Which of the following does NOT limit a person's readiness for flight duty?

A person's readiness for flight duty is crucial for safety and operational effectiveness. Donating blood, being impaired by alcohol, and having a suspected detrimental condition all have specific guidelines and implications regarding a pilot's or crew member's ability to perform flight duties safely.

When it comes to donating blood, there is a stipulated wait period post-donation before a person is considered fit for flight duty again, as it could lead to reduced stamina or physiological stresses that impact performance. Similarly, being impaired by alcohol is a clear and serious infraction against readiness requirements, as alcohol significantly affects cognitive and motor skills. A suspected detrimental condition entails that a pilot may have an underlying health issue that could potentially interfere with their effectiveness or safety while flying, hence this would limit their readiness as well.

On the contrary, obtaining appropriate crew rest is essential for maintaining readiness. This practice ensures that flight crews are well-rested and alert, which is a fundamental requirement for flight safety. Adequate rest is vital in preventing fatigue and enhancing decision-making and performance, making it a positive contributor to flight readiness rather than a limitation. Therefore, it stands out as the option that does not restrict readiness for flight duties.