Answer: No. Placing a patient in an aircast and teaching him how to use it does not constitute a strapping procedure. You should bill using the E/M code for the patient's visit that day (99201-99215 for outpatient visits), and you should not bill separately for the fitting.
If your practice is licensed to bill for durable medical equipment (DME), you can bill for the aircast using L4350 (Ankle control orthosis, stirrup style, rigid, includes any type interface [e.g., pneumatic, gel], prefabricated, includes fitting and adjustment). Note that this code includes the fitting and adjustment, so simply applying the aircast would not justify reporting an E/M code along with L4350, unless you also diagnosed the patient that day or treated a separate condition as well.