![](https://flightsafety.org/wp-content/uploads/2023/04/atsb-pitot-tubesScreenshot-2023-04-21-122832-e1682107239831.png)
The flight crew of an Airwork Boeing 737 freighter observed a 340-ft discrepancy in altitude readings between the captain’s and first officer’s display screens after departure from Perth, Western Australia, as well as small differences in airspeed and Mach number readings.