Unmanned Aircraft Systems operational risk management: A Review of the PUMA AE

The AeroVironment’s Puma AE is a small unmanned aircraft system (or vehicle to be more specific) that is intended to be utilized in situations requiring low operational cost and very little manpower.  It is small in size and weight and requires minimal logistical operations.  The Puma AE in particular is designed for tactical intelligence, surveillance and reconnaissance missions.  It is capable of transmitting live video directly to the Ground Control System and can navigate autonomously due to its GPS-based system.  Below is the date for the Puma AE in regards to its specifications, preliminary hazards list (PHL), preliminary hazards assessment (PHA), operational hazard review and analysis (OHR&A), and ORM assessment tool (see Figure 1).

SPECIFICATIONS

Payloads	Gimbaled payload, 360 degree continuous pan, +10 to -90 degrees tilt, stabilized EO, IR camera, and IR Illuminator all in one modular payload.
Range	15 km
Endurance	3.5+ hours
Speed	37-83 km/h, 2-45 knots
Operating Altitude	500 ft (152 m) AGL
Wing Span	9.2 ft (2.8 m)
Length	4.6 ft (1.4 m)
Weight	13.5 lbs (6.1 kg)
GCS	Common GCS with Raven, Wasp and Shrike
Launch Method	Hand-launched, rail launch (optional)
Recovery Method	Autonomous or manual deep-stall landing

Figure 1. Specifications of the sUAS the Puma AE.  The table lists various specifications of the PUMA including payloads, range, endurance, speed, operating altitude, wing span, length, weight, GCS, launch method and recovery method.  Specifications borrowed from Avinc.com.

Next, the preliminary hazards assessment (PHA) tool will be discussed.  This tool is a semi-quantitative analysis utilized in the launch and operations of the Puma AE in order to aid in the identification of all possible hazards and/or accidental events that could ultimately result in an accident.  Further, it is used to help rank said accidental events according to their level of severity and it can also be utilized in the identification of required hazard controls and follow up actions.  In the case of sUASs, the PHA tool can be completed to perform a complete risk analysis of the Puma. 

There are several important components to the PHA but the following are the most critical items to consider: 1) hazardous conditions 2) safety related interfaces 3) environmental constraints 4) operating, test, maintenance, built-in-tests, diagnostics and emergency procedures, 5) facilities, property installed equipment and training 6) Safety equipment, safeguards and 7) malfunctions to system/software (Barnhart, Hottman, Marshall, & Shappee, 2011).  This list helps establish risk prior to launch (see Figure 2).  Further, the following is an example of the PHA for the Puma AE:

PRELIMINARY HAZARDS WORKSHEET ANALYSIS

System: Puma AE       Operating mode:                     Analyst:                      Date:

Ref.	Hazard	Accidental event	Probable causes	Contingencies/Preventative actions	Prob.	Sev.	Other/Comments

Ref. = Reference Prob. = Probability Sev. = Severity

Figure 2. An example of a Preliminary Hazards Assessment worksheet for the sUAS, Puma AE. 

           

Following this list an Operation Hazard Review and Analysis (OHR&A) should be developed (Figure 3).  Although at first glance the OHR&A seems quite similar to the PHA, this particular list differs in that it focuses on specific items that could arise within the actual UAS flight operation.  In this list, there are two primary differences.  The first is that the operational stage checklist is added.  This allows the individual to track these events for various operational stages of flight.  The second and more important section added is the ‘action review’ column.  In the PHA, the aim was primarily to identify safety issues early on in UAS operations; however, the goal with OHR&A is to continue that safety protocol and review the actions taken and their results throughout the process.  According to the text, the action review column is used to list if the identified mitigating actions implemented from the PHA were adequate in responding to the hazard (Barnhart, Hottman, Marshall, & Shappee, 2011).

OPERATION HAZARD REVIEW AND ANALYSIS

System: Puma AE       Operating mode:                     Analyst:                      Date:

Operational Stage:     [ ] Planning     [ ] Staging       [ ] Launch      [ ] Flight      [ ] Recovery

Ref.	Action Review	Hazard	Accidental event	Probable causes	Contingencies/ Preventative actions	Prob.	Sev.	Other/ Comments

Ref. = Reference Prob. = Probability Sev. = Severity

Figure 3. An example of an Operation Hazard Review and Analysis for the sUAS, Puma AE.

Finally, the Operational Risk Management (ORM) is a tool utilized for the evaluation of typical operational hazards.  It takes common operational hazards into consideration and ranks them in regards to their level of severity and the probability of their occurrence.  As a small UAS, the PUMA AE is susceptible to various hazards.  The following is a example of an ORM worksheet for the risk assessment of the PUMA AE (see Figure 4).

PUMA AE Risk Assessment
Date:		Aircraft: PUMA AE			Serial #:
UAS Crew/Station:	_______________/____________           _______________/____________
	_______________/____________           _______________/____________
Mission Type	SUPPORT	TRAINING	PAYLOAD CHECK	EXPERIMENTAL
	1	2	3	4
Hardware Changes	NO			YES
	1			4
Software Changes/Calibration	NO			YES
	1			4
Airspace of Operation	WIDE OPEN	MINIMAL HAZ	MODERATE HAZ	ABUNDANT HAZ
	1	2	3	4
Operator Experience with this Aircraft	EXPERT	ADVANCED	INTERMEDIATE	NOVICE
	1	2	3	4
Flight Time	DAY			NIGHT
	1			4
Type of Flight	LOS	LOS/BLOS	BLOS	FPV
	1	2	3	4
Visibility	> 10 MILES	6-9 MILES	2-5 MILES	< 2 MILES
	1	2	3	4
Surface Winds		0-5 KTS	5-15 KTS	> 15 KTS
		2	3	4
Forecast Winds		0-5 KTS	5-15 KTS	> 15 KTS
		2	3	4
Weather Deteriorating	NO			YES
	1			4
Other Airspace Activity	NO			YES
	1			4
Established Lost Link Procedures	YES			NO
	1			NO FLIGHT
GPS Satellites Acquired	ALL 3	2	1	NONE
	1	2	3	4
Proper "home" Location Set	YES			NO
	1			4
Potential For Tx/Rx Interference	NONE	SOME	MODERATE	SEVERE
	1	2	NO FLIGHT	NO FLIGHT
Total
	RISK LEVEL
	18-27	28-36	37-45	45-56
	LOW	MEDIUM	SERIOUS	HIGH
Aircraft Number: __________________       Aircraft Type:  _______________________
Flight Released By:  _____________________________  Date: ____________  Time: ____________

Figure 4. PUMA AE Operational Risk Management worksheet.  This worksheet is borrowed/adapted from: Barnhart, R., Hottman, S., Marshall, D., & Shappee, E. (2011).Introduction to Unmanned Aircraft Systems. London: CRC Press. page 128.

References

Avinc.com (2014).  Puma AE: Introducting new capabilities.  Retrieved from

http://www.avinc.com/downloads/DS_Puma_Online_10112013.pdf

Barnhart, R., Hottman, S., Marshall, D., & Shappee, E. (2011). Introduction to Unmanned

Aircraft Systems. London: CRC Press.