Formation Geometries and Route Optimization for Commercial Formation Flight

Formation flight provides an effective way to dramatically reduce fuel burn without fundamental changes to the aircraft flying today. A two aircraft echelon formation is investigated along with three different three aircraft formations. A three aircraft inverted-V formation geometry is shown to have many favorable characteristics compared to other formation geometries. All of the aircraft in this formation need very small aileron deflections to trim in roll, for most spanwise spacings the formation is statically stable, and the total formation induced drag is insensitive to high levels of positioning uncertainty. A trade study was conducted to determine the fuel savings and difference in flight times that result from applying formation flight to missions of different stage length and different spacings between the origin cities. For a two aircraft echelon formation, the maximum fuel savings were 4% with a tip-to-tip gap between the aircraft equal to 10% of the span and 10% with a tip overlap equal to 10% of the span . For the three aircraft inverted-V formation, the maximum fuel savings were about 7% with tip-to-tip gaps equal to 10% of the span and about 16% with tip overlaps equal to 10% of the span. A case study examined the use of formation flight on five FedEx flights from the pacific northwest to Memphis, TN. The purpose of this study was to quantify the fuel burn reduction achievable in a commercial setting without changing the flight schedule. With tip-to-tip gaps of about to 10% of the span it was shown that fuel savings of approximately 4% could be achieved for the set of five flights. With a tip-to-tip overlap of about 10% of the span the overall fuel savings are about 11.5% if the schedule is unchanged. This translates to saving approximately 700,000 gallons of fuel per year for the set of five flights.

[1]  John D'Azzo,et al.  Tight Formation Flight Control , 2001 .

[2]  Jason L. Speyer,et al.  Peak-seeking control with application to formation flight , 1999, Proceedings of the 38th IEEE Conference on Decision and Control (Cat. No.99CH36304).

[3]  Mario Innocenti,et al.  Autonomous formation flight , 2000 .

[4]  Jason L. Speyer,et al.  Decentralized controllers for unmanned aerial vehicle formation flight , 1996 .

[5]  Jack D. Mattingly,et al.  Aircraft engine design , 1987 .

[6]  Miroslav Krstic,et al.  Formation Flight Optimization Using Extremum Seeking Feedback , 2003 .

[7]  Max M Munk,et al.  The Minimum Induced Drag of Aerofoils , 1979 .

[8]  William H. Mason,et al.  Optimum spanloads in formation flight , 2002 .

[9]  David Gingras,et al.  Experimental investigation of a multi-aircraft formation , 1999 .

[10]  John-Paul Clarke,et al.  Continuous Descent Approach: Design and Flight Test for Louisville International Airport , 2004 .

[11]  Robert Thomas Jones,et al.  The Spanwise Distribution of Lift for Minimum Induced Drag of Wings Having a Given Lift and a Given Bending Moment , 1950 .

[12]  Louis E Buzogany.  Automated Control of Aircraft in Formation Flight , 1993 .

[13]  Mario Innocenti,et al.  Formation flight control - A behavioral approach , 2001 .

[14]  Rajeeva Kumar,et al.  Adaptive control of UAVs in close-coupled formation flight , 2000, Proceedings of the 2000 American Control Conference. ACC (IEEE Cat. No.00CH36334).

[15]  Ilan Kroo,et al.  An interactive system for aircraft design and optimization , 1992 .

[16]  Geoffrey Bower,et al.  MULTI-OBJECTIVE AIRCRAFT OPTIMIZATION FOR MINIMUM COST AND EMISSIONS OVER SPECIFIC ROUTE NETWORKS , 2008 .

[17]  P. Lissaman,et al.  Formation Flight of Birds , 1970, Science.

[18]  F. Hainsworth.  INDUCED DRAG SAVINGS FROM GROUND EFFECT AND FORMATION FLIGHT IN BROWN PELICANS , 1988 .

[19]  R. J. Ray,et al.  F/A-18 Performance Benefits Measured During the Autonomous Formation Flight Project , 2002 .

[20]  John D'Azzo,et al.  Close formation flight control , 1999 .

[21]  Ilya V. Kolmanovsky,et al.  Predictive energy management of a power-split hybrid electric vehicle , 2009, 2009 American Control Conference.

[22]  Romeo Ortega,et al.  Proceedings of the 42nd IEEE Conference on Decision and Control, 2003 , 2003 .

[23]  Stephen P. Boyd,et al.  Distributed optimization for cooperative agents: application to formation flight , 2004, 2004 43rd IEEE Conference on Decision and Control (CDC) (IEEE Cat. No.04CH37601).

[24]  Jennifer Hansen,et al.  Induced Moment Effects of Formation Flight Using Two F/A-18 Aircraft , 2002 .

[25]  William B. Blake,et al.  Comparison of Predicted and Measured Formation Flight Interference Effects , 2001 .

[26]  Eugene Lavretsky,et al.  F/A-18 AUTONOMOUS FORMATION FLIGHT CONTROL SYSTEM DESIGN , 2002 .

[27]  J.M. Fowler,et al.  A formation flight experiment , 2003, IEEE Control Systems.

[28]  D. Hummel.  Aerodynamic aspects of formation flight in birds , 1983 .

[29]  Jack Ryan,et al.  An Overview of Flight Test Results for a Formation Flight Autopilot , 2002 .

[30]  Romeo Ortega,et al.  Proceedings of the 40th IEEE Conference on Decision and Control, 2001 , 2001 .

[31]  Ashok Gopalarathnam,et al.  Optimum downwash behind wings in formation flight , 2003 .

[32]  Paul R Rohs.  A Fully Coupled, Automated Formation Control System for Dissimilar Aircraft in Maneuvering Formation Flight , 1991 .

[33]  Emilio Frazzoli,et al.  Efficient coordination of multiple-aircraft systems , 2003, 42nd IEEE International Conference on Decision and Control (IEEE Cat. No.03CH37475).

[34]  Cutts,et al.  ENERGY SAVINGS IN FORMATION FLIGHT OF PINK-FOOTED GEESE , 1994, The Journal of experimental biology.

[35]  J.P. Desai,et al.  On controlling aircraft formations , 2001, Proceedings of the 40th IEEE Conference on Decision and Control (Cat. No.01CH37228).

[36]  William A. Crossley,et al.  Point to Point Commercial Aircraft Service Design Study Including Formation Flight and Morphing , 2004 .

[37]  Ashok Gopalarathnam,et al.  Ideal Aerodynamics of Ground Effect and Formation Flight , 2004 .

[38]  Mario Innocenti,et al.  Experimental Evaluation of Vision Algorithms for Formation Flight and Aerial Refueling , 2004 .