Analysis of the Vertical Navigation (VNAV) Function - Pilot’s reports about VNAV issues

 

SOURCES:

Lance Sherry
RAND Honeywell International, Inc.
Phoenix, Arizona

Michael Feary
NASA Ames Research Center
Moffett Field, California

Peter Polson
Department of Psychology
University of Colorado, Boulder, Colorado

Randall Mumaw
Boeing - Commercial Airplane Group
Seattle, Washington

Everett Palmer
NASA Ames Research Center
Moffett Field, California

Cockpit automation is to use automation to build intelligent agents that automate operator tasks.

 

"To command effectively, the human operator must be involved and informed. Automated systems need to be predictable and capable of being monitored by human operators. Each element of the [cockpit] system must have knowledge of the other's intent." This is the spirit of the guidelines developed by Billings for human-centered automation. (Billings, C. E. (1997).

 

Pilots generally use the VNAV function during the climb and cruise phases of flight.

In a survey of 203 pilots (questionnaire at the end of this post) at a major U.S. airline, McCrobie et al., found that:

 - 73% of pilots used VNAV in climb phase;

 - 20% used the function in descent; and,

 - 5% use the function in approach.

The VNAV function (also known as the PROF function) accounts for the majority of reported human factor issues with cockpit automation. 

Vakil & Hansman's review of Aviation Safety Reporting System (ASRS) reports, an anonymous incident  reporting data-base for pilots, found that 63% of pilot-cockpit interaction issues were in the control of the coupled vertical/speed trajectory of the aircraft performed by the VNAV function.

 

Each new generation of aircraft has increasing levels of flight deck automation that have improved the safety and efficiency of airline operations. The full potential of these technologies has not been fully realized however. A case in point is the potential to improve operations during the workload-intensive descent and approach phases of flight. The Vertical Navigation (VNAV) function of the Flight Management System (FMS) serves as an intelligent agent during these phases by automatically selecting appropriate targets (e.g. altitude, speed, and vertical speed) and pitch/thrust control modes to satisfy the objectives of each leg of the flightplan. This decision-making logic is complex and has raised several sets of human factors related concerns. 

A cognitive engineering analysis of the NASA Research VNAV function (representative of the PROF function on Airbus aircraft and the VNAV functions in modem Boeing airplanes) identified that the current design of the user interface for the VNAV function violates two basic principles of cognitive engineering for interfaces between operators and complex automation:

 

1. The VNAV button is overloaded in descent and approach phases of flight.

 

Selecting the VNAV button results in the engagement one of six possible VNAV commanded trajectories.

 

2. Flight Mode Annunciator (FMA) for the VNAV function is overloaded in descent and approach phases of flight.

The same FMA is used to represent different trajectories commanded by the VNAV function.

 

Overloading of user-interface input devices and overloading of display feedback are well known sources of operator confusion. 

These principles are considered to contribute directly to the difficulties pilots have in learning, understanding, and predicting complex automation behavior. 

The airlines are effectively relying on the pilot community to discover and informally communicate to each other ways of using the function in all flight regimes. This is reflected in a series of surveys that found that pilots request additional training on VNAV and other FMS functions over all other aircraft systems.

 

The VNAV function provides three automated features:

 

1. VNAV automatically selects altitude targets and speed targets according to pilot MCP entries and the altitude and speed constraints in the FMS flightplan.

 

2. VNAV automatically selects pitch and thrust control modes to fly to the targets.

For example during descent, VNAV chooses between a FLCH descent, a vertical speed (fixed rate-of descent), and an FMS path descent. In the case where VNAV selects vertical speed control mode, VNAV also selects the vertical speed target. 

3. For the descent and approach, VNA V automatically provides an optimum path that is used as the reference for all automated altitude/speed target and control mode selections.

   

Automated selection of VNAV targets 

A study of the soft-ware of contemporary VNAV functions, Sherry & Poison, found that the typical VNAV function automatically chooses the active altitude target from a possible list of sixteen, and chooses the active speed target from a possible list of twenty-six. Pilots are generally familiar with only a small set of these targets that occur most frequently and are self-explanatory.

 

For example, the VNAV altitude target is almost always the pilot entered MCP altitude. In rare cases, when the MCP altitude has been raised above a constraint altitude in the climb phase of the FMS flightplan (or lowered below a constraint altitude in the descent phase of the FMS flightplan), the VNAV function will capture and maintain the constraint altitude (and not the MCP Altitude). Hutchins  describes scenarios in which pilots became confused with the relationship between the MCP altitude and the FMS flightplan altitude. 

The remaining altitude targets automatically selected by VNAV cover "comer cases" and are rarely observed during revenue service operations. For example, the VNAV function will automatically level the aircraft off if there is a conflict between the direction of the pilot entered MCP altitude and the phase of the flightplan. Dialing the MCP altitude below the aircraft in the climb phase of the flightplan results in an immediate level off. Other unusual altitude targets include; an intermediate level-off at 10,000 feet during descent to bleed off speed to satisfy the 10,000ft/250kt. restriction, an intermediate level-off to intercept the glideslope, or when the aircraft has descended below the Minimum Descent Altitude (MDA) on a non-precision approach.

 

3 keys to demystifying VNAV selection of targets 

First a deep understanding of the FMS flightplan and,

Second how the altitude and speed constraints are used to determine targets is required.

 

This must be coupled with knowledge of the dynamic relationship between the MCP and the FMS flightplan for selecting targets. 

Third, the "comer case" targets of the VNAV function must be understood.

Automated selection of VNAV pitch/thrust control modes 

Automated mode selection by the VNAV function of pitch/thrust control modes can be confusing in two ways. The most common source of confusion is the autonomous transition of the mode without pilot action. These "silent" mode transitions are made when VNAV detects that certain criteria have been satisfied. For example, when the aircraft speed exceeds a threshold (typically 20 knots) above the FMS path speed, VNAV will autonomously switch control modes from VNAV-PATH to VNAV SPEED. These thresholds are generally not annunciated on cockpit displays. 

The second source of confusion is the selection of control modes made by VNAV given the circumstances of the aircraft. For example, several pilots prefer to perform descents to crossing restrictions with a FLXed rate of descent (i.e. vertical speed mode). By triangulating time (or distance) to the waypoint and remaining altitude, pilots can ensure making the restriction. In certain circumstances VNAV will choose speed-on pitch with idle thrust and request airbrakes to make the restriction. 

The key to understanding the choice of control modes made by the VNAV function is to understand the overall FMS philosophy on how descents are flown.

 

Automatic use of FMS optimum path as a reference 

One of the biggest contributors to pilot confusion with VNAV is the FMS computed optimum path. The path, computed by the FMS using models of aircraft performance, takes into account the regulations and constraints of standard arrival procedures (STARs) and published approaches. The nuances of the path, such as how far way from waypoints deceleration as reinitiated, are non-intuitive and worse not displayed in the cockpit.

 

When the aircraft is capturing and maintaining the path, the aircraft altitude control is earth-referenced with the goal of placing the aircraft 50-ft above the runway threshold. This operates much like the glide slope except that the reference be a misprovided by the FMS, not a ground-base transmitter. Unlike other up-and- way control modes, the aircraft will maintain the path without drift in the presence of wind. 

When the FMS optimum path is not constrained by crossing restrictions and appropriate wind entries have been made, the aircraft will descend at the desired speed with the throttles at idle. When the path is constrained or wind entries are sufficiently inaccurate, speed must be maintained using throttles (for underspeed) and airbrakes (for overspeed).

 

This "earth-referenced" control of altitude has been observed to confuse pilots who, on request from ATC to expedite the descent, add thrust or extend airbrakes. Because VNAV is controlling to the path, these actions simply increase or decrease speed without any effect on aircraft rate-of-descent.

 

The key to understanding the VNAV behavior in descent is to have full knowledge of the FMS optimum path. 

Pilots must understand the differences between airmass-referenced descents, such as FLCH, and earth referenced descents on the path. 

Pilots primarily monitor the behavior of the VNAV function by monitoring the trajectory of the aircraft. 

Pilots are "surprised" by the behavior of the VNAV function when the aircraft trajectory or the thrust indicators do not match their expectations. For example, when the aircraft vertical speed fails to decrease as the aircraft approaches an assigned altitude, pilots wonder whether the VNAV function is commanding a capture to the altitude. 

Secondary sources of information on VNAV include the Flight Mode Annunciator (FMA), targets on the Primary Flight Display (PFD) altitude tape and speed tape, and various MCDU pages (e.g. RTE/LEGS (or F-PLN), PROG page, CLB/CRZ/DES pages). 

Research Autopilot was demonstrated to be a source of pilot errors. This input device resulted in two different autopilot behaviors depending on the situation when it was selected. Selecting the vertical speed wheel: 

l. when the aircraft was outside the capture region, commanded the aircraft toffy to the assigned altitude (and armed the capture).

 

2. when the aircraft was inside the capture region, commanded the aircraft toffy away from the assigned altitude (and disarmed the capture) Frequently pilots were unaware of the dual nature of the vertical speed wheel, or could not distinguish between the dual "modes" of the wheel. As a result pilots were surprised by the behavior commanded by the autopilot. See also Palmer, Degani & Heymann, and NTSB.

 

There are six behaviors commanded by the VNAV function during the descent and approach phases of the flightplan, when the goal of VNAV is to DESCEND TO THE FINAL APPROACH FIX (FAF):

 

1. Descend on FMS Optimum Path 

2. Descend Return to Optimum Path from Long (Late) 

3. Descend Converge on Optimum Path from Short (Early) 

4. Maintain VNAV Altitude (i.e. altitude constraints, MCP altitude, or other VNAV altitudes) 

5. Descend Open to VNAV Altitude to Protect Speed 

6. Descend to VNAV Altitude, Hold to Manual Termination 

The basic underlying concept of the VNAV function is that the VNAV function constructs and strives to fly an optimum path to the FAF. This path is a geographically-fixed pathway from the cruise flight level to the runway that is designed to optimize fuel bum and time, and takes into account the altitude crossing restrictions, and speed and time constraints. It is flown in much the same way as the aircraft flies a glideslope beam. 

To stabilize the aircraft at the FAF the VNAV function commands trajectories to capture and maintain the path. The appropriate trajectories are determined by decision-making rules embedded in the software that take into account the position and speed of the aircraft relative to the path and other parameters. The VNAV function will automatically transition between commanded behaviors based on the situation perceived by the automation based on sensor data. 

For example, when the aircraft is commanded to initiate the descent before the optimal FMS computed Top-of-Descent, the VNAV function automatically commands a VNAV Behavior to Descend and Converge on the Optimum Path, usually with a fixed rate-of-descent. The rate-of-descent is selected such that the aircraft converges on the optimum path (Figure 2).

Alternatively, when the aircraft initiates the descent beyond the Top-of-Descent, the VNAV function automatically commands a VNAV Behavior to Descend and Return to Optimum Path. This VNAV behavior commands a descent at idle-thrust. Some VNAV functions increase the speed target to ensure convergence of the path (Figure 2).

 

Frequently the VNAV function determines that additional drag is required to converge on the optimum path and requests extension of the air-brakes via an ND and MCDU message.

Attitudes-Toward-Automation Questionnaire

 

Please indicate your agreement or disagreement with the following statements by circling the words that best describe your feelings:

 

1. I am concerned about a possible loss of my flying skills with too much automation.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

2. The automation in my current aircraft works great in today's ATC environment.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

3. I always know what mode the autopilot/flight director is in.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

4. I use the automation mainly because my company wants me to.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

5. Automation frees me of much of the routine, mechanical parts of flying so I can concentrate on "managing" the flight.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

6. In the automation of my current aircraft, there are still things that happen that surprise me.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

7. I make fewer errors in the automated airplanes than I did in the older models.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

8. Automation helps me stay "ahead of the airplane".

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

9. I spend more time setting up and managing the automation (CDU, FMS) than I would hand-flying or using a plain autopilot.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

10. Automation does not reduce total workload, because there is more to monitor now.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

11. I always consult the flight mode annunciator to determine which mode the autopilot/ flight director is in.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

12. Training for my current aircraft was as adequate as any training I have had.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

13. I use automation mainly because it helps me get the job done.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

14. It is easier to bust an altitude in an automated airplane than in other planes.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

15. Sometimes I feel more like a "button pusher" than a pilot.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagree

 

16. There are still modes and features of the autoflight system that I don't understand.

 

☐Strongly Agree ☐Agree ☐Neutral ☐Disagree ☐Strongly Disagre

Training for Pilots - Flight Simulations - Big Issue of Air Safety

Training for pilots

Treinamento para pilotos

Human Translation
by George Rock

Flight simulation is used extensively in the aviation industry for the training of pilots and other flight crew in both civil and military aircraft. It is also used for the training of maintenance engineers in aircraft systems, and has applications in aircraft design and development, also in aviation and other research.

Simulação de voo é usada amplamente na indústria da aviação para o treinamento de pilotos e outra tripulação de voo em ambas aeronaves, civil e militar. Ela é também usada para treinamento de engenheiros de manutenção em sistemas de aeronave, e tem aplicações em projeto e desenvolvimento de aeronave, também, em aviação e outras pesquisas.

Several different types of devices are utilized in modern flight training. These range from simple Part-Task Trainers (PTTs) that cover one or more aircraft systems to Full Flight Simulators (FFS) with comprehensive aerodynamic and systems modeling. This spectrum encompasses a wide variety of fidelity in both physical cockpit characteristics and quality of software models, as well as various implementations of sensory cues such as sound, motion, and visual systems. The following training device types are in common use:

Vários diferentes tipos de dispositivos são utilizados em treinamento moderno de voo. Estes variam de simples Treinadores de Meia-Tarefa (PTTs) que cobrem um ou mais sistemas da aeronave aos Simuladores Integrais de Voo (FFS) com aerodinâmica abrangente e modelagem de sistemas. Este espectro engloba uma ampla variedade de fidelidade em ambas características física da cockpit e qualidade de modelos de software, tanto quanto várias implementações de sinais sensoriais tais como som, movimento e sistemas visuais. Os seguintes tipos de dispositivos de treinamento são de uso comum:

• Cockpit Procedures Trainer (CPT) - Used to practice basic cockpit procedures, such as emergency checklists, and for cockpit familiarization. Certain aircraft systems may or may not be simulated. The aerodynamic model is usually extremely generic if one is even present at all. CPTs are usually not regulated.

• Treinador de Procedimentos de Cockpit (CPT) - Usado para prática básica de procedimentos de cockpit, tais como checklist de emergência, e para familiarização de cockpit. Certos sistemas de aeronave podem ou não podem ser simulados. O modelo aerodinâmico é usualmente extremamente genérico, se um estiver mesmo presente ao todo. CPTs não são usualmente regularizados.

•Aviation Training Device (ATD) - Used for basic training of flight concepts and procedures. A generic flight model representing a "family" of aircraft is installed, and many common flight systems are simulated.

• Dispositivo de Treinamento de Aviação (ATD) - Usado para treinamento básico de conceitos e procedimentos de voo. Um modelo genérico de voo representando uma "família" de aeronaves é instalada, e muitos sistemas comuns ao voo são simulados.

• Basic Instrument Training Device (BITD) - A basic training device primarily focused on generic instrument flight procedures.

• Dispositivo Básico de Treinamento de Instrumento (BITD) - Um dispositivo básico de treinamento primariamente focado em procedimentos genéricos de voo por instrumentos.

• Flight and Navigation Procedures Trainer (FNPT) - Used for generic flight training. A generic, but comprehensive flight model is required, and many systems and environmental effects must be provided.

• Treinador de Procedimentos de Voo e navegação (FNPTR) - Usado para treinamento genérico de voo. Um genérico, mas abrangente modelo de voo é exigido, e muitos sistemas e efeitos ambientais devem ser fornecidos.

• Flight Training Device (FTD) - Used for either generic or aircraft specific flight training. Comprehensive flight, systems, and environmental models are required. High level FTDs require visual systems but not the characteristics of a Full Flight Simulator (FFS).

• Dispositivo de Treinamento de Voo (FTD) - Usado para treinamento, ou genérico ou de voo específico de aeronave. Voo abrangente, sistemas e modelos ambientais são exigidos. Nível alto de FTD exigem sistemas visuais, mas não as características de um Simulador Integral de Voo (FFS).

• Full Flight Simulator (FFS) - Used for aircraft-specific flight training under rules of the appropriate National Civil Aviation Regulatory Authority. Under these rules, relevant aircraft systems must be fully simulated, and a comprehensive aerodynamic model is required. All FFS require outside-world (OTW) visual systems and a motion platform.

• Simulador Integral de Voo (FFS) - Usado para treinamento de voo de aeronave específica sob regras da Autoridade Nacional Reguladora de Aviação Civil. Sob estas regras, sistemas relevantes da aeronave devem ser totalmente simulados, e um modelo aerodinâmico abrangente é exigido. Todos FFS exigem sistemas visuais do lado de fora do mundo (OTW) e uma plataforma de movimentos.

• Full Mission Simulator (FMS) - Used by the military to denote a simulator capable of training all aspects of an operational mission in the aircraft concerned.

• Simulador Integral de Missão (FMS) - Usado pelos militares para denotar um simulador capaz de treinar todos aspectos de uma missão operacional numa considerada aeronave.

Entertainment

Entretenimento

 Amateur flight simulation refers to the simulation of various aspects of flight or the flight environment for purposes other than flight training or aircraft development. A large number of free or commercial flight simulators are available:

Simulação amadora [não profissional] de voo refere-se à simulação de vários aspectos de voo ou o ambiente de voo para propósitos outros do que treinamento de voo ou desenvolvimento de aeronave. Um grande número de simuladores de voo livres ou comerciais estão disponíveis:

• FlightGear, a free and open source flight simulator

• FlightGear, um simulador de voo com [código fonte] livre e aberto

• X-Plane, also includes a Space Shuttle and Mars flight simulators

• X-Plane, também inclui um simulador de Transporte Espacial e Simuladores de Voo em Marte

• YS Flight Simulation 2000, a freeware flight simulator targeted at low end systems

• YS Simulação de Voo 2000, um software livre de simulador de voo mirado em sistemas de pouca finalidade

• Microsoft Flight Simulator Series - its latest installment (Microsoft Flight Simulator X) now includes space as an area to be discovered, with a payware space shuttle available.

• MicrosoftFlight Simulator Séries - sua última versão (Microsoft Flight Simulator X) agora indlui espaço como uma área a ser discoberta, com um aplicativo pago de transporte espacial disponível.

Motion in flight simulators

Movimento em simuladores de voo

A Full flight simulator (FFS) duplicates relevant aspects of the aircraft and its environment, including motion. This is typically accomplished by placing a replica cockpit and visual system on a motion platform. A six degree-of-freedom (DOF) motion platform using six jacks is the modern standard, and is required for the so-called Level D flight simulator standard of civil aviation regulatory authorities such as FAA in the USA and EASA in Europe. Since the travel of the motion system is limited, a principle called 'acceleration onset cueing' is used. This simulates initial accelerations well, and then returns the motion system to a neutral position at a rate below the pilot's sensory threshold in order to prevent the motion system from reaching its limits of travel.

Um Simulador Integral de Voo (FFS) duplica aspectos relevantes da aeronave e seu embiente, incluindo movimentação. Isto é tipicamente efetuado pela colocação de uma réplica da cockpit e sistema visual numa plataforma de movimentos. Uma plataforma de movimentos de seis graus de liberdade (DOF) usando seis macacos [hidráulicos] no padrão moderno, e é exigido para o tão falado Simulador de Voo Nível D padrão das autoridades regulatórias de aviação civil tais como FAA nos Estados Unidos e EASA na Europa. Uma vez que o movimento do sistema de movimentação é limitado, um princípio chamado 'sinal de início de aceleração' é usado. Este simula bem acelerações iniciais, e depois retorna o sistema de movimento à uma posição neutra numa razão abaixo do início da reação sensorial do piloto para impedir o sistema de movimentação de atingir seus limites de movimento.

Flight simulator motion platforms used to use hydraulic jacks but electric jacks are now being used. The latter do not need hydraulic motor rooms and other complications of hydraulic systems, and can be designed to give lower latencies (transport delays) compared to hydraulic systems. Level D flight simulators are used at training centers such as those provided by Airbus, FlightSafety International, CAE, BoeingTraining and Flight Services (ex-Alteon) and at the training centers of the larger airlines. In the military, motion platforms are commonly used for large multi-engined aircraft and also in helicopters, except where a training device is designed for rapid deployment to another training base or to a combat zone.

Plataformas de movimentação de simulador de voo costumam usar macacos hidráulicos, mas macacos elétricos estão agora sendo usados. Este último não necessita de salas de motor hidráulico e outras complicações de sistemas do sistema hidráulico, e podem ser projetados para darem latências (atrasos de transporte) comparado aos sistemas hidráulicos. Simjuadores de voo Nível D são usados em centros de treinamento tais como aqueles fornecidos pela Airbus, FlightSafety International, CAE, BoeingTraining e Flight Services ( ex-Alteon) e nos centros de treinamento de helicópteros, exceto onde um dispositivo de treinamento é projetado para difusão rápida para uma outra base de treinamento ou para uma zona de combate.

Statistically significant assessments of training transfer from simulator to the aircraft are difficult to make, particularly where motion cues are concerned. Large sample sizes of pilot opinion are required and many subjective opinions tend to be aired, particularly by pilots not used to making objective assessments and responding to a structured test schedule. However, it is generally agreed that a motion-based simulation gives the pilot closer fidelity of flight control operation and aircraft responses to control inputs and external forces. This is described as "handling fidelity", which can be assessed by test flight standards such as the numerical Cooper-Harper rating scale for handling qualities. Generally, motion-based aircraft simulation feels like being in an aircraft rather than in a static procedural trainer. In a re-structuring of civil flight training device characteristics and terminology that will take place in about 2012, the Level D Full flight simulator will be re-designated an ICAO Type 7 and will have improved specifications for both motion and visual systems. This is a result of a rationalisation of worldwide civil flight training devices through which 27 previous categories have been reduced to seven.

Estatisticamente significantes avaliações de baldeação de treinamento do simulador para a aeronave são dificeis de se fazer, particularmente onde sinais de movimentos são considerados. Quantidades grandes de exemplos de opinião de piloto são exigidas e muitas opiniões subjetivas tendem a ser ventiladas, particularmente por pilotos não acostumados a fazer avaliações obejtivas e responder a um planejamento de teste estruturado. Todavia, isso é geralmente entendido que uma simulação de movimentos baseados, dá ao piloto a mais próxima fidelidade do controle operadional e respostas da aeronave às interferências de controle e forças externas. Isto é descrito como "fidelidade de manuseio", a qual pode ser avaliada por padrões de teste de voo, tais como a escala numérica de taxa Cooper-Harper para qualidades de manuseio. Geralmente, simulação de aeronave em movimentação simulada parece estar numa aeronave mais que num treinador de procedimento estático. Numa reestruturação de dispositivo de treinamento de voo civil, características e terminologia que tomarão lugar em 2012, o simulador integral de voo Nível D será renomeado um ICAO Tipo 7 e terá especificações melhroradas para ambas movimentação e sistemas visuais. Isto é um resultado de uma racionalização de dispositivos mundiais de treinamento de voo civil através dos quais 27 categorias anteriores foram reduzidas a sete.

Procedure

Procedimento

In order for a Flight Simulation Training Device (FSTD) to be used for flight crew training or checking, it must be evaluated by the local National Aviation Authority (NAA), such as the Federal Aviation Administration (FAA) in the United States. The training device in question is evaluated against a set of regulatory criteria, and a number of both objective and subjective tests are conducted on the device. The results of each test, along with other significant information about the FSTD and its operator, are recorded in a Qualification Test Guide (QTG).

A fim de que um Dispositivo de Treinamento de Simulação de Voo (FSTD) seja usado para treinamento de tripulação de voo ou exame, ele deve ser avaliado pela Autoridade Nacional de Aviação local (NAA), tal como a Administração Federal de Aviação (FAA) nos Estados Unidos [a ANAC no Brasil]. O dispositivo de treinamento em questão é avaliado diante de uma série de critérios regulatórios, e um número de ambos, testes objetivos e subjetivos, são conduzidos no dispositivo. O resultado de cada teste, acompanha outra informação significante acerca do FSTD e seu operador, são registrados num Guia de Teste de Qualificação (QTG).

The result of the initial evaluation of the FSTD, called the Master QTG (MQTG), details the baseline performance of the device as accepted by the qualifying authority. A periodic re-evaluation, called a recurrent qualification, is performed regularly, generally in one year intervals (although the interval can be as low as six months for some FAA evaluations and as high as three years for some European evaluations), and the performance of the device is evaluated against the MQTG. Any significant deviations may result in the suspension or revocation of the device's qualification.

O resultado da avaliação inicial do FSTD, chamado Master QTG (MQTG), detalha a performance fundamental do dispositivo como aceitada pela autoridade qualificadora. Uma reavaliação periódica, chamada qualificação recorrente, é efetuada regularmente, geralmente em intevalos de um ano (embora o intervalo possa ser tão curto quanto seis meses para algumas avaliações da FAA e tão longo quanto três meses para algumas avaliações Européias), e a performance do dispositivo é avaliada diante do MQTG. Quaisquer desvios significantes podem resultar na suspensão ou revogação da qualificação do dispositivo.

The criteria against which an FSTD is evaluated are defined in one of a number of regulatory and/or advisory documents. In the United States and China, FSTD qualification is regulated in 14 CFR Part 60. In most of Europe, as well as several other parts of the world, the relevant regulations are defined in JAR-FSTD A and JAR-FSTD H. The testing requirements vary between the different levels of qualification, but almost all levels require that the FSTD show that it matches the flight characteristics of the aircraft or family of aircraft being simulated.

Os critérios diante dos quais um FSTD é avaliado, são definidos dentro de um número de documentos regulatórios e/ou consultivos. Nos Estados Unidos e China, qualificação FSTD é regulada na 14 CFR Part 60. Em muitos [países] da Europa, tanto quanto várias outras partes do mundo, as regras relevantes são definidas na JAR-FSTD A e JAR-FSTD H. As exigências de teste variam entre os diferentes níveis de qualificação, mas quase todos níveis exigem que o FSTD mostre que ele equipara características de voo de aeronave ou família de aeronave sendo simulada.

The main exception to the above process is the evaluation of an ATD by the FAA. Rather than other FSTD, where each device is evaluated on an individual basis, ATDs are evaluated as a model line. When a manufacturer wishes to have a model of ATD approved, a document that contains the specifications of the model line and that proves compliance with the appropriate regulations is submitted to the FAA. If this document, called a Qualification Approval Guide (QAG) is approved, all future devices conforming to the QAG are automatically approved, and individual evaluation is neither required nor available.

A principal exceção para o processo acima é a avaliação de um ATD pela FAA. Relativamente outro FSTD, onde cada dispositivo é avaliado numa base individual, ATDs são avaliados como uma linha de modelo. Quando um fabricante deseja ter um modelo de ATD aprovado, um documento que contém as especificações da linha de modelo e que prova estar de acordo com a regulamentação apropriada é submetido ao FAA. Se este documento, chamado Manual de Aprovação de Qualificaão (QAG) for aprovado, todos dispositivios futuros de acordo com o QAG são automaticamente aprovados, e avaliação individual não é requerida nem disponível.

Until the publication of Part 60, qualification was called certification, and QTGs were called Approval Test Guides (ATGs). The terms certification and ATG no longer have any regulatory meaning other than for FSTD that remain qualified under FAA AC 120-45 or any other legacy standard.

Até a publicação da Part 60, qualificação era chamada certificação, e QTGs eram chamados manuais de Teste de Aprovação (ATGs). Os termos certificação e ATG não mais têm qualquer significação regulatória outra que seja para FSTD que permanece qualificado sob FAA AC 120-45 ou qualquer outro padrão herdado.

Flight Simulator "levels" and other categories

"Níveis" de Simulador de Voo e outras categorias

The following levels of qualification are currently being granted for both airplane and helicopter FSTD:

Os seguintes níveis de qualificação estão atualmente sendo garantidos para ambos, FSTD de avião e helicóptero:

US Federal Aviation Administration (FAA)

dministração Federal de Aviação dos Estados Unidos (FAA)

Flight Training Devices (FTD)

 Dispositivos de Treinamento de Voo (FTD)

• FAA FTD Level 4 - Similar to a Cockpit Procedures Trainer (CPT). This level does not require an aerodynamic model, but accurate systems modeling is required. Helicopter only.

• FAA FTD Nível 4 - Similar a um Treinador de Procedimentos de Cockpit (CPT). Este nível não exige um modelo aerodinâmico, mas modelação de sistemas acurados é exigida. Somente helicóptero.

• FAA FTD Level 5 - Aerodynamic programming and systems modeling is required, but it may represent a family of aircraft rather than one specific model.

• FAA FTS Nível 5 - Maquete de sistemas e programação aerodinâmica é exigida, mas ela pode representar uma família de aeronave em vez de um modelo específico.

• FAA FTD Level 6 - Aircraft model specific aerodynamic programming, control feel, and physical cockpit are required.

• FAA FTD Nível 6 - programação aerodinâmica de específica maquete de aeronave, sensor de controle e cockpit fisica são exigidos.

• FAA FTD Level 7 - Model specific. All applicable aerodynamics, flight controls, and systems must be modeled. A vibration system must be supplied, and this is the first level to require a visual system. Helicopter only.

• FAA FTS Nível 7 - Maquete Específica. Todas aerodinâmicas aplicáveis, controles de voo e sistemas devem estar modelados. Um sistema de vibração deve ser fornecido e este é o primeiro nível para requer um sistema visual. Somente helicóptero.

Full Flight Simulators (FFS)

Simuladores Integrais de Voo (FFS)

• FAA FFS Level A - A motion system is required with at least three degrees of freedom. Airplane only.

• FAA FFS Nível A - Um sistema de movimentação é exigido com pelo menos três graus de autonomia. Avião somente.

• FAA FFS Level B - Requires three axis motion and a higher-fidelity aerodynamic model than Level A. The lowest level of helicopter flight simulator.

• FAA FFS Nível B - Exige movimentos nos três eixos e um modelo aerodinâmico de mais alta fidelidade que o Nível A. O mais baixo nível de simulador de voo de helicóptero.

• FAA FFS Level C - Requires a motion platform with all six degrees of freedom. Also lower transport delay (latency) over levels A & B. The visual system must have an outside-world horizontal field of view of at least 75 degrees to each pilot.

• FAA FFS Nível C - Exige uma plataforma com todos seis graus de autonomia. Também o mais baixo atraso de transferência (latência, retardo de movimentação) sobre os níveis A & B. O sistema visual deve ter um campo de vista hrizontal do lado externo do mundo de pelo menos 75 graus para dada piloto.

• FAA FFS Level D - The highest level of FFS qualification currently available. Requirements are for Level C with additions. The motion platform must have all six degrees of freedom, and the visual system must have an outside-world horizontal field of view of at least 150 degrees, with a Collimated (distant focus) display. Realistic sounds in the cockpit are required, also a number of special motion and visual effects.

• FAA FFS Nível D - O mais alto nível de qualificação FFS atualmente disponível. Exigências são as do Nível C com adições. A plataforma de movimentos deve ter todos seis graus de autonomia, e o sistema visual deve ter um campo de visão horizontal de pelo menos 150 graus, com uma tela Collimated (distância focal). Sons realísticos na cockpit são exigidos, também um número de movimentos especiais e efeitos visuais.

European Aviation Safety Agency (EASA, ex JAA)

Agência Européia de Segurança da Aviação (EASA, ex-JAA)

Flight Navigation and Procedures Trainer (FNTP)

Treinador de Procedimentos e Navegação de Voo (FNTP)

• EASA FNPT Level I

• EASA FNTP Nível I

• EASA FNPT Level II

• EASA FNTP Nível II

• EASA FNTP Level III

• EASA FNTP Nível III

• MCC - Not a true "level" of qualification, but an add-on that allows any level of FNPT to be used for multi crew cooperation training.

• MCC - Não um verdadeiro "nível" de qiualificação, mas um adicional que permite qualquer nível de FNTP ser usado para treinamento de cooperação de tripulação múltipla.

 Flight Training Devices (FTD)

Dispositivos de Treinamento de Voo (FTD)

• EASA FTD Level 1

• EASA FTD Nível 1

• EASA FTD Level 2

• EASA FTD Nível 2

• EASA FTD Level 3 - Helicopter only.

• EASA FTD Nível 3 - Somente helicóptero.

Full Flight Simulators (FFS)

Simuladores Integrais de Voo (FFS)

• EASA FFS Level A

• EASA FFS Nível A

• EASA FFS Level B

• EASA FFS Nível B

• EASA FFS Level C

• EASA FFS Nível C

• EASA FFS Level D

• EASA FFS Nível D

 Credits

The training or checking credits allowed of an FSTD are based on the level of qualification and the operator's training curriculum. For some experienced pilots, Level D FFS may be used for Zero Flight Time (ZFT) conversions from one type of aircraft to another. In ZFT conversions, no aircraft flight time is required, and the pilot first flies the aircraft (under the supervision of a Training Captain) on a revenue flight.

Credenciais

As credenciais de treinamento ou exames permitidos de um FSTD são baseadas no nível de qualificação e no currículo de treinamento do operador. Para alguns pilotos experientes, Nível D FFS pode ser usado para conversões Tempo Zero de Voo (ZFT) de um tipo de aeronave para um outro. Em conversões ZFT, nenhum tempo de voo de aeronave é exigido, e o piloto primeiro voa a aeronave (sob a supervisão de um Comandante Instrutor) num voo de rendimento.

Manufacturers
Fabricantes

Full Flight Simulator manufacturers include;
Fabricantes de Simulador Integral de Voo incluém:

• FlightSafety International (FSI) (United States),
• Frasca International, Inc.
• L-3 Link
• Rockwell Collins
• Opinicus
• CAE Inc.
• Mechtronix Systems (Canada)
• Mechtronix System (Canadá)
• Sim Industries in the Netherlands
• Indra Sistemas in Spain
• Indra Systems (United States)
• Havelsan in Turkey
• AXIS Flight Training Systems in Austria
• Thales Group in France and the UK
• CSTS Dinamika in Russia
• Aerosim

The UK Thales site at Crawley, near London Gatwick airport, is a successor to the ex-Rediffusion simulator factory. Another flight simulator manufacturer is Aerosim located in Burnsville, Minnesota, USA; their focus is making FTDs and VPTs (virtual procedure trainers).

O site da UK Thales em Crawley, perto do aeroporto Gatwick, é uma sucessora da fábrica de simulador ex-Rediffusion. Uma outra fabricante de simulador de voo a Aerosim localizada em Burnsville, Minnesota, USA; o foco delas está em fazer FTDs e VPTs (treinadores de procedimentos cirtuais).

There are currently about 1280 Full Flight Simulators (FFS) in operation worldwide, certificated for pilot training in the Commercial Air Transport (CAT) sector by the relevant National Civil Aviation Regulatory Authorities (NAA, such as the FAA for the USA and EASA for Europe), of which about 550 are in the USA, 75 in the UK, 60 in China (PRC), 50 each in Germany and Japan, and 40 in France. Of these, some 450 were made by CAE, mainly in their Montreal factory, about 380 by Thales and its predecessors Rediffusion, (Singer) Link-Miles, and Thomson CSF, and about 280 by FlightSafety International. L-3 Communications operates a facility in Arlington, Texas which manufactures flight simulators for the military; the division (Link Simulation and Training) traces its legacy back to Link's original invention.

Há atualmente cerca de 1280 Simuladores Integrais de Voo (FFS) em operação no mundo, certificados para treinamento no setro de Transporte Aéreo Comercial pelas Autoridades Nacionais Regulatórias de Aviação Civil pertinentes (NAA, tais como a FAA para os Estados Unidos e  EASA para Europa), das quais cerca de 550 estão nos Estados Unidos, 75 no Reino Unido, 60 na China (PRC), 50 na Alemanha e Japão, cada e 40 na França. Destes, uns 450 foram feitos pela CAE, principalmente nas suas fábicas em Montreal, cerca de 380 pela Thales e seus antecessores Rediffusion, (Singer) Link-Miles, e Thompson CSF, e cerca de 280 pela FlightSafety Internacional. A L-3 Communications opera uma instalação em Arlington, Texas, , a qual fabrica simuladores de voo para os militares; a divisão ( Link Simulation and Training) traça sua herança de volta à invenção original da Link.

Flight simulators are also extensively used for research in various aerospace subjects, particularly in flight dynamics and man-machine interaction (MMI). Both regular and purpose-built research simulators are employed. They range from the simplest ones, which resemble video games, to very specific and extremely expensive designs such as LAMARS, installed at Wright-Patterson Air Force Base, Ohio. This was built by Northrop for the Air Force Research Laboratory (AFRL) and features a large scale five degrees of freedom motion system to a unique design and a 360 degree dome-mounted visual system. The most advanced research simulator with sustained G-capability, unlimited attitude control and a reconfigurable cockpit was developed in a joint-venture of TNO and AMST GmbH and is called DESDEMONA.

Simuladores de voo são também extensivamente usados para pesquisa em vários assuntos aeroespaciais, particularmente em dinamicas de voo e interação homem-máquina (MMI). Ambos simuladores comuns e de propósito construídos para pesquisa são empregados. Eles variam dos simples, os quais lemgram 'video games', aos projetos muito específicos e extremamente caros, tais como LAMARS, instalado na Base da Força Aérea Wright-Pattersen, Ohio. Este foi consttuído pela Northrop para o Laboratório de Pesquisa da Força aérea (AFRL) e caracteriza uma escala grande de cinco graus de autonomia do sistema de movimentos para um único projeto e um sistema visual de 360 graus com cúpula montada. O mais avançado simulador de pesquisa com suporte de capacidade-G [gravidade], ilimitado controle de atitude e uma cockpit reconfigurável foi desenvolvido por um consórcio da TNO e AMST GmbH e é chamada DESDEMONA.

Instructor operating stations

Estações de operação do Instrutor

Most simulators have Instructor Operating Stations (IOS). At the IOS, an instructor can quickly create any normal and abnormal condition in the simulated aircraft or in the simulated external environment. This can range from engine fires, malfunctioning landing gear, electrical faults, storms, downbursts, lightning, oncoming aircraft, slippery runways, navigational system failures and countless other problems which the crew need to be familiar with and act upon.

Muitos simuladores têm Estações de Operação de Instrutor (IOS). Nas IOS, um isntrutor pode rapidamente criar qualquer condição normal e anormal na aeronave simulada ou no ambiente exrterno simulado. Isto pode variar de fogos no motor, mau funcionamento do trem de pouso, falhas elétricas, tempestades, correntes de ar descendentes, raios, aproximação de aeronave, pistas de pouso escorregadias, falhas de sistemas de navegação e incontáveis outros problemas, com os quais a tripulação necessita estar familiarizada e agir em resposta.

Many simulators allow the instructor to control the simulator from the cockpit, either from a console behind the pilot's seats, or, in some simulators, from the co-pilot's seat on sorties where a co-pilot is not being trained. Some simulators are equipped with PDA -like devices in which the instructor can fly in the co-pilot seat and control the events of the simulation, while not interfering with the lesson.

Muitos simuladores permitem o instrutor controlar o simulador da cockpit, ou de uma console atrás dos assentos do piloto, ou, em alguns simuladores, do assento do co-piloto viagem curta onde um co-piloto não está sendo treinado. Alguns simuladores são equipados com PDA - como dispositivos nos quais o instrutor pode voar no assento do co-piloto e controlar os eventos de simulação, enquanto não interferindo com a lição.

Flight simulators are an essential element in individual pilot as well as flight crew training. They save time, money and lives. The cost of operating even an expensive Level D Full Flight Simulator is many times less than if the training was to be on the aircraft itself and a cost ratio of some 1:40 has been reported for Level D simulator training compared to the cost of training in a real Boeing 747 aircraft.

Simuladores de voo são um elemento essencial na pilotagem individual tanto quanto no treinamento de tripulação. Eles poupam tempo, dinheiro e vidas. O custo de operação mesmo num caro Simulador Integral de Voo Nível D, é muitas vezes menor que se o treinamento fosse ser na própria aeronave e uma taxa de custo de cerca de 1: 40 tem sido relatada para treinamento em simulador Nível D comparada ao custo de treinamento numa aeronave Boeing 747 real.

Modern high-end flight simulators
Simuladores de voo modernos de alta finalidade

High-end commercial and military flight simulators have large field-of-view (FoV) image generation and display systems of high resolution. All civil Full Flight Simulators (FFS) and many military simulators for large aircraft and helicopters also have motion platforms for cues of real motion. Platform motions complement the visual cues and are particularly important when visual cues are poor such as at night or in reduced visibility or, in cloud, non-existent. The majority of simulators with motion platforms use variants of the six cylinder Stewart platform to generate cues of initial acceleration. These platforms are also known as Hexapods (literally "six feet") and use an operating principle known as Acceleration onset cueing (which see). Motion bases using modern hexapod platforms can provide about +/- 35 degrees of the three rotations pitch, roll and yaw, and about one metre of the three linear movements heave, sway and surge.

Simuladores de voo de alta finalidade comercial e militar têm grandes sistemas campo de visão de telas e geração de imagem de alta resolução. Todos Simuladores Integrais de Voo civis (FFS) e muitos simjuladores militares para grandes aeronaves e helicópteros també, têm plataformas de movimentação para sinais de movimentos reais. Movimentos de plataforma complementam os sinais visuais e são particularmente importantes quando sinais visuais são pobres, tais como à noite ou em visibiidade reduzida ou, em nuvem, ou não existentes. A maioria de simuladors com plataforma de movimentos usam variantes de plataforma Stewart de seis cinlindros para gerar sinais de aceleração iniciaal. Estas plataformas são também conhecidas como Hexapods (literalmente, "seis pés") e usam um princípio de operação conhecido como Sinal de  Aceleração Inicial (o qual vê). Bases de Movimentação usando platafomas hexapod modernas podem fornecer cerca de +/- 35 graus das das três rotações, arfagem, rolagem e guinada, e cerca de um metro dos três movimentos lineares, puxar, balançar e ondular.

The NASA Ames Research Center
O Centro de Pesquisa Ames da NASA

in "Silicon Valley" south of San Francisco operates the Vertical Motion Simulator. This has a very large-throw motion system with 60 feet (+/- 30 ft) of vertical movement (heave). The heave system supports a horizontal beam on which are mounted rails of length 40 feet, allowing lateral movement of a simulator cab of +/- 20 feet. A conventional 6-degree of freedom hexapod platform is mounted on the 40 ft beam, and an interchangeable cabin is mounted on the hexapod platform. This design permits quick switching of different aircraft cabins. Simulations have ranged from blimps, commercial and military aircraft to the Space Shuttle. In the case of the Space Shuttle, the large Vertical Motion Simulator was used to investigate a longitudinal pilot-induced oscillation (PIO) that occurred on an early Shuttle flight just before landing. After identification of the problem on the VMS, it was used to try different longitudinal control algorithms and recommend the best for use in the Shuttle programme. After this exercise, no similar Shuttle PIO has occurred. The ability to simulate realistic motion cues was considered important in reproducing the PIO and attempts on a non-motion simulator were not successful (a similar pattern exists in simulating the roll-upset accidents to a number of early Boeing 737 aircraft, where a motion-based simulator is needed to replicate the conditions).

No "Vale do Silício" ao Sul de São Francisco opera o Simulador de Movimento Vertical. Este tem um sistema de movimento de  lançamento muito grande com 18 metros (+/- 9 metros) de moviemento vertical (puxão). O sistema de puxão suporta uma viga horizontal na qual são montados trilhos de 12 metros de comprimento, permitindo movimento lateral de uma cabine de  simulador de +/- 6 metros. Uma plataforma hexapod convencional 6 graus de autonomia é monada na viga de 12 metros, e uma cabine intercambiável é montada na plataforma hexapod. Este desenho permite rápida mudança de diferentes cabine de aeronave. Simulações têm alcançado desde dirigíveis, aeronave comercial e militar até espaçonave. No caso de espaçonave , o grande Simulador de Movimento Vertical foi usado para investigar uma oscilação longitudinal induzida pelo piloto (PIO) que ocorreu num voo prévio do ônibus espacial exatamente antes do pouso.  Após identificação do problema no VMS, isso foi usado para tentar algorítmos diferentes de controle longitudinal e recomendados sinais de movimento realísticos simulados foram considerados importantes em reprodução do PIO  e tentativas num simulador sem movimento não tiveram sucesso (um padrão similar existe em simulação de acidentes de transtorno de rolagem  para um número de aeronave Boeing 737 antigo, onde umsimulador baseado em movimento é necessário para reproduzir as condições).

AMST Systemtechnik (Austria) and TNO Human Factors (the Netherlands) have developed the Desdemona flight simulation system for the Netherlands-based research organisation TNO. This large scale simulator provides unlimited rotation via a gimballed cockpit. The gimbal sub-system is supported by a framework which adds vertical motion. Furthermore, this framework is mounted on a large rotating platform with an adjustable radius. The DESDEMONA simulator is designed to provide sustainable g-force simulation with unlimited rotational freedom.

O AMST Systemtechnik (Aústria) e TNO Fatores Humanos (a Holanda) têm desenvolvido o sistema de simulação de voo DESDEMONA para TNO organização de pesquisa baseada na Holanda. Este simulador de grande escala fornece rotação ilimitada via uma cockpit pivot. O subsistema de pivot é suportado com um raio ajustável. O simulador DESDEMONA é projetado para fornecer simulação de força-G sustentável com ilimitada liberdade de rotação.