Short Flight Research Articles

A Novel Method for Using Small Unoccupied Aerial Vehicles to Survey Wildlife Species and Model Their Density Distribution

There is growing interest from research and conservation groups in the potential for using small unoccupied aerial vehicles (UAVs; <2 kg) to conduct wildlife surveys because they are affordable, easy to use, readily available and reliable. However, limitations such as short flight endurance, and in many situations, aviation regulations, have constrained the use of small UAVs in survey applications. Thus, there is a need to refine survey methods adapted to small UAVs that conform to standard operations within aviation law. We developed a novel survey approach based on a grid sampling design using two multirotor UAVs (Phantom 4 Pros) flying simultaneously, within visual line of sight, from our vessel base-station. We used this approach to assess the fine-scale distribution and abundance of dugongs (Dugong dugon) in the remote waters of the Pilbara, Western Australia during three field seasons across 2 years. We surveyed 64 non-overlapping survey cells in random order one or more times and obtained complete image coverage of each surveyed cell of our 31 km2 survey area. Our sampling design maximizes sampling effort while limiting survey time by surveying four cells, two at a time, from one location. Overall, we conducted 240 flights with up to 17 flights per day (mean = 14 flights per day) and could obtain complete coverage of up to 11.36 km2per day. A total of 149 dugongs were sighted within the 50,482 images which we manually reviewed. Spatially-explicit models of dugong density distribution (corrected for availability and perception bias) were produced using general additive models to identify areas more or less used by dugongs (range of corrected dugong densities across all field season = 0.002–1.79 dugongs per 0.04 km2). Dugong abundance estimates ranged from 47 individuals in June 2019 (CV = 0.17) to 103 individuals in May 2018 (CV = 0.36). Our method, which proved convincing in a real-word application by its feasibility, ease of implementation, and achievable surface coverage has the potential to be used in a wide range of applications from community-based local-scale surveys, to long-term repeated/intensive surveys, and impact assessments and environmental monitoring studies.

High Temperatures Decrease the Flight Capacity of Diaphorina citri Kuwayama (Hemiptera: Liviidae).

Simple SummaryFlight capacity is directly associated with the spread of vector-transmitted plant pathogens. However, vector flight capacity could be affected by environmental conditions such as temperature and humidity. Here, we studied the effect of high temperatures and humidity in the flight capacity of Diaphorina citri, the main vector of the Huanglongbing disease of citrus. Our data suggest that high heat environments affect the propensity of D. citri to engage in long-distance flights, as well as the duration and distance flown, regardless of the humidity level. This information is fundamental to understand the dispersion of D. citri under different environmental conditions. Diaphorina citri Kuwayama (Hemiptera: Liviidae), commonly known as Asian citrus psyllid (ACP), is an invasive insect pest and the vector of the bacterium causing Huanglongbing (HLB), a lethal disease of citrus. In the United States, ACP has been established in all citrus-producing zones, all of which have different environmental conditions. The spread of ACP and, more importantly, HLB, has progressed differently depending on the state, with more rapid spread in Florida and Texas than in California. Climatic variations between the regions are likely a strong factor in the difference in the rate of spread. Despite this, it is unknown how the flight capacity of D. citri is influenced by high temperatures (>30 °C) and subsequently, low humidity experienced in California but not in Texas or Florida. In this study, by using a custom-made, temperature-controlled flight mill arena, we assessed the effect of high temperatures on the flight capacity and flight propensity of D. citri under low (20–40%) and high (76–90%) relative humidity conditions. We found that temperature and humidity influence the propensity to engage in short or long-distance flight events. Psyllids exposed to temperatures above 43 °C only performed short flights (˂60 s), and a high relative humidity significantly decrease the proportion of long flights (≥60 s) at 26 and 40 °C. The flight capacity for insects who engaged in short and long flights was significantly affected by temperature but not by humidity. For long flyers, temperature (in the 26–43 °C range) was negatively correlated with distance flown and flight duration. The most favorable temperature for long dispersion was 26 °C, with suboptimal temperatures in the range of 32–37 °C and the least favorable temperatures at 40 and 43 °C. In conclusion, D. citri is able to fly in a broad range of temperatures and efficiently fly in high and low humidity. However, temperatures above 40 °C, similar to those experienced in semi-arid environments like Southern California or Arizona, are detrimental for its flight capacity.

SIMERICS 해석 프로그램을 이용한 DJI MAVIC PRO Platinum의 공력특성에 대한 수치해석 연구

UAVs (called drones) have been a subject of great interest in recent years due to various applications. However, they still have some technical limitations such as short flight times, limited load capacity and noise. Recently, DJI developed MAVIC Pro Plantium with two interesting features of low-noise blades and trapezoidal arrangement of blades. In the present study, we are to investigate the aerodynamic characteristics of DJI MAVIC PRO Plantium by using SIMERICS MP of SIMERICS in order to improve our understanding of the aerodynamic performance of drones. First, the study on single blade analysis showed that the low-noise blade with winglet produces improved thrust as compared to the original blade without winglet. Also, the interference between multiple blades is significantly dependent on the shape of the arrangement of blades, resulting in different mean thrust and thrust fluctuations.

Influence of solvents on a near-field electrospun straight fine fibre

Near-field electrospinning (NFES) has been pursued in additive manufacturing for the fabrication of artificial extracellular matrix with controlled pattern structures from a continuous straight fine fibre. Due to short flight time, achieving a deposition of a solidified straight fine fibre can potentially be affected by the properties of a solvent. Therefore, this article presents an investigation of the effects of solvents on an NFES straight fine fibre. Dichloromethane (DCM), acetone, chloroform, toluene and dimethylformamide were the five solvents in this investigation. They were tested at the standoff distances of 3, 5 and 10 mm, and by using the needle gauges of 22G, 24G and 26G. According to the results, DCM having a relatively low boiling temperature and moderate dielectric constant delivered the smallest diameter straight uniform fibre. Furthermore, a solvent having a moderate boiling temperature and low dielectric constant is expected to deliver a thinner straight uniform fibre.

Seasonal changes in body size and mass of Red Knots Calidris canutus during autumn migration through southern Baltic

Body size and mass of 1,458 juvenile and 558 adult Knots were measured during autumn migration in Puck Bay, Poland, between 1983 and 1999. The measurements fit well with those gathered along the migration route of Siberian Knots Calidris c. canutus. All linear measurements of adults, except body mass adjusted for size, were significantly higher than those of juveniles. Shorter wing in juveniles than in adults seems to be a general rule regardless of geographical region. Adult females migrated ahead of males, confirmed by decreasing mean measurements. Juveniles carried larger relative energy stores than adults. Puck Bay may be an emergency feeding place for adult Knots, whereas juveniles may use it as one of many stop-over sites. Juveniles were significantly smaller, but had higher adjusted body mass, in late September than earlier, indicating a behavioural difference between late and early birds during preceding stages of migration. Late juveniles probably follow a time-minimising strategy with larger fuel stores and fewer stop-over sites, whereas birds passing in August migrate with very small energetic reserves, making only short flights and stops.

Mosquito Vector Production across Socio-Economic Divides in Baton Rouge, Louisiana.

We investigated the role of socio-economic factors in the proliferation of mosquito vectors in two adjacent but socio-economically contrasting neighborhoods in Baton Rouge, LA, USA. We surveyed mosquito larvae habitat, mosquito larvae, and adult mosquitoes during the summer of 2020. We also evaluated the number of requests for mosquito abatement services in the years preceding the study for each area. While we did not find differences in terms of the most abundant species, Culex quinquefasicatus (F1,30 = 0.329, p = 0.57), we did find a higher abundance of mosquito habitats, particularly discarded tires, as well as larvae (z = 13.83, p < 0.001) and adults (F1,30 = 4.207, p = 0.049) of the species Aedes albopictus in the low-income neighborhood. In contrast, mosquito abatement requests were significantly higher in the high socio-economic neighborhood (z = −8.561, p < 0.001). This study shows how factors such as adjudicated properties, discarded tires and pest abatement requests can influence the abundance of mosquito vectors, disproportionately affecting low-income groups. This study also highlights how Aedes spp. may be better indicators than Culex spp. of socio-economic differences between nearby neighborhoods, due to their short flight range and habitat preferences, and this should be considered in future studies attempting to detect such disparities in the future.

Fuel Tankering: Economic Benefits and Environmental Impact for Flights Up to 1500 NM (Full Tankering) and 2500 NM (Partial Tankering)

The majority of emissions from aviation come from the combustion of the fuel required to operate each flight. Keeping the fuel consumption required for a safe flight to the absolute minimum is therefore the simplest and most effective way to ensure that emissions from that flight are kept to a minimum. In practice, however, the fuel load is determined by each aircraft operator on the basis of a number of criteria maximizing first cost efficiency, rather than fuel savings. In this context, tankering is the practice of carrying more fuel than is necessary for the safe execution of the flight to avoid or minimize refueling at the destination airport. It offers an economic advantage when there is a significant difference in fuel prices between the departure and arrival airports, but considerably increases the amount of emissions produced, because the more fuel an aircraft carries, the heavier it is, and carrying this extra weight increases its fuel consumption. This paper presents the steps followed by EUROCONTROL in conducting a first study to estimate the number of times this practice would offer an economic benefit and the amount of extra CO2 emissions that would result. This study, limited to flights up to 1500 and 2500 NM, corresponding mainly to short and medium-haul flights, estimates that, in 2018, 21% of ECAC (In this paper, ECAC refers to the geographical region defined by the 44 member states that signed the European Civil Aviation Conference) flights would perform fuel tankering beneficially. This would represent a net saving of 265 M€ per year for the airlines, but the burning of 286,000 tonnes of additional fuel (equivalent to 0.54% of ECAC jet fuel used), or 901,000 tonnes of CO2 per year. At a time when aviation is challenged for its contribution to climate change, the use of fuel tankering for economic reasons is therefore highly questionable.

From Space Tourism to Commercial Suborbital Travel

After several announcements last years, the recent successful flights with Jeff Bezos and Richard Branson as passengers have brought the space tourism topic back at the top of news headlines. Indeed, several projects have undergone incremental and careful development steps last years to ensure a sufficient reliability of such flights with passengers on board. The perfect re-entry of both the New Shepard system of Blue Origin and the Unity system of Virgin Orbit in July 2021 are now opening the path for commercial space tourism flights, with several hundreds of candidates having paid either substantial advance payments or even the total ticket price and a rising demand after these demonstrations. This evolution can be compared with the first flights in the aeronautical field starting in 1919, when, at the end of WW1, experienced pilots and proven (ex-military) planes were used to carry air tourists at short turn-around flights. This rapidly evolved a few years later in regular commercial Point-to-Point air traffic, with the first air connection Paris London Paris. We can easily forecast a similar evolution in suborbital transport of cargo and passengers after the first wave of space tourism. Similar as with the first aviation tourism, where passengers got a first sensation of flying and were then brought back to the starting point after a few minutes, suborbital space experience will soon evolve in so called pointto-point suborbital flights, covering intercontinental travel in 60-80 minutes in one go, which now takes up more than 21 hours, like a trip London-Sydney with one stopover. This article will focus on the feasibility of such development, focusing in the first place on the potential business case and the economic rationale. It will be demonstrated that for ‘time-poor, cash-rich’ people such suborbital intercontinental travel will be a viable option and a potential market.

Modeling and Control of a Quadrotor UAV Equipped With a Flexible Arm in Vertical Plane

In the field of unmanned aerial vehicles (UAVs), aerial manipulations are receiving considerable attention because of their potential application to tasks such as pick and place, detection, and inspection. However, short flight endurance times and concerns about the safety to surroundings during interacting heavily limit the expansion of aerial manipulations in real implementations. To overcome these challenges, this paper focuses on a system in which a quadrotor UAV is equipped with a lightweight and flexible arm. Based on the infinite-dimensional dynamics, the mathematic model of system is described by a hybrid partial differential equation-ordinary differential equation (PDE-ODE). An easily implementable controller is derived from a Lyapunov functional construction related to the energy of the system. The proposed controller ensures global Lyapunov stability for nonlinear system and local asymptotic stability for the linearized system. Further, it is shown that the proposed controller realizes stable motion of the aerial manipulator as well as vibration control of the flexible arm. Finally, numerical simulations are conducted to investigate the validity of the proposed controller.

Wilbur Wright Meets Lady Liberty by Robert Burleigh

Reviewed by: Wilbur Wright Meets Lady Liberty by Robert Burleigh Elizabeth Bush Burleigh, Robert Wilbur Wright Meets Lady Liberty; illus. by Wendell Minor. Ottaviano/Holt, 2021 [40p] Trade ed. ISBN 9781627793681 $19.99 Reviewed from digital galleys R 5-8 yrs Skeptics turned into believers on September 29, 1909, when Wilbur Wright glided into the air over New York Harbor, circled around the Statue of Liberty, and made a perfect landing to the gasps of appreciation of thousands of onlookers, many of whom had doubted this flying thing was for real. Burleigh offers a short account of a short flight but maximizes the tension and triumph by drawing out the details, from Wright's attire ("Has this man—dressed like an ordinary office worker … really invented a machine that can fly?") to the tricky maneuvering around Lady Liberty ("If even one tip of the Flyer's wing touches the stature, he will spin crazily out of control and plunge to his death"). Minor's watercolors situate viewers on the ground, sharing the view, and in the pilot's seat, sharing the challenge. The audience is also privy to fictionalized conversations among a father, mother, and son, each with a different take on Wright's upcoming glory or doom; only deep within the endnotes is the boy identified as Juan Trippe, who actually attended the event and would go on to become a pivotal figure in commercial aviation. Appropriate to the title, Lady Liberty takes pride of place in many scenes. Notes on the Wrights' earlier flights, and the pair of 1909 flights over New York, are appended. Copyright © 2021 The Board of Trustees of the University of Illinois

Spring-loaded body mass equivalent horizontal reactive countermovement jump ground contact and flight times, but not peak forces, are comparable to vertical jumping

Horizontal (cylinder-based) sledge jumping has been shown to ameliorate multi-system deconditioning induced by long-term bed-rest. However, biomechanics differ from 1 g vertical jumping, in particular prolongation of ground contact times (GCT), reduction of peak force, rate of force development (RFD) (and presumably stretch shortening cycle [SSC] efficacy) and stiffness, whilst also requiring relatively complex equipment. Thus, we sought to determine if horizontal spring-loaded countermovement jumps were more analogous to vertical jumping.9 healthy (5 female) subjects (27 ± 7yrs; 169.0 ± 5.3 cm; 63.6 ± 2.6 kg) performed 10 reactive countermovement jumps vertically, and horizontally (randomized) when lay on a spring-loaded carriage performed against loading (at lift-off) equivalent (±6%) to their body weight. Jump kinetics, kinematics and lower limb/trunk electromyographic activity were compared between conditions (paired t-tests).Mean flight and GCTs did not differ, however, peak jump height (p = 0.003; d = −0.961) was greater when jumping horizontally. In contrast, ground reaction forces (zGRF) during take-off (p < 0.001; d = 1.645) and landing (p = 0.002; d = 1.309), peak acceleration (p = 0.001; d = 1.988), leg stiffness (p = 0.001; d = 2.371) and RFD (p = 0.023; d = 1.255) were lower horizontally. Mean rectus femoris activity was lower during landing (p = 0.033; d = 0.691) when horizontal, but did not differ during either take-off or land-lift. Mean medial gastrocnemius activity was significantly (p = 0.018; d = 0.317) lower during horizontal take-off.Spring-loading (1 g at take-off) maintained short GCTs and flight times presumably maintaining muscle SSC efficacy in a manner that appears intuitive (in young active subjects), simple, robust and potentially compatible with spaceflight. Whether appropriate jump characteristics can be achieved in older subjects and in μg/hypogravity needs to be determined. However, greater jump height, lower peak zGRF, RFD and leg stiffness along with reduced lower limb and trunk muscle activity suggests that 1 g at take-off is insufficient to replicate vertical jump biomechanics. Thus, further investigation is warranted to optimize, and evaluate spring-loaded jumping as a gravity-independent multi-systems countermeasure on Earth, and in Space.

The Impact of Illegal Waste Sites on the Transmission of Zoonotic Cutaneous Leishmaniasis in Central Tunisia

Illegal waste disposal represents a risk health factor for vector-borne diseases by providing shelter for rodents and their ectoparasites. The presence of the Phlebotomus papatasi vector of Leishmania major, an etiologic agent of zoonotic cutaneous leishmaniasis (ZCL), was assessed at illegal waste sites located at the vicinity of villages in endemic areas of Central Tunisia. The study was performed over a two-year period over three nights from July to September 2017, and over three nights in September 2018. Household waste is deposited illegally forming dumpsites at the vicinity of each village and contains several rodent burrows of Psammomys obesus, the main reservoir host of L. major. Sandflies were collected from rodent burrows in the natural environment and in dumpsites using sticky traps and were identified at species level. Female sandflies were tested for the presence of L. major by PCR. Our entomological survey showed that Phlebotomus papatasi is the most abundant sandfly species associated with rodent burrows in these waste sites. The densities of P. papatasi in dumpsites are significantly higher compared to the natural environment. The minimum infection rate of P. papatasi with L. major in these illegal waste sites is not significantly different compared to the natural environment. Considering the short flight range of P. papatasi, increases in its densities, associated with burrows of P. obesus in illegal waste sites located at the edge of villages, expands the overlap of infected ZCL vectors with communities. Thus, illegal waste sites pose a high risk of spreading ZCL to neighboring home ranges. Waste management is an environmentally friendly method of controlling sandfly populations and should be included in an integrated management program for controlling ZCL in endemic countries.

Experience Using a Forehead Continuous Deep Temperature Monitoring System During Air Evacuation

ObjectiveThe present study describes the utility of a forehead continuous deep temperature monitoring system by the staff members of a doctor helicopter (DH). MethodsA questionnaire survey was performed for all flight doctors who had used this system during transportation by the DH to assess its merits and demerits. ResultsThe major benefits of this system were its easy usability, disposable nature, low labor cost, continuous demonstration of the deep temperature in a prehospital setting, and low invasiveness. However, drawbacks of this system include its cost; need for a power supply; need for a few minutes for calibration to obtain stable results of temperature, making it impossible to verify the effects of intervention for body temperature during a short flight; and lack of a detachable measuring pad for the forehead when a patient has an injury on the face or head and hyperhidrosis. In addition, the system's attached cables may hamper medical interventions. ConclusionWe reported the experience of DH staff using a forehead continuous deep temperature monitoring system in the prehospital setting. Further studies will be required to determine the indications for using such a system in the prehospital setting.

Significance of residual stresses in fatigue life prediction of micro gas turbine blades

The aim of this study is to investigate the significance of residual stresses in fatigue analyses of micro gas turbine blades in order to attain accurate fatigue life estimates; such studies have not been adequately investigated. This was achieved by manufacturing test samples using Additive Manufacturing (AM). The samples were subsequently heat-treated in order to mimic the operating conditions of the engine and then evaluated experimentally for the presence of residual stresses. In order to incorporate these residual stresses into engine operating conditions, an ABAQUS Finite Element Analysis (FEA) was conducted to define stresses which are effective during operation. Subsequently, a fatigue software (Fe-safe) was used to determine the fatigue behavior of the bladed disk while taking into consideration the in-plane residual stresses. The results acquired from this study showed an average residual stress contribution of 70% towards the fatigue life estimated cycles to failure of engines undertaking short flight missions. As the flight time increases, the residual stress influence decreases due to stress relaxation. This study, therefore, concluded that the inclusion of in-plane residual stresses in fatigue life estimates is significant for turbine blades operating at short flight time intervals with less effect on long mission operations.

Numerical study of debris flight in a tornado-like vortex

This paper presents the numerical study on the flight behaviour of spherical compact debris in a tornado-like wind field. The tornado-like vortex corresponding to a swirl ratio of 0.7 was generated using Large-eddy Simulation and the trajectories of 2250 individual debris particles placed in the flow were computed using Lagrangian-particle tracking. The debris corresponded to five groups (A, B1, B2, B3 and C) based on the value of the Tachikawa number (K) which ranged between 0.6 and 2.5. An analysis of the simulated flow field revealed that the tornado-like vortex consisted of two main features - a core at the centre with low velocity (∼0.25 m/s) which was surrounded by thick vortex wall composed of high velocity magnitudes (∼9.4 m/s). Updraft flows were observed around the core of the vortex and as a result, debris positioned around the core radius region were found to be 24% more likely to become wind-borne than debris positioned at the vortex wall region. Three groups of debris (B1, B2 and B3) with varying mass and density were studied for the aerodynamic similarity by retaining the fixed value of K = 1.2; all three debris groups exhibited the propensity to travel with similar flight characteristics. An analysis of the data pertaining to the fight behaviour of the three debris group (A, B1 and C) with varying K revealed that the low mass debris group A (K = 2.5) had the highest propensity to become wind-borne and was more likely to travel for the longest time with considerable variability observed in individual debris trajectories. However, somewhat counterintuitively, the high mass debris group C (K = 0.6) were found to have the furthest impact range despite their short flight duration; this was due the high mass debris being ejected out of the vortex with greater inertia, while debris with a lower mass had a tendency to be trapped in the flow that circulates around the vortex core.

Kablolu İHA Sistemleri ve Uygulamaları

Son yıllarda İHA sistemlerinin sivil ve askeri kullanımı hızla artmaktadır. Ancak uçuş sürelerinin kısa olması ve faydalı yük kapasitelerinin düşük olması gibi önemli kullanım kısıtları mevcuttur. Gelişen teknolojiyle birlikte İHA’ların bu kullanım kısıtlarına çözüm önerisi olarak farklı yapılarda İHA sistemleri tasarlanmıştır. Kablolu drone sistemleri ve kablolu aerostat sistemleri genel kabul görmüş çözümlerden birkaçıdır. Kablolu drone sistemleri daha düşük irtifalarda kesintisiz görev yapabilen drone temelli bir çözümdür. Bu çalışmalar sayesinde farklı uygulama alanlarında hizmet verilmeye başlanmıştır. Bu çalışmada İHA sistemleri ile bu sistemlerin avantaj ve dezavantajları sunulmuştur. Ayrıca kablolu drone ve kablolu aerostatların çalışma yapıları anlatılmış ve kullanım alanlarıyla ilgili örnekler verilmiştir.

Inciting the past: Okinawan literature and the decolonising turn

This article reads contemporary Okinawan literature in relation to the increasingly urgent question of decolonisation, focusing on the writing of Sakiyama Tami. Sakiyama’s texts are radically playful, inciting the materiality of Japanese orthographies to create a literary language of difference. These strategies are both deconstructive and destructive in their efforts to express the multilingual reality of contemporary Okinawa against a history of war and oppression. However, Sakiyama’s writing shows how such strategies are necessary to give authentic voice to Okinawa’s experiences of violent military occupation and resist the appropriation of those narratives by national Japanese literary or linguistic standards. The urgency of this project emanates from the context of historical revisionism against which these texts were written, and a contemporary political climate in which Okinawans and their efforts to speak out against their ongoing colonisation have been being framed in terms of terrorism or erased. In Sakiyama’s texts, questions of language, memory, history and violence abound, and suggest links between her work and a wider project of decolonisation that has only just begun in East Asia. This article seeks to trace the strategies with which Sakiyama incites these questions through her 2002 essay Shimakotoba de kachāshī and a short story Night Flight on Pingihira Hill, first published in 2007. Since both texts remain untranslated into English, and even challenge the act of translation by celebrating linguistic distinctions, this essay seeks to forge a productive encounter to enliven both studies of Okinawan fiction and broader decolonising approaches to literature envisaged therein.

Correlation RTOF diffractometry at long-pulse neutron source: II. Analysis of frequency windows and diffraction peak profiles

Neutron RTOF diffractometry is a special correlation technique, combining the use of a fast Fourier chopper for modulation of the incident neutron beam intensity and the reverse time-of-flight (RTOF) method for data acquisition. This approach allows one to achieve a high-resolution level of the instrument over a wide range of interplanar spacing dhkl at a relatively short flight distance between the chopper and the sample position. Recently, a new high-performance DAQ system for recording RTOF data in a list mode was implemented on high-resolution Fourier diffractometers operating at the long-pulse neutron source – the IBR-2 reactor – in FLNP JINR (Dubna, Russia). One of the most important features of list-mode data acquisition is the possibility to analyze real frequency window of the Fourier chopper and compensate the chopper phase mismatch, which is crucial for obtaining diffraction peaks with a symmetric Gaussian profile. This paper discusses the experience of using list-mode DAQ for analysis of real frequency windows reconstructed from pickup signal events. In addition, a comparison of various frequency windows and their influence on the diffraction peak shape is performed.

Integrating light‐level geolocation with activity tracking reveals unexpected nocturnal migration patterns of the tawny pipit

Migratory birds complete their seasonal journeys between breeding and non‐breeding sites with a series of migratory flights that are separated by prolonged stopovers. While songbirds are the most common taxa among migratory birds, empirical data on flight and stopover behaviour along their entire migratory journeys are still rare. Here, we integrate activity and barometric pressure tracking with classical light‐level geolocation to describe migration behaviour of tawny pipits Anthus campestris breeding in central Europe. Surprisingly, tracked pipits used, on average, as many as 10 stopover sites during their six week, &gt; 5000 km long autumn migration. This conforms to a typical hop‐type pattern of migration. In contrast to common knowledge which considers the tawny pipit as a typical diurnal migrant, our data revealed that more than two thirds of all migratory movements were carried out at night. Nocturnal departure times were highly variable within individuals and spread across the entire night while landing most often took place within the first few hours after sunrise. Consequently, there was a negative relationship between departure timing relative to sunset and flight duration. Short flights of up to 2 h were most common and median flight duration was 4.5 h. There was a hyperbolic relationship between flight duration and maximum flight altitude and flight altitudes during night were two times higher compared to daytime. The overall ratio of flight versus stopover duration during migration was on average 1:6.5. This closely matches predictions from theoretical models. We show that multi‐sensor tracking has the potential to provide unprecedented details on migratory behaviour of individual birds along their entire migratory journeys, and it also improves the precision of geographical locations derived from light‐level geolocators.

Commercial airline protocol during COVID-19 pandemic: An experience of Thai Airways International.

Coronavirus disease 2019 (COVID-19) pandemic has affected the aviation industry. Existing protocols have relied on scientifically questionable evidence and might not lead to the optimal balance between public health safety and airlines' financial viability. To explore the implementation feasibility of Thai Airways International protocol from the perspectives of passengers and aircrews. An online questionnaire survey of passengers and an in-depth interview with aircrews. Two randomly selected repatriation flights operated by Thai Airways International using Boeing 777 aircraft (TG476 from Sydney and TG492 from Auckland to Bangkok). 377 Thai passengers and 35 aircrews. The mean age of passengers was 28.14 (95%CI 26.72 to 29.55) years old; 57.03% were female. TG492 passengers were mostly students and significantly younger than that of TG476 (p<0.0001) with comparable flying experience (p = 0.1192). The average body temperature was 36.52 (95%CI 36.48 to 36.55) degrees Celsius. Passengers estimated average physical distances of 1.59 (95%CI 1.48 to 1.70), 1.41 (95%CI 1.29 to 1.53), and 1.26 (95%CI 1.12 to 1.41) meters at check-in, boarding, and in-flight, respectively. Passengers were checked for body temperature during the flight 1.97 (95%CI 1.77 to 2.18) times on average which is significantly more frequent in longer than shorter flight (p<0.0001). Passengers moved around or went to the toilet during the flight 2.00 (95%CI 1.63 to 2.37) and 2.08 (95%CI 1.73 to 2.43) times which are significantly more frequent in longer than shorter flight (p = 0.0186 and 0.0049, respectively). The aircrews were satisfied with the protocol and provided several practical suggestions. The protocol was well received by the passengers and aircrews of the repatriation flights with some suggestions for improvement.