Takeoff Run Research Articles

U.S. wildlife strikes by phase of flight

Aircraft collisions with birds and other wildlife are of increasing concern to the aviation industry. The U.S. Federal Aviation Administration (FAA) developed the National Wildlife Strike Database to better define the wildlife strike problem. The purpose of this study was to determine the difference in the annual wildlife strike reports by phase of flight in the United States of America from 2010 to 2019. The phases of flight were categorized as found in the FAA Wildlife Strike Database: take-off run, landing roll, departure, arrival, climb, descent, en route, local, taxi, parked, and approach. We excluded reports with an unknown phase of flight from the study. This information provides airports with an objective baseline to aid in the evaluation of wildlife risk mitigation programs. The analysis showed a significant difference in annual wildlife strike reports by phase of flight. Approach had the highest mean number of wildlife strikes, whereas parked had the lowest mean number of strikes.

Paragliders' launch trajectory is universal

We designed and built a reduced-scale model experiment to study the paragliding inflation and launching phase at given traction force. We show that the launch trajectory of a single skin glider is universal, that is, independent of the exerted force. As a consequence, the length of the take-off run required for the glider to reach its “ready to launch” vertical position is also universal. We successfully compare our results to full-scale experiments and show that such universality can be understood through a simple theoretical model.

Формування областей основних параметрів модифікацій транспортного літака за умовами його базування

Along with the unique flight performance indicators and economic indicators that characterize heavy transport aircraft, the priority is also to ensure the basing for their heavier modifications at the airfields declared for the base aircraft. This problem arises at the very early stage of the modification creation, when its main parameters such as the gross mass at takeoff and thrust-to-weight ratio are formed. This is due to the very essence of creating a modification ‑ increasing its carrying capacity (which leads to increase in the gross mass at takeoff and flight range ) with an increased payload by increasing the mass of fuel on board. Ensuring growth of flight and hour , performance underlies the creation of all modifications of transport category aircraft. For heavier modifications than their base aircraft, it is further complicated by the fact that the base models are based on the runways of the second and first class airfields, which creates an insurmountable limitation on the available runway length. The second limitation is the value of the decision-making speed during takeoff, in case of failure of the critical engine during the takeoff run, which predetermines the required length of the runway. Since the takeoff masses of aircraft modifications of this type continue to increase, the problem of their basing on the runways of existing airfields arises by forming the takeoff weight relationship – decision-making speed in case of a critical engine failure ‑ thrust-to-weight ratio, providing the basing of a heavier modification at the airfield declared for the base aircraft . To implement this condition, a model for determining the speed , in which a safe termination of the takeoff run is possible in the event of a critical engine failure. The resulting model allows to take into account a number of restrictions due to the properties of heavy aircraft, such as the minimum and maximum thrust of the cruise engines, which makes it possible to make reasonable recommendations in the operating rules for aircraft of this type. Taking into account the expressions obtained to determine , a model has been formed to determine and assess the required thrust-to-weight ratio of a heavier modification by condition for modifications with a takeoff weight of more than 300 tons. It has been established that the required relative thrust-to-weight ratio should be within . Defining parameters such as , and is the basis for the implementation of other modification changes in the heavy transport aircraft.

Simulator Verification of Cessna 172 RG Repeated Take-Off Runs in Extreme Temperature Conditions

Abstract The paper presents the results of the research of performance measurement of a selected aircraft type in the take-off phase under extreme temperature conditions. For this purpose, a flight simulator of the Cessna 172 RG aircraft from the ELITE Company was used. For the purpose of verifying the take-off run length, the article provides a measurement methodology that was developed using information obtained during experimental take-offs. The aim was to obtain a procedure that would allow for repeated take-off runs in the same conditions with the possibility of changing individual influencing factors. Considering the whole measurement chain, the article analyses the influencing factors and quantifies their impact on the uncertainty of the measurement result. The data obtained experimentally we compared with the data in the Flight Manual and at the end carried out the assessment of the impact of global warming on the take-off run of the Cessna 172 RG and generally on the safety of the take-off and on air transport..

Method for Determining Takeoff Weight and Thrust-To-Weight Ratio of Aircraft Variants by Decision Speed with Engine Failed at Takeoff Run

In modern time the aircraft variants creation is main trend in the aviation industry. One the aspect of the aircraft safety is its safety take-off [1]. The aircraft parameters like relative take-off weight and thrust-to-weight ratio can determine many its performance include take-off. Their influence on decision speed during take-off of modified transport category airplanes are explored. The analytic model is simple and high efficiency way for the first approach of airplane`s safety analyses. The problem is solved by analytics modelling airplane motion on runway during take-off. Quantitative estimation of influence of the airplane weight and thrust-to-weight ratio variation on decision speed of continued or aborted take-off with critical engine failure is given on the base of example of heavy cargo airplane. The application of this way for the airplanes safety analysis is important for each types of aircraft. Estimation model is given in dimensionless parameters and so is applicable for any type of transport category airplanes.

Takeoff Monitoring Algorithm with Prediction

A takeoff-monitoring algorithm is proposed that allows predicting the rate of an aircraft takeoff run and recognizing emergency situations that require reject the takeoff. The algorithm is based on combined use of a polynomial approximation of the dependence of the takeoff speed on time and the CUSUM test to detect abrupt changes in the dynamics of the aircraft. Mathematical modeling of the algorithm is presented using a model of a lightweight aircraft.

Carrier deck launching of adapted land-based airplanes

VTOL Harrier aircraft has been the basic combat airplane for many Navies, but it will soon be retired from service. Three main alternatives appear: to incorporate another, already existing or under development airplane; to design a completely new aircraft; or to modify an existing land-based airplane to achieve carrier suitability. The present paper is part of a study to assess the feasibility of the third option. In former papers, the authors have addressed, firstly, the compatibility criteria of land-based airplanes with aircraft carriers and, secondly, the details of the approach guidance and the recovery manoeuvre, which showed the need of major modifications in wing structure and landing gear. The research proposed here studies the airplane performance during the take-off manoeuvre from mid-size carriers, formed by a flat deck take-off run followed by a ski-jump and the subsequent flyaway.

Effect of the wing trailing-edge flaps and spoilers position on the jet-vortex wake behind an aircraft during takeoff and landing run

The large-scale vortex structure of flow in the near wake behind an aircraft during its run on a runway is investigated numerically. The geometrical aircraft configuration was taken close to a mid-range commercial aircraft like Boeing 737-300. It included all essential elements: a body (fuselage), wings with winglets, horizontal and vertical stabilizers, engine nacelles, nacelle pylons, inboard flap track fairings, leading-edge and trailing-edge flaps, and spoilers. The position of flaps and spoilers corresponded to the takeoff and landing run conditions. Computational simulation was based on solving the Reynolds averaged Navier–Stokes equations closed with the Menter Shear Stress Transport turbulence model. Patterns of streamlines, fields of the axial vorticity and the turbulent intensity, vertical and horizontal velocity profiles in the wake are compared and discussed for both run regimes. The flow model was preliminary tested for validity by comparison of the calculated velocity profiles behind a reduced-scale aircraft model with those obtained in special wind tunnel experiments.

The Replication Hypothesis along the Take-Off Run and a System of Equilibrium Equations at the Lift-Off of a Protobird

An extant bird resorts to flapping and running along its take-off run to generate lift and thrust in order to reach the minimum required wing velocity speed required for lift-off. This paper introduces the replication hypothesis that posits that the variation of lift relative to the thrust generated by the flapping wings of an extant bird, along its take-off run, replicates the variation of lift relative to the thrust by the flapping wings of a protobird as it evolves towards sustained flight. The replication hypothesis combines experimental data from extant birds with evidence from the paleontological record of protobirds to come up with a physics-based model of its evolution towards sustained flight while scaling down the time span from millions of years to a few seconds. A second hypothesis states that the vertical and horizontal forces acting on a protobird when it first encounters lift-off are in equilibrium as the protobird exerts its maximum available power for flapping, equaling its lift with its weight, and its thrust with its drag.

Investigation on the Dynamic Response of a Wide-Chord Fan Blade Under Ground Vortex Ingestion

This paper presents a computational study of the dynamic response of the fan blade owing to the excitations from the ingested ground vortex when the turbofan engine is operating on the ground or during the takeoff run. Firstly a numerical method consisting of static, modal and transient analyses is proposed to investigate the dynamic vibration characteristics of a fan blade model with pre-vibration. Modal analysis is conducted to find the critical speed of blade resonances, and the intersection of the fourth engine order and the second bending mode is identified for the study. Secondly, transient analyses of the vortex ingestion are carried out to investigate the resulting blade responses. Various parameters, including different ingestion timings, rotating speeds, ingestion positions and modes of pre-vibration are discussed. Results of dynamic displacement and stress illustrate that the effect of the ingested vortex is significant. Especially when the fan blade is working at the critical speed where engine orders intersect with the dynamic frequencies, the stress is amplified by 276.6% and the displacement is amplified by 156.7%. This paper demonstrates a preliminary method to connect the flow excitations of the ground-ingested vortex and the fan blade vibration characteristics, and provides a helpful reference to the further study of the fan blade vibration.

МЕТОД І ЗАСОБИ УТРИМАННЯ НАЗЕМНИХ ЗЛІТНО-ПОСАДКОВИХ ПЕРЕМІЩЕНЬ МОДИФІКАЦІЙ ЛІТАКІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ НА РІВНІ ЇХ БАЗОВОГО ВАРІАНТА

The problem of improving the takeoff and landing runway characteristics of heavier modifications of the transport category aircraft was further developed on the condition of equality of ground displacements of heavier modifications and their base variant by creating a method of formation of the “take-off mass - thrust-to-weight ratio” characteristics and using the fundamentally new local structures of additional slotted spoilers in extendable flaps and additional energetic chambers in landing gear shock absorber systems. The development of such a method and the use of additional slotted spoilers and energetic chambers in the shock absorber systems can provide for the basing of heavier modifications at the aerodromes assigned for the base aircraft.The problem of providing takeoff and landing characteristics (TLC) of more productive modifications of the transport category aircrafts is due to objective circumstances of ensuring their operation at the aerodromes assigned to the base aircraft on the basis of which the modifications are developed. The increase in productivity inevitably leads to an increase in the takeoff and landing mass and to an increase in the ground movements of modifications, i.e. the increase in the take-off and run distance, the distance of the rejected take-off and the required length of the runway. This increase significantly reduces flight safety.In the article the method of selection of basic parameters of modifications according to TLC deterministic values is proposed. The idea of the method lies in the fact that the main parameters of the modifications, such as take-off weight, thrust-to-weight ratio, specific load on the wing, etc., are selected from the condition that the main TLC of the modifications (takeoff run length, landing run, decision-making speed, distance length of rejected take-off and the required length of the runway) should be approximately the same with the similar parameters of the base version.By implementing this method, the areas for the existence of modifications of regional, mid-range and long-haul aircrafts within the coordinates "take-off mass-thrust-to-weight ratio" with a set of constraints, arising from changes in modifications, are determined. In addition, to implement such a method, it is proposed to use fundamentally new structures: additional slotted spoilers in extendable flaps and additional energetic chambers in the landing gear shock absorber systems. The development of such a method and the use of additional slotted spoilers and energetic chambers in the shock absorber systems can provide for the basing of heavier modifications at the aerodromes assigned for the base aircraft.The implementation of the conceptual provisions proposed in this paper and the use of AEC in the shock absorber systems for the modification of the An-140 aircraft and with an increased take-off weight (m0 = 3 t)of specific wing load of p = 432 kg / m2 allows:- to reduce the landing run of the aircraft modification by 136 m;- to keep the required runway length of An-140 modifications (m0 = 24 t) at the level of its basic version (m0 = 24 t) and, thus, to provide for the basing of heavier modifications of the An-140 aircraft on the airfields of the class 3;- to significantly improve the takeoff and landing characteristics of the basic version of An-140 (m0 = 21 t), i.e. to reduce the required length of the runway of this aircraft to 1150 m and thereby ensure its possible operation on the airfields of the class 4.

Trade off studies of hybrid-electric aircraft by Fuzzy Logic methodology

In this paper, an innovative methodology for the conceptual design of hybrid-electric powered aircraft is proposed. The main idea is the optimization of the designed airplane through the negotiation and settling down of the high-level requirements. This optimization problem is multiobjective, as the goal is the minimization of the fuel and maximum takeoff weight, the time reduction of the climb phase and the enhancement of the safety level during takeoff. The safety level is evaluated as the minimum altitude reached during the climb soon after the takeoff at which the aircraft is able to succeed in an emergency landing in case an engine failure occurs. In order to fulfil these objectives, the three Top Level Aircraft Requirements (TLARs) are relaxed. In more details, the payload and the range - i.e. the maximum distance flown by the airplane - are reduced, while the takeoff run distance (namely the takeoff field length) is increased. A one more design variable is considered, the hybridization degree, meant as the ratio between the electric power and the total propulsive power. The proposed design and optimization methodology is based on the Fuzzy Logic approach. For each objective function, a fuzzy set is defined. The fuzzy sets fix the boundaries of acceptable resulting objectives included between a minimum and a maximum value. The consideration of all the fuzzy sets identifies the optimal solution, which is characterized by the maximum customer's satisfaction degree. An Overall Aircraft Design (OAD) environment is set up, in which a deterministic optimizer and fuzzy rules are implemented. The design and optimization problem is analysed and the optimal solution is obtained. The results demonstrate that the optimal solution is achieved by a hybrid airplane. Furthermore, the negotiation of the three requirements entails an improvement of the customer's satisfaction.

Power optimization of a single propeller airplane take-off run on the basis of lateral maneuver limitations

The problem of selecting optimal take-off run power of a single propeller airplane on the basis of the lateral maneuver limitations is analyzed in this paper. The single propeller reactive torque as the function of engine power and speed generates non-aerodynamic asymmetric load disturbance. The capability of lateral flight control surfaces to compensate for this asymmetric load and perform the required maneuver defines the safe flight envelope boundaries in the form of engine power setting – airspeed relation. The take-off run length consisting of acceleration, decision making, brake activation and airplane stopping length distances is calculated for engine power settings along the safe flight boundaries defined by the lateral flight control capabilities. The minimum of take-off run along thus defined safe flight boundary determines the engine optimal power setting. The results are presented for the example of the single propeller airplane on concrete runway surface.

Exergetic sustainability assessment of a HALE UAV using dodecene fuel

Exergetic sustainability performances of a high altitude long endurance (HALE) unmanned aerial vehicle (UAV), having a single turbofan engine and using dodecene as its fuel were investigated all along its flight profile, taking place in between 0-16 km altitudes. The maximum instant exergy efficiency was obtained as ∼31.30% at the beginning of level flight; the maximum cumulative exergy efficiency was obtained as ∼27.58% at ∼30.5 h of flight; the maximum instant environmental effect factor was obtained as 138.12 at the beginning of take-off run; the minimum cumulative environmental effect factor was obtained between ∼25 h and ∼32 h as 1.17; the maximum instant exergetic sustainability index was obtained at the beginning of level flight as 1.015 and the maximum cumulative exergetic sustainability index was obtained as ∼0.855 in between ∼25 h and ∼27 h of flight.

Formulation of a nonlinear mathematical model to simulate accelerations of an AAMV in take-off and landing phases

Aerodynamically alleviated marine vehicle (AAMV) is a high speed craft equipped with aerodynamic surfaces that operating in ground effect zone provides this craft with the ability to achieve much higher cruising speeds. Reducing the take-off mode of an AAMV is highly desirable. Additionally, it is seen where there is a considerable reserve thrust take-off can occur in the lower get-away speeds that shorten the take-off run and, therefore, is favourable. Accordingly, in this study an attempt has been made to develop a nonlinear mathematical model for an AAMV to simulate accelerations in take-off and landing phases, using semi-empirical equations mainly proposed for mono-hull high-speed craft, which concurrently take into account the hydrostatic, hydrodynamic, aerodynamic and thrust forces. The developed model of dynamics has been well validated against the existing experimental data of an AAMV model test calm water resistance. Finally, the effects of various hydrodynamic and aerodynamic parameters on accelerations and thus total resistance and get-away speed of an AAMV in take-off phase have been investigated. This model has the ability to provide the designers with the valuable data on influence of various hydrodynamic and aerodynamic factors on accelerations of an AAMV in take-off phase, which can be usefully employed to lessen the get-away speed and take-off run.

Emission of Sound by an Aircraft During its Take-Off Run Along the Runway

We consider the problem of emission of sound by an airplane in the stage of its take-off run along the runway of an airdrome under the conditions of wind action. The aircraft engines play the role of the sources of sound. In the problem, they are modeled by point sources moving in air with a constant acceleration parallel to the plane interface between the acoustic and solid elastic half spaces. The solution of the problem is obtained by using the Fourier integral transformation with respect to time and space coordinates and the method of stationary phase. We also perform the numerical analysis of the spacetime distributions of sound pressure and the levels of sound pressure for the case of take-off of a sixengine An-225 “Mriya” aircraft.

A Method to Calculate the Aircraft Ground Minimum Control Speed Based on Mathematical Simulation

The airworthiness compliance of the ground minimum control speed (VMCG) must be shown before the type certificate of a transport category airplane is issued under CCAR-25. A method to calculate VMCG based on mathematical simulation is provided. All forces and moments act on the aircraft in the takeoff run are considered in this method. The model of the pilot's operation in airworthiness compliance flight test of VMCG is established in this method, and the time interval between the instant at which the critical engine is failed and the instant at which the pilot recognizes and reacts to the engine failure is considered in the model. Based on this method, VMCG is obtained through the mathematical simulation of the takeoff run of an aircraft after the critical engine is failed. VMCG calculated by the method presented in this paper can be used to guide the airworthiness design and VMCG flight tests of an aircraft.

Intake Ground Vortex Prediction Methods

For an aircraft turbofan engine in ground operations or during the takeoff run, a ground vortex can occur that is ingested and could adversely affect the engine performance and operation. The vortex characteristics depend on the ground clearance, the intake flow capture ratio, and the relative wind vector. It is a complex flow for which there is currently very little appropriate quantitative preliminary design information. These aspects are addressed in this work, where a range of models are developed to provide a method for estimating the key metrics, such as the formation boundary and the ground vortex size and strength. Three techniques are presented that use empirical, analytical, and semiempirical approaches. The empirical methods are primarily based on a large data set of modelscale experiments that quantitatively measure the ground vortex characteristics for a wide range of configurations. These include the effects of intake ground clearance, approaching boundary-layer thickness, intake Mach number, and capture velocity ratio. Overall, the models are able to predict some of the key measured behaviors, such as the velocity ratio for maximum vortex strength. With increasing empiricism for key subelements of the model construction, an increasing level of agreement is found with the experimental results. Overall, the three techniques provide a relatively quick and easymethod in establishing the important vortex characteristics for a given headwind configuration, which is of significant use from a practical engineering perspective.

Lidar Observations of Aircraft Exhaust Plumes

Abstract A series of field campaigns has been made at British airports using a rapid-scanning lidar and other instrumentation in order to measure the dispersion of exhaust plumes from commercial aircraft. The lidar operated at a wavelength of 355 nm and was thus effectively eye safe. Analysis software for the lidar signals has been elaborated to enable the rather weak signals (typically a few tens of percent of ambient backscatter) from aircraft exhaust to be distinguished and to facilitate automatic processing of the measurements obtained. Such processing can deliver images, animations, and numerical parameterizations of the dispersing plumes. Overall, 1353 air traffic movements were monitored over two campaigns at Manchester and 439 in a single campaign at Heathrow. All modes were observed: taxiing, takeoff, rotation, climb-out, approach, and landing. Of these, the most complete dataset was that obtained for the start of the takeoff run: in this mode, the source is on full power but is still moving relatively slowly. Emissions thus remain at their most concentrated. For the same reason, this is the most important mode in respect to local air quality. Tire smoke on landing was likewise easily detected. Conversely, the lidar could only see the engine emissions from about 30% of the aircraft on approach. These data have been archived in an accessible form and are currently being used to develop improved regulatory dispersion models for airports.

Algorithms for calculating some flight characteristics and design parameters of a superlight piston-engined aircraft

Algorithms for calculating superlight aircraft design parameters at the early stage of design are described, namely, maximum speed, time of landing or takeoff run, of maneuvering with well-known piston engine power and propeller characteristics.