+.BI "--ceiling=" "value[:thickness]"
+Create an overcast ceiling (feet above sea level). May optionally specify
+a thickness (feet) which defaults to 2000.
+.TP
+.BI "--com1=" "frequency"
+Set the initial COM1 radio frequency.
+.TP
+.BI "--com2=" "frequency"
+Set the initial COM2 radio frequency.
+.TP