Disclosed is a method of monitoring pressure in a fire suppression system of an aircraft, the method providing: receiving a first pressure-vessel measured pressure from a first pressure-vessel pressure transducer connected to a first pressure-vessel; receiving a second pressure-vessel measured temperature from a second pressure-vessel temperature sensor connected to a second pressure-vessel; calculating a first pressure-vessel estimated pressure from the second pressure-vessel measured temperature; comparing the first pressure-vessel measured pressure With the first pressure-vessel estimated pressure; and providing a depressurization alert when a difference between the first pressure-vessel measured pressure and the first pressure-vessel estimated pressure is greater than a threshold thereby avoiding unscheduled aircraft downtime due to an erroneous or missing temperature measurement in the first pressure-vessel.