Your Selections

Entry, descent, and landing
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

new

Neural Lander Uses AI to Land Drones Smoothly

  • Magazine Article
  • TBMG-35288
Published 2019-10-01 by Tech Briefs Media Group in United States

Landing multi-rotor drones smoothly is difficult. Complex turbulence is created by the airflow from each rotor bouncing off the ground during a descent. This turbulence is not well understood nor is it easy to compensate for, particularly for autonomous drones. That is why takeoff and landing are often the two most difficult parts of a drone flight. Drones typically wobble and inch slowly toward a landing until power is finally cut and they drop the remaining distance to the ground.

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.
new

Electromagnetic Characteristic Comparison of Superconducting Synchronous Motor Characteristics for Electric Aircraft Propulsion Systems

IHI Corporation-Hitoshi Oyori
The University of Tokyo-Yutaka Terao, Yusuke Ishida, Hiroyuki Ohsaki
Published 2019-09-16 by SAE International in United States
This paper describes the comparison of electromagnetic characteristics of two different superconducting-motor structures for electrified aircraft propulsion systems. Future electrified aircraft demand higher output (over 16 kW/kg) and higher efficiency (> 98%) for their motors in comparison with current ones. To satisfy the demands, two kinds of superconducting motors are dealt in this study: one is partially superconducting motors (PSCMs), made of superconducting field coils and copper armature windings; the other is the fully superconducting motors (FSCMs) made of superconducting field/armature windings. They are cooled at 20 K with liquid hydrogen. We designed these two motors with finite element method to obtain the output density of 16-20 kW/kg for future electrified propulsion systems. We selected 3.0- and 5.0 MW superconducting motors, considering the application to aircraft for almost 180 passengers and 44 MW rated power for take-off. Also, we evaluated the motor weight using two kinds of cryostat materials: stainless steel (SUS) and fiber-reinforced plastic (FRP). The results show that the 5.0 MW PSCM using FRP achieved the output density of 16.9 kW/kg and the…
This content contains downloadable datasets
Annotation ability available
new

Origami-Inspired Material Softens Impact Forces

  • Magazine Article
  • TBMG-35127
Published 2019-09-01 by Tech Briefs Media Group in United States

Landing is stressful on a rocket’s legs because they must handle the force from the impact with the landing pad. One way to combat this is to build legs out of materials that absorb some of the force and soften the blow. Inspired by the paper-folding art of origami, researchers created a paper model of a metamaterial that uses “folding creases” to soften impact forces and instead promote forces that relax stresses in the chain.

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Aircraft Ground Deicing/Anti-Icing Training and Qualification Program

G-12T Training and Quality Programs Committee
  • Aerospace Standard
  • AS6286A
  • Current
Published 2019-06-26 by SAE International in United States
This document establishes the minimum training and qualification requirements for ground-based aircraft deicing/anti-icing methods and procedures. All guidelines referred to herein are applicable only in conjunction with the applicable documents. Due to aerodynamic and other concerns, the application of deicing/anti-icing fluids shall be carried out in compliance with engine and aircraft manufacturers’ recommendations. The scope of training should be adjusted according to local demands. There are a wide variety of winter seasons and differences of the involvement between deicing operators, and therefore the level and length of training should be adjusted accordingly. However, the minimum level of training shall be covered in all cases. As a rule of thumb, the amount of time spent in practical training should equal or exceed the amount of time spent in classroom training.
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Type IV Anti-Icing Fluid Subjected to Light Freezing Rain: Visual and Thermal Analysis

UQAC - AMIL-Jean-Denis Brassard, Caroline Laforte, Christophe Volat
Published 2019-06-10 by SAE International in United States
Deicing the aircraft using fluid, prior takeoff is mandatory; since a thin layer of ice or snow can compromise the safety. With the same idea, to use anti-icing fluid during a frozen precipitation to protect the aircraft is also essential. Commercialized anti-icing fluids all pass the process of qualification as described in the SAE documents. One of these documents specifies a set of tests that reproduce freezing precipitation to obtain endurance time and then the holdover timetables. The endurance time is determined by visual inspection: when 30% of the plate is covered with frozen contaminants. With the evolution of technology and the venue of new tools, it may simplify the process, and at least confirm the observations. This paper proposed a thermal and visual analysis of the behavior of a Type IV fluid subjected to light freezing rain. During the precipitation, the plate temperature is measured with thermocouples and recorded using a visual camera and an IR camera. The use the visual camera in conjunction with the IR camera allowed to understand how the water…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Frostwing Co-Operation in Aircraft Icing Research

Aalto University-Pekka Koivisto
Federal Aviation Administration (FAA)-Thomas Bond
Published 2019-06-10 by SAE International in United States
The aerodynamic effects of Cold Soaked Fuel Frost have become increasingly significant as airworthiness authorities have been asked to allow it during aircraft take-off. The Federal Aviation Administration and the Finnish Transport Safety Agency signed a Research Agreement in aircraft icing research in 2015 and started a research co-operation in frost formation studies, computational fluid dynamics for ground de/anti-icing fluids, and de/anti-icing fluids aerodynamic characteristics. The main effort has been so far on the formation and aerodynamic effects of CSFF. To investigate the effects, a generic high-lift common research wind tunnel model and DLR-F15 airfoil, representing the wing of a modern jet aircraft, was built including a wing tank cooling system. Real frost was generated on the wing in a wind tunnel test section and the frost thickness was measured with an Elcometer gauge. Frost surface geometry was measured with laser scanning and photogrammetry. The aerodynamic effect of the frost was studied in a simulated aircraft take-off sequence, in which the speed was accelerated to a typical rotation speed and the wing model was then…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Photogrammetric Frost Roughness Measurements in Cold-Soaked Conditions

Baylor University-Taber Miyauchi, Stephen T. McClain, Tongxin Zhang, Dennis L. O'Neal
Federal Aviation Administration (FAA)-James T. Riley
Published 2019-06-10 by SAE International in United States
Cold-soaked fuel frost (CSFF) is a form of aircraft wing contamination that occurs when a vehicle caries sufficient fuel for multiple trips or take-offs and landings. Following the first trip, which may reach altitudes above 10,000 m (33,000 ft), the fuel for the subsequent trips is carried in the wing tanks and may reach temperatures below -25 °C. In certain times of the year at some airports, temperatures and humidity levels will form CSFF on the aircraft wing surfaces over the fuel tanks. Unless an exemption is granted for the specific aircraft model, aircraft are not allowed to takeoff if the wing surfaces are contaminated by frost. Because aircraft operators desire to minimize vehicle time spent at airports, aircraft manufacturers are expected to pursue designs that safely operate with CSFF at takeoff and to pursue certification exemptions for aircraft models enabling CSFF takeoffs. To assist manufacturers in the design of future aircraft and to assist regulators in evaluating certification exemption requests, more information about frost roughness characteristics and evolution in CSFF conditions is required. However,…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Surface Contamination Effects on CRM Wing Section Model

Dimensium Limited-Tomi Rosnell
Finnish Transport and Communications Agency-Erkki Soinne
Published 2019-06-10 by SAE International in United States
The aerodynamic effects of Cold Soaked Fuel Frost have become increasingly significant as aircraft manufacturers have applied for to allow it during aircraft take-off. The Federal Aviation Administration and the Finnish Transport Safety Agency signed a Research Agreement in aircraft icing research in 2015 and started a research co-operation in frost formation studies, computational fluid dynamics for ground de/anti-icing fluids, and de/anti-icing fluids aerodynamic characteristics. The main effort has been so far on the formation and effects of CSFF. To investigate the effects a HL-CRM wing wind tunnel model, representing the wing of a modern jet aircraft, was built including a wing tank cooling system. Real frost was generated on the wing in a wind tunnel test section and the frost thickness was measured with an Elcometer gauge. Frost surface geometry was measured with laser scanning and photogrammetry. The aerodynamic effect of the frost was studied in a simulated aircraft take-off sequence, in which the speed was accelerated to a typical rotation speed and the wing model was then rotated to an angle of attack…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Landing Response Analysis on High-Performance Aircraft* Using Estimated Touchdown States

SAE International Journal of Aerospace

Aeronautical Development Agency, India-P.S. Suresh, Niranjan Kumar Sura
Indian Institute of Technology Madras, India-K. Shankar
  • Journal Article
  • 01-12-01-0001
Published 2019-04-08 by SAE International in United States
A novel use of state estimation methods as initial input for a landing response analysis is proposed in this work. Six degrees of freedom (DOF) non-linear landing response model is conceived by considering longitudinal dynamics of aircraft as a rigid body with heave-and-pitch motions coupled onto a bicycle landing gear† arrangement. The DOF for each landing gear consist of vertical and longitudinal motions of un-sprung mass, considering strut bending flexibility. The measurement data for state estimation is obtained for three landing cases using non-linear flight mechanics model interfaced with pilot-in-loop simulation. State estimation methods such as Upper Diagonal Adaptive Extended Kalman Filter (UD-AEKF) with fuzzy-based adaptive tuning and Un-scented Kalman Filter (UKF) were adapted for landing maneuver problem. On the basis of estimation error metrics, aircraft state from UKF is considered during onset of touchdown. These estimated states are used as an initial condition for the six DOF non-linear landing response model, numerically solved in Matlab environment. The dynamic responses such as displacement, velocity, and acceleration for the aircraft and the loads on landing gears…
This content contains downloadable datasets
Annotation ability available

Flexible, Spinning Heat Shield for Spacecraft

  • Magazine Article
  • TBMG-33912
Published 2019-03-01 by Tech Briefs Media Group in United States

Heat shields are essentially used as the brakes to stop spacecraft from burning up and crashing on entry and reentry into a planet's atmosphere. Current spacecraft heat shield methods include huge inflatables and mechanically deployed structures that are often heavy and complicated to use.