Final answer:
The correct action when icing is suspected on an airplane is to activate the deicing equipment, ensuring it is addressing the ice accumulation effectively.
Step-by-step explanation:
When icing is suspected on an airplane that is equipped with deicing equipment, the correct procedure for the pilot would be to first verify whether icing is actually occurring. If confirmed, the pilot should activate the deicing equipment appropriate for the type and amount of icing. This action may include using pneumatic deicing boots, electrical heating systems, or other forms of anti-icing or deicing techniques available on the aircraft. It is vital for the pilot to closely monitor the situation to ensure that the systems are effectively removing the ice and not to continue to fly as normal, land the airplane immediately, or increase the altitude without ensuring that it is safe to do so under the icing conditions.