Browse Topic: Stall warning indicators

Items (29)

Minimum Performance Standard Stall Warning Equipment

12/22/2020

This Aerospace Standard covers two basic Stall Warning Systems, one measures air flow and pressure distribution on the airfoil and the other measures the angle of airflow with respect to an arbitrary reference line. Each type of system includes, as a minimum, a sensor and the means for activating a device which warns the pilot of an impending stall.

A-4 Aircraft Instruments Committee

Flight in Icing Regulatory Evolution and the Influence on Aircraft Design

2019-01-19586/10/2019

Flight in icing for transport category aircraft certification presents a particularly challenging set of considerations to establish adequate safety commensurate with the associated risk while balancing design complexity and efficiency. A review highlighting important aspects of the regulatory evolution and guiding principles for flight in icing certification is presented, including the current standards and recent rulemaking activity. While historical icing certification relied on a simple yet subjective requirement to demonstrate that an aircraft is capable of operating safely within the prescribed icing envelopes, the certification requirements associated with demonstrating an adequate level of safety have progressively evolved into more explicit quantitative performance and qualitative handling qualities standards now scattered throughout the Federal Aviation Administration (FAA) Title 14 Code of Federal Regulations (CFRs) Part 25 Subpart B Flight standards which are largely harmonized with other regulatory agencies. Recent rulemaking activity, including the potential branching of the regulatory structure to address modern fly-by-wire aircraft not envisioned at the inception of the original flight standards, have firmly engrained flight in icing certification as a major design consideration with potentially large economic disparities depending on the design approach. A discussion is then presented illustrating how the regulatory standards influence the design space; while some phases of flight can integrate icing considerations into the aircraft design such that there is no perceptible operational effect, other phases of flight may not be able to fully mitigate icing considerations through the basic aircraft design and performance and are therefore susceptible to appreciable operational and associated economic impacts borne by the operator. The focus of this paper is to provide awareness for how the philosophical approach to flight in icing certification has shaped the associated design landscape and highlight the importance of flight in icing certification in the design phase.

Leopold, David

Training and Qualification Program for Deicing/Anti-icing of Aircraft on the Ground

AS6286 (Historical)11/29/2016

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 the level and length of training should therefore be adjusted accordingly. However, the minimum level of training shall be covered in all cases. As a rule of thumb, each hour of classroom training should at least equal the same amount (or include more) of practical training wherever this is relevant. Both basic and recurrent practical training shall be performed and documented periodically.

G-12T Training and Quality Programs Committee

Real-Time Flight Envelope Monitoring System

TBMG-12782

2/1/2012

The objective of this effort was to show that real-time aircraft control-surface hinge-moment information could be used to provide a robust and reliable prediction of vehicle performance and control authority degradation. For a given airfoil section with a control surface — be it a wing with an aileron, rudder, or elevator — the control-surface hinge moment is sensitive to the aerodynamic characteristics of the section. As a result, changes in the aerodynamics of the section due to angle-of-attack or environmental effects such as icing, heavy rain, surface contaminants, bird strikes, or battle damage will affect the control surface hinge moment. These changes include both the magnitude of the hinge moment and its sign in a time-averaged sense, and the variation of the hinge moment with time. The current program attempts to take the real-time hinge moment information from the aircraft control surfaces and develop a system to predict aircraft envelope boundaries across a range of conditions, alerting the flight crew to reductions in aircraft controllability and flight boundaries.

Stall Warning Instrument (Turbine Powered Subsonic Aircraft)

AS439A (Current)2/16/2008

This standard covers stall warning instruments to provide positive warning to the pilot of an impending stall. Stall, as defined for the purpose of this standard, is the minimum steady flight speed at which the airplane is controllable.

A-4 Aircraft Instruments Committee

STALL WARNING INSTRUMENT

AS403A (Current)2/16/2008

A-4 Air Data Subcommittee

The Effect of Wing Leading Edge Contamination on the Stall Characteristics of Aircraft

2007-01-32869/24/2007

Lessons learned from analysis of in-service icing incidents are described. The airfoil and wing design factors that define an aircraft's natural stall characteristics are explored, including the aerodynamic effects of contamination. Special attention is given to contamination in the form of “roughness” along wing leading edges typical of frost. In addition, the key aerodynamic effects of ground proximity and sideslip/crosswind during the take-off rotation are described. An empirical method, that can be used to predict a wing's sensitivity to wing leading edge roughness, is demonstrated. The paper explores the in-service differences of aircraft that incorporate “hard”, “supercritical” and “slatted” wings. The paper attempts to explain why the statistical evidence appears to favor the slatted wing for winter operations.

Tanner, Clinton E.

In-Flight Simulator Evaluation of a Flight Reference Display for Powered-Lift STOL Aircraft

9400133/1/1994

A new flight reference display for powered-lift STOL aircraft was proposed and evaluated in actual flight environment. The display was developed to provide a simple monitoring system of STOL safety margins with good handling characteristics in place of a speed indicator. Using this display, pilots repeated simulated approaches of the experimental jet STOL “ASKA” using the VSRA as an in-flight simulator. In the evaluation, emphasis was placed on agreement between the display and the motion cues experienced by the pilot. Pilot comments and flight data confirmed satisfactory control characteristics and safety margin presentation of the display.

Tanaka, Keiji, Funabiki, Kohei, Terui, Yushi, lnagaki, Toshiharu

Stall Warning Using Contamination Detecting Aerodynamics

92201010/1/1992

Aerodynamically monitoring the performance of an aircraft's lifting surface provides the missing component in stall warning. The missing component is the ability to measure the premature loss of lift due to contamination such as insect deposits, snow, slush, or ice on the lifting surface. Conventional stall warning systems, which use a fuselage mounted angle of attack sensor, do not measure the actual stalling condition at the wing. The key to determining an early stall due to the presence of contamination is to measure the flow directly at the lifting surface. Local velocity changes in a region above the upper surface of the wing provide a consistent indication of an approaching aerodynamic stall even when contamination is present. This method of stall warning also offers new levels of safety during low level windshear recovery and takeoff performance monitoring.

Catlin, Paul A.

A Simulator Study of a Flight Reference Display for Powered-Lift STOL Aircraft

9120679/1/1991

The present study deals with a proposed flight reference display for powered-lift STOL aircraft. The display design was aimed at providing pilots with new control cues for keeping its flight safety in low-speed and high-power approach. The display utilizes angle of attack, pitch angle and airspeed to indicate the flight reference for maintaining the flight safety margins. The display integrates the flight reference into an analogue airspeed scale. Piloted simulation using a moving-base flight simulator was conducted to verify the display which was designed on the basis of the flight test results of “ASKA”, the experimental STOL aircraft of National Aerospace Laboratory. The test results confirmed that performance of the display was satisfactory for both flight reference tracking and safety margin monitoring, and proper values of coefficients of the display equations were obtained. Flight tests with the new display are scheduled to finally confirm the best combination of the coefficients which compromises sensitivity to change in safety margin with handling qualities of flight reference regulation.

Nakamura, Masaru, Terui, Yushi, Tanaka, Keiji, Kawahara, Hiroyasu

STALL WARNING INSTRUMENT (Turbine Powered Subsonic Aircraft)

AS439 (Historical)5/1/1991

A-4 Aircraft Instruments Committee

Windshear--Optimum Trajectory, Human Factors and Miscellaneous Information

9019959/1/1990

Optimal trajectory studies of aircraft in wind shear have resulted in insight as how to best fly an aircraft in a wind shear; these also question some previous (and current) recommendations. Recent accidents and incidents give new support for some old ideas. Human factors problems of information transfer to and from the cockpit and pilot interface with the aircraft are discussed. Some miscellaneous information is included for the record with reintroduction of some old data which are important but not currently provided to pilots. Because of the chronological record, the miscellaneous information is discussed first.

Melvin, William W.

AIRBORNE WINDSHEAR SYSTEMS

ARP4102/11A (Historical)11/1/1989

This document recommends criteria for Airborne Windshear Systems, including operational objectives, characteristics, and functional requirements. The recommendations of this document apply to transport aircraft, and describe the operational objectives of windshear alerting systems, situational displays, guidance systems, and detection/avoidance systems.

S-7 Flight Deck Handling Qualities Stds for Trans Aircraft

Stability and Control Augmentation System of “ASKA”

87233412/1/1987

“ASKA” is a STOL airplane with Upper Surface Blown type (USB) flaps used to perform research on powered lift technology developed by the National Aerospace Laboratory (NAL). ASKA has four high bypass ratio turbofan engines mounted above and forward of the wings, hydraulically actuated flight controls, and the Stability and Control Augmentation System (SCAS). The SCAS is a triple redundant system with three digital computers. In order to develop and evaluate its control laws, flight simulator tests have been conducted for 9 years during the design phase. Four flights have been devoted to evaluate functions of the SCAS and the control laws. The significant features of the control laws are to realize satisfactory flying qualities in the deep backside region at low airspeeds. As ASKA has not tested the flights in such regions up to present, this paper includes only the design features of the SCAS control laws, the results of the flight simulator tests, and interim outcomes of the flight tests on shallow USB flap configurations.

Kobayashi, Osamu, Tsujimoto, Takashi, Okada, Noriaki, Bando, Toshio

The Advantages of a Primary Flight Display

86173010/13/1986

With the advent of CRT displays in the cockpits of civil transport aircraft, the opportunity is now here to provide pilots with more meaningful information than could be done with the old electro-mechanical instruments. If this is done in an intelligent and well-researched manner, a significant advance in safety and operating efficiency can be gained. There is no advantage in simply reproducing the conventional attitude indicator and flight director on the CRT screen. The object of this presentation is to describe the innovative features of one type of primary flight display (PFD) with which the author has experience and to discuss the advantages it provides over conventional instrumentation from the viewpoint of a line pilot and flight instructor. This PFD is one component of the electronic flight instrument system'(EFIS) which is standard on the current series of Airbus models.

Hutchinson, J.E.

Airbus A320 Side Stick and Fly By Wire — An Update

86180110/1/1986

This paper discusses the side stick and fly by wire elements of the Airbus Industrie A320. After discussion of the cockpit and the effect on it of the side sticks, the arrangements of the side sticks themselves is discussed, travel, forces and electronic coupling. The control laws form the body of the paper with some emphasis on the new things that become possible with fly by wire that Airbus Industrie has vested in A320. Pitch roll and yaw control are discussed in detail and so to are the protection systems that will contain the flight path within safe limits. Some illustrations of the functioning of the protection system in flight on a test A300 equiped with the A320 control laws will be presented.

Corps, S. G.

MINIMUM PERFORMANCE STANDARD STALL WARNING EQUIPMENT

AS8014 (Historical)9/8/1986

A-4 Aircraft Instruments Committee

United Airlines Windshear Training Update

851920

10/14/1985

Windshear training at United Airlines has evolved over the last 3 years from a demonstration of simulator wind models constructed from past accidents to a completely integrated training program which combines the essential elements of windshear recognition, avoidance, precautions, and recovery technique. Both the safety strategy and the development phases are discussed. Particular emphasis is placed on the human engineering aspects of windshear and on crew coordination.

Simmon, David A.

SR-71 Digital Automatic Flight and Inlet Control System

851977

10/14/1985

This paper presents a description and treats the integration of a new triple channel multi-rate Digital Automatic Flight and Inlet Control System (DAFICS) into the SR-71 aircraft. Predicted airframe longevity to the year 2000 and aging automatic flight control/air inlet control analog systems dictated a modernization program to insure supportability over the life span of the aircraft. Aerodynamic consideration and development rationale is provided. A functional system description identifies the systems being replaced. Simulation, hardware/software development, redundancy management and flight experience is presented. Finally, digital and analog control comparisons are made and improvements discussed.

DeGrey, R. P., Nelson, R. L., Meyer, J. E.