Sunday, December 8, 2019

UAS Crewmember/Operator Requirements


The most important factor when selecting, certifying and training UAS operators is safety.  Having no onboard human on the aircraft adds a high degree of complexity to UAS. It is therefore very important to not only select the right crew members but also people who are detail-oriented and safety conscious. Many UAS accidents are caused by crew errors. Although many are as a result of Human interface systems in the Ground Control Stations, a few as also a result of improper flight operations procedures taken by UAS operators especially during takeoff and landing.
When it comes to the size and endurance of UAS, one has to look at the differences from military and civilian systems. Due to FAA restrictions, most civil UAS are either at or below the required 55 pounds. The bigger and longer endurance systems are used by the military. UAS technology development and the FAA’s efforts to integrate UAS into the National Airspace System is sure to blow open the limitations on payload and endurance for civil use. A good example is the Ikhana UAS that is being used to test Detect and Avoid technologies. When it comes to qualifications, most military UAS operators will rank higher since they have flown countless hours of UAS flights in training with flights in higher payload and endurance UAS systems.
Flight Training is an ongoing process. Although a pilot might be skilled on a particular UAS or system, there is still a need to continually train and refresh one’s knowledge especially as new technologies are being developed and imbedded into systems.

Sunday, December 1, 2019

UAS Mishaps and Accidents


Many UAS accidents occur due to the Pilot error or inexperience with the UAS they are operating. Such accidents like the drone that injured an Australian triathlete, the UAS that flew into bystanders in Virginia crowd, and the UAS that flew into people attending a Bull run in Spain were as a result of lack of Pilot experience with the UAS or loss of situational awareness of the UAS they were flying.
Other drone pilots also seem to not understand the hazards of the UAS propellers. Another major issue affecting UAS operators is the issue of situational awareness and obstacle avoidance. Many crashes currently involving UAS seems to result from crashes with objects or into people. FAA PART 107 has enabled many operators to obtain the training and skill required for UAS operation but most often struggle to see and avoid obstacles and aircraft when operating drones at extended range, limiting their current operation to closed, line-of-sight environments.
As a result of the frequent crashes and accidents during UAS operation especially BLOS flights, it is necessary to equip UAS with GPS tracking and situational awareness onboard systems in order to reduce pilot/operator error, operational risk, and bring with it a trust that allows for scalability and use of truly autonomous vehicles (Iris, 2016)

Reference

Iris. (2016, June 15). Retrieved from Irisonboard: https://www.irisonboard.com/2016/06/15/why-situational-awareness-is-absolutely-necessary-for-industrial-drones/


Sunday, November 24, 2019

UAS and Manned Aircraft Autonomy

UASs have become so useful due to their ability to do jobs that have been classified, too dull, dirty, and dangerous for humans. To be able to accomplish these tasks, UAS will have to fly autonomously, that is, fly without a human directly manipulating the flight systems inside the aircraft. However, the definition can be very vague. Many UAS missions still require humans to supervision and intervention, and most times, preprogram flight paths. For this reason, most UAS can be said to be automated. However, many UAS have are becoming autonomous with varying levels of autonomy. The levels of automation range from level 0 where the pilot has complete control of the UAS to Level 5, where the UAS has control of all flying operations and tasks. For a UAS to be deemed fully autonomous, the UAS will have to control itself under all circumstances with no human intervention. This includes full automation of all flying operations under any given conditions (Radovic, 2019).     
For automation, most aircraft use autopilot systems that the pilot can switch to especially during cruise altitudes. This autopilot mode is especially useful because humans generally need rest during long periods of the task. Airbus aircraft are integrated with a fly-by-wire technology that assists the pilot makes precise control inputs during highly dynamic maneuvers with large surface controls.  stabilize the aircraft and adjust the flying characteristics without the pilot's involvement and to prevent the pilot operating outside of the aircraft's safe performance envelope.                                                                                                                             
  However, just like many current autonomous systems, humans are still required to monitor autonomous systems and take control when necessary. Although equipped with fly-by-wire technology, the A320-214 Flight 1529 that got ditched into the Hudson was able to allow the pilot to assume control of the aircraft to successfully and safely ditch. For a UAS to be deemed fully autonomous, the UAS will have to control itself under all circumstances with no human intervention. This includes full automation of all flying operations under any given conditions (Radovic, 2019). AI can be applied to UAS automaton capabilities such as sense and avoid capabilities so the UAS can precisely determine the best course of action and maneuver to avoid a collision.

Reference

Radovic, M. (2019, March 11). DroneII. Retrieved from DroneLife: https://dronelife.com/2019/03/11/droneii-tech-talk-unraveling-5-levels-of-drone-autonomy/


Sunday, November 17, 2019

Physiological Issues in UAS


We all know that some drugs may compromise a pilot’s ability to control the aircraft and/or adversely affect judgment and decision making. The difficulty comes for investigators in trying to quantify the known detriment that comes with various medications and the physical conditions that require their use. The Federal Aviation Authority. The FAA has provided pilots with a list of medications that are generally safe when used to treat a common ailment (GO) and those that are not (NO-GO) (FAA, 2019). Under these guidelines, FAA says to avoid medications or ingredients that are Sedating or having a Hang-over effect. Such medications can include brompheniramine, Benadryl Dayquil Advil PM, Tylenol PM which contains diphenhydramine.
When conducting UAS operations and one needs to take OTC medications, it is generally safe to follow dosing intervals suggested by the FAA. The dosage interval suggests that If a medication says to take it 4 times per day, the dosing interval would be 6 hours and the wait time after the last dose would be 30 hours (6 hours x 5 = 30 hours). Therefore, the UAS operator can continue operation after the 30hours.
Fatigue, irritability, confusion, and other changes to your mental state such as a brain fog, which is usually characterized by memory problems, lack of mental clarity, poor concentration, and inability to focus which will make any operation of the UAS unsafe.
Reference
FAA. (2019). Retrieved from https://www.faa.gov/news/safety_briefing/2018/media/SE_Topic_18-10.pdf

Sunday, November 10, 2019

RQ 11 Raven Operational Risk Management (ORM) Assessment Tool



The RQ Raven Small Unmanned Aerial Vehicle is one of the most frequently used UAS in the US military. With the ability to be operated in a manual or autonomous mode, it can be rapidly deployed and used in low-altitude surveillance and reconnaissance missions. With a wing spanning about 4.5 feet and weighing 4.2 pounds, the Raven can fly and ay missions for up to 10 kilometers. (Aerovironment, 2019). In order to reduce the chance of mishaps, it is important to manage the risks associated with the operation of the UAS using the Operational risk Management assessment tool.
 Preliminary Hazard List
The first task is to identify the potential hazards that will likely be encountered during operation of the UAS. This involves brainstorming with stakeholders and coming up with the potential list of hazards and then assigning a probability and severity level to the identified risks/hazards. In the list, hazards that have been identified are System Malfunctions, Loss of Link/Communication, Wrong Maintenance, Remote Pilot Error, Mid-air collision, Terrain collision, stall, flyaway, Aggressive maneuvers, and failure to launch vehicles.

Preliminary Hazard List
Track#
Hazard
Probability
Severity
RL
Mitigating Action
RRL
Notes






1

1.

System Malfunction
occasional(C)
Critical II
3
Preventive maintenance
1

2
Loss of Link/Communication
probable(B),
Marginal
3
Reposition GCS
1

3
Wrong Maintenance
remote (D)
Critical
1
Proper Maintenance, training
1

4
Remote Pilot Error
Probable(D)
Critical
2
Proper training, procedures
1

5
Mid-air collision
Remote(D)
Catastrophic
3
Check flight data, weather conditions before the flight
1

6
Terrain collision
Probable(B)
Critical
1
Avoid High obstacle areas
1

7
Stall
Remote(D)
Critical
1
Adjust altitude
1

8
Flyaway
Remote(D)
Critical
1
Verify routes before the flight
1

9
Aggressive maneuver
Occasional (C)
Marginal
1
Return UAS to Base
1

10
Failure to launch
Frequent(A)
Critical
2
Check procedures before launch, Use mounted launch
1


Preliminary Hazard Assessment (PHA)
The next phase is to conduct a preliminary hazard analysis (PHA) by finding the best possible ways to mitigate the listed hazards or risks. Based on the listed hazards, the mitigation procedures are listed in Table 1. After the mitigation procedures are applied to the risks, another probability and severity level is conducted showing the residual risk. The residual risk is usually equal or less than the risk/hazard initially.
Operational Hazard Review and Analysis (OHR&A)
The Operational Hazard Review and Analysis (OHR&A) tool is like a preliminary hazard list. The difference is that the OHR&A is used to analyze whether the mitigation procedures adequately addressed the risks listed in the PHL. If they were not adequately addressed, they are listed again in the OHR&A.
RQ 11 Raven Risk Assessment
UAS flight training





Risk

Risk Level


1
2
3
4
Pilot Error

Automated Pilot


Manual control
Terrain collision

Large area free of obstacles
Large area with some obstacles
No obstacle
Obstacle present in area
Failure to launch

Mounted launch


Hand launch
Stall

100-300ft AGL


400ft AGL
Total Value

Low
0-20

Moderate
21-40

High
41-60



Finally, an ORM&A table showing if it is safe to fly the UAS. Each line of risk is added to get the total risk which determines the level of risk for the mission. for example, the total of the risk assessment is 25, which places the mission at moderate risk.

Reference


Aerovironment. (2019). Retrieved from https://www.avinc.com/uas/view/raven