Scheduled Maintenance On Thursday 4/18 from 4:00 AM to 6:00 AM EST and Friday 04/20 from 1:00 AM to 2:00 AM EST, Technical Publications App will be unavailable as we prepare for the introduction of exciting new features. We appreciate your patience as we strive to enhance the Aero portal experience.
Scheduled Maintenance We will be conducting scheduled maintenance on 4/19 from 10:00 PM EST to 4/20 9:00 PM EST. During this time MyAerospace applications will be temporarily unavailable. We apologize for any inconvenience this may cause.​​

Your browser is not supported.

For the best experience, please access this site using the latest version of the following browsers:

Close This Window

By closing this window you acknowledge that your experience on this website may be degraded.

CPDLC Corner

The CPDLC uplink message 148, or UM148, is widely used in both FANS and ATN environments. It delivers the message, "WHEN CAN YOU ACCEPT" when a controller needs to know how soon an aircraft can accept a specified altitude or flight level.

This message is sometimes misinterpreted by flight crews as a clearance to climb or descend. To help eliminate any confusion, in January we posted a short video on the Honeywell Aerospace YouTube channel that demonstrates how to properly respond to a UM148.