Final answer:
The aircraft must typically be grounded until the CVR is fixed unless the regulating aviation authority provides a specific exemption or grace period. Continuing to fly without a CVR is not generally allowed because it is an essential safety device.
Step-by-step explanation:
If your aircraft doesn't have a functioning Cockpit Voice Recorder (CVR) but has a functioning Flight Data Recorder (FDR), the correct course of action according to aviation regulations generally depends on the jurisdiction and the specific rules of the aviation authority that governs your operation. However, for most commercial operations, it is mandatory to have both the CVR and the FDR functioning to continue flying.
Option A (Continue flying without any restrictions) would not typically be correct, as the CVR is an important safety device that records cockpit audio and is vital in the event an incident needs to be investigated. Option B (Ground the aircraft until the CVR is fixed) is often the requirement unless an exemption or grace period is provided by the aviation authority. Option C (Fly for a maximum of 90 days provided the FDR remains serviceable) could be the correct answer if the regulatory body allows for a specific dispensation period during which the plane can fly without a functioning CVR, but the exact duration can vary. Option D (Only operate during daylight hours) does not relate to the CVR issue and typically wouldn't be applicable. Most regulators will require operators to repair the CVR promptly and may allow a specific, limited time for operation until the CVR must be repaired or replaced.