Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 31 - 59 of 59

Full-Text Articles in Engineering

Global Aviation System: Towards Sustainable Development, Marina P. Bonser Dr. Jan 2019

Global Aviation System: Towards Sustainable Development, Marina P. Bonser Dr.

International Journal of Aviation, Aeronautics, and Aerospace

Aviation around the world has integrated into a global system. As the integration process continues, more aspects and levels of it need to be lead towards the sustainable development of the whole system via advancing strategic management, global communication proficiency, and technological expertise. It becomes essential to enrich global language (English) proficiency with cross-cultural communication competence not only for communication in the air but also for airport security, passenger and cargo services, aircraft and equipage engineering, building, and maintenance. Nowadays lower levels of management need more advanced strategic thinking and problem solving skills, and higher levels of management need global …


Brand Awareness, Purchase Intention And Price Premium Of International Airlines Operating Between Australia And The United Kingdom, Yi Gao, Nigel Wai Keong Choy Jan 2019

Brand Awareness, Purchase Intention And Price Premium Of International Airlines Operating Between Australia And The United Kingdom, Yi Gao, Nigel Wai Keong Choy

International Journal of Aviation, Aeronautics, and Aerospace

Brand equity has a profound impact on the pricing and sales of consumer products and services. Inspired by existing literature on customer-based brand equity in various domains, this study examines brand awareness (a dimension of brand equity), purchase intention and price premium of international airlines operating on a specific aviation market, Australia - the United Kingdom. Through surveying a sample of 259 participants in the metropolitan Melbourne area, the study captures a snapshot of brand recognition and brand preference of international airlines among local travelers. Statistically significant association is found between brand awareness and purchase intention, and between brand awareness …


Comparison Of Fixed-Wing Unmanned Aircraft Systems (Uas) For Agriculture Monitoring, Joseph Cerreta, Kristine M. Kiernan Jan 2019

Comparison Of Fixed-Wing Unmanned Aircraft Systems (Uas) For Agriculture Monitoring, Joseph Cerreta, Kristine M. Kiernan

International Journal of Aviation, Aeronautics, and Aerospace

Florida citrus growers need inexpensive methods to observe citrus plants to detect disease and stress consistently. Health vegetation indices, such as the Normalized Difference Vegetation Index (NDVI) collected from Unmanned Aircraft Systems (UAS), can be used to identify variation in plant health. Simple-to-operate UAS may enable growers to determine within-field variation more frequently than with inspections from scouts, providing more frequent knowledge about the crop condition. This research compared two low-cost fixed-wing UAS, a $5,000 Parrot Disco Pro Ag and a $16,690 senseFly eBee, each equipped with a Parrot Sequoia multispectral camera, to determine if there were differences in the …


Determination Of Takeoff And Landing Distances Using An Ipad Performance Application For The Diamond Da40, Tyler A. Babb, Christina Hiers Aug 2018

Determination Of Takeoff And Landing Distances Using An Ipad Performance Application For The Diamond Da40, Tyler A. Babb, Christina Hiers

International Journal of Aviation, Aeronautics, and Aerospace

All pilots are required to calculate aircraft performance parameters prior to flight. This includes takeoff and landing distances. Traditionally, pilots in training have planned for takeoff and landing performance using paper charts provided by the manufacturer. However, professional pilots use devices such as Flight Management Systems (FMS), Electronic Flight Bag (EFB) applications, or on-board performance computers (OPC) to make such calculations. During primary flight training, student pilots could make performance calculations with proper software, similar to the method they will typically use at the professional level. Recently an iPad application was released which can calculate numerous performance parameters for specific …


The Perceived Value Of Frequent Flyer Program Benefits Among Australian Travelers, Yi Gao, Madeline Carrigg, Robert Lewinski, Danielle Polderman, Paul Tkalcevic Jul 2018

The Perceived Value Of Frequent Flyer Program Benefits Among Australian Travelers, Yi Gao, Madeline Carrigg, Robert Lewinski, Danielle Polderman, Paul Tkalcevic

International Journal of Aviation, Aeronautics, and Aerospace

Understanding the perceived value of frequent flyer program benefits is crucial for commercial operations of airlines. This study aimed to investigate if travelers value various benefits provided by airlines and if such valuation correlates with certain characteristics of travelers. Through a scenario-based questionnaire it was confirmed that travelers do value extra and premium benefits offered by airlines, and such valuation increases along with the distance of route. It was also been found that top-tier members were willing to make a much higher offer for the same benefits on long-haul international route than members of lower status, but such difference in …


Book Review: Fundamentals Of International Aviation, Alan Bender Jun 2018

Book Review: Fundamentals Of International Aviation, Alan Bender

International Journal of Aviation, Aeronautics, and Aerospace

Not applicable.


Us Regional Airline Pay Scale Changes, Alex Nikle, Elizabeth Bjerke May 2018

Us Regional Airline Pay Scale Changes, Alex Nikle, Elizabeth Bjerke

International Journal of Aviation, Aeronautics, and Aerospace

The United States regional air carrier industry has recently undergone a substantial transformation in pilot salaries and hiring practices. Regional airlines are employing professional aviators at unprecedented rates in response to economic growth, regulatory reform, and legacy air carrier retirements. The combination of these factors has spurred demand for qualified air carrier pilots. As the hiring continues to increase, regional airlines are finding new ways to attract certified pilots to include: salary increases, bonuses incentives, and legacy airline employment flow agreements. The following report analyzes the salary changes that have occurred at US regional airlines from 2007-2017. From this data, …


The Role Of Mentoring In The Careers Of Female Airline Transport Pilots, Paul E. Cline Feb 2018

The Role Of Mentoring In The Careers Of Female Airline Transport Pilots, Paul E. Cline

International Journal of Aviation, Aeronautics, and Aerospace

Women have been a part of aviation since its inception, yet they have been traditionally underrepresented in the ranks of commercial pilots. This study explored what role mentoring played in the lives and careers of female Airline Transport Pilots (ATP).

It was determined that there was no statistically significant difference in self-reported perceptions of success between female ATP who had been mentored and those who had not. Of the female ATP who had been mentored, those who reported an informal mentoring relationship rated their relationship higher than those who reported a formal mentoring relationship when it came to career oriented …


Assessment And Comparison Of Aviation Manufacturing Industries Throughout Mexico And Brazil, Omar E. Morsi, Kelly A. Whealan-George, Aaron D. Clevenger Jan 2018

Assessment And Comparison Of Aviation Manufacturing Industries Throughout Mexico And Brazil, Omar E. Morsi, Kelly A. Whealan-George, Aaron D. Clevenger

International Journal of Aviation, Aeronautics, and Aerospace

This literature review serves to provide insight and understanding in regards to the evolving aviation manufacturing industry throughout the globe and more specifically, Mexico and Brazil. Increased demand for aircraft units both in the commercial and private sectors have led to unprecedented expansions in aircraft manufacturing across the industry. In order to illuminate certain potentials and current growth levels of such industries, this review will delve into an array of information and specifications in regards to economic, political, and cultural influences throughout both Mexican and Brazilian markets respectively. In conclusion, the review will identify the transformation of an aviation manufacturing …


A Novel Approach For Missing Combat Support Aircraft Search Acceleration Using Vtol Uas, Mohammed Ba Zuhair, Wisam Yousef, Issam Samara, Vladislav Varsegov Jan 2018

A Novel Approach For Missing Combat Support Aircraft Search Acceleration Using Vtol Uas, Mohammed Ba Zuhair, Wisam Yousef, Issam Samara, Vladislav Varsegov

International Journal of Aviation, Aeronautics, and Aerospace

In this paper, an approach to accelerate search operations for a missing combat support aircraft using a portable waterproof autonomous vertical takeoff and landing unmanned aerial system called “flying locator beacon” is described. The latter is connected with both flight data and cockpit voice recorders with a parallel bus and may be deployed from the empennage during extreme emergency scenarios, which is detected when few flight parameters are overrun leading to an air crash stimulating behavior. Landing of the flying locator beacon strictly takes place on global latitude and longitude coordinates only of integer values enabling significant minimization of search …


Uas Maintenance: A Critical Component In Maintaining Airworthiness, Bettina M. Mrusek, Kristy W. Kiernan, Patti J. Clark Jan 2018

Uas Maintenance: A Critical Component In Maintaining Airworthiness, Bettina M. Mrusek, Kristy W. Kiernan, Patti J. Clark

International Journal of Aviation, Aeronautics, and Aerospace

Over the last several decades, the notion of traditional aircraft design has significantly changed. While there are many modern aircraft that resemble earlier models, their components, systems, and overall architecture have evolved, including the introduction of small unmanned aircraft systems (sUAS). Despite the growing consumer attraction to own and operate these aircraft, the subsequent impact on safety is an area of intense concern. The requirement of an established maintenance program for manned aircraft is rooted in ensuring that all aircraft are deemed safe for flight. Preventive maintenance schedules are based on component reliability data, which minimizes unnecessary maintenance while preventing …


Assessing The Risks: An Analysis Of Wildlife-Strike Data At The Three Busiest Brazilian Airports (2011-2016), Flavio A. C. Mendonca Ph.D., Chenyu Huang Ph.D., Thomas Q. Carney Ph.D., Mary E. Johnson Ph.D. Jan 2018

Assessing The Risks: An Analysis Of Wildlife-Strike Data At The Three Busiest Brazilian Airports (2011-2016), Flavio A. C. Mendonca Ph.D., Chenyu Huang Ph.D., Thomas Q. Carney Ph.D., Mary E. Johnson Ph.D.

International Journal of Aviation, Aeronautics, and Aerospace

Brazil is the largest country in Latin America and has a considerable amount of air traffic volume domestically and internationally. Wildlife strikes are an increasing safety and economic concern for aviation operations in Brazil. The Brazilian Aeronautical Accidents Investigation and Prevention Center (CENIPA) has published annual reports summarizing the results of analyses of the data in a national level since 2009. The goal of this study was to supplement the CENIPA’s annual reports with information derived from the analysis of wildlife strikes to aviation, during 2011-2016, from the three busiest international commercial airports in Brazil: Guarulhos, Brasília, and Galeão. A …


Effects Of System Reliability And Time Pressure On Autonomous Unmanned Aerial Vehicle Operator Performance And Mental Workload, Dahai Liu, Rania Ghatas, Christina Frederick-Recascino, Dennis Vincenzi Ph.D. Apr 2017

Effects Of System Reliability And Time Pressure On Autonomous Unmanned Aerial Vehicle Operator Performance And Mental Workload, Dahai Liu, Rania Ghatas, Christina Frederick-Recascino, Dennis Vincenzi Ph.D.

International Journal of Aviation, Aeronautics, and Aerospace

Unmanned Aerial Vehicles (UAVs) are in the midst of aviation’s next generation. UAVs are being utilized at an increasing rate by military and security operations and are becoming widely popular in usage for activities such as search and rescue and weather research to homeland security and border patrol. In order for a safer integration of UAV’s within the National Airspace System (NAS), many research questions need to be addressed. This study examined the effects of system reliability and time pressure on UAV operator performance and mental workload. Twenty-four undergraduate and graduate students, male and female, from Embry-Riddle Aeronautical University participated …


An Evaluation Of The Relationships Between Collegiate Aviation Safety Management System Initiative, Self-Efficacy, Transformational Safety Leadership And Safety Behavior Mediated By Safety Motivation, Daniel Kwasi Adjekum Apr 2017

An Evaluation Of The Relationships Between Collegiate Aviation Safety Management System Initiative, Self-Efficacy, Transformational Safety Leadership And Safety Behavior Mediated By Safety Motivation, Daniel Kwasi Adjekum

International Journal of Aviation, Aeronautics, and Aerospace

The study conceptualized Safety Management System (SMS) initiative, self-efficacy, and transformational safety leadership as constructs that relates to safety behavior (measured by safety compliance and safety participation) when mediated by safety motivation using a quantitative approach. Structural equation modeling techniques was used to derive a final measurement model that fit the empirical data and was used to test the study hypotheses. Utilizing a sample of 282 collegiate flight students and instructors from a large public university in the US, a 46-item survey was used to measure respondent’s perceptions on the study variables. The results indicate that perceptions of SMS policy …


Opening Autonomous Airspace–A Prologue, Samuel M. Vance Apr 2017

Opening Autonomous Airspace–A Prologue, Samuel M. Vance

International Journal of Aviation, Aeronautics, and Aerospace

The proliferation of Unmanned Aerial Vehicles (UAV), and in particular small Unmanned Aerial Systems (sUAS), has significant operational implications for the Air Traffic Control (ATC) system of the future. Integrating unmanned aircraft safely presents long-standing challenges, especially during the lengthy transition period when unmanned vehicles will be mixed with piloted vehicles. Integration of dissimilar systems is not an easy, straight-forward task and in this case is complicated by the difficulty to truly know what is present in the airspace. Additionally, there are significant technology, security and liability issues that will need resolution to ensure property and life are protected and …


Integration Of Military Unmanned Aerial Systems (Uas) Into The Us National Airspace System: The Relationship Between Uas Accidents And Safety Concerns, Omar J. Hamilton, Timm J. Bliss, Chad Depperschmidt Jan 2017

Integration Of Military Unmanned Aerial Systems (Uas) Into The Us National Airspace System: The Relationship Between Uas Accidents And Safety Concerns, Omar J. Hamilton, Timm J. Bliss, Chad Depperschmidt

International Journal of Aviation, Aeronautics, and Aerospace

The purpose of this study was to discover if a relationship existed between the most common safety concerns and the most common UAS accidents with regards to the integration of military unmanned aerial systems (UAS) into the National Airspace System (NAS). This study examined the most common causes of UAS accidents over a five-year period, the level of safety concerns and common concerns from UAS military pilots and sensor operators. The quantitative data was derived from the Air Force, Navy and Army Safety Offices, while the qualitative data was derived from an online questionnaire and follow-up interviews of US Air …


Integrating Fatigue Management With Safety Management Systems For Commercial Flightcrew Operations, Arnold W. Starr Jr. Jan 2017

Integrating Fatigue Management With Safety Management Systems For Commercial Flightcrew Operations, Arnold W. Starr Jr.

International Journal of Aviation, Aeronautics, and Aerospace

Fatigue remains a significant hazard in commercial aviation and has been a major concern among all stakeholders for decades. This review of the literature explores the current prescriptive structure of the regulatory environment (Part 117) and its effect on fatigue management. To illustrate the impact of fatigue on flight operations, this article includes a brief analysis of two National Transportation Safety Board (NTSB) accident reports where fatigue was indicated as a factor. Current research in fatigue management and efforts by the Federal Aviation Administration point to the benefits of using a Safety Management Systems (SMS) methodology to manage fatigue. Using …


Estimating Airport Operations At General Aviation Airports Using The Faa Npias Airport Categories, Mary E. Johnson, Yue Gu Jan 2017

Estimating Airport Operations At General Aviation Airports Using The Faa Npias Airport Categories, Mary E. Johnson, Yue Gu

International Journal of Aviation, Aeronautics, and Aerospace

The number of annual aircraft operations (take-offs and landings) is a significant concern to both airport owners and operators and to governmental agencies because operations data are one of the most important criteria used for determining future investments in airports. However, estimating the number of aircraft operations at non-towered general aviation airports is challenging work due to the lack of counts from air traffic control towers or useful estimates developed using models. Previous work in estimating annual aircraft operations has resulted in models and sampling methods that are imprecise or difficult to use. In 2014, new classification categories of 2,939 …


Impact Of Us Low Cost Carriers Entrance To The Airline Market In Colombia, South America, Carolina Anderson, Tamilla Curtis, Robert F. Moss, Maryjo O. Smith, Gerson Mey Jan 2017

Impact Of Us Low Cost Carriers Entrance To The Airline Market In Colombia, South America, Carolina Anderson, Tamilla Curtis, Robert F. Moss, Maryjo O. Smith, Gerson Mey

International Journal of Aviation, Aeronautics, and Aerospace

This study researched the impact of US low cost carriers’ entrance to the airline market in Colombia, South America. The study analyzed the overall market share between Florida and Colombia after U.S. low cost carriers entered the market and finds that the market share for the Colombian flag carrier Avianca and U.S. legacy carrier American Airlines, who used to dominate this market, has decreased; however, the total passenger demand has increased. This increase in passenger demand can be attributed in part to U.S. low cost carriers opening new city pairs and allowing passengers to fly direct to the U.S. from …


Investigation Into Unmanned Aircraft System Incidents In The National Airspace System, Rohan S. Sharma Nov 2016

Investigation Into Unmanned Aircraft System Incidents In The National Airspace System, Rohan S. Sharma

International Journal of Aviation, Aeronautics, and Aerospace

With the promulgation of Federal Aviation Regulations for small unmanned aircraft systems, the volume of unmanned flight operations is expected to increase, which demands an analysis of potential hazards to the National Airspace System. Descriptive statistics were used to investigate reports archived in the Aviation Safety Information and Analysis and Sharing system involving unmanned aircraft systems, as well as the FAA UAS Sightings Reports database. The frequency of reports involving airspace violations, and Near Mid-air Collisions by unmanned aircraft systems as well as an analysis of the location, sponsor category, phase of flight, altitude, and airspace type in which the …


Increasing Collegiate Flight Training Fleet Utilization Through The Use Of An Aircraft Assignment Algorithm, John H. Mott, Daniel Henao, Mitchell S. Hodgen, Darcy M. Bullock Jul 2016

Increasing Collegiate Flight Training Fleet Utilization Through The Use Of An Aircraft Assignment Algorithm, John H. Mott, Daniel Henao, Mitchell S. Hodgen, Darcy M. Bullock

International Journal of Aviation, Aeronautics, and Aerospace

The operational efficiency of fleet aircraft employed for student flight training in collegiate aviation programs is strongly influenced by scheduling, among other factors. The average utilization rate for the fleet operated by the Purdue University School of Aviation and Transportation Systems was found to be 24% (Avery, 2014), and there is no data to suggest that that this rate is atypical in similar institutional programs. Mott and Bullock (2015) identified several means by which the utilization rate could be increased, and improvements in the dispatch and scheduling process were a key component of those recommendations. This article describes a scheduling …


Peer Reviewed Safety Management System (Sms): Collaboration For Continuous Improvement (Literature Review), Michael F. Canders Ph.D. Cfii Mar 2016

Peer Reviewed Safety Management System (Sms): Collaboration For Continuous Improvement (Literature Review), Michael F. Canders Ph.D. Cfii

International Journal of Aviation, Aeronautics, and Aerospace

Safe operations are essential for organizational success, perhaps no more so than in aviation. A culture of safety can be a leading contributor to an aviation organization’s success but developing such a culture and maintaining it can be very challenging. Collegiate aviation programs provide an exceptional opportunity to teach essential safety culture components to new aviators. A Safety Management System (SMS) is an effective framework to present and reinforce key safety principles and can be effectively tailored for the collegiate aviation flight training environment. Some aviation colleges may have developed a safety program or SMS but sharing and benchmarking the …


A Cross-Sectional Investigation Of The Relationships Education, Certification, And Experience Have With Knowledge, Skills, And Abilities Among Aviation Professionals, Daryl Watkins, Jason M. Newcomer, Matthew P. Earnhardt, James W. Marion, Rose A. Opengart, Aaron M. Glassman Jan 2016

A Cross-Sectional Investigation Of The Relationships Education, Certification, And Experience Have With Knowledge, Skills, And Abilities Among Aviation Professionals, Daryl Watkins, Jason M. Newcomer, Matthew P. Earnhardt, James W. Marion, Rose A. Opengart, Aaron M. Glassman

International Journal of Aviation, Aeronautics, and Aerospace

The aviation industry is a complex system with many different segments and as such, makes hiring the right person a complicated endeavor. Previous research suggested that knowledge, skills, and abilities (KSAs) are composed of elements that include education, certification, and experience (ECE). The relative importance of ECE is dependent on the type of job within the aviation sector. The objective of this mixed-methods concurrent triangulation study was to examine aviation industry professionals’ perceived relationship between their ECE and the development of their KSAs. The convenience sample consisted of 404 professionals in the aviation industry who completed the KSA Composite Measure …


Examining How Breakdowns In Pilot Monitoring Of The Aircraft Flight Path, Robert Sumwalt, David Cross, Dennis Lessard Aug 2015

Examining How Breakdowns In Pilot Monitoring Of The Aircraft Flight Path, Robert Sumwalt, David Cross, Dennis Lessard

International Journal of Aviation, Aeronautics, and Aerospace

Aircraft accident and incident data reveal that serious safety consequences can arise when flight crewmembers fail to properly monitor the aircraft flight path. This research study reviewed human factors literature to better understand why pilots fail to properly monitor, and analyzed accident and incident data. Recommendations for improving monitoring performance were formulated, which may be useful to air carriers in implementing a new Federal Aviation Administration requirement that calls for specific training in monitoring.


Bio-Fuel Alternatives In South African Airways (Saa) Operations - Is It An Effective Response To Vulnerability Over Carbon Taxes And Penalty?, Daniel Kwasi Adjekum Jul 2015

Bio-Fuel Alternatives In South African Airways (Saa) Operations - Is It An Effective Response To Vulnerability Over Carbon Taxes And Penalty?, Daniel Kwasi Adjekum

International Journal of Aviation, Aeronautics, and Aerospace

The paper did a comparative analysis of the carbon emission and European Union Emission Trading Surcharges (EU ETS) of South African Airways (SAA) current fleet that used aviation jet A1 fuel and the same fleet if it had used a 25% bio-fuel ‘drop in’ for the European routes within the first quarter of the 2014 flying year (FY 14). Operational data in terms of the flight scheduled, aircraft type, total time enroute, route stage length, passenger estimates were obtained through SAA’s flight operations website. An independent t–test was conducted to compare means of the emissions. The mean carbon dioxide …


Efficient General Computational Method For Estimation Of Standard Atmosphere Parameters, Nihad E. Daidzic Ph.D., Sc.D. Mar 2015

Efficient General Computational Method For Estimation Of Standard Atmosphere Parameters, Nihad E. Daidzic Ph.D., Sc.D.

International Journal of Aviation, Aeronautics, and Aerospace

Knowledge of standard air temperature, pressure, density, speed of sound, and viscosity as a function of altitude is essential information in aircraft design, performance testing, pressure altimeter calibration, and several other aeronautical engineering and aviation science applications. A new efficient computational method for rapid calculations of standard atmospheric parameters up to 86 orthometric km is presented. Additionally, mass and weight of each standard atmospheric layer were calculated using a numerical integration method. The sum of all fractional masses and weights represents the total mass and weight of Earth’s atmosphere. The results obtained here agree well with measurements and models of …


Regional Aviation Early Career Pilot Attributes Study, Stewart Wayne Schreckengast, Douglas A. Drury Feb 2015

Regional Aviation Early Career Pilot Attributes Study, Stewart Wayne Schreckengast, Douglas A. Drury

International Journal of Aviation, Aeronautics, and Aerospace

The Regional Aviation Association of Australia (RAAA) has identified a need to better understand the concerns of its members in the attraction and retention of early career pilots. RAAA has further identified the need to better understand any shortcomings in professional aviation training programs in Australia so as to provide appropriate guidance from an industry point of view. The RAAA Training and Education Committee (TEC) facilitated the undertaking of this study with its members. This study provides insight into the technical and non-technical attributes that aviation manager’s value in early career pilots.


Situational Leadership Styles In United States Air Force Air Traffic Control Towers, William D. Melton, Chad L. Depperschmidt, Timm J. Bliss Dec 2014

Situational Leadership Styles In United States Air Force Air Traffic Control Towers, William D. Melton, Chad L. Depperschmidt, Timm J. Bliss

International Journal of Aviation, Aeronautics, and Aerospace

Leadership in air traffic control facilities is critical to the safe, orderly, and efficient flow of air traffic. The purpose of this qualitative study was to determine the preferred leadership style for United States Air Force air traffic control tower watch supervisors. A panel of 10 functional experts completed a 25 question scenario-based survey to establish a baseline for this study’s four research questions. A purposeful sample of eight control tower chief controllers representing the eight United States Air Force major commands were interviewed and their responses were compared to the mean of the experts panel. The data from the …


Reliability Of Eyewitness Reports To A Major Aviation Accident, Dave English, Michael Kuzel Nov 2014

Reliability Of Eyewitness Reports To A Major Aviation Accident, Dave English, Michael Kuzel

International Journal of Aviation, Aeronautics, and Aerospace

There is a paucity of studies on the reliability of eyewitness reports to aviation crashes. We examine witness statements to a widely observed major airline accident to determine if reported accident investigator distrust of details in eyewitness reports is supported by empirical evidence. The extensive archival witness record (N > 300) of a wide-body airliner crash in clear daylight conditions is subjected to statistical analysis to test eyewitness reliability. Even with over 200 witnesses within a three square kilometre (1.6 square mile) area answering a binary observation question, the variance is sometimes high enough to preclude forming statistically significant conclusions …