ASCI 491 Module 3 Blog Post

Technology and Data in Aircraft Maintenance

Over the last two decades, and especially in the last ten years, I have seen a shift in aviation maintenance practices toward technology driven maintenance plans.  Technology has enabled aircraft operators and maintenance technicians to use sensors, failure data, and predictive analytics to determine when systems and components fail.

In the civilian sector as well as the Department of Defense, aircraft and accompanying ground systems will tell the user when they need to be fixed.  While the “glossy brochure” may not always equal the reality of what happens on the flight line, it is truly amazing how far we have come in predictive analytics and conditioned based maintenance.

The Government Accountability Office published a report in Dec 2022 titled “Military Readiness: Actions Needed to Further Implement Predictive Maintenance on Weapon System” that included 16 recommendations for the Military Services to implement predictive maintenance and assess performance (Defense Acquisition University, n.d.).

Definitions:

• CBM (Condition Based Maintenance) – the practice of performing maintenance only when a specific condition warrants the action, as opposed to time based or predictive maintenance (Meissner et al., 2021).

• CBM+ (Condition Based Maintenance Plus) – a Department of Defense readiness enabler and strategic approach to life cycle management that is cost effective.  It uses hardware, software, communication, processes, and other tools to improve maintenance processes and practices (Crooks & Plawecki, 2021).

• IVHM (Integrated Vehicle Health Management) – Sensors and technology onboard an aircraft that can collect, analyze, record, and transmit performance data to determine future failure conditions (Crooks & Plawecki, 2021).

• PHM (Prognostics and Health Management) – technology used for early fault detection and projection of fault detection (Meissner et al., 2021).

In some platforms it is now possible to: 

• Determine failures on engines and transmissions based on sensor data from onboard collection during a normal flight (i.e. non-functional check flight).

• Perform early removal of components ahead of failure based on mean time between failure data.

• Adjust scheduled maintenance intervals based on use IVHM feedback and criticality.

Maintenance professionals that can interpret and understand the outputs of the information age and then convert outputs into more reliable systems and airframes will succeed in the maintenance departments of the future. 

References:

Crooks, K., & Plawecki, N. (2021). Novel Approach to CBM+ Implementation on Aviation Systems. 2021 Annual Reliability and Maintainability Symposium, 1–6. https://doi.org/10.1109/RAMS48097.2021.9605703

Defense Acquisition University. (n.d.). Condition Based Maintenance Plus. Retrieved on August 22, 2023 from, https://www.dau.edu/acquipedia/pages/ArticleContent.aspx?itemid=503

Meissner, R., Rahn, A., & Wicke, K. (2021). Developing prescriptive maintenance strategies in the aviation industry based on a discrete-event simulation framework for post-prognostics decision making. Reliability Engineering & System Safety, 214, 107812. https://doi.org/10.1016/j.ress.2021.107812

ASCI 491 Mod 1 Blog Post

Boeing 737 MAX Drives Certification Reform

One series of events that impacted the U.S. transportation industry are the two Boeing 737 MAX accidents that occurred in the later half of 2018 and the first half of 2019.  During my Management of Production and Operations course, there were several students that chose to focus their final research presentations about the two crashes that claimed 346 lives and destroyed two Boeing 737 MAX airframes (Picheta, 2019).  

Investigations determined that the maneuvering characteristics augmentation system (MCAS) was not an adequate design due to lack of redundancy, poor software programing, and a sensor system that is prone to failure (Demirci, 2022).

This highlighted a failure in the monitoring and certification of commercial airline products by the Federal Aviation Administration (FAA).  The FAA had delegated up to 96 percent of certification processes to Boeing, which started as far back as 2005 (Herkert et al., 2020).  Positive change was manifest in certification reform efforts by the FAA.  In the last two years, the FAA has delegated less responsibility to manufactures, provides more oversight, conducts more thorough reviews of aircraft system operations, and utilizes independent safety experts for certification projects (Federal Aviation Administration, n.d.).  

While the loss of life in these two aircraft mishaps is tragic, the event caused positive change in the FAA’s certification process, which will help prevent future mishaps from occurring.

Resources:

Demirci, S. (2022). The requirements for automation systems based on Boeing 737 MAX crashes. Aircraft Engineering and Aerospace Technology, 94(2), 140-153. https://doi.org/10.1108/AEAT-03-2021-0069

Federal Aviation Administration. (n.d.). Aircraft certification: Certification reform efforts. Retrieved August 6, 2023, from https://www.faa.gov/aircraft/air_cert/airworthiness_certification/certification_reform

Herkert, J., Borenstein, J., & Miller, K. (2020). The Boeing 737 MAX: Lessons for Engineering Ethics. Science and Engineering Ethics, 26(6), 2957-2974. https://doi.org/10.1007/s11948-020-00252-y

Picheta, R. (2019, March 11). Ethiopian Airlines crash is second disaster involving Boeing 737 MAX 8 in months. CNN. https://www.cnn.com/2019/03/10/africa/ethiopian-airlines-crash-boeing-max-8-intl/index.html

Weather Hazards

Severe Thunderstorms

There is no shortage of weather phenomenon that affect the ability to safely operate an aircraft.  In fact, many of the systems employed in the airframe are specifically designed and built to allow for operation in adverse and extreme weather conditions.  Anti-icing systems, heating, cooling, radar, rain removal, navigational aids, and landing systems are all designed to help the aircraft and crew negotiate the different elements of weather.

Regardless of the amount of thoughtful design and flight planning, there are some weather events that should be avoided completely.  This is the reason that Severe Thunderstorms rank as the greatest weather risk to aviation operations.

There are three main factors that must be available for a thunderstorm to form:

Moisture – Thunderstorms are more likely when the surface dew point is greater than 55 degrees Fahrenheit.

Lifting – Something must be the initial push that causes air to rise.  This could be a frontal boundary, a low-pressure system, or low-level differential heating caused by the sun.

Instability – Is caused when air rises vertically.  This can happen when a less dense air parcel moves upward through air that is more dense.

The picture above shows a cold front advancing, which starts the lifting of warm and moist air over the top of the cold air mass plowing underneath.  This creates instability as the warm air rises vertically and condenses.

Thunderstorms can come in all shapes and sizes.  A single-cell thunderstorm or a small squall line might not be that concerning, but a supercell thunderstorm (pictured above) that is ten miles in diameter, reaches 50,000 feet AGL, and lasts for over an hour, is something that grabs a pilot’s attention.  During flight planning, pilots and aircrew should find a method to circumvent this severe weather or stay on the ground.

Word Count: 298

References:

Federal Aviation Administration (FAA). (2016). Pilot’s Handbook of Aeronautical Knowledge (PHAK). https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/phak/

Haby, J. (n.d.). Thunderstorm Ingredients. Weather.gov. https://www.weather.gov/source/zhu/ZHU_Training_Page/thunderstorm_stuff/Thunderstorms/thunderstorms.htm#top

Midwestern Regional Climate Center. (n.d.). Living with weather: Thunderstorms. https://mrcc.purdue.edu/living_wx/thunderstorms/index.html

Air Traffic Control Entities

Civilian ATC and Military ATC at Sea

There are many similarities between the Air Traffic Control that manages the Controlled Airspace for Civil Airports and the Air Traffic Control that manages the Airspace around a Navy Carrier.  Civil Aviation and Military Aviation both have functions that that provide for safe air operations including:

• Ground Control
• Tower Control
• Radar and Navigational Aids
• Runway / Landing Markings and Lights
• Automated Terminal Information Service

Many of the policies and procedures are very similar for Civil Airports and Navy Ships up until it is time to perform a landing.  Landing on the ship is the largest difference between Naval Aviation and Civil Aviation.  It takes a great deal of time and practice to land an aircraft on a moving runway or landing pad.

Typically the ships tower (or Primary Flight Control) functions as the ATC within five miles of the ship.  The Air Officer (Air Boss) and his assistant (Mini Boss) control and manage all movement of aircraft in and around the ship.  There are Sailors providing radar services, instrument approaches, and controlling the air space.  There are also LSOs (Landing Signal Officers) and LSEs (Landing Signal Enlisted) that assist the pilot in landing the aircraft on spot or to an arrested landing during their final approach.

Fixed Wing Aircraft – land with an arresting hook that catches a wire to stop the forward momentum with an arrested landing.

Rotary Wing Aircraft and VTOL Aircraft – land vertically on a spot with the assistance of an LSE or LSO to land in the correct location.

The Air Boss and Mini Boss maintain constant communication with the ship’s Captain to adjust the position of the ship to bring the relative wind off the nose of the boat to ensure aircraft are landing into the wind.  There is a benefit to being able to move the runway to suit the desired landing profile.

The aircraft and its crew must land in a very specific location to prevent damage to the ship or aircraft.  For helicopters, there are three foot squared boxes that the landing gear must be inside when landing on the ship.  The use of the LSE and the LSO is one of the main differences in final approach and landing; they are critical to meet the precise landing locations on a moving ship.

Word count: 387

References:

Allen, F. V. (2019, December 10). Meet the US Navy's new $13 billion aircraft carrier. CNET. https://www.cnet.com/pictures/meet-the-navys-new-13-billion-aircraft-carrier/

Federal Aviation Administration (FAA). (2016). Pilot’s Handbook of Aeronautical Knowledge (PHAK). Retrieved https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/phak/

Navy. (n.d.). Air Traffic Controller. https://www.navy.com/careers/air-traffic-controller

The Airport and the Environment

Noise Pollution

Of the listed main environmental impacts (air, noise, and water pollution), it seems as though noise pollution is the most commonly addressed and complained about by the average citizen in close proximity to the airport.  While air and water pollution are very important and have a large impact on the environment, noise pollution is annoying right now.  Unwanted sound is nuisance to the senses and can rally a community in opposition to an airport and the FAA.

Airport managers struggle with the length, frequency, and cumulation of sound levels over time; so much so that they hire companies to study the effects of noise and conduct noise modeling to determine the degree to which noise will have an effect on the population.  An example in the Visser and Wijnen chapter mentioned that even socioeconomic factors are considered because noise tolerance is lower in communities that have more affluent residents. Tools like the Integrated Noise Model are standard methods to determine noise impacts from airports on the civilian community.

 

Denver International Airport, pictured above, moved from Stapleton International Airport out of Denver 25 years ago due to noise issues and safety concerns.

Many airports have decided to move out of built up areas, such as large cities, to avoid the noise impacts to residents in housing communities.  However, Denver International Airport is now being surrounded by housing developments as the suburban areas around Denver expand.  Despite safety warnings and warnings of noise issues, the surrounding cities of Aurora and Commerce City continue to build.  This trend is repeated over and over in many cities like those surrounding DFW International Airport and those Airports in Southern California.

A potential solution is to move 50+ miles from any city and then refuse development of any land within the airspace.  Transportation to and from the terminals could be provided through the use of high speed rail or high speed train.  The Shinkansen in Japan travels nearly 200 miles an hour.  Something like this option would enable transportation in a fraction of time of the normal vehicle airport commute, while allowing for appropriate standoff for noise pollution.

Word Count: 359

References:

Aguilar, J. (2020, January 12). Denver airport warns of development “creep” as Aurora gives blessing to new houses nearby. Denver Post. https://www.denverpost.com/2020/01/12/dia-aurora-development-runway-noise/

Federal Aviation Administration (n.d.). The FAA Airport Noise Program. https://www.faa.gov/newsroom/faa-airport-noise-program

Gallagher, T. (2021, November 16). Noise pollution: How are airports and airlines addressing the issue?. Euronews.next. https://www.euronews.com/next/2021/11/16/noise-pollution-how-are-airports-and-airlines-addressing-the-issue

Visser, H., & Wijnen, R. (2008). Management of the environmental impact at airport operations. Nova Science Publishers, Incorporated.

Legislative Acts

Air Traffic Control

The establishment of the Air Traffic Control Systems Command Center on July 29, 1970 was an important piece on legislation by the Federal Aviation Administration.  In the early days of aviation in the United States, aircraft controllers used immature means to track aircraft and routes.  The inability to communicate with aircraft over radio and tracking aircraft manually on maps and blackboards led to many high-profile accidents in the 1930s.

In the 1960s, the Federal Aviation Administration pressed to modernize the current air traffic control system.  The goal was to automate the manual system to an automated radar traffic control system (ARTS).  The Air Traffic Control Systems Command Center (ATCSCC) integrated the following:

• Central Flow Control Facility 
• Airport Reservation Office
• Air Traffic Service Contingency Command Post
• Central Altitude Reservation Facility

Today, the ATCSCC seeks out issues and provides solutions to mitigate inefficiencies that are identified in the National Air Space System (NAS).  The ATCSCC uses traffic management initiatives to manage air traffic through the using and monitoring:

• Ground Delay Programs
• Ground Stops
• Airspace Flow Programs
• Weather
• Equipment Outages
• Runway Closures
• National Emergencies

Looking to the future of aviation, the ATCSCC is preparing for regulation and control of space operations and operations including unmanned aerial vehicles.  All these desires to operate in new areas will require control of airspace and routes and an all-encompassing system to track and monitor future air traffic.

In conclusion, if not for the creation of the Air Traffic Control Systems Command Center it would be unlikely that the airline industry could operate inside the United States with the current safety record.  The complex network of Air Route Traffic Control Centers, Terminal Radar Approach Control Facilities, and Air Traffic Control Towers rely on the ATCSCC to help manage the nation’s air traffic and make improvements to balance constraints on the NAS .

Word Count: 307

References:

Air Traffic Control Tower Operators, 14 C.F.R. § 65 (2022).

Federal Aviation Administration. (n.d.). A brief history of the FAA. Retrieved February 15, 2022, from https://www.faa.gov/about/history/brief_history

Federal Aviation Administration. (n.d.). Air Traffic Control System Command Center. Retrieved February 15, 2022, from https://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/systemops/nas_ops/atcscc

Team-Based Human Factors Challenges

 The Infamous Tow Crew

    Human Factors in aviation could be described as the study and application of human capabilities and limitations when interfacing with information technology, equipment, aircraft, and other people.  The FAA has a much more complicated definition that can be found at the site referenced below, but it centers around what humans can do and the limitations they have while carrying out their work (FAA, n.d.).

Towing aircraft is a team sport and I would consider it a team-based aviation activity.  It is a process that is repeated so often, that it can become monotonous, boring, and is often viewed as trivial.  Despite aircraft towing being so simple and monotonous, tow mishaps are a leading cause of Class C (accidents that cost between 50k and 500k dollars) mishaps in Naval Aviation (Eckstein, 2018).

Why do we run aircraft into inanimate objects in the military and civilian sector?  For many reasons:

• Failure to maintain situational awareness.
• Lack of tow driver experience.
• Lack of brake rider experience.
• Many tow events take place during the night check.
• Failure to sound alarm ahead of impacts due to inexperience and fear of reprisal.

There are six individuals required to tow most aircraft in Naval Aviation.  They include a tow director, a tug driver, a brake rider, two wing walkers, and someone to watch the tail of the aircraft.  

These are some of the steps that have been taken to ensure tow evolutions are conducted safely and to minimize human factors that can cause mishaps:

• Tow Brief conducted with Maintenance Control and Quality Assurance before all aircraft movements.
• Ensure all people know their job and what is required.
• Ensure qualification and certification of every person before each movement.
• Use more senior maintainers during complex movements.
• Increase supervision during night check towing evolutions.

By understanding the task at hand and briefing all potential challenges and risks in each tow evolution, many of the human factors that could induce risk can be mitigated.

Word Count: 325

References:

Airplanes from the desk of Jesse. (2019, August 10). Aircraft Towing. http://www.libyanarabairline.com/aircraft-towing/

Eckstein, M. (2018, June 22). Less experienced maintainers contribute to rise in Naval Aviation mishaps. U. S. Naval Institute News. https://news.usni.org/2018/06/22/less-experienced-maintainers-contribute-rise-naval-aviation-mishaps

Federal Aviation Administration (FAA). (n.d). The Role of Human Factors in the FAA. https://www.hf.faa.gov/role.aspx