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Fossils of the remarkable dromaeosaurid Microraptor gui and relatives clearly show well-developed flight feathers on the hind limbs as well as the front limbs. No modern vertebrate has hind limbs functioning as independent, fully developed wings; so, lacking a living example, little agreement exists on the functional morphology or likely flight configuration of the hindwing. Using a detailed reconstruction based on the actual skeleton of one individual, cast in the round, we developed light-weight, three-dimensional physical models and performed glide tests with anatomically reasonable hindwing configurations. Models were tested with hindwings abducted and extended laterally, as well as with a previously described biplane configuration. Although the hip joint requires the hindwing to have at least 20[degrees] of negative dihedral (anhedral), all configurations were quite stable gliders. Glide angles ranged from 3[degrees] to 21[degrees] with a mean estimated equilibrium angle of 13.7[degrees], giving a lift to drag ratio of 4.1:1 and a lift coefficient of 0.64. The abducted hindwing model's equilibrium glide speed corresponds to a glide speed in the living animal of 10.6 m x [s.sup.-1]. Although the biplane model glided almost as well as the other models, it was structurally deficient and required an unlikely weight distribution (very heavy head) for stable gliding. Our model with laterally abducted hindwings represents a biologically and aerodynamically reasonable configuration for this four-winged gliding animal. M. gui's feathered hindwings, although effective for gliding, would have seriously hampered terrestrial locomotion. biomechanics | bird flight evolution | feathered dinosaurs | model tests | tetrapteryx www.pnas.org/cgi/doi/10.1073/pnas.0911852107

We analyzed differences in wing morphology between sexes and among age classes of Western Sandpipers (Calidris mauri) to assess possible relationships with differential migration, acrobatic aerial displays, and potential vulnerability to predation, using size-constrained component analysis. Data on wing morphology of all four sex and age classes were available from birds spending the nonbreeding season in northwestern Mexico, and data on females were available from throughout the annual cycle. During the nonbreeding season, females had longer and more pointed wings than males. Within each sex, adults had longer and more pointed wings than immature birds. Throughout the annual cycle, adult females tended to have longer and more pointed wings than immature females. The longer and more pointed wings of females are consistent with selection on flight efficiency for longer migration distances. The shorter and rounder wings of males ate consistent with stronger selection for agility in flight during acrobatic aerial displays, but also with weaker selection for flight efficiency because of shorter migration distances. The rounder wings of immature birds ate most consistent with stronger selection for take-off performance as an antipredator adaptation, at a cost of lower flight efficiency during long-distance migratory flight. Considering intraspecific sex and age class differences in wing morphology of species with differential migration complements interspecific comparisons assessing the relative importance of selective agents acting on this character. Key words: aerial displays, Calidris mauri, intraspecific variation, migration distance, vulnerability to predation, Western Sandpiper, wing morphology. Analizamos las diferencias en la morfologia del ala entre sexos y clases de edad de Calidris mauri para evaluar su relacion con la migracion diferencial, los vuelos acrobaticos y el riesgo de depredacion, utilizando un analisis de componentes de tamano restringido. Recolectamos datos sobre la morfologia del ala de ambos sexos y clases de edad durante la epoca no-reproductiva en el noroeste de Mexico, y solo de hembras a traves del ciclo anual. Durante la epoca no-reproductiva, las hembras tuvieron alas mas largas y puntiagudas que los machos. En cada sexo, los adultos tuvieron alas mas largas y puntiagudas que los inmaduros. A traves del ano, las hembras adultas tendieron a tener alas mas largas y puntiagudas que las hembras inmaduras. Las alas mas largas y puntiagudas de las hembras concuerdan con la mayor eficiencia requerida para vuelos migratorios largos. Las alas mas cortas y redondas de los machos concuerdan con la mayor agilidad requerida durante los vuelos acrobaticos, pero tambien pueden relacionarse en cierto grado con la eficiencia de vuelo porque su distancia de migracion es mas corta. Las alas mas redondas de los inmaduros concuerdan con alas adaptadas para aumentar el desempeno durante el despegue y reducir el riesgo de depredacion, a pesar del bajo desempeno durante vuelos migratorios largos. Considerar las diferencias intraespecificas dadas por los sexos y la edad en la morfologia del ala en especies con migracion diferencial, complementa las comparaciones interespecificas que evaluan la importancia relativa de los factores que determinan la morfologia del ala.

Study of Drosphilid wings revealed that phenotypic space had 10 dimensions for 10 wing traits but fewer genetic dimensions. The mismatch in dimensionality of P and G matrix may restrict evolution to fewer dimensions.

Microraptor gui, a four-winged dromaeosaur from the Early Cretaceous of China, provides strong evidence for an arboreal-gliding origin of avian flight. It possessed asymmetric flight feathers not only on the manus but also on the pes. A previously published reconstruction shows that the hindwing of Microraptor supported by a laterally extended leg would have formed a second pair of wings in tetrapteryx fashion. However, this wing design conflicts with known theropod limb joints that entail a parasagittal posture of the hindlimb. Here, we offer an alternative planform of the hindwing of Microraptor that is concordant with its feather orientation for producing lift and normal theropod hindlimb posture. In this reconstruction, the wings of Microraptor could have resembled a staggered biplane configuration during flight, where the forewing formed the dorsal wing and the metatarsal wing formed the ventral one. The contour feathers on the tibia were positioned posteriorly, oriented in a vertical plane for streamlining that would reduce the drag considerably. Leg feathers are present in many fossil dromaeosaurs, early birds, and living raptors, and they play an important role in flight during catching and carrying prey. A computer simulation of the flight performance of Microraptor suggests that its biplane wings were adapted for undulatory 'phugoid' gliding between trees, where the horizontal feathered tail offered additional lift and stability and controlled pitch. Like the Wright 1903 Flyer, Microraptor, a gliding relative of early birds, took to the air with two sets of wings. arboreal origin of flight | Chinese feathered dinosaurs | phugoid gliding | Wright 1903 Flyer

Wing morphology is crucial for flight performance and foraging ecology in bats. We describe variations in 5 wing parameters within the 5 species of European horseshoe bats (genus Rhinolophus) based on data taken from 3,081 adult individuals. All 5 species belong to a single ecological guild. Measurements were taken from live bats in the field in southeastern Europe (Bulgaria, Greece, and Turkey), where all 5 species occur in sympatry. Examination of our data shows that the species and accordingly their wings differ substantially in size. Albeit grossly similar in form, we additionally found several size-independent differences in wing shape. For example, the smallest species, Rhinolophus hipposideros, and to a lesser extent also R. blasii, have extremely short hand wings, enabling highly maneuverable search flight close to vegetation. The largest species, R. ferrumequinum, and the 2nd largest one, R. mehelyi, have rather long hand wings, allowing fast and economic commuting flight over longer distances. We argue that both size and shape are likely to play a role for niche separation between species. We found both sexual and geographic variation within species. There was sexual dimorphism for most parameters, with females being larger than males. Populations of R. mehelyi in southeastern Europe had significant variation in wing measurements. This was not so for R. ferrumequinum and R. euryale. We give a discriminant function based on only 2 parameters that correctly assigned 98% of the 3,081 individuals to species. This function may prove useful for identification of museum specimens. Key words: guild structure, Rhinolophus, wing measurements, wing morphology

The larval development of the Drosophila melanogaster wings is organized by the protein Wingless, which is secreted by cells adjacent to the dorsal-ventral (DV) boundary. Two signaling processes acting between the second and early third instars and between the mid- and late third instar control the expression of Wingless in these boundary cells. Here, we integrate both signaling processes into a logical multivalued model encompassing four cells, i.e., a boundary and a flanking cell at each side of the boundary. Computer simulations of this model enable a qualitative reproduction of the main wild-type and mutant phenotypes described in the experimental literature. During the first signaling process, Notch becomes activated by the first signaling process in an Apterous-dependent manner. In silico perturbation experiments show that this early activation of Notch is unstable in the absence of Apterous. However, during the second signaling process, the Notch pattern becomes consolidated, and thus independent of Apterous, through activation of the paracrine positive feedback circuit of Wingless. Consequently, we propose that appropriate delays for Apterous inactivation and Wingless induction by Notch are crucial to maintain the wild-type expression at the dorsal-ventral boundary. Finally, another mutant simulation shows that cut expression might be shifted to late larval stages because of a potential interference with the early signaling process.

The pattern of development of integumentary structures and associated tissues in the megachiropteran bat Rousettus amplexicaudatus is described on the basis of 18 specimens ranging in crown--rump length (CRL) from 8.5 to 44.4 mm. The ontogenetic sample encompasses specimens that correspond to stages 16 through 22 of the phyllostomid Carollia perspicillata (late-embryonic) as well as fetal stages. Although the earlier stages of R. amplexicaudatus show little deviations in relative timing of anatomy from Carollia, later ones are increasingly different. Integumentary structures show different degrees of developmental penetrance. Derived features in embryonic stages are clearly reflected in adult structures such as a great enlargement of the handplate in relation to the footplate at the moment in which both are fully differentiated. We propose that patagium morphogenesis includes development of dactylopatagium by initial retention and posterior growth of interdigital tissue, coupled with digit elongation; and development of pro-, plagio-, and uropatagium in association with wing muscles unique to bats. Additionally, allometric trends in wingspan, total wing area, arm-wing area, and hand-wing area were estimated with respect to CRL. Changes in the terminology of some Carollia stages (16 and 18) are proposed to facilitate comparisons across bat species. Key words: Chiroptera, development, integument, Megachiroptera, Pteropodidae, Rousettus amplexicaudatus, staging, wing development

The dietary niche and morphological adaptations of a species should be highly correlated. However, conflicting selective pressures may make predictions about diet difficult without additional knowledge of a species' life history. We tested the reliability of predicting a bat's diet from its wing morphology using data for Spix's disk-winged bat (Thyroptera tricolor). The species had been predicted to fall within either the aerial hawking or gleaning foraging group. We compared the results of a theoretical (canonical discriminant function analysis of morphology) and an applied (analysis of droppings) method of diet determination. Our results place T. tricolor in the gleaning functional group with a 77% probability according to morphology. Correspondingly, a large proportion of the diverse diet consisted of nonflying prey, such as spiders, insect larvae, and other silent prey, which should be difficult to detect using echolocation. Although some flying prey were taken, it is clear that T. tricolor regularly gleans prey from surfaces, indicating that for this species, morphology is a useful indicator of diet. However, the breadth of the diet; the high proportion of jumping spiders, leafhoppers, and insect larvae; and the extremely small size of prey were unique features of the diet that could not be predicted from morphology alone. Thus, although comparative statistical methods and the analysis of wing morphology may be helpful to predict the general ecological niche, only detailed investigation of the life history may yield the detail needed for understanding the link between morphology and ecology of individual species. Key words: discriminant function analysis, ecological niche, fecal analysis, gleaning, wing morphology

Investigators report that local heat causes an increase in skin blood flow consisting of two phases. The first is solely sensory neural, and the second is nitric oxide mediated. We hypothesize that mechanisms behind these two phases are causally linked by shear stress. Because microvascular blood flow, endothelial shear stress, and vessel diameters cannot be measured in humans, bat wing arterioles (26.6 [+ or -] 0.3, 42.0 [+ or -] 0.4, and 58.7 [+ or -] 2.2 [micro]m) were visualized noninvasively on a transparent heat plate via intravital microscopy. Increasing plate temperature from 25 to 37[degrees]C increased flow in all three arterial sizes (137.1 [+ or -] 0.3, 251.9 [+ or -] 0.5, and 184.3 [+ or -] 0.6%) in a biphasic manner. With heat, diameter increased in large arterioles (n = 6) by 8.7 [+ or -] 0.03% within 6 min, medium arterioles (n = 8) by 19.7 [+ or -] 0.5% within 4 min, and small arterioles (n = 8) by 31.6 [+ or -] 2.2% in the first minute. Lidocaine (0.2 ml, 2% wt/vol) and [N.sup.G]-nitro-L-arginine methyl ester (0.2 ml, 1% wt/vol) were applied topically to arterioles (~40 [micro]m) to block sensory nerves, modulate shear stress, and block nitric oxide generation. Local heat caused only a 10.4 [+ or -] 5.5% increase in diameter with neural blockade (n = 8) and only a 7.5 [+ or -] 4.1% increase in diameter when flow was reduced (n = 8), both significantly lower than control (P < 0.001). Diameter and flow increases were significantly reduced with [N.sup.G]-nitro-L-arginine methyl ester application (P < 0.05). Our novel thermoregulatory animal model illustrates 1) regulation of shear stress, 2) a nonneural component of the first phase, and 3) a shear-mediated second phase. The time course of dilation suggests that early dilation of small arterioles increases flow and enhances second-phase dilation of the large arterioles. nitric oxide; in vivo; shear stress doi:10.1152/ajpregu.00929.2005.

We report the wing bones of a small passeriform bird from the early Oligocene of France, which are among the earliest fossil remains of Passeriformes in Europe. The specimen is clearly distinguished from oscines, to which all extant European passeriforms belong, and closely resembles suboscine passerines in presumably derived features. If future, more complete specimens support its assignment to the suboscines, it would be the earliest fossil record of this passeriform taxon. Together with other fossils from the early Oligocene of Germany, it indicates that nonoscine passerines colonized Europe before the arrival of oscines. Key words: early Oligocene, fossil birds, Passeriformes, suboscines. Anunciamos el hallazgo de huesos del ala de una pequena ave paseriforme del Oligoceno temprano de Francia, que esta entre los restos fosiles mas tempranos de paseriformes en Europa. El especimen se distingue claramente de los oscines, al cual pertenecen todos los paseriformes europeos vivientes, y se asemeja marcadamente a los paseriformes suboscines en rasgos presumiblemente derivados. Si hallazgos futuros de especimenes mas completos apoyan su asignacion a los suboscines, seria el registro fosil mas temprano de este taxon paseriforme. Junto con otros fosiles del Oligoceno temprano de Alemania, este hallazgo indica que los paserinos no oscines colonizaron Europa antes de la llegada de los oscines.

Wing development in Drosophila is a common model system for the dissection of genetic networks and their roles during development. In particular, the RTK and TGF-[beta] regulatory networks appear to be involved with numerous aspects of wing development, including patterning, cell determination, growth, proliferation, and survival in the developing imaginal wing disc. However, little is known as to how subtle changes in the function of these genes may contribute to quantitative variation for wing shape, per se. In this study 50 insertional mutations, representing 43 loci in the RTK, Hedgehog, TGF-[beta] pathways, and their genetically interacting factors were used to study the role of these networks on wing shape. To concurrently examine how genetic background modulates the effects of the mutation, each insertion was introgressed into two wild-type genetic backgrounds. Using geometric morphometric methods, it is shown that the majority of these mutations have profound effects on shape but not size of the wing when measured as heterozygotes. To examine the relationships between how each mutation affects wing shape hierarchical clustering was used. Unlike previous observations of environmental canalization, these mutations did not generally increase within-line variation relative to their wild-type counterparts. These results provide an entry point into the genetics of wing shape and are discussed within the framework of the dissection of complex phenotypes.

Regulation of wingless genes, arrow and DFrizzled-2 receptors by endocytic routing for normal pattern formation in Drosophila wing is presented.

Abstract: Feather mites show a high diversity of distribution patterns on the wings of birds, but we are currently unable to make precise predictions about the distribution of mites on [...]

The role of the homeotic gene Ultrabithorax in regulating signaling pathways during haltere development in embryos of Drosophila is studied.

Butterflies produce complex and diverse wing patterns by mechanisms that are generally unknown. We have employed a pharmacological approach to explore the molecular mechanisms of pattern formation. In a screen of over 200 compounds injected into developing Junonia coenia pupae, we identified several specific sulfated polysaccharides that caused widespread, dose-dependent effects on adult wing patterns. These compounds were well tolerated and permitted butterflies to eclose normally and take flight at moderate levels of effect. Heparin and closely related chondroitin sulfates caused stage-specific expansion of distal and proximal band systems and reduction and repatterning of eyespots. Dextran sulfate and fucoidan, whose structures are widely divergent from heparin and one another, caused contraction of distal and proximal systems, but had no effect on eyespots. Nonsulfated or nonpolymeric saccharides were without effect. Pattern alterations were indistinguishable from those reported for extreme cold shock and exposure to sodium tungstate and 'molsin'. When administered after cold shock or coinjected with heparin, dextran sulfate reversed all patterning effects. We suggest that the primary effect of polysaccharide treatments is to alter the interpretation of gradients of positional information along the proximodistal axis of the pupal wing. Keywords: Butterfly; Pattern formation; Heparin; Morphogen; Wing; Cold shock; Ground plan

Through the evolution of natural flight systems, it is expected that many have been optimized to provide enhanced efficiency. With this in mind the current study was conducted to determine whether flight configurations found in nature might be appropriately applied to fixed-wing mechanical flight systems to provide performance improvements through energy savings. Four different biologically inspired wings were designed and experimentally tested against a planar elliptic configuration used as a baseline. Two of the configurations show performance improvements over the baseline, using two different comparison techniques. Surface oil flow visualizations at the wingtips highlight differences that provide insight into the flow physics of the improvements.

Variation in vein position and wing shape of Drosophila melanogaster depends on many genes. In the following, we report the results of a QTL analysis of wing shape in D. melanogaster. We identified QTL responsible for natural variation for wing shape and analyzed their interactions with developmental genetic signaling pathways important for vein positioning. The QTL analysis indicated that the total number of QTL segregating in this population is likely to be very large. The locations of putative QTL identified in this study were compared to those identified in previous studies and, while there is more correspondence across studies than expected by chance on the third chromosome, the studies appear to have identified different QTL. Using a complementation design, we tested for interactions among these QTL with the Hedgehog and Decapentaplegic signaling pathways, which are important for the development and position of vein pairs L3-L4 and L2-L5. Three QTL showed strong interactions with these two pathways, supporting the hypothesis that these QTL are involved in these pathways. Naturally segregating variation can therefore act through known signaling pathways to produce variation in vein position.

This paper reports geographic variation in wingtip patterns of Black-legged Kittiwakes (Rissa tridactyla) from the circumpolar Arctic. The amount of black in the wingtip increased and the amount of white decreased from Arctic Canada--west Greenland, counterclockwise to the Pacific. Differences were greatest between Pacific and Atlantic, but were also apparent within the Atlantic sample. Patterns of variation were not clinal. Known levels of philopatry in kittiwakes would tend to maintain both phenotypic and genotypic differences between regions, but the similarity of birds from Newfoundland, British Isles, and Barents Sea suggests some degree of dispersal over this wide area. Wingtip pattern data support continued separation of Pacific and Atlantic kittiwakes into two subspecies under the biological species concept. Under the phylogenetic species concept, Pacific and Atlantic Black-legged Kittiwakes may represent two species. Key words: geographic variation, kittiwakes, Rissa tridactyla, taxonomy, wingtip patterns.

The present work is a detailed analysis of the numerical and positional parameters of cell proliferation in all of the derivatives of the wing disk. We have made use of twin clones resulting from mitotic recombination events at three different ages of development. The interfaces between twin clones indicate the relative position in the anlage of the mother cells. Interface types vary with age of clone initiation and with wing regions. They are indicative of the main allocation of postmitotic cells of the growing clones. Growth is exponential and intercalar, i.e., the progeny of ancestor cells becomes more and more separated. Clones are compact, indicating that daughter cells tend to remain side by side. The shape of the clones is wing region characteristic. Subpopulations of cells grow preferentially along veins and wing margins and show characteristic shapes in different pleural regions. The shape and size of the adult wing regions largely depend on the shape of clones and hence of the allocation of successive rounds of daughter cells. The role of mitogenic morphogens in wing size and shape is discussed.

Research is presented concerning the use of a moving ground low-speed wind tunnel to investigate the flowfield phenomena and performance characteristics of a wing subject to ground effect.

Research is presented concerning the modeling of the wing structures of swept and straight aircraft wings which are loaded by external stores. The aeroelastic and structural tailoring of the wings is discussed.

Research is presented concerning the use of the design optimization software ASTROS to analyze and improve aircraft role performance in the Mach number range of 0.8-1.2 at an altitude of 35,000 feet.

Research is presented concerning the postponement of whirl-flutter instability in tilt-rotor aircraft through the wing couplings. An experimental set up which is based on a small-scale model is discussed.

Research is presented concerning the use of an optical motion capture method in the analysis of dynamic and static aeroelastic deformation of structures within wind tunnels. A comparison of results for flutter and free vibration is made.

Research is presented concerning the aerodynamics of small low-aspect-ratio wings on micro aerial vehicles. The experimental measurement of pitching, lift and drag for Reynolds numbers between 60,000 and 200,000 is discussed.

A combined three-dimensional viscous/inviscid analysis method is introduced for wing flowfield calculations.

The use of 3M riblets on reducing viscous drag on a swept wing with a general aviation wing airfoil section at low speeds has been assessed. The surface-pressure distributions, total drag, mean velocity, turbulence intensity and Reynold shear-stress profiles were measured at a chord Reynolds number of 0.75 X 10 raised to the 6th power, at an incidence range of 0 to 6 deg. Results indicate maximum and total viscous drag reductions of 6 and 8%, respectively, at zero incidence. These results are comparable to those obtained on two-dimensional flat plates and airfoils.

The increasing popularity of the aerodynamic development of laminar wings for commercial airplanes has stimulated research on a strategy to employ modern experimental and numerical methods to elucidate on the flow velocities around the wings. Laser Doppler anemometry (LDA) was found to be useful in providing local velocity data. However, special LDA systems have to be developed. Studies on LDA systems revealed two optical units suitable for in-flight velocity measurements on airplane wings.

A study was conducted to analyze buffeting flows over delta wings. Flow visualization and velocity measurements were conducted over a delta wing, over a wide range of angles of attack to examine the transition between helical mode instability and vortex shedding. The interaction between leading-edge vortex breakdown and a rigid flat plate was then examined by flow visualization. Results indicated other unsteady flow phenomena that promote the buffeting of wings and fins.

A study was conducted to analyze the location of the onset of rivulet formation in the surface-water flow over a wing supporting a NACA 4412 airfoil. The rivulet formation was examined using wind-tunnel studies. A framework was then developed to determine the formation of rivulets when the surface-tension shear stress correlates with the interface shear stress created by aerodynamic forces on the liquid. Results indicated that the location of rivulet onset correlated with the aerodynamic shear stress and surface-tension shear stress.

A recessive semi-lethal mutation resulting from the insertion of a P-lacW transposon at the cytological position 23A on the polytene chromosomes of Drosophila melanogaster was found to affect the unfolding and expansion of the wings resulting in a loss of venation and a marked decrease in their size. Lethality was polyphasic with numerous animals dying during early larval development and displaying apparently collapsed tracheal trees. The gene was therefore designated as congested-like tracheae, or colt. The colt mutation resulted from the insertion of a P-lacW transposon within the coding region of a 1.4-kb transcript. Wild-type function was restored by inducing a precise excision of the P-lacW transposon, while a deletion of the colt locus, produced by imprecise excision of the P element, showed a phenotype similar to that of the original P insert. The colt gene consists of a single exon and encodes a protein of 306 amino acids made of three tandem repeats, each characterized by two predicted transmembrane segments and a loop domain. The COLT protein shares extensive homology with proteins in the mitochondrial carrier family and particularly with the DIF-1 protein of Caenorhabditis elegans, which has been shown to be maternally required for embryonic tissue differentiation. Our analysis revealed that zygotic colt function is dispensable for normal embryonic morphogenesis but is required for gas-filling of the tracheal system at hatching time of the embryo and for normal epithelial morphogenesis of the wings.

We measured postnatal changes in wing morphology and flight capability in free-ranging Phyllostomus hastatus (Chiroptera: Phyllostomidae). Area of wing, wingspan, and aspect ratio increased until volancy, while wing loading reached its lowest values at and after weaning. Young began to fly in their 7th week, when wing area, aspect ratio, and wingspan had reached 84, 95, and 89%, respectively, of values for adult females. Foraging time increased as young achieved volancy. Estimates of flight speed and power requirements from theoretical predictions yield flight speeds that are lowest around weaning, power requirements that increase consistently, and a cost of transport that decreases to a constant level at weaning. Thus, wing morphology of young may function to maximize maneuverability and minimize energy requirements during the vulnerable period of first flight. Wing loading of adult females fluctuated greatly with seasonal changes in body mass. Wing loading of nonreproductive females, a factor of their greater wing area and lower body mass, was significantly lower than in males. An upper limit on the ability to accomodate increased mass may affect wing morphology in this species. Key words: Phyllostomus hastatus, Chiroptera, wing loading, flight

Size and shape are fundamental features of organisms. Ideally, the methods used to describe size and shape must be sensitive enough to detect small differences, and at the same time provide interpretation that is visually satisfying. I compared shape of wings among Eptesicus fuscus, Myotis lucifugus, Pipistrellus hesperus, and Tadarida brasiliensis using three methods of morphometric analysis; principal-components analysis on traditional measures of lengths and areas, principal-components analysis of interlandmark distances, and relative-warp analysis. These species were chosen to test the efficacy of each morphometric analysis at discovering and describing differences in both size and shape. Although principal-components analyses provided similar aggregations of species based on variable loadings, only relative-warps analysis provided clear pictures as to how species differ. The molossid bat, T. brasiliensis, had narrower wings than the vespertilionid bats; this shape was not due to compression of the entire wing, but to a complicated rotation around the fifth digit. The vespertilionid bats were difficult to discern based on wing shape alone, but the warp analysis showed that P. hesperus and M. lucifugus are more similar in shape of wing than either is to E. fuscus. Each method of analysis of shape has strengths, but relative-warp analysis provided both the power to discriminate among minor differences in shape of species within families, and the graphical capability to display those differences in a visually pleasing way. Key words: bats, morphometrics, principal components, wing shape, warp analysis

An experiment attempts to explore the role of vorticity distribution in the vortical flow over a delta wing with a 45 deg sweep. The results of the study show that a primary vortex exists where mean velocity excess is around 1.3 U^0 and mean vorticity is at a maximum. Details of the study are presented.

Aircraft designers use delta wings or highly swept slender wings to achieve a balance between maneuverability and performance at high subsonic speeds. A new study uses the surface-reflective visualization technique (SRV) to examine the vortical flowfield of a 65 deg sweep, non-cambered, leading edge delta wing in a high subsonic airflow. The study shows that the SRV system is effective for visualizing flowfields both before and after vortex breakdown. The existence of symmetric and asymmetric vortex breakdown is observed. Details of the study are presented.

A Pareto ranking-based Multiobjective Genetic Algorithm has been applied to a transonic wing planform's multidisciplinary optimization. An analysis model comprising wing-box structure equations, algebraic weight and potential flow was used to identify planform shapes with most fuel weight, least weight and least drag under the constraints of structural strength and lift. A good compromised solution was achieved among various other Pareto solutions.

A method has been developed for enhancing the aileron to improve a high-performance aircraft's roll rate at high dynamic pressure. The adverse twisting of the aileron rotation is counteracted by identifying camber distribution and antisymmetric twist on a realistic flexible wing to recover the lost roll rates. Roll rate is fully recovered at all dynamic pressures via the method for recambering and retwisting the flexible wing. Strain energy is assessed using a full-scale realistic wing.

The flow structure over a delta wing with a leading-edge flap is largely dependent on the flap deflection angle and angle of attack when the flap is statically deflected on the windward side. The vortex breakdown location can be substantially delayed when the oscillating leading-edge flap has a time scale of almost one convection time scale. The vortex breakdown location is not delayed so effectively when the convection time scale is much longer than the oscillating leading-edge flap time scale. There is a phase shift in the development of vortex breakdown due to the vortical structures' mutual interaction over the wing surface.

Vortex invariants are unlikely to be able to provide improvements to existing extended-Betz methods for enhancing the definition of multiple vortex wakes structures. Other methods, such as numerical analysis, may be useful in determining the vortex wakes' rolled-up structure, or other techniques should be sought for enhancing the reliability of the extended-Betz methods. The methods could still be used to estimate the far-field vortex structure, but the predictions have limited applications.

Research shows that deflection of the tapered vortex flaps enhances the lift/drag ratio in a 70 degree delta wing over a narrower lift coefficient range than measured previously for a 60 degree delta wing. The highest lift/drag ratio is achieved for the 70 degree delta wing when the separated region's spanwise length on the vortex flap surface nearly coincides with the vortex flap width. Experiments were undertaken to study the wing sweepback angle's effect on the performance of the vortex flap on a 70 degree delta wing model.

Research shows that the leeward wing half causes unsteady aerodynamics which mostly determine the roll dynamics of a 60 degree delta wing oscillating around a 30 degree inclined axis. The 60 degree delta wing's roll-trim characteristics can be predicted at nonzero sideslip with the use of tools designed for analyzing a 65 degree delta wing's roll oscillations, provided the effective attack angle is near to the roll axis' inclination angle.

Calculation methods are reviewed for prediction and comparison of fatigue performance of various elements under aircraft loading spectra. Discussion is presented of standardized S-N lines, used for damage calculation, and of test results obtained for standardized aircraft wing loading frequency distributions. The predictive accuracy of the relative nominal-stress-approach and of the relative local-strain-approach is verified for various related aircraft loading cases. The prediction of the effect of different design factors (design stress, loading frequency distribution, specimen geometry and material) is discussed for realistic loading spectra. The limitations of the considered fatigue life calculation methods are pointed out.

The critical-state responses of a 65-degree delta wing subjected to ramp-and-hold and harmonic rolling motions were isolated in force and moment experiments. The time it took for the rolling moment coefficient to reach steady-state value was determined for several ramp motions. Relaxation times were large for numerous motions, especially those exceeding the 5-degree critical state. Results also show that roll-rate effects on critical-state transients were insignificant.

A new approach is proposed for predicting high-angle-of-attack, longitudinal aerodynamic properties of slender wing planforms. Vortex breakdown location and its variation with incidence were predicted using a semiempirical method. Vortex lift expressions were also coupled with breakdown predictions. The approach was validated through comparisons with other planforms.

Wichita State University's 2 x 3 ft water tunnel was used to analyze the effect of a canard on delta wing vortices. Delta-shaped wing-generated leading-edge vortices improves aircraft performance at high angles of attack. Results indicate that canard and dynamic pitch motion delays vortex breakdown. However, locating canards close to the main delta wing resulted in favorable delays.

Prandtl's lifting line theory holds that wings in incompressible steady flows are converted to line vortices of variable circulation situated at their quarter-chord lines. The theory presents an equation wherein the quarter-chord vortex circulation is calculated with consideration to the wing section's effective angle of attack and local lift. However, a new asymptotic theory claims that Prandtl's theory can be applied to arched nonplanar wings if a smaller wing sweep is used.

A strain-actuated active aeroelastic wing is subjected to open- and closed-loop tests to demonstrate a novel aeroelastic control actuation method. The tests employed robust control laws and linear quadratic Gaussian (LQG) control laws based on classical rationalization, sensitivity LQG and other models. Results show a significant power spectral density reduction, vibration suppression and load alleviation. However, actuator/sensor and performance metric selection, the authority of piezoelectric actuators, high plant variation and weak multiple input/multiple output control laws limit aeroelastic control performance.

A stability analyzer based on temporal and spatial formulations was used to calculate natural transition and transonic flows of an aircraft. Wing designers employ natural transition approximations for enhancing lift and decreasing skin friction. The analyzer was compared with recognized method developed by the Office National d'Etudes et de Recherches Aerospatiales/Centre d'Etudes et de Recherches de Toulouse. Results show that temporal formulation yielded results similar to those of spatial frequency tracking technique.