Weather Hazards

Thunderstorms 

Do you need a Thunder Buddy? ... You just might if you plan to fly near Thunderstorms!

    Thunderstorms are, without a doubt, the greatest weather hazard to aviation operations. All thunderstorms produce conditions that are extremely hazardous to aircraft. Although numerous combinations exist, it's nearly impossible to visually determine which hazards you may face when encountering a deadly thunderstorm (FAA, 2016).

    Thunderstorms form when there is sufficient moisture and the air mass currents are unstable. As warm moist air rises into cooler layers of the Troposphere, the moisture condenses into water droplets. The cooled air drops lower in the atmosphere, warms, and then rises again by the warm updrafts. The cycle of rising and falling is called a Convection Cell. In small amounts, this causes clouds to form. In large amounts, thunderstorms may form. Thunderstorms can be formed by a single relatively small convection cell (SINGLE-CELL), multiple convection cells (MULTI-CELL), or one single very large convection cell (SUPERCELL) (Thunderstorms / Center for Science Education, n.d.).

    The most dangerous type of thunderstorm system in aviation is that of the Squall Line, a narrow band of active thunderstorms that may stretch across an entire state making it difficult to navigate around. (FAA, 2016). Penetrating a Squall Line may also be impossible unless there is a sufficient gap. Although, navigating through a gap in a Squall Line should be avoided because even flying near thunderstorms is risky flying behavior. If a destination airport is beyond a squall line, it would be best to immediately look for a suitable divert airport where one could wait until the storm passes, especially for those pilots who are not IFR-rated and flying VFR.

Thunderstorm Hazards

    Although not all thunderstorms will produce every type of hazard, they typically manifest with a combination of the following hazards:

Hail

    Hail is not only hazardous to ground-laden structures and objects. Hail can be extremely hazardous to aircraft because thunderstorms can "throw" hail outwards for many miles. Aircraft windows, radomes, engines, and other structures may be damaged by hail when encountered. And just because there is rain at ground level near a thunderstorm, don't discount the possibility of hail at higher altitudes.

Turbulence

    Thunderstorms have the potential to create hazardous turbulence; the strongest occurring within the updrafts and downdrafts. Shear Turbulence is also a hazard that can occur several thousand feet above and up to 20 miles away laterally from a thunderstorm (FAA, 2016).

Icing

    The updrafts within a thunderstorm carry large amounts of moist air upwards. As the air cools and condensates it can become supercooled. When this supercooled air comes into contact with an aircraft, it can instantly freeze on the surfaces of the aircraft.

Navigating Around Thunderstorms

    It's not impossible to fly during inclement weather. There are, however some challenges involved in doing it safely. Starting with the preflight weather briefing, a pilot should become familiar with the forecasted weather at the origin, along the route, and at the destination. Before every flight, the pilot should obtain a weather briefing from a Flight Service Station (FSS) specialist. Receiving a proper briefing could potentially be the difference between being caught in a storm, or changing the flight route to avoid a potential storm.

    Advanced avionics equipment such as weather radar or an ADS-B IN Flight Information Weather Service-Broadcast (FIS-B) can serve as invaluable tools when navigating troublesome weather, however, the best resource an aviator has is communication with Air Traffic Controllers (ATC). ATC can route air traffic around storms in real time. It's truly amazing how efficiently a controller can direct air traffic around storms as shown in this video of air traffic into Atlanta-Hartsfield.

References:

Federal Aviation Administration. (2016). Pilot’s Handbook of Aeronautical Knowledge: FAA-H-8083-25B (ASA FAA Handbook Series) (2016th ed.). Aviation Supplies & Academics, Inc. https://www.faa.gov/sites/faa.gov/files/regulations_policies/handbooks_manuals/aviation/phak/15_phak_ch13.pdf

Kappell, J. (2014, May 28). Types of Thunderstorms and the Dangers they Pose - WDRB Weather Blog. WDRB. https://fox41blogs.typepad.com/wdrb_weather/2014/05/types-of-thunderstorms-and-the-dangers-they-pose.html

Thunderstorms | Center for Science Education. (n.d.). UCAR. https://scied.ucar.edu/learning-zone/storms/thunderstorms#:%7E:text=Thunderstorms%20form%20when%20warm%2C%20moist,%2C%20warms%2C%20and%20rises%20again.

Air Traffic Control Entities

     Within the United States, the Federal Aviation Administration (FAA) is responsible for controlling all air traffic within the National Airspace System (NAS).  It accomplishes this daunting task of keeping aircraft safe in ever-increasing crowded airspace through the coordinated efforts of various Control Entities. Each Control Entity is responsible for directing air traffic through, or sometimes over, their Area of Responsibility (AOR), which typically also coincides with a particular phase of an aircraft's flight from one location to another. 

    Focusing on the graphic at the top of this blog post, I'll explain the various domestic Control Entities within the United States and their responsibilities, helping to draw the similarities and differences between each. 

Ground- 

    Although not depicted above, "Ground Control" is responsible for the movement of aircraft and vehicles within an airport's taxiways, inactive runways, holding areas, and parking areas. Ground is responsible for preventing ground incursions or collisions and efficiently directing traffic to or from runways.

Tower-

    The tower is responsible for active runways and coordinates arrivals (landings) and departures (take-offs) within class B, C, and D airspace (FAA, 2016). An aircraft must have clearance from the tower to taxi onto a runway for a departure and must also be cleared to land when arriving. An aircraft that is preparing to depart has first had communications with Ground before switching over to the tower for take-off clearance. Conversely, an aircraft preparing to land will communicate with the tower after having been in communication with the Terminal Radar Approach Control (TRACON) controller.

TRACON-

    Also referred to as "Approach", TRACON is responsible for controlling air traffic between the take-off and landing phases and the en-route phase of flight (Martin, 2014). TRACON facilities are located at every major airport and every aircraft flying within an airport's airspace will communicate with the TRACOM of that area for directions into, out of, or through the airspace. When preparing to land, TRACOM will direct an aircraft to switch over to the Tower controller for clearance to land. After having departed an airport, TRACOM will direct an aircraft to contact the applicable Air Traffic Control Center (ATCC) that controls air traffic within that AOR.

Center-

    An ATCC, more commonly referred to as a "Center", is responsible for controlling traffic in the areas between airport airspace. Centers are designed to typically provide ATC services for aircraft operating under an Instrument Flight Rules (IFR) flight plan. Centers essentially "own" the airspace of their region providing route clearance, separation, and vectoring for approach on decent. It is also important to note that Centers are responsible for publishing Notice to Air Missions (NOTAM) notices that announce abnormal conditions or hazards within the National Airspace System (NAS) (Air Route, n.d.).

References

Air Route Traffic Control Center. (n.d.). CFI Notebook. https://www.cfinotebook.net/notebook/air-traffic-control/air-route-traffic-control-center

Martin, E. (2014, July 24). Airspace 201: The Air Traffic Control System. Phoenix East Aviation. https://pea.com/blog/posts/airspace-201-air-traffic-control-system/

Transportation, U.S. Department of & Federal Aviation Administration. (2016). Pilot’s Handbook of Aeronautical Knowledge (FAA-H-8083-25B - 2016): [B/W edition]. CreateSpace Independent Publishing Platform. https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/phak

The Effects of Airport Congestion on Air Pollution

 The Effects of Airport

Congestion on Air Pollution

    It's no secret that aircraft operations are a significant contributor to carbon emissions and air pollution, specifically the air pollution found around major airports.  Aircraft engines release many different types of byproducts into the surrounding air including carbon dioxide, nitrogen oxides, carbon monoxide, sulfur oxides, and hydrocarbons (from fuel) that are unburned or partially combusted, particulates, and other trace compounds (Schlenker & Walker, 2011).

Sources of Aviation Air Pollution

    When we think of aircraft operations, typically what comes to mind is takeoff, landing, and flying at cruise altitude from one location to another. There is, however, another aspect of aircraft contributing to air pollution that some may not consider: aircraft operations on the ground. This includes taxiing to or from the terminal gate, Auxiliary Power Unit operation while parked, and even ground support equipment operation (airfield vehicles, aircraft tow tractors, baggage vehicles, etc.).  Although they seem insignificant, these contributing sources are, in fact, very important when you consider their impact on pollution directly surrounding airports. In 2014 an air quality study performed by the University of Southern California's Keck School of Medicine found that pollution from aircraft at Los Angeles International Airport was affecting the airports surrounding neighborhoods more than had been previously believed (Peterson, 2014).

Aviation Air Pollution Quick Facts

-    Aircraft engine idling produces more CO and NO emissions per minute than any other stage of flight

-    Aircraft engine emissions are higher during low power when the engine is less efficient 

-    Average taxi time from gate to runway increased by 23% from 1995 to 2007

(Schlenker & Walker, 2011)

The following graphic shows the breakdown of emissions contributions at Frankfurt International Airport in 2005. As the data is old and improvements have been made since this time, the charts are shown here only to put into perspective the proportions of emissions each category contributes.

(Zaporozhets & Synylo, 2020)

What does this mean?

Simply put, congestion at airports directly impacts the emissions output of aircraft, and therefore overall air pollution, at a given airport. In 2011, Schlenker and Walker even found that airport delays on the east coast of the United States led to more airfield congestion at LAX, which directly impacts air pollution levels around the Los Angeles area.

Ways to Reduce Airport Air Pollution

-    Halt the use of Auxiliary Power Units at terminal gates and instead use ground power and externally supplied air conditioning

-    Reduce taxi times by keeping aircraft at the gate until its departure slot is confirmed

-    More Direct taxi routes that would limit idle power time of engines

-    Taxi procedures that limit aircraft to one engine when safe and practical

-    Use of electric, natural gas, hydrogen, or compressed air ground-support vehicles

-    Use of efficient tow tractors to move aircraft from gate to runway without using aircraft engines

-    Assigning aircraft to the closest open gate from the runway to lower taxi time

-    Optimizing arrival and departures when external delays may increase congestion

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References

Improving air quality. (n.d.). Aviation Benefits Beyond Borders. https://aviationbenefits.org/environmental-efficiency/improving-air-quality/

Peterson, M. (2014, May 30). Air pollution from LAX jets worse than previously known, says USC study. KPCC - NPR News for Southern California - 89.3 FM. https://www.kpcc.org/2014-05-29/air-pollution-from-lax-jets-worse-than-previously

Schlenker, W., & Walker, W. (2011, November). AIRPORTS, AIR POLLUTION, AND CONTEMPORANEOUS HEALTH. National Bureau of Economic Research. https://www.nber.org/system/files/working_papers/w17684/w17684.pdf

Zaporozhets, O., & Synylo, K. (2020). Modeling of Air Pollution at Airports. Environmental Impact of Aviation and Sustainable Solutions. https://doi.org/10.5772/intechopen.84172

ADS-B: Improving Controlled Airspace   

    Signed into law in December of 2003, the Century of Aviation Reauthorization Act introduced the concept of a Next Generation Air Transportation System (NextGen) (FAA, n.d.). NextGen aims to enable more efficient and safe management of the air transportation system. Since its inception, NextGen has grown and evolved to include various changes in the way air traffic is managed. One such recent mandate that has had an overwhelming impact on the safety of flight is the requirement for aircraft to utilize Automatic Dependent Surveillance-Broadcast (ADS-B) Out equipment. 

    ADS-B is a system that transmits an aircraft's GPS position to the ground to Air Traffic Controllers (ATC), enhancing their ability to safely direct air traffic through controlled air space. Another "mode", ADS-B "In", can also be used to enable air-to-air transmission of position data from one aircraft to another, greatly enhancing situational awareness. In the past, ATC relied solely upon radar-based systems and two-way radio communication to direct air traffic. The great benefit of ADS-B is that it is automatic and dependent, which means that in normal operation it requires no input from the pilot to transmit necessary data to ground stations about the aircraft's position, speed, or direction of flight.

    FAR § 91.225 mandates that after January 1, 2020, all aircraft operating within specific limits of various controlled airspace must be equipped with ADS-B "Out" equipment, unless otherwise authorized by the FAA (ADS-B, 2021). Specifically, aircraft are required to be equipped with ADS-B, and be operational, when they operate in the following controlled airspace areas:

• Class A, B, and C airspace;
• Class E airspace at or above 10,000 feet MSL, excluding airspace at and below 2,500 feet agl;
• Within 30 nautical miles of a Class B primary airport (the Mode C veil);
• Above the ceiling and within the lateral boundaries of Class B or Class C airspace up to 10,000 feet;
• Class E airspace over the Gulf of Mexico, at and above 3,000 feet MSL, within 12 nm of the U.S. coast. (AOPA, n.d.).

This graphical illustration helps to understand exactly where ADS-B Out is mandated to be used:

    

    This FAR has greatly benefitted the aviation industry on an international level. It has enhanced ATC's ability to safely direct air traffic both in the sky and on the ground, as well as enables reduced aircraft separation (Spire, 2022). Because ADS-B reduces the need for standard separation, aircraft can follow more direct flight routes, which lowers fuel consumption, further reducing operating costs and carbon emissions (Spire, 2022). ADS-B has also been proven to reduce aviation accident rates. In fact, when it was still being developed and tested, the accident rate in ADS-B-equipped locations in Alaska fell by nearly 50 percent (MITRE, 2015).

References:

ADS-B: Enabling the Next Momentous Transformation in Air Traffic. (2015, April 14). The MITRE Corporation. https://www.mitre.org/publications/project-stories/adsb-enabling-the-next-momentous-transformation-in-air-traffic-control

Automatic Dependent Surveillance-Broadcast (ADS-B) Out equipment and use, 14 U.S.C. 

            § 91.227 (2021). https://www.ecfr.gov/current/title-14/chapter-I/subchapter-F/part-91/subpart- 

            C/section91.225

Spire. (2022, April 19). How ADS-B has Shaped the Modern Aviation Industry. Spire : Global Data and Analytics. https://spire.com/wiki/how-ads-b-has-shaped-the-modern-aviation-industry/

Where is ADS-B Out Required? (n.d.). AOPA. https://www.aopa.org/go-fly/aircraft-and-ownership/ads-

            b/where-is-ads-b-out-required

 Human Factors In Aviation Maintenance

                

    They say, that so long as there are humans involved in a process, there will be errors made. We refer to this as human error. However, no process is successful without human input and, in fact, is necessary under most circumstances because humans possess the ability to make rational and informed decisions. This creates somewhat of a "double-edged sword"; humans are necessary to ensure that safe decisions are made throughout many different areas of the aviation industry but are also the leading cause of mistakes and errors. In fact, human error is a major contributing causal factor in 80 percent of aviation-related mishaps (Begur & Babu, 2016). Of that 80 percent, it is said that between 15 and 20 percent of aviation mishaps are attributed to maintenance errors (Drury, 2000). Factors that lead to human error are known as Human Factors and come in many forms. Some examples include stress, fatigue, pressure to meet deadlines, lack of proper training, or even incompetence, to name just a few.

Combating Training Deficiencies 

    The complex nature of maintaining and repairing aeronautical systems and equipment calls for advanced technical training. As required by law, maintenance technicians must possess the necessary skills and credentials to ensure aircraft airworthiness. It is no secret, however, that the aviation industry is constantly evolving and changing, and so too must the maintenance technician. It's true that "you don't know what you don't know". Another factor that can lead to a lack of training is incomplete or insufficient on-the-job training. If a full spectrum of knowledge is not passed down from more senior technicians to those with less experience, it can lead to an extreme loss of knowledge within even just a few "generations" of technicians. A comprehensive training program can mitigate a lack of training within an organization, but it requires the full support of everyone within the organization from the most junior mechanic to the most senior executives. This is where the Team Resource Management concept becomes very useful.

WORD COUNT: 327

References:

Begur, S., & Babu, J. (2016). Human Factors in Aircraft Maintenance. International Advanced Research Journal in Science, Engineering and Technology, 3(3), 14–17. https://doi.org/10.17148/IARJSET.2016.3303

Drury, C. (2000, November). Human Factors in Aviation Maintenance. RTO AVT Lecture Series, Sofia, Bulgaria. https://skybrary.aero/sites/default/files/bookshelf/2504.pdf

Team Resource Management (TRM). (2021, May 24). SKYbrary Aviation Safety. https://skybrary.aero/articles/team-resource-management-trm

Insider Threats 

Within the Aviation Industry

    Since the early 2000s, it has become a routine for airline passengers to be processed through security screening checkpoints. At first thought, most do not think much of it. In fact, some may even find it a nuisance. The truth, however, is that the physical security checkpoints located at airports, train stations, and ferry or boat terminals are just one level of the many necessary security processes that the Transportation Security Administration (TSA) uses to thwart terrorism and criminal activity.

An Emerging Threat

    Insider threats are those where personnel within an organization use their access, authority, or understanding of an organization to do harm to the organization (Cybersecurity, n.d.). The TSA has been countering insider threats since its inception, however, it was not until 2013 that it formally established a program aimed at countering insider threat activity (TSA, n.d.). Typically insider threats do not relate to terrorism, but rather to industrial sabotage, theft, or smuggling (TSA, n.d.). 

    Some examples of insider threats could include sabotage of an aircraft by an airline mechanic, a flight crew member smuggling drugs, an airline employee stealing an aircraft and intentionally crashing it, and the list goes on. You can now see how an employee within the Transportation Security Sector (TSS) or aviation industry could use their access or knowledge of an organization to carry out criminal activity. One must only use their imagination to think of ways an insider threat could do grave harm.

    The TSA has many layers of security aimed at providing security throughout the various different levels and areas within the TSS. Of these layers that protect against insider threats are: Intelligence, Crew Vetting, Behavior Detection, Random Employee Screening, Trained Flight Crew, and Passengers. There are others, however, that may indirectly provide protection against insider threats. 

    Because there are already many protections in place, improvements in combating insider threats are far limited. One area, however, that can always be improved is that of Behavior Detection. An employee may never demonstrate traits or show signs that he or she is a possible insider threat. They may initially pass a background check and go for years showing no sign of a threat. However, circumstances change and this is where coworkers and leadership within an organization can have an impact in detecting an insider threat. It doesn't take specialized training to recognize when someone's behavior patterns change. Maybe they become reckless in their duties, seem to stop caring, their spending habits change, or they just don't seem to be themselves. Although these behaviors do not guarantee that one is for sure an insider threat, recognition and reporting of behavior changes might just be enough to stop someone who intends to use their access, knowledge, or position to do harm.

    As coworkers, it is our responsibility to look out for each other; to keep each other safe and protected as well as those who rely on us as professionals within the aviation industry. So the next time you recognize behavior changes in a coworker, engage them and see how they are doing. If it persists, ensure you report your observations to leadership so that action can be taken. It may be the only thing standing in the way of an insider threat within your organization. 

References

Defining Insider Threats | CISA. (n.d.). Cybersecurity & Infrastructure Security Agency. https://www.cisa.gov/defining-insider-threats

James, A. [Anthony James]. (2020, March 6). Anthony James (@Cut_2_Fit) / [Tweet]. Twitter. https://mobile.twitter.com/cut_2_fitCombating Insider Threats

Transportation Security Administration. (n.d.). Insider Threat Roadmap 2020. TSA.Gov. https://www.tsa.gov/sites/default/files/3597_layout_insider_threat_roadmap_0424.pdf

 Aircraft Anti-Ice and Deicing Systems

Making flight through adverse conditions possible

    Flying in hazardous weather requires aircraft to utilize specialized systems to ensure a safe flight. One such condition is icing conditions. Ice that forms on an aircraft's wings, propellers, control surfaces, or windshield can be extremely detrimental to maintaining proper thrust, lift, and control of the aircraft. There are several methods in which to prevent or remove ice from the surface of an aircraft. Anti-ice systems are designed to prevent or drastically reduce the formation of ice on an aircraft during flight, whereas deicing systems are designed to remove ice that has already formed. Failures of either type of system can have deadly consequences, however certain processes and procedures can be put into place to ensure that doesn't happen.

Anti-Ice

When supercooled water comes into contact with an object, it can immediately freeze. Aircraft utilized anti-icing to prevent the formation of ice on critical surfaces of the aircraft and are designed to be activated prior to entering icing conditions in flight (NASA, n.d.). Anti-icing can be accomplished by heating the surfaces (hot pneumatic air or electrically), or fluid can be used that lowers the freezing point so that ice does not form when supercooled water or ice crystals contact the surface.

Deicing

Aircraft deicing systems are designed to remove ice that may have formed. One common method of deicing is the use of deicing boots that inflate to break up ice formations and dislodge them from various surfaces.

What happens when icing systems fail?

When icing systems either fail or are not activated in icing conditions, ice is likely to form on surfaces that are critical to the aerodynamics of the aircraft. The formation of ice reduces thrust, increases drag, reduces lift, and increases weight. To put into perspective just how detrimental icing can be, see the table below which illustrates the effects icing has on stall speed and drag increase through various instances ranging from "all iced" and "deiced" (Flight Safety Foundation, 2018)

Mitigation

Anti-ice and deicing systems are not effective unless they are fully functional and operate as intended when necessary. To ensure that such systems are operational, they should be regularly tested on the ground. Such system tests should be a part of every aircraft preflight procedure, especially when there is a potential for an aircraft to fly into known icing conditions. Aircraft whose icing systems are not functional should be restricted from flight or, if dispatched with faulty equipment, be restricted from flying into known icing conditions. When icing systems are fully functional, it is also critical that they are activated prior to entering icing conditions.

References

Flight Safety Foundation. (2018, February 27). Discoveries on Ice. https://flightsafety.org/asw-article/discoveries-on-ice/

NASA. (n.d.). In-Flight Icing: Aircraft Design for Icing - Anti-Icing Systems. A Pilot’s Guide to Inflight Icing. https://aircrafticing.grc.nasa.gov/1_1_3_6.html#:%7E:text=The%20anti%2Dicing%20fluid%20runs,on%20propeller%20blades%20and%20windshields.

Stoll, R. (2020, May). UBC ATSC 113 - Aircraft Icing. Weather for Sailing, Flying & Snow Sports. https://www.eoas.ubc.ca/courses/atsc113/flying/met_concepts/03-met_concepts/03g-Icing/index.html