Information concerning MTRs is also included on the chart cover.The effective date of the chart is printed on the other side of the folded chart.Also noted is an explanation of the off-route obstruction clearance altitude (OROCA).Cities near congested airspace are shown in black type and their associated area chart is listed in the box in the lower left-hand corner of the map coverage box.
![enroute 4 key enroute 4 key](https://ae01.alicdn.com/kf/HTB1JozvHVXXXXagXFXXq6xXFXXX8/Carving-programming-software-SAI-EnRoute-4-0-English-full-version-with-mounting-video-to-teach.jpg)
![enroute 4 key enroute 4 key](https://img.yumpu.com/49846437/1/500x640/enroute-42011-installation-instructions.jpg)
![enroute 4 key enroute 4 key](https://harperchalice.com/wp-content/uploads/2021/04/Key-Points.jpg)
En route high-altitude charts provide aeronautical information for en route instrument navigation at or above 18,000' MSL.AeroNav Products maintains and produces the charts for the U.S.Your ability to fly instruments safely and competently in the system is greatly enhanced by understanding the vast array of data available to the pilot on instrument charts.The objective of IFR en route flight is to navigate within the lateral limits of a designated airway at an altitude consistent with the ATC clearance.