Accelerate-Stop Distance Available (ASDA)
Calculate the Accelerate-Stop Distance Available, ASDA = TORA + stopway, from the Take-Off Run Available (TORA) and the stopway length. ASDA is one of the four declared distances and has a critical safety role: it is the distance available to accelerate to the decision speed (V₁) and, if the pilot aborts the takeoff (engine failure or other), still stop safely. The stopway is a paved (or adequately strong) area beyond the runway, able to bear the aircraft in an emergency stop, not used in normal operation. Unlike the clearway (for the airborne aircraft), the stopway is for the aircraft on the ground, braking. ASDA is decisive in the balanced field length concept: the point where the distance to continue takeoff (one engine out) equals the distance to abort and stop defines V₁ and the required runway length. Enter the TORA and the stopway length.
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Distância de parada disponível (ASDA)
A ASDA (Accelerate-Stop Distance Available — distância de aceleração e parada disponível) é ASDA = TORA + stopway, uma das quatro distâncias declaradas da pista, com um papel crítico de segurança. É a distância disponível para a aeronave acelerar até a velocidade de decisão (V₁) e, caso o piloto precise abortar a decolagem — por uma falha de motor, um alarme ou qualquer anomalia detectada antes de V₁ —, conseguir parar com segurança. A stopway (zona de parada) é uma área ao final da pista, pavimentada ou de resistência adequada para suportar o peso da aeronave numa frenagem de emergência, mas que não é usada na operação normal. A diferença em relação à clearway é fundamental: a clearway é para o avião no ar (subindo), enquanto a stopway é para o avião no solo (freando). A ASDA é o coração do conceito de comprimento de campo balanceado (balanced field length): existe uma velocidade V₁ para a qual a distância necessária para continuar a decolagem com um motor inoperante se iguala exatamente à distância necessária para abortar e parar. Esse equilíbrio define a V₁ e o comprimento de pista mínimo para operar a aeronave com segurança em qualquer cenário de falha. Informe a TORA e o comprimento da stopway.
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Take-Off Distance Available (TODA)
Calculate the Take-Off Distance Available, TODA = TORA + clearway, from the Take-Off Run Available (TORA) and the clearway length. TODA is one of the four declared distances of a runway, central ICAO operational concepts. The clearway is an obstacle-free rectangular area beyond the runway over which the aircraft can complete the initial climb to a minimum height — it extends takeoff distance without extra pavement, since the aircraft is already airborne. The declared distances (TORA, TODA, ASDA, LDA) are published for each runway threshold and used by pilots and dispatchers to verify, for each takeoff, that the aircraft — with its weight, configuration and the day's conditions — fits the available runway with required margins. Enter the TORA and the clearway length.
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The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.