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

Engineering Commons

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

Articles 1 - 30 of 33

Full-Text Articles in Engineering

Fatigue Issues And Mitigation Strategies In Collegiate Aviation, Flavio A. C. Mendonca Ph.D., Julius Keller, Erik Levin, Aaron Teo Dec 2019

Fatigue Issues And Mitigation Strategies In Collegiate Aviation, Flavio A. C. Mendonca Ph.D., Julius Keller, Erik Levin, Aaron Teo

Publications

The reduction of fatigue-related accidents has been in the NTSB most wanted list since 2016 (NSTB, 2019).

Most research studies have focused on fatigue identification and management within the commercial and/or military aviation environments (Caldwell et al., 2009; Gawron, 2016; Sieberichs & Kluge, 2016).

However, collegiate aviation may be the most challenging in terms of fatigue mitigation. Flight instructors and students often have schedules which may increase the risks for fatigue.


Mitigating The Risk Of Bird Strikes: The Use Of Virtual Reality During Flight Training, Flavio A. C. Mendonca Ph.D., Julius Keller Ph.D., Chien-Tsung Lu, Chenyu Huang Ph.D. Dec 2019

Mitigating The Risk Of Bird Strikes: The Use Of Virtual Reality During Flight Training, Flavio A. C. Mendonca Ph.D., Julius Keller Ph.D., Chien-Tsung Lu, Chenyu Huang Ph.D.

Publications

There were 193,969 wildlife strikes in the US from 1990 through 2017. Wildlife strikes annually cost the US civil aviation industry, on average, $186 million in monetary losses and 111,284 hours of aircraft downtime (Dolbeer & Begier, 2019). According to the Federal Aviation Administration (FAA), Aeronautical Decision-Making (ADM) is a systematic approach that encourages pilots to identify hazards and manage risks (FAA, 2016). Additionally, it helps aviators to make timely and safe decisions. Even though it is practically impossible to eliminate the risk of bird strikes, crewmembers play a vital role in the accident prevention process (Mendonca, Carney, & Fanjoy, …


A Step Toward Ending Long Airport Security Lines: The Modified Boarding Pass, Joel Lee Dec 2019

A Step Toward Ending Long Airport Security Lines: The Modified Boarding Pass, Joel Lee

Doctoral Dissertations and Master's Theses

Anyone who has traveled by air has most likely experienced long airport security lines. Yet not much is known about its cause because few have considered if passengers have created this problem for themselves. The present study attempts to fill this research gap by suggesting that when passengers are not well-prepared for security screening, they delay the process by making mistakes and not complying with procedures. This lack of preparedness can be attributed to several shortcomings of security signposts. This study proposes the use of a modified boarding pass as an alternative form of signage to help passengers better prepare …


Computational Model For Pedestrian Movement And Infectious Diseases Spread During Air Travel: A Molecular Dynamics-Like Numerical Approach, Pierrot Derjany Dec 2019

Computational Model For Pedestrian Movement And Infectious Diseases Spread During Air Travel: A Molecular Dynamics-Like Numerical Approach, Pierrot Derjany

Doctoral Dissertations and Master's Theses

There is direct evidence of the transmission of fatal infectious pathogens in large human gatherings. Air transportation is no exception. The mixing of susceptible and infectious individuals in this high-density man-made environment involves pedestrian movement which is generally not taken into account in modeling studies of disease dynamics. This thesis addresses this problem through a multiscale model that combines pedestrian dynamics with stochastic infection spread models. This generic model is applicable to several directly transmitted diseases. Through this multiscale framework, the effectiveness of certain layout and strategies in suppressing the disease spread in highly crowded locations such as airplanes, airports …


An Evaluation Of The Operational Restrictions Imposed To Congonhas Airport By Iac 121-1013, Glanski O.C. Pacheco Jr., Marcus Camargo Nov 2019

An Evaluation Of The Operational Restrictions Imposed To Congonhas Airport By Iac 121-1013, Glanski O.C. Pacheco Jr., Marcus Camargo

Graduate Student Works

The objective of this study is to propose a review of the operational restrictions imposed on Congonhas airport by IAC 121-1013, seeking a balance between flight safety and operational efficiency.

The researchers calculated the landing performance (using specific software), taking into account particular aircraft system failures that increase landing distance. The results indicated that the measures imposed by the IAC have little or no effect on the operational safety increase. Additionally, the restrictions created operational complexity for the airport and reduced its efficiency by impacting airline costs. At the end of the study, the researchers suggest a reissue of the …


Cleared To Land: Pilot Visual Detection Of Small Unmanned Aircraft During Final Approach, Ryan J. Wallace, Samuel M. Vance, Jon M. Loffi, Jamey Jacob, Jared C. Dunlap, Taylor A. Mitchell, Robert Thomas, Seabrook R. Whyte Oct 2019

Cleared To Land: Pilot Visual Detection Of Small Unmanned Aircraft During Final Approach, Ryan J. Wallace, Samuel M. Vance, Jon M. Loffi, Jamey Jacob, Jared C. Dunlap, Taylor A. Mitchell, Robert Thomas, Seabrook R. Whyte

International Journal of Aviation, Aeronautics, and Aerospace

Sighting reports of unmanned aircraft systems (UAS) by pilots, air traffic controllers, and other aviation stakeholders have continued to rise since the Federal Aviation Administration (FAA) began tracking in 2014. In 2018, the FAA received 2,307 such reports, with 22.8% (n = 526) occurring during the final approach phase of flight. The threat of a midair collision between a manned aircraft and UAS is heightened during the final approach phase of flight, as the aircraft transitions from higher-altitude airspace to the low-altitude arena, now shared with drones. Absent UAS sense and avoid systems, pilots are forced to rely on …


The Flight Risk Perception Scale (Frps): A Modified Risk Perception Scale For Measuring Risk Of Pilots In Aviation, Scott R. Winter, Dothag Truong, Joseph R. Keebler Sep 2019

The Flight Risk Perception Scale (Frps): A Modified Risk Perception Scale For Measuring Risk Of Pilots In Aviation, Scott R. Winter, Dothag Truong, Joseph R. Keebler

Publications

Risk and risk perception remain focal areas of research within the aviation domain. The purpose of the current study was to assess an existing measure of a 26-item self-risk perception scale for pilots. A sample of 490 participants was used in the present study, and a confirmatory factor analysis was conducted on the original 26-item instrument. The findings indicated that there was a poor model fit of the original instrument. Through the use of modification indices, a new 13-item scale was produced, which resulted in a second-order CFA model. Flight risk was shown to be the second-order construct with general …


Bird Hazard Mitigation Training For Part 141 General Aviation Pilots: An Experimental Study, Flavio A. C. Mendonca, Richard O. Fanjoy Phd, Thomas Q. Carney Aug 2019

Bird Hazard Mitigation Training For Part 141 General Aviation Pilots: An Experimental Study, Flavio A. C. Mendonca, Richard O. Fanjoy Phd, Thomas Q. Carney

Publications

From 1990 through 2018 ==> 209,950 wildlife strikes in the U.S.,

Approximately 95% of those incidents involved birds;

Seventy aircraft destroyed as a result of wildlife strikes!

13 bird strikes 32 ==> fatalities;

  • 244 wildlife strikes ==> 319 people injured!
  • 224 bird strikes ==>299 people injured!

General aviation community;

  • 97% of the strikes occurred below 3,500 feet AGL;
  • There were 22,775 wildlife strikes ==> 26% caused damage to the aircraft!


Wildlife Hazard Management: An Analysis Of Wildlife Strikes Data From The Five Busiest Airports In Brasil: 2011-2018, Flavio A. C. Mendonca, Julius Keller, Carlos F. G. Schonhardt Aug 2019

Wildlife Hazard Management: An Analysis Of Wildlife Strikes Data From The Five Busiest Airports In Brasil: 2011-2018, Flavio A. C. Mendonca, Julius Keller, Carlos F. G. Schonhardt

Publications

Brasil ==> the largest country in Latin America - 8.514.876 Km²;

Booming aviation industry;

  • From 2008 through 2017 ==>7.1% per year;
  • 104 million passengers in 2018;
  • International destinations – 21.8 million (~20%);
  • U.S. - 4.4 million passengers;
  • Argentina – 3.8 million passengers;
  • Portugal & Chile – 1.7 million passengers;
  • Brazilian Airlines – 38.3%.

Domestic Passengers 200 million in 2030; International Passengers 55 million in 2030.


Comparative Analysis Of Small Unmanned Aircraft Systems Operations Manuals, Stephen M. Cigal Jul 2019

Comparative Analysis Of Small Unmanned Aircraft Systems Operations Manuals, Stephen M. Cigal

Student Works

With over 100,000 remote pilots in the United States, individuals and companies are rapidly incorporating unmanned aircraft system technologies into their everyday life and businesses models. The companies that use these technologies must comply with federal and state regulations in order to maintain a safe environment to operate. These operations must also be accepted by the general public. Since the FAA regulations for small unmanned aircraft systems (sUAS) went into effect in 2016, supplemented by additional state and/or local requirements, some companies have generated operations manuals (OM) to ensure consistent, safe flight that meets these requirements. By analyzing the OM’s …


English Language Proficiency And Aviation Safety, Robert Fowler Jr. Jul 2019

English Language Proficiency And Aviation Safety, Robert Fowler Jr.

Student Works

The goal of this research study is to determine if aviation incidents and accidents due to deficiencies in English language proficiency have increased in the last 10 years based on data from the National Aeronautics and Space Administration (NASA) Aviation Safety Reporting System (ASRS). In addition, this study will determine whether deficiencies in English language proficiency have a significant impact on aviation safety. There are currently 184,636 student pilots according to the Federal Aviation Administration Airmen Certification System. Included in this number are 11,776 student pilots with a foreign address (Federal Aviation Administration [FAA], 2019). Findings presented at a NASA …


The Effect Of Electronic Flight Bags In Flight Training On Preflight Skill Development And Aeronautical Decision Making, Shlok Misra, Michele Halleran Jun 2019

The Effect Of Electronic Flight Bags In Flight Training On Preflight Skill Development And Aeronautical Decision Making, Shlok Misra, Michele Halleran

Student Works

This study was designed to evaluate the effects of utilizing Electronic Flight Bags (EFBs) in flight training with emphasis on preflight skill development and Aeronautical Decision Making. The study participants were student pilots or private pilots who used EFBs in flight training and had not logged more than 100 total flight hours. The study utilized a simulation of the preflight process of a Visual Flight Rules cross-country flight in which the participants answered questions related to the flight preparation. Fifty percent of the study’s population completed this survey with the information provided through an EFB and the other 50% sample …


Forensic Analysis Of Spy Applications In Android Devices, Shinelle Hutchinson, Umit Karabiyik May 2019

Forensic Analysis Of Spy Applications In Android Devices, Shinelle Hutchinson, Umit Karabiyik

Annual ADFSL Conference on Digital Forensics, Security and Law

Smartphones with Google's Android operating system are becoming more and more popular each year, and with this increased user base, comes increased opportunities to collect more of these users' private data. There have been several instances of malware being made available via the Google Play Store, which is one of the predominant means for users to download applications. One effective way of collecting users' private data is by using Android Spyware. In this paper, we conduct a forensic analysis of a malicious Android spyware application and present our findings. We also highlight what information the application accesses and what it …


Safety Culture Awareness In Aviation Maintenance: Foundations To Present, Tori Kobayashi May 2019

Safety Culture Awareness In Aviation Maintenance: Foundations To Present, Tori Kobayashi

Student Works

Safety Culture awareness in aviation maintenance organizations is necessary for the performance of effective maintenance and the safe operation of aircraft. Maintenance organizations that promote a strong culture of safety encourage honesty and integrity within the workplace. The environment where maintenance is performed differs from other aviation related operations. The promotion of safety in maintenance operations has been proven over time in publications written by the earliest pioneer in aviation safety, Jerome Lederer. The awareness of safety culture in aviation maintenance has evolved with the industry to the present day.


The Changing Face Of Airmanship And Safety Culture Operating Unmanned Aircraft Systems, Tracy Lamb May 2019

The Changing Face Of Airmanship And Safety Culture Operating Unmanned Aircraft Systems, Tracy Lamb

Student Works

The notion of using drones for commercial purposes has evolved in the past 5 years from the initial “boom” of excitement around this, somewhat of a novelty and curiosity, to more calculated and sophisticated use of unmanned aircraft systems (UAS), or drones. In the hands of true professionals, drones can offer highly efficient and profitable solutions for industrial, and commercial inspections and other data capturing tasks. The appetite for safe and efficient collection of data is a changing face of safety cultures and how teams and individuals apply airmanship principles, and how inspection crew and UAS crew interact. UAS are …


Aviation Safety Action Program In The United States Air Force: Mobility Aircrews’ Intentions To Use Safety Reporting, Travis Jared Whittemore May 2019

Aviation Safety Action Program In The United States Air Force: Mobility Aircrews’ Intentions To Use Safety Reporting, Travis Jared Whittemore

Doctoral Dissertations and Master's Theses

No abstract provided.


Search And Rescue: The Importance Of Using Tracking Systems In Rural 135 Operations, April Larsen, Brent D. Bowen Apr 2019

Search And Rescue: The Importance Of Using Tracking Systems In Rural 135 Operations, April Larsen, Brent D. Bowen

Student Works

In January 2020, under the NextGen initiative put in place by the Federal Aviation Administration (FAA), all aircraft flying in controlled airspace, both general aviation and commercial operations, will be required to have an Automatic Dependent Surveillance – Broadcast (ADS–B) system installed and operational. However, this is not required for Title 14 Code of Federal Regulations (CFR) Part 135 operations taking place outside of controlled airspace. Part 135 of the Federal Aviation Regulations (FAR) refers to aircraft operating as on-demand or air taxi services. A substantial amount of these operator’s bases, as well as flights, are conducted outside of controlled …


High Consequence Safety Research And Policy: The Us Airline Application, Calissa Spooner, Tori Kobayashi, Brent D. Bowen Apr 2019

High Consequence Safety Research And Policy: The Us Airline Application, Calissa Spooner, Tori Kobayashi, Brent D. Bowen

Student Works

The implementation of safety programs in Flight Operations has been successful since the Federal Aviation Administration formally introduced Safety Management Systems (SMS) procedures in 2000. The addition of safety programs like SMS into aviation organizations has been confirmed to improve safety culture, communication, and overall hazard mitigation. This research explores the changes and improvements that are made in maintenance programs where an SMS is formally implemented. In the United States it is legal for children under the age of twenty-four months to fly in commercial aircraft on the lap of a parent or guardian, while being unsecured or unrestrained. Throughout …


Aviation Safety, Quality, And Economic Impact: A Policy Research System, Calissa Spooner, Tori Kobayashi, Cindy Greenman, Brent D. Bowen, Kaetlyn Blocker Apr 2019

Aviation Safety, Quality, And Economic Impact: A Policy Research System, Calissa Spooner, Tori Kobayashi, Cindy Greenman, Brent D. Bowen, Kaetlyn Blocker

Student Works

The United States airline industry is experiencing an underlying mix of challenges in areas of Quality, Safety, and Economics. This research focuses on three major components and the economic impact of each. The first aspect, Airline Quality and Safety Analysis, lays down a focus on imperative safety factors that affect major airlines in overall performance. Quality and Safety findings relate to potential safety shortcomings in the second aspect, aviation maintenance Safety Management Systems (SMS). The third aspect involves implementing the Policy Research Construct (PRC) methodology, which relates the underlying challenges in Airline Quality, Safety, and Economic areas by conducting research …


Efficacy Of The Localized Aviation Mos Program In Ceiling Flight Category Forecasts, Douglas D. Boyd, Thomas A. Guinn, Thomas A. Guinn Mar 2019

Efficacy Of The Localized Aviation Mos Program In Ceiling Flight Category Forecasts, Douglas D. Boyd, Thomas A. Guinn, Thomas A. Guinn

Publications

(1) Background: Flying in instrument meteorological conditions (IMC) carries an elevated risk of fatal outcome for general aviation (GA) pilots. For the typical GA flight, aerodrome-specific forecasts (Terminal Aerodrome Forecast (TAF), Localized Aviation Model Output Statistics Program (LAMP)) assist the airman in pre-determining whether a flight can be safely undertaken. While LAMP forecasts are more prevalent at GA-frequented aerodromes, the Federal Aviation Administration (FAA) recommends that this tool be used as supplementary to the TAF only. Herein, the predictive accuracy of LAMP for ceiling flight categories of visual flight rules (VFR) and instrument flight rules (IFR) was determined. (2) Methods: …


Flight Data Analysis: A Mixed Methodology Construct, Tori Kobayashi, Brent D. Bowen, Brian J. Roggow Feb 2019

Flight Data Analysis: A Mixed Methodology Construct, Tori Kobayashi, Brent D. Bowen, Brian J. Roggow

Student Works

This exploratory study utilizes large data sets emanating from flight data recorders on a fleet of general aviation training aircraft. These flight data sets reveal and provide potential correlations between pilot experience levels and in-flight engine events within a flight school environment. The origin of this research comes from the collection of flight data that is produced during a flight school aircraft operation and analyzed by an Aviation Safety staff at a major flight training university. These data were collected over a period of six calendar months during the calendar year 2018. The raw data is analyzed through a Flight …


Beyond 2020 Nextgen Compliance: Human Factors And Cognitive Loading Issues For Commercial And General Aviation Pilots, Mark D. Miller, Sam Holley Jan 2019

Beyond 2020 Nextgen Compliance: Human Factors And Cognitive Loading Issues For Commercial And General Aviation Pilots, Mark D. Miller, Sam Holley

Publications

As previously identified by the authors, digitized flight decks have realigned SHELL model components and introduced cognitive overload con­cerns. Considering changes from implementing Next Generation air traffic management requirements in 2020, the authors assess digitized interfaces associated with cockpit displays of information integral to performance based navigation and similar operations. Focus is placed on Automatic Dependent Surveillance Broadcast, digitized communications, and expanded electronic flight bags. The ADSB (In) cockpit display will enable pilots to have flight visual awareness on aircraft, terrain, weather and hazards to flight through live satellite updates every second. Increased optical demands and cognitive loading are anticipated …


Low Level Turbulence Detection For Airports, Anthony O' Connor, Derek Kearney Jan 2019

Low Level Turbulence Detection For Airports, Anthony O' Connor, Derek Kearney

International Journal of Aviation, Aeronautics, and Aerospace

Abstract—— Low level wind shear and turbulence present a serious safety risk to aircraft during the approach, landing and take-off phases. Despite many advances in on-board and ground based warning systems. Wind shear remains a formidable force that coupled with a microburst can overpower any aircraft. Aviation reports have concluded that pilots need to have improved information in relation to tailwinds, wind shear and wind variations on approach and during the landing phases. Low level wind shear continues to cause disruption, delays and contribute to aircraft crashes. As recently as 2016, two Boeing aircraft crashed while attempting a Go-around …


Effects Of Exit Doors And Number Of Passengers On Airport Evacuation Effeciency Using Agent Based Simulation, Jie Chen, Dahai Liu, Sirish Namilae, Sang-A Lee, Jennifer E. Thropp, Younho Seong Jan 2019

Effects Of Exit Doors And Number Of Passengers On Airport Evacuation Effeciency Using Agent Based Simulation, Jie Chen, Dahai Liu, Sirish Namilae, Sang-A Lee, Jennifer E. Thropp, Younho Seong

International Journal of Aviation, Aeronautics, and Aerospace

Many factors determine the efficiency of evacuation at an airport during emergencies. These factors are very complicated and many times, unpredictable. The Federal Aviation Administration provides numerous advisory circulars and regulations for managing airport evacuation. However, a thorough literature review suggests that research on airport evacuation is still very limited. A study was designed to simulate an airport evacuation to address this problem. This study selected a local certificated airport in the United States for this purpose. We developed and validated a situation model using AnyLogic to investigate evacuation time at this airport. Using different variables, such as the number …


Fatigue Identification And Management In Flight Training: An Investigation Of Collegiate Aviation Pilots, Flavio A. Coimbra Mendonca Mr, Julius Keller, Chientsung Lu Jan 2019

Fatigue Identification And Management In Flight Training: An Investigation Of Collegiate Aviation Pilots, Flavio A. Coimbra Mendonca Mr, Julius Keller, Chientsung Lu

International Journal of Aviation, Aeronautics, and Aerospace

Objective: The purpose of this study was to evaluate collegiate aviation students’ self-awareness of their fatigue issues; to investigate possible causes of fatigue afflicting collegiate aviation students; and to investigate the collegiate aviation students’ lifestyle and perceptions of personal solutions to fatigue.

Background: Pilot fatigue is a significant safety hazard in aviation operations. Several factors can contribute to fatigue, including inadequate sleep, long work hours, and inadequate nutritional habits. Some factors, such as social and academic activities, could be unique for Title 14 Code of Federal Regulations (CFR) Part 141 collegiate aviation pilots. Previous studies have addressed fatigue in …


The Application Of Signal Detection Theory Principles To Aircraft Certification, John M. Maris Ph.D, Alexander V. Ilyin Ph.D Jan 2019

The Application Of Signal Detection Theory Principles To Aircraft Certification, John M. Maris Ph.D, Alexander V. Ilyin Ph.D

International Journal of Aviation, Aeronautics, and Aerospace

This paper presents the application of Signal Detection Theory (SDT) concepts to the certification of optional systems that provide operational or system safety benefits. The method and analysis yield quantitative requirements for the system performance that account for the risks and benefits of the potential system. This is in contrast to the standard certification approach which only focuses on Failure Conditions, and does not examine potential system benefits. A case study of an aircraft spotter on an electronic moving map illustrates that substantial safety improvements may be achieved even with the relatively low levels of software reliability associated with Commercial …


Crew Resource Management For Large Unmanned Aircraft Systems Operations, Peter S. Neff Jan 2019

Crew Resource Management For Large Unmanned Aircraft Systems Operations, Peter S. Neff

International Journal of Aviation, Aeronautics, and Aerospace

Abstract

The author explored the application of crew resource management (CRM) principles to commercial flight operations conducted by large unmanned aircraft systems (UAS). Currently, there is no regulatory structure governing the operation of large UAS in commercial flight operations. However, the National Aeronautics and Space Administration (NASA) forecasted the future by demonstrating the feasibility of large remotely piloted UAS flight in June 2018 by flying Ikhana, a modified MQ-9 Predator B aircraft, over a 415-mile route in Class A and in Class E airspace over southern California (Kooser, 2018). Ikhana is a 10,500-pound aircraft with a wingspan of 66 feet …


Development Of A Statistical Model To Predict Australian Flight Students’ Valuation Of Aviation Safety, Michael Chiu, Nickolai Isaksen, Steven Leib Jan 2019

Development Of A Statistical Model To Predict Australian Flight Students’ Valuation Of Aviation Safety, Michael Chiu, Nickolai Isaksen, Steven Leib

Journal of Aviation/Aerospace Education & Research

This study was a quantitative approach to explore whether certain demographic factors, exposure to safety training, flight experience, and engagement could be used to develop a predictive model for how Australian flight students and early career pilots valued safety. Participants were given an online Likert-scale survey to determine their valuation of safety based on SMS safety sub-cultures, safety training, engagement, as well as provided basic demographic metrics including age, flight experience, gender. In addition, a second group of participants representing local Australian culture were given a survey to determine their safety valuation. Linear regression was used to develop the best …


Mro Cybersecurity Swot, Danita Baghdasarin Jan 2019

Mro Cybersecurity Swot, Danita Baghdasarin

International Journal of Aviation, Aeronautics, and Aerospace

This article intended to identify gaps in the safety management system (SMS) framework when it comes to dealing with cyber risks and hazards in the maintenance, repair, and overhaul (MRO) industry. Cybersecurity is currently a concern of the aviation industry, but organizations in the MRO industry do not seem to be aware of any specific risks and hazards and therefore are not prepared to handle them. Concerns are largely around the increasing reach of aviation and the digital transformation of infrastructure, but the body of knowledge does not go into any greater detail. As a result, it is hard to …


Urban Flow And Small Unmanned Aerial System Operations In The Built Environment, Kevin A. Adkins Jan 2019

Urban Flow And Small Unmanned Aerial System Operations In The Built Environment, Kevin A. Adkins

International Journal of Aviation, Aeronautics, and Aerospace

The Federal Aviation Administration (FAA) has put forth a set of regulations (Part 107) that govern small unmanned aerial system (sUAS) operations. These regulations restrict unmanned aircraft (UA) from flying over people and their operation to within visual line of sight (VLOS). However, as new applications for unmanned aerial systems (UAS) are discovered, their capabilities improve, and regulations evolve, there is an increasing desire to undertake urban operations, such as urban air mobility, package delivery, infrastructure inspection, and surveillance. This built environment poses new weather hazards that include enhanced wind shear and turbulence. The smaller physical dimensions, lower mass and …