Which item is NOT required in a minimum aircraft survival kit according to the IALSE?

A minimum aircraft survival kit is designed to provide essential tools and supplies to increase the chances of survival in an emergency situation. The items included in this kit are selected based on their practicality and utility in wilderness survival scenarios.

While a sleeping bag can certainly provide warmth and comfort in an emergency, it is not considered essential for survival in the same way that the other items are. Water purification tablets are critical for ensuring access to safe drinking water, the signal mirror is crucial for signaling rescue aircraft or personnel from a distance, and a whistle is useful for attracting attention when help is nearby. Each of these items serves a specific purpose that directly contributes to survival.

Therefore, although a sleeping bag may enhance comfort, it does not possess the same level of indispensable utility in a survival scenario compared to the other items listed. This distinction is what makes it the correct choice for the question about what is not required in a minimum survival kit according to IALSE guidelines.