A malfunction in which high voltage in the distributor jumps between the terminals and causes the wrong spark plug to fire.

"Cross (fix) at (altitude)" (air traffic control). A phrase used by ATC when a specific altitude restriction at a specified fix is required.

"Cross (fix) at or above (altitude)" (air traffic control). A phrase used by ATC when an altitude restriction at a specified fix is required. It does not prohibit the aircraft from crossing the fix at a higher altitude than specified; however, the higher altitude must not be one that will violate a succeeding altitude restriction or altitude assignment.

"Cross (fix) at or below (altitude)" (air traffic control). A phrase used by ATC when a maximum crossing altitude at a specific fix is required. It does not prohibit the aircraft from crossing the fix at a lower altitude; however, the aircraft must be at or above the minimum IFR altitude.