Fernando Dones - Academia.edu (original) (raw)

Papers by Fernando Dones

Research paper thumbnail of The RASCAL Vehicle: A Functional View of the Modern Airborne Laboratory

Proceedings of the Vertical Flight Society 79th Annual Forum

Fernando Dones is Boeing Technical Fellow and a recognized expert on Flight Controls Systems and ... more Fernando Dones is Boeing Technical Fellow and a recognized expert on Flight Controls Systems and Fly-by-Wire technology across the aerospace industry. His expertise was developed over a 42 year career making technical leadership contributions on programs such as Advanced Digital/Optical Control System (ADOCS), CH-47, BellBoeing 609, Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL), EMARSS, a variety of other Programs, and Adaptive Vehicle Management System, and designed the Vehicle Management System architecture of the DARPA CRANE vehicle. His contributions to these programs include systems architectures, redundancy management algorithms, FCS actuator servo loop approaches with safety monitors, and software architectures optimized for system safety and handling quality performance. His broad practical experience complemented by deep technical understanding and ability to explain complex concepts make him a highly sought technical advisor and a celebrated mentor. Carl...

Research paper thumbnail of Hazards Analysis and Failure Modes and Effects Criticality Analysis (FMECA) of Four Concept Vehicle Propulsion Systems

suggestions. The authors would like to acknowledge the NASA RVLT Team for sponsoring this work an... more suggestions. The authors would like to acknowledge the NASA RVLT Team for sponsoring this work and for their insight and forward-thinking nature and the FAA for their support in the execution of this project. Their continued insight and support throughout the duration of the project was invaluable. Available from Level of Review: This material has been technically reviewed by NASA technical management.

Research paper thumbnail of An Advanced Fly-By-Wire Flight Control System Designed For Airborne Research - Concept To Reality

Research paper thumbnail of A Systems Engineering Approach for Enabling Research and Development in the Vertical Lift Autonomy Flight Sciences Domain

Research paper thumbnail of Joint Common Architecture (JCA) Recommendations

Research paper thumbnail of Leadership Practices and Professional Needs Among Secondary School Principals: A Phenomenological Study

International Journal of Research Publications, 2020

This phenomenological research project was conducted to explore the leadership practices and prof... more This phenomenological research project was conducted to explore the leadership practices and professional development needs of secondary school principals. It aimed to articulate the lived experiences and characteristics of school principals as curriculum leaders and school managers. The participants for this study were the 5 (five) Secondary School Principals of Secondary Schools of Division of Siargao who already 5 (five) years and above experience in have handling a school. The participants were chosen by purposive sampling. The methods utilized in this study include direct observation, interview and document analysis. Also important in this study was the utilization of triangulation. Mertler (2006) describes triangulation as an invaluable aspect of qualitative research, allowing the researcher to connect various sources of data and establish trustworthy findings with as little bias as possible. This study was guided by the three grand tour questions. The first grand tour question which had three subquestions divulged the lived experiences that secondary school principals encompass in leadership practices. The second grand tour question revealed the professional characteristics and professional needs of the secondary school principals in their role as curriculum leaders and school managers. The last grand tour question was able to expose the emerging themes that can be drawn from the prevailing codes of the lived experiences of the successful school principal. The researcher identified six thematic patterns that were relevant to the research topic. The six predominant themes that emerged were: school principals focused on managing teachers and improving school's feature, school principals created a motivating and engaging learning environment for teachers and students, school principals established sustainable linkages and partnerships with stakeholders, school principals utilized results of assessment in managing performance, school principals exhibit mutual understanding of an effective school leader and school principals expressed the need for professional development. Based on the findings, school principals may consider the emerging themes that were drawn from this study to be applied in their respective administrations. These themes were claimed effective by the seasoned school principal participants hence they are believed to be reliable and significant. Moreover, future research could also be conducted which will replicate this study that would determine how well the findings of this study hold up under different demographic circumstances. It would be especially interesting to conduct a similar study in an area of the country with a larger sample size to allow future researchers to gather richer, varied and comprehensive data of successful school principals.

Research paper thumbnail of <title>Transition of optical sensors for aircraft from engineering to manufacture</title>

Specialty Fiber Optic Systems for Mobile Platforms and Plastic Optical Fibers, 1993

The practices needed to transfer the techniques to fabricate state-of-the-art optical sensor devi... more The practices needed to transfer the techniques to fabricate state-of-the-art optical sensor devices for aircraft applications from a laboratory environment to a production environmental have been analyzed. The experience gained from the development of several types of technologies as applied to sensors has been used as a baseline to generate procedural guidelines to begin the transfer of technology. Views on the design methods required during the development phase, in view of an inevitable production phase are presented.

Research paper thumbnail of Ladar fiber optic sensor system for aircraft applications

SPIE Proceedings, 1993

A ladar fiber optic sensor (LFOS) for aircraft applications is described. Chirped intensity- modu... more A ladar fiber optic sensor (LFOS) for aircraft applications is described. Chirped intensity- modulated ranging is used to estimate linear position. LFOS technology offers several advantages over other fiber optic sensor techniques proposed for aircraft position sensing applications, including small and robust transducer heads, inherent multiplexing capability, and inherent fault isolation capability. LFOS sensors have been integrated inside a flight control surface hydraulic actuator and inside a pilot's sidestick controller. Closed loop operation of the actuator using the LFOS sensor for position feedback was successfully demonstrated in the laboratory. The LFOS sensors in the sidestick controller were used as inputs to fly a flight simulator. The current LFOS interface electronics is contained on two VME circuit cards, with the capability to service four multiplexed sensors. Excellent performance has been achieved. Deviation from linearity over a 7-in. stroke is better than 0.05% of full scale. The RMS measurement noise is less than 15 microns for a 1 millisecond measurement interval.

Research paper thumbnail of <title>Environmental testing of a linear time-division-multiplexed optical position sensor</title>

Fly-by-Light, 1994

Frost condensing on the code plate of an optical transducer may cause degraded performance by dif... more Frost condensing on the code plate of an optical transducer may cause degraded performance by diffusing reflected light. A test was performed to evaluate effects of temperature and humidity on a prototype time domain multiplexed optical position sensor. Temperature was varied from -55 to 125 degree(s)C and humidity from 0 to 100%. In addition, the test attempted to generate frost inside the transducer to interfere with operation of its code plate and read head. Overall, there were no significant losses due to humidity. There was no direct evidence that frost was present on the code plate at any time, though given the mechanical resistance of the transducer shaft at low temperature points, it appears likely that there was some frost buildup. Temperature effects were more pronounced as a loss of 2 dB or more was observed at low temperatures. There was no evidence of frost-induced losses.

Research paper thumbnail of <title>Overview of time division multiplexing sensor technology</title>

Fly-by-Light, 1994

Fiber optic technology has been implemented within diverse areas of aircraft vehicle management s... more Fiber optic technology has been implemented within diverse areas of aircraft vehicle management systems, including propulsion and flight controls. At least four different fiber- based technologies have been demonstrated in the laboratory and some have accumulated flight hours while installed in technology demonstration aircraft. Some key technologies developed thus far include Time Division Multiplexing (TDM), Wavelength Division Multiplexing (WDM), dual wavelength analog, and Ladar. Some variations in these technologies have also been shown to have promise, such as transmissive vs. reflective encoders, where the number of interconnect fibers are reduced. TDM technology has been actively developed since 1982 as a result of the US Army sponsored Advanced Digital Optical Control System program. This paper provides an overview of the TDM technology and its status when viewed in light of the key flight control system requirements. Description of the TDM sensor concept, the associated electronics, delay line fiber technology and fiber connector requirements is provided. A comparison with WDM technology is also described.

Research paper thumbnail of <title>Optical cavity resonance in a fly-by-light flight control system</title>

Fly-by-Light, 1994

Optical pulse reflections in the signal paths of a fly-by-light flight control system employing t... more Optical pulse reflections in the signal paths of a fly-by-light flight control system employing time division multiplexing can interfere with data returning date to the receiver. To determine how reflections of the interrogation pulse may interfere with optical data signals returning from an optical transducer to the flight control computer. Fresnel reflection theory and geometric optics are used to predict the intensity and return times of the pulse reflections at the receiver. A channel with multiple connectors and a 12-bit position transducer is considered as an example of a typical channel in a fly-by-light flight control system. The optical power and return times of the pulse reflections in the example channel are predicted and are compared with the optical power and return time window of the returning data signal. To check the analytical prediction, a dynamic simulation of the example optical channel is used to model the signal behavior. Although the analysis shows that the reflections from the connector interfaces can interfere with the transducer data by arriving at the same time as the data, these spurious signals can be rejected if the optical receiver is designed properly. It is recommended that the Fresnel reflection intensity, the number of disconnects in the interconnect cable and the relative insertion loss of the interconnect cable compared to that of the transducer must be minimized to warrant reliable operation and simpler receiver design.

Research paper thumbnail of An Advanced Fly-By-Wire Flight Control System for the RASCAL Research Rotorcraft: Concept to Reality

There's a problem with your browser or settings. Your browser or your browser's setting... more There's a problem with your browser or settings. Your browser or your browser's settings are not supported. To get the best experience possible, please download a compatible browser. If you know your browser is up to date ...

Research paper thumbnail of The RASCAL Vehicle: A Functional View of the Modern Airborne Laboratory

Proceedings of the Vertical Flight Society 79th Annual Forum

Fernando Dones is Boeing Technical Fellow and a recognized expert on Flight Controls Systems and ... more Fernando Dones is Boeing Technical Fellow and a recognized expert on Flight Controls Systems and Fly-by-Wire technology across the aerospace industry. His expertise was developed over a 42 year career making technical leadership contributions on programs such as Advanced Digital/Optical Control System (ADOCS), CH-47, BellBoeing 609, Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL), EMARSS, a variety of other Programs, and Adaptive Vehicle Management System, and designed the Vehicle Management System architecture of the DARPA CRANE vehicle. His contributions to these programs include systems architectures, redundancy management algorithms, FCS actuator servo loop approaches with safety monitors, and software architectures optimized for system safety and handling quality performance. His broad practical experience complemented by deep technical understanding and ability to explain complex concepts make him a highly sought technical advisor and a celebrated mentor. Carl...

Research paper thumbnail of Hazards Analysis and Failure Modes and Effects Criticality Analysis (FMECA) of Four Concept Vehicle Propulsion Systems

suggestions. The authors would like to acknowledge the NASA RVLT Team for sponsoring this work an... more suggestions. The authors would like to acknowledge the NASA RVLT Team for sponsoring this work and for their insight and forward-thinking nature and the FAA for their support in the execution of this project. Their continued insight and support throughout the duration of the project was invaluable. Available from Level of Review: This material has been technically reviewed by NASA technical management.

Research paper thumbnail of An Advanced Fly-By-Wire Flight Control System Designed For Airborne Research - Concept To Reality

Research paper thumbnail of A Systems Engineering Approach for Enabling Research and Development in the Vertical Lift Autonomy Flight Sciences Domain

Research paper thumbnail of Joint Common Architecture (JCA) Recommendations

Research paper thumbnail of Leadership Practices and Professional Needs Among Secondary School Principals: A Phenomenological Study

International Journal of Research Publications, 2020

This phenomenological research project was conducted to explore the leadership practices and prof... more This phenomenological research project was conducted to explore the leadership practices and professional development needs of secondary school principals. It aimed to articulate the lived experiences and characteristics of school principals as curriculum leaders and school managers. The participants for this study were the 5 (five) Secondary School Principals of Secondary Schools of Division of Siargao who already 5 (five) years and above experience in have handling a school. The participants were chosen by purposive sampling. The methods utilized in this study include direct observation, interview and document analysis. Also important in this study was the utilization of triangulation. Mertler (2006) describes triangulation as an invaluable aspect of qualitative research, allowing the researcher to connect various sources of data and establish trustworthy findings with as little bias as possible. This study was guided by the three grand tour questions. The first grand tour question which had three subquestions divulged the lived experiences that secondary school principals encompass in leadership practices. The second grand tour question revealed the professional characteristics and professional needs of the secondary school principals in their role as curriculum leaders and school managers. The last grand tour question was able to expose the emerging themes that can be drawn from the prevailing codes of the lived experiences of the successful school principal. The researcher identified six thematic patterns that were relevant to the research topic. The six predominant themes that emerged were: school principals focused on managing teachers and improving school's feature, school principals created a motivating and engaging learning environment for teachers and students, school principals established sustainable linkages and partnerships with stakeholders, school principals utilized results of assessment in managing performance, school principals exhibit mutual understanding of an effective school leader and school principals expressed the need for professional development. Based on the findings, school principals may consider the emerging themes that were drawn from this study to be applied in their respective administrations. These themes were claimed effective by the seasoned school principal participants hence they are believed to be reliable and significant. Moreover, future research could also be conducted which will replicate this study that would determine how well the findings of this study hold up under different demographic circumstances. It would be especially interesting to conduct a similar study in an area of the country with a larger sample size to allow future researchers to gather richer, varied and comprehensive data of successful school principals.

Research paper thumbnail of <title>Transition of optical sensors for aircraft from engineering to manufacture</title>

Specialty Fiber Optic Systems for Mobile Platforms and Plastic Optical Fibers, 1993

The practices needed to transfer the techniques to fabricate state-of-the-art optical sensor devi... more The practices needed to transfer the techniques to fabricate state-of-the-art optical sensor devices for aircraft applications from a laboratory environment to a production environmental have been analyzed. The experience gained from the development of several types of technologies as applied to sensors has been used as a baseline to generate procedural guidelines to begin the transfer of technology. Views on the design methods required during the development phase, in view of an inevitable production phase are presented.

Research paper thumbnail of Ladar fiber optic sensor system for aircraft applications

SPIE Proceedings, 1993

A ladar fiber optic sensor (LFOS) for aircraft applications is described. Chirped intensity- modu... more A ladar fiber optic sensor (LFOS) for aircraft applications is described. Chirped intensity- modulated ranging is used to estimate linear position. LFOS technology offers several advantages over other fiber optic sensor techniques proposed for aircraft position sensing applications, including small and robust transducer heads, inherent multiplexing capability, and inherent fault isolation capability. LFOS sensors have been integrated inside a flight control surface hydraulic actuator and inside a pilot's sidestick controller. Closed loop operation of the actuator using the LFOS sensor for position feedback was successfully demonstrated in the laboratory. The LFOS sensors in the sidestick controller were used as inputs to fly a flight simulator. The current LFOS interface electronics is contained on two VME circuit cards, with the capability to service four multiplexed sensors. Excellent performance has been achieved. Deviation from linearity over a 7-in. stroke is better than 0.05% of full scale. The RMS measurement noise is less than 15 microns for a 1 millisecond measurement interval.

Research paper thumbnail of <title>Environmental testing of a linear time-division-multiplexed optical position sensor</title>

Fly-by-Light, 1994

Frost condensing on the code plate of an optical transducer may cause degraded performance by dif... more Frost condensing on the code plate of an optical transducer may cause degraded performance by diffusing reflected light. A test was performed to evaluate effects of temperature and humidity on a prototype time domain multiplexed optical position sensor. Temperature was varied from -55 to 125 degree(s)C and humidity from 0 to 100%. In addition, the test attempted to generate frost inside the transducer to interfere with operation of its code plate and read head. Overall, there were no significant losses due to humidity. There was no direct evidence that frost was present on the code plate at any time, though given the mechanical resistance of the transducer shaft at low temperature points, it appears likely that there was some frost buildup. Temperature effects were more pronounced as a loss of 2 dB or more was observed at low temperatures. There was no evidence of frost-induced losses.

Research paper thumbnail of <title>Overview of time division multiplexing sensor technology</title>

Fly-by-Light, 1994

Fiber optic technology has been implemented within diverse areas of aircraft vehicle management s... more Fiber optic technology has been implemented within diverse areas of aircraft vehicle management systems, including propulsion and flight controls. At least four different fiber- based technologies have been demonstrated in the laboratory and some have accumulated flight hours while installed in technology demonstration aircraft. Some key technologies developed thus far include Time Division Multiplexing (TDM), Wavelength Division Multiplexing (WDM), dual wavelength analog, and Ladar. Some variations in these technologies have also been shown to have promise, such as transmissive vs. reflective encoders, where the number of interconnect fibers are reduced. TDM technology has been actively developed since 1982 as a result of the US Army sponsored Advanced Digital Optical Control System program. This paper provides an overview of the TDM technology and its status when viewed in light of the key flight control system requirements. Description of the TDM sensor concept, the associated electronics, delay line fiber technology and fiber connector requirements is provided. A comparison with WDM technology is also described.

Research paper thumbnail of <title>Optical cavity resonance in a fly-by-light flight control system</title>

Fly-by-Light, 1994

Optical pulse reflections in the signal paths of a fly-by-light flight control system employing t... more Optical pulse reflections in the signal paths of a fly-by-light flight control system employing time division multiplexing can interfere with data returning date to the receiver. To determine how reflections of the interrogation pulse may interfere with optical data signals returning from an optical transducer to the flight control computer. Fresnel reflection theory and geometric optics are used to predict the intensity and return times of the pulse reflections at the receiver. A channel with multiple connectors and a 12-bit position transducer is considered as an example of a typical channel in a fly-by-light flight control system. The optical power and return times of the pulse reflections in the example channel are predicted and are compared with the optical power and return time window of the returning data signal. To check the analytical prediction, a dynamic simulation of the example optical channel is used to model the signal behavior. Although the analysis shows that the reflections from the connector interfaces can interfere with the transducer data by arriving at the same time as the data, these spurious signals can be rejected if the optical receiver is designed properly. It is recommended that the Fresnel reflection intensity, the number of disconnects in the interconnect cable and the relative insertion loss of the interconnect cable compared to that of the transducer must be minimized to warrant reliable operation and simpler receiver design.

Research paper thumbnail of An Advanced Fly-By-Wire Flight Control System for the RASCAL Research Rotorcraft: Concept to Reality

There's a problem with your browser or settings. Your browser or your browser's setting... more There's a problem with your browser or settings. Your browser or your browser's settings are not supported. To get the best experience possible, please download a compatible browser. If you know your browser is up to date ...