Vários relatórios de acidente do R22 indicam que a rotação do rotor cai e o motor tenderá a sobrevelocidade em caso de falha da correia 'V'. Do relatório do Departamento de Segurança de Transporte da Austrália Fiabilidade do sistema de transmissão por correia do helicóptero Robinson R22 :
NTSB occurrence report: LAX92LA034
... pilot reported that the engine RPM indicator suddenly pegged at the top of the gauge and the rotor RPM began rapidly decreasing. ... Examination ... revealed that the forward v-belt was split longitudinally and displaced from the transmission pulleys. The rear belt was found off the engine and transmission pulleys.
CAA occurrence report: 99/23
... there was a bang and the engine ‘revved up’, but power to the main rotor was lost. The power loss to the main rotors was due to broken v-belts.
NTSB occurrence report: NYC08LA043
... , the engine’s RPM sharply increased and the main rotor RPM alarm sounded. Post-accident examination of the helicopter drive system revealed that the v-belts had rolled off the sheaves
NTSB occurrence report: N993KC
The pilot ... heard a loud ‘bang’. The pilot ... observed the engine RPM was excessively high, the rotor RPM was below 80 percent and the low rotor RPM warning horn was sounding. The on-scene investigation noted that one of the v-belts to the main rotor drive system had separated, which caused the other belt to slip off the upper spindle.
Em caso de suspeita de falha na correia, espera-se que o piloto tente aterrissar enquanto preparado para uma autorrotação. Do Manual de Voo do R-22 :
... if the clutch light flickers or stays on for a longer time than usual, it can indicate a belt or bearing failure in the vee-belt drive. If that occurs, immediately pull the CLUTCH circuit breaker. Select the closest safe landing site and make a normal power-on landing. Be prepared to enter autorotation should failure of the drive system occur. The smell of burning rubber may also indicate an impending belt failure.
Note que não há conversa sobre o acelerador. Embora o R22 tenha dois cintos V, ele não é projetado para voar com um único (embora pareça haver alguns exemplos disso). Meu palpite é que é melhor para o piloto não mexer com o acelerador por duas razões - se o problema está em outro lugar, reduzir a rpm teria efeitos adversos e se a correia realmente se fosse, seria melhor para o piloto concentre-se em salvar as pessoas primeiro e depois o motor.