather. Global Hawk lacks deicing and lightning protection and the on-board weather and optics equipment cannot see a storm ahead of its flight path. Therefore, certain adverse weather missions are restricted. At the same time, the Global Hawk lacks the ability to operate in dense airspace without prior intensive preparation since there is no pilot on board to integrate civilian traffic with its own.

There are also challenges that need to be addressed when using communication links over long distances. The transmission of radio signals and its associated processing will introduce latencies such as time delays between pilot control inputs, aircraft response execution, and the display of the responses to ground operators. Such latencies will be more obvious when the link is via a geostationary satellite. At the same time, there can also be voice latencies when Global Hawks are used to relay voice communications between UA and ATC. Therefore, operators have to be aware of these limitations and ensure that communications do not reach a level that is disruptive to safe operations.
The system must also cater for any lost links and if such event occurs, the UA must be capable enough to continue flight in accordance with any expected contingencies programmed in the Global Hawk such as link reacquisition and flight terminations. With the highly automated Global Hawk, there is also a challenge for operators to remain vigilant during its operation. Even though Global Hawks can be operated with full autonomy, operators are still able to inject any command to the UA in case of any need for diversion due to weather or other unforeseen circumstances. As such, good situational awareness of operators during the prolonged hours of Global Hawk flights is important.
 
Applications
There are many uses of the Global Hawk UAS today. They have been used to support humanitarian efforts including California wildfires, hurricane Ike, Haiti earthquakes and the tsunami in Japan (NAGSMA, 2011). NASA had previously used Global Hawks for hurricane research, examining greenhouse effects and conducting autonomous aerial refueling trials. The most recent application by NASA was to use it to study severe El Nino weather over the Pacific Ocean (Northrop Grumman, 2016). With the ability to fly at ceilings of 65,000 feet for 30 hours, the NASA Global Hawk enables meteorological entities to study intense and remote weather conditions and major floods that were previously unreachable.
 
Conclusion
Global Hawk is a valuable asset to any organization that utilizes it for both LOS and BLOS operations. Similar to other HALE UASs, there will be continued challenges for its BLOS usage due to inherent issues of communication latencies and sustained crew situational awareness during highly automated phases of operations. However, while many of the world’s aviation authorities are resolving the numerous issues regarding the integration of UAS into the national airspace system, Global Hawks in the meantime can be regarded as an ongoing research and development investment rather than just an operational aircraft. It still remains the most advanced known HALE unmanned aircraft system capable of BLOS operation anywhere in the world (Rogoway, 2014).

References
Airforce-technology (n.d.). RQ-4A/B Global Hawk HALE reconnaissance UAV, United States of America. Retrieved from http://www.airforce-technology.com/projects/rq4-global-hawk-uav/

Gatlin, A. (2003). The Global Hawk. Retrieved from http://www.456fis.org/GLOBAL_HAWK.htm

Kinzig, B., & MacAulay-Brown (2010). Global Hawk systems engineering case study. Retrieved from http://www.lboro.ac.uk/media/wwwlboroacuk/content/systems-net/downloads/pdfs/GLOBAL%20HAWK%20SYSTEMS%20ENGINEERING%20CASE%20STUDY.pdf

Naftel, J. C. (2011). NASA global hawk: Project overview and future plans. Retrieved from http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110011985.pdf

NAGSMA (2011, March 28). Press release from external sources, Northrop Grumman submits final proposal for NATO alliance ground surveillance. Retrieved from http://www.nagsma.nato.int/news/Lists/Press%20Releases/DispForm.aspx?ID=7

Northrop Grumman (n.d.). RQ-4 Global Hawk maritime demonstration system. Retrieved from http://www.northropgrumman.com /Capabilities/RQ4Block10GlobalHawk/Documents/GHMD-New-Brochure.pdf

Northrop Grumman (2016, February 5). NASA Global Hawk studies severe El Nino weather over the Pacific Ocean. Globe NewsWire. Retrieved from https://globenewswire.com/news-release/2016/02/05/808255/10159833/en/NASA-Global-Hawk-Studies-Severe-El-Nino-Weather-over-the-Pacific-Ocean.html

Q4 HALE enterprise. (2012). Northrop Grumman Systems Corporation. Retrieved from http://www.northropgrumman.com/Capabilities/GlobalHawk/Documents/Brochure_Q4_HALE_Enterprise.pdf

Rogoway, T. (2014). Why the USAF’s massive $10 billion Global Hawk UAV is worth the money. Foxtrot Alpha. Retrieved from http://foxtrotalpha.jalopnik.com/why-the-usafs-massive-10-billion-global-hawk-uav-was-w-1629932000

USAF (2014, October 27). RQ-4 Global hawk. Retrieved from http://www.af.mil/AboutUs/FactSheets/Display/tabid/224/Article/104516/rq-4-global-hawk.aspx