451 - ATPL Question Bank in English - Which of the following describe approved emergency landing-gear extension arrangements, rather than an unapproved gas substitution? 1) Replacing the specified nitrogen with CO2 in a nitrogen-rated blowdown system without manufacturer approval. 2) Using compressed nitrogen in a blowdown system designed for nitrogen. 3) Replacing the specified nitrogen with compressed oxygen without manufacturer approval. 4) Using the installed mechanical/manual emergency-extension mechanism. 5) Using the installed gravity/freefall emergency-extension arrangement. Select all the correct statements.

Question 451 - Aircraft General Knowledge - Airframe, Systems, Powerplant - ATPL - Airline Transport Pilot Licence