An aircraft is equipped with three engines that operate independently. The probability of an engine failure is .01. What is the probability of a successful flight if only one engine is needed for the successful operation of the aircraft?
1. Define the probability of an engine failure as \( P(\text{failure}) = 0.01 \).
2. Since the engines operate independently, the probability of all three engines failing simultaneously is:
   \[
   P(\text{all fail}) = P(\text{failure})^3 = (0.01)^3 = 0.000001
   \]
3. The probability of a successful flight is the complement of the probability that all three engines fail. Therefore:
   \[
   P(\text{success}) = 1 - P(\text{all fail}) = 1 - 0.000001 = 0.999999
   \]

The final answer is \(\boxed{0.999999}\).