quarta-feira, 13 de março de 2019

Stick Shaker & AOA System Anomalies - RECOGNITION AND RECOVERY TECHNIQUES



Stick shaker. An artificial stall warning system is required for airplane certification if the natural prestall buffet characteristics of the airplane are insufficient to warn the flight crew of an impending stall. This warning must be in a form other than visual to be effective, even if the flight crew is not looking at the instrument panel. Beginning with early commercial jetliners, standard practice has been to equip these airplanes with a stick shaker as a means of stall warning. Some airplanes also have employed stick nudgers or stick pushers to improve stall avoidance and stall characteristics. All these indications have been driven by an AOA threshold, which is usually a function of flap configuration, landing gear configuration, or both.
Because of the effect of Mach number on stall AOA, the stall warning AOA typically was set at a conservative level to accommodate gross weight and altitude variations expected in the terminal area.
It should be noted that the stall warning schedule does not follow the buffet boundary at very high Mach numbers. The buffet here is caused by Mach buffet, or too high a speed. Setting the stall warning system to activate at this point may lead the flight crew to believe the airplane is near stall and increase, rather than decrease, speed.
The early stall warning system thresholds were not set to be effective at cruise altitudes and speeds because they did not correct for Mach number. This kept the system simple. The stick shaker was set at an AOA effective for low altitudes but at too high a value for cruise. Natural stall buffet was found to give satisfactory warning at higher Mach numbers.
Later stall warning systems used Mach number from the pitot or static air data system to adjust the stall warning AOA threshold down as Mach number increased. This provided the flight crew with a stall warning related to the actual available performance. However, it also made the stall warning system dependent on good pitot and static data, a factor that will be considered in the next section on the dedicated AOA indicator.
SYSTEM ANOMALY RECOGNITION AND RECOVERY TECHNIQUES
Regardless of the nature of erroneous flight instrument indications, some basic actions are key to survival. The longer erroneous flight instruments are allowed to cause a deviation from the intended flight path, the more difficult recovery will be. Some normal procedures are designed, in part, to detect potential problems with erroneous flight instruments to avoid airplane upsets. Examples are the 80-kn call on takeoff and callouts for bank angle exceedances. In some cases the flight crew may need to recover the airplane from an upset condition: unintentional pitch greater than 25 deg nose high or 10 deg nose low, bank angle in excess of 45 deg, or flying at airspeed inappropriate for conditions. As the condition deteriorates, it becomes more dynamic and stressful. This stress increases the difficulty flight crews experience in determining, believing, and adjusting to using the correct instruments and ignoring the faulty instruments. Regardless of the situation, good communication between crewmembers is essential, and several basic actions are paramount:
Recognizing an unusual or suspect indication.
Keeping control of the airplane with basic pitch and power skills.
Taking inventory of reliable information.
Finding or maintaining favorable flying conditions.
Getting assistance from others.
Using checklists

ACCIDENT AND INCIDENT CASE STUDIES
Erroneous flight information such as the many and varied symptoms of pitot-static anomalies can confuse an unprepared flight crew. Because of the confusion caused by multiple and sometimes conflicting alerts and warnings, the flight crew may not recognize an air data error and may fail to respond appropriately. The following accidents and incidents show what can happen when a crew is confronted with unreliable or erroneous flight information.
In December 1974, a Boeing 727 crashed 12 min after takeoff while on a positioning flight from Buffalo, New York, in the United States. Three crewmembers were killed and the airplane was destroyed. The U.S. National Transportation Safety Board (NTSB) determined that the probable cause of the accident was flight crew failure to recognize and correct the airplane's high angle of attack and low speed stall. The stall was precipitated by the crew's reaction to erroneous airspeed indications caused by atmospheric icing blockage of the pitot probe. The pitot heat switch had not been turned to the ON position.
 In April 1991, the crew on a large corporate jet survived the following incident. On the previous leg, the captain's airspeed/Mach indicator and the standby airspeed/Mach indicator were erratic. The ground crew was unable to duplicate the problem. The next leg was at night in visual conditions. It was uneventful until the crew observed the first officer's airspeed/Mach indicator begin an uncommanded increase as the airplane climbed through FL310. Passing FL330, the captain's airspeed remained steady, but the first officer's airspeed pointer exceeded "barber pole," and the high-speed aural clacker activated. The autothrottles were disconnected, and at that point the captain's airspeed indicator began to show a decrease in airspeed that coincided with the standby airspeed/Mach indicator. Because of problems reported on the previous leg, the crew assumed that the captain's instruments were faulty. As the first officer's airspeed/Mach indicator kept increasing, the crew pulled the power back to silence the clacker, but the first officer's airspeed continued to increase and the captain's airspeed indicator continued to decrease. The airplane began to shake, which the crew assumed was high-speed Mach tuck. At FL340, the pitch was increased and stick shaker activated. The crew suddenly realized that they were entering a stall. While performing stall recovery procedures, they experienced severe vertigo, spatial disorientation, and confusion over determining the actual airspeed. Though the clacker was still sounding, fuel flow, attitude, and N1 were calculated for descent. Appropriate checklists were run and the circuit breakers were pulled to silence the clacker. Using calculated attitude and power settings, a descent, instrument landing system approach, and uneventful landing were accomplished. Maintenance later confirmed that the first officer's central air data computer had failed.
 In February 1996, a Boeing 757 crashed after takeoff from the International Airport of Puerto Plata, Dominican Republic. After climbing through 7,300 ft, the airplane descended until it crashed into the Atlantic Ocean about 5 mi off the coast of the Dominican Republic. All 189 people on board were killed, and the airplane was destroyed. Data from the cockpit voice recorder (CVR) and flight data recorder (FDR) indicate that the airspeeds displayed to the captain during the takeoff roll were incorrect and that the captain was aware of this during the takeoff roll. Nevertheless, the captain decided to continue the takeoff, and the first officer notified the captain when the airplane reached V1 and Vr. Shortly after takeoff, the captain commented that his airspeed indicator had begun to operate, even though it indicated unrealistic airspeeds. A normal climbout ensued, and the captain engaged the center autopilot. During the climb, at an altitude of 4,700 ft, RUDDER RATIO and MACH/SPD TRIM advisory messages appeared on the engine indication and crew alerting system display unit. For the next several minutes, the crewmembers discussed the significance of these advisory messages and expressed confusion about the airspeed. At an altitude of about 7,000 ft, the captain's airspeed indicator showed 350 knots, and an overspeed warning occurred, immediately followed by activation of the stall warning system stick shaker. Flight crew confusion about appropriate airspeed, thrust setting, and proper pitch attitude was evident as the airplane stalled, descended, and then crashed. The erroneous readings from the captain's airspeed indicator are consistent with a blocked pitot tube. Comments by the first officer recorded on the CVR suggest that his pitot probe was not obstructed, and he was seeing correct airspeed indications on his display.
 In October 1996, a Boeing 757 crashed into the Pacific Ocean about 30 mi off the coast of Lima, Peru. The flight crew declared an emergency immediately after takeoff because of erroneous airspeed and altitude indications and was attempting to return to Lima when the accident occurred. Data from the CVR and FDR revealed that the airspeed and altitude readings were normal during the takeoff roll. However, as the airplane began to climb, the flight crew noticed that the airspeed indications were too low and the altitude indications were increasing too slowly. Shortly after takeoff, the windshear warning activated, despite calm wind conditions and no significant weather activity. The flight crew declared an emergency and expressed confusion about the airplane's airspeed and altitude displays. Analysis of FDR data indicates that the airplane subsequently climbed to a maximum altitude of approximately 13,000 ft. When the airplane descended, the captain's altitude and airspeed displays were still erroneous, but at that point they indicated higher-than-actual conditions. During descent, the first officer's displayed airspeed slowed to the point of stall warning stick shaker activation. Meanwhile, the captain's airspeed read over 350 knots, and the overspeed warning was sounding. Flight crew confusion about airspeed and altitude was evident as the airplane continued its final descent. At impact into the Pacific Ocean, the captain's flight instruments were reading approximately 9,500 ft and 450 kn. The erroneous indications recorded by the FDR are consistent with a partial blockage of the captain's static ports.
 Three valuable lessons emerged from the investigations of these events. First, the effects of flight instrument anomalies appear during or immediately after takeoff. Second, flight crews must overcome the startle factor associated with rare anomalous events and immediately begin to implement specific corrective procedures and techniques. Finally, flight crews should acquire enough system knowledge to be able to determine the difference between valid and faulty display information.




AOA – Angle of Attack probe has been used as a primary performance parameter for years on some military aircraft, particularly on fighters. There are many good reasons for this.
In general, fighters operate more often at the extremes of the envelope, often flying at maximum lift for minimum radius turns. For other applications, AOA minimizes the pilot (usually single-place) workload by giving a simple target to fly. AOA is accurate enough for these applications. In addition, the higher sweep and lower aspect ratio of the wing reduce the sensitivity to AOA errors.
AOA has proved particularly useful for approach to aircraft carriers, where it is important to maintain a consistent approach attitude for each landing. In this case, 'backside' approach techniques are used, where glide path is controlled primarily by changes in thrust while the aircraft is held at a fixed AOA. Use of this technique during approach on commercial jet airplanes would be contrary to the pitch commands provided by the flight director bars, and to the speed hold mode of the autothrottle, which is often used during approach.



quarta-feira, 31 de outubro de 2018

Flying Down To Lower Published Minimums - Landing with Synthetic Vision





Watch it in good practice                                           Veja visão sintética na prática


Tradução Humana por George Rocha
ENGLISH
PORTUGUÊS


Combined visions systems that offer both a synthetic vision guidance system using a digital database and an enhanced flight vision system - EFVS using infrared and visible light sensors.  That could enable flight crews to fly below published instrument approach minimums down to 150 ft. height above terrain (HAT), on any instrument approach that has vertical guidance, using an SVGS. At that point, pilots could use an EFVS for a close-in look to continue the approach to touchdown and rollout in accordance with new FAR Part 91.176(a).

Sistemas de visões combinados com que oferecem tanto um Sistema de Orientação de Visão Sintética [SVGS] usando um banco de dados digital e um Sistema  Aumentado de Visão de Voo - EFVS usando infravermelho e sensores de luz visível, Isso poderia permitir aos pilotos voarem abaixo dos mínimos publicados de aproximação por  instrumento descendo até  150 pés de altura acima do terreno (Height Above Terrain), em qualquer aproximação de instrumento que tenha orientação vertical, usando um SVGS. Nesse ponto, pilotos poderiam usar um EFVS para uma olhada em “close” para  continuar a aproximação até o toque na pista e corrida de parada de acordo com a nova regulamentação da FAA Part 91.176(a).




Advisory Circular AC20-185 only provides guidance for approval of SVGS equipment integrated with head-down PFDs for operational credit to fly down to 150 ft. height above touchdown on straight-in Category I ILS approaches. And then only with special authorization.

Informe Circular AC20-185 só fornece orientações de aprovação de equipamento SVGS integrado com PFDs  para cabeça baixada com ganho operacional para voar até 150 pés de altura acima do toque na pista em aproximações diretas de ILS Categoria I. E depois só com autorização especial.

Notably, AC20-185 specifies that an SVGS cannot be used for credit to fly below 200 ft. HAT on GLS or LPV approaches.
Notavelmente, o [Informe] AC20-185 especifica que um SVGS  não pode ser usado para ganho de  voar abaixo de 200 pés HAT, em aproximações GLS ou LPV.



In contrast, an EFVS requires the use of a HUD, “or equivalent display”,according to AC90-106A. Most CVS equipment developers presume that the FAA will update guidance documents and rules to allow both an SVGS and EFVS to be used with HUDs for operational credit to fly down to lower minimums. PFDs will be used for backup to the HUDs for CVS-aided approaches.   
Em contraste, um EFVS requer o uso de um HUD, "ou tela equivalente", de acordo com o [Informe] AC90-106A. A maioria dos desenvolvedores de equipamentos de Visão Sintética presume que a FAA irá atualizar documentos de orientação e regras para permitir que ambos, um SVGS (Synthetic Vision Guidance System ) e um EFVS (Enhanced Flight Vision System) sejam usados com HUDs [Head-Up Displays] como ganho operacional para voar descendo mais abaixo dos mínimos [publicados]. Os PFDs [Primary Flight Displays] serão usados para auxiliar os HUDs em aproximações auxiliadas por CVS.                       



Using a single display for a CVS, rather than a separate PFD for an SVGS and HUD for an EFVS, is essential because it enables pilots to blend both, or switch between, SVGS and EFVS backgrounds as needed on the HUD. Otherwise, it would be quite difficult to make the switch between looking head down at an SVGS on a PFD and then head up at an EFVS on a HUD at 150 ft. HAT. So close to the ground, pilots would have just 12 sec., or so, to make the switch before the mains touched the pavement.

Usando uma única tela para um CVS, ao invés de um PFD separado para um SVGS e um HUD para um EFVS, é essencial, porque isso permite aos pilotos misturarem ambos, ou alternarem o plano de fundo entre, SVGS e EFVS conforme necessário no HUD. Caso contrário, seria muito difícil fazer a troca entre olhar tendo a cabeça baixada em um SVGS  acoplado em um PFD e depois olhar com a cabeça erguida em um EFVS acoplado em um HUD na Altura de 150 pés Acima do Terreno.
Tão perto do solo, os pilotos teriam apenas 12 segundos, ou mais, para fazer a troca antes dos trens de pouso principais tocarem a pista.



The relatively new Part 91.176, which replaces Part 91.175(l) and (m), allows credit for use of qualified enhanced flight vision systems during straight-in instrument approaches to fly below the published decision altitude or decision height. Systems qualified for approach, in accordance with Part 91.176(b), allow descent from published minimums down to 100 ft. height above touchdown using EFVS approach systems. At that point, the flight crew must be able to see, with their own eyes, specifically defined landmarks and/or lights to continue the approach. For equipment approved as an EFVS landing system, in accordance with Part 91.176(a), it may be used all the way to touchdown and rollout in. Without an approved EFVS, the crew must make the transition to the visual segment of the approach using unaided eyesight, in accordance with Part 91.175(c).

A Regulamentação 91.176 relativamente nova, que substitui a Regulamentação 91.175(l) e (m), permite ganho para uso de qualificados sistemas de voo com visão realçada durante aproximações diretas por instrumentos para voar abaixo da altitude de decisão ou altura de decisão publicada. Os sistemas qualificado para aproximações, em conformidade com a Regulamentação 91.176(b), permitem descida a partir dos mínimos de descida publicados  mínimos até 100 pés de altura acima do ponto de toque usando sistemas de aproximação EFVS. Nesse ponto, os pilotos devem ser capazes de avistar, com seus próprios olhos, pontos de referência e/ou luzes especificamente definidos para continuar a aproximação. Para equipamento aprovado como um sistema de pouso EFVS, em conformidade com a Regulamentação 91.176(a), ele poderá ser usado em todo o percurso até o ponto de toque na pista e corrida de parada. Sem um EFVS aprovado, a tripulação deve fazer a transição para o segmento da aproximação  visual usando visão sem ajuda, em conformidade com a Regulamentação 91.175(c).

segunda-feira, 28 de maio de 2018

Online Game To Recruit Young Pilots - NexGen Pilots Training - USAF



USAF Is Building An Online Game To Recruit Young Pilots

USAF Está Construindo um Jogo Online para Recrutar Pilotos Jovens

May 24, 2018

May 24, 2018 Lara Seligman | Aerospace Daily & Defense Report

Tradução Humana por George Rocha

em 28/05/2018

ENGLISH                                                                PORTUGUÊS

Move over “The Last Starfighter.” A new online game could revolutionize the way the U.S. Air Force finds and recruits young pilots.
Dê lugar a "O último Starfighter". Um novo jogo on-line poderia revolucionar a forma como a Força Aérea dos Estados Unidos encontra e recruta pilotos jovens.

Drawing on data from Air Education and Training Command’s (AETC) “Pilot Training Next” initiative, the service is developing an online game directed at high school and college-aged individuals who show the skills and personality traits needed to excel in pilot training and other areas, AETC Commander Lt. Gen. Steven Kwast told reporters May 24.
Baseado em dados da iniciativa “Próxima Geração de Treinamento de Piloto” do Comando de Treinamento e Educação Aérea AETC), o serviço está desenvolvendo um jogo online direcionado aos indivíduos em idade de Ensino Médio e universitária que mostram as habilidades e características de personalidade necessárias para se destacarem na formação de piloto e outras áreas, o comandante o Tenente-General Steven Kwast da AETC informa em 24 de Maio.
By asking participants to run through a few scenarios, make decisions and answer questions, the Air Force can measure a myriad of personal characteristics from critical thinking skills to moral compass, Kwast said.
Ao pedir aos participantes para executarem através de alguns cenários, tomar decisões e responder a questões, a Força Aérea pode medir uma infinidade de características pessoais de habilidades de pensamento crítico até orientação moral, Kwast disse.

“I can measure critical thinking, creative thinking, conceptual thinking, contextual thinking, collaborative thinking, constructive thinking. I can tell if you are empathetic, I can tell if you cheat, I can tell if you cut corners, I can tell if you are morally courageous under pressure or whether you save your own skin,” Kwast said.
"Eu posso medir o pensamento crítico, pensamento criativo, pensamento conceitual, pensamento contextual, pensamento colaborativo, pensamento construtivo. Posso dizer se você é empática,  posso dizer se você trapaceia, posso dizer se você toma atalhos que sacrificam a qualidade, posso dizer se você é moralmente corajoso sob pressão ou se você salva sua própria pele," Kwast disse.
Kwast acknowledged the similarities between the effort and the fictional arcade game featured in the 1984 movie “The Last Starfighter.” But the idea behind the real-life game is to match potential young airmen to jobs in which they will excel, Kwast stressed.
Kwast reconheceu as semelhanças entre o esforço e o jogo de fliperama fictício apresentado no filme de 1984 "O último Starfighter". Mas a ideia por trás do jogo da vida real é combinar potenciais jovens aviadores com empregos em que eles se destacarão, Kwast ressaltou.
“Boy, there is nothing more powerful than having a person do something they love and they are good at and then giving them the tools to develop their skill to be better and better and better,” Kwast said.
"Rapaz, não há nada mais poderoso do que uma pessoa ter de fazer algo que ama e é boa nisso,  e em seguida, dando a elas as ferramentas para desenvolverem suas habilidades para se tornarem cada vez mais melhores",  Kwast disse.
Kwast is hopeful the Air Force will release the first iteration of the game this summer, he said.
Kwast está esperançoso de que a Força Aérea lançará a primeira iteração do jogo neste verão, ele disse.
A big question mark is how the Air Force will protect participants’ privacy. This is a particularly tricky matter for participants who are underage.
Um grande ponto de interrogação é como a Força Aérea protegerá a privacidade dos participantes. Isto é uma questão particularmente difícil para os participantes que são menores de idade.
The details are not yet fully formed, Kwast said. But he stressed that the Air Force will have access to IP addresses, not names or faces, and participants will be required to sign a privacy policy.
Os detalhes ainda não estão completamente formados, Kwast disse. Mas ele ressaltou que a Força Aérea terá acesso aos endereços IP, não nomes ou rostos, e os participantes serão obrigados a assinar uma política de privacidade.
“I’ll probably send a message to that IP address saying, ‘Go tell your mom and dad that you are special, and I will offer you a $100,000 signing bonus and I will send you to Harvard for four years for free if you are willing to tell your parents to come in to the recruiting station,’” Kwast said. This way, “We preserve the values of our society but we can still see the talent.”
"Eu provavelmente enviarei uma mensagem para aquele endereço IP dizendo, 'Vai dizer a sua mãe e seu pai que você é especial, e oferecerei  a você um bonus de assinatura de R$ 380.000 e enviarei você para Harvard por quatro anos gratuitos se você estiver disposto a contar a seus pais que quer entrar para o Estação de recrutamento'", Kwast disse. Desta forma, "nós preservamos os valores da nossa sociedade, mas podemos ainda ver o talento."
Critical to the effort will be Pilot Training Next, or as Kwast likes to call it, “Learning Next,” which kicked off in February at a U.S. Army Reserve facility in Austin, Texas. The ultimate aim of the initiative is to accelerate the Air Force’s traditional pilot training syllabus by leveraging virtual reality (VR) and artificial intelligence (AI). Over the next few months, the team will gather information about human performance by measuring students’ heart rates, breathing rates, cognitive habits and more. For example, trackers embedded within the VR headsets will follow the movement of the student’s eye in real time, measuring cognitive loads.
Essencial para o esforço será a “Próxima Geração de Treinamento de Piloto”, ou como Kwast gosta de chamar, "Próxima Geração de Aprendizagem”,  a qual se iniciou em Fevereiro em uma unidade da Reserva do Exército dos Estados Unidos, em Austin, Texas. A meta final da iniciativa é acelerar o tradicional programa de formação de piloto da Força Aérea ao alavancar Realidade  Virtual (VR) e inteligência artificial (AI). Durante os poucos próximos meses, a equipe coletará informações acerca do desempenho humano ao medir taxas de batimentos cardíacos de  alunos, taxas de respiração, hábitos cognitivos e muito mais. Por exemplo, rastreadores embutidos dentro dos fones de ouvido de VR seguirão o movimento do olho do estudante em tempo real, medindo de cargas cognitivas.
Drawing on this information, the Air Force will build a database that will yield insights into human learning.
Baseando-se nesta informação, a Força Aérea construirá um banco de dados que produzirá percepções n a aprendizagem humana.
Kwast expects this method to proliferate throughout the Air Force, he said.
Kwast espera que este método se prolifere por toda a Força Aérea, ele disse.
The hope is that the new game will move the Air Force away from the “industrial age” method of placing new airmen in jobs based on the Air Force’s requirements, rather than the individual’s talents, Kwast said.
A esperança é que o novo jogo afastará a Força Aérea do método da "idade industrial" de colocar novos aviadores em postos de trabalho com base em requisitos da Força Aérea, em vez de talentos  individuais, Kwast disse.
“The more people that start doing this the more data we get and the more refined is not only our ability to teach but our ability to recruit,” Kwast said. The effort takes advantage of “the tools of our age to accelerate the learning of the force to be more ready and more lethal than any other Air Force on planet Earth.”
"Quanto mais pessoas que iniciarem fazer isto, mais dados conseguiremos, e o mais refinado não é  somente  a nossa capacidade de ensinar, mas a nossa habilidade para recrutar", Kwast disse. O esforço se aproveita das "ferramentas da nossa era para acelerar o aprendizado da força para estar  mais preparada e mais letal do que qualquer outra Força Aérea no planeta Terra."