LOW-LEVEL AND TACTICAL FORMATION
Using the same scale on the Plotter, draw time ticks on the right side of the course
line that show minutes from the previous turnpoint. These time ticks start at zero at
one turnpoint and count up to the next one indicating time elapsed on the leg. Flights
are planned for a constant indicated airspeed of 180 kts or 3 NM per minute (no
Chart Updating Manual. (CHUM). This is the most time consuming and tedious step in chart
construction. It is also one of the most important. It allows you to compute accurate MSA, ESA
and night altitudes and ensures that we will maintain clearance from all obstacles. TPC and JOG
charts are published from information from many years ago. All obstruction data (towers,
powerlines, etc.) added since the publication of the original charts is published in the CHUM.
This information must be manually drawn, in ink, onto your charts. Only the obstructions that
will affect the route of flight within 22 NM need to be CHUMed.
For TRARON 31 and TRARON 35 use only.
The first way to get CHUM is through the National Imagery and Mapping Agency website.
NIMA's website (http://www.nima.mil) provides Electronic-CHUM or ECHUM. Click
through the following as applicable:
Products and Services
Aeronautical Information Homepage,
Electronic Chart Updating Manual (ECHUM),
Go to ECHUM and choose current edition by month and year,
Choose Flight Corridor or MTRs (for SR166 or VR151) as applicable.
ECHUM allows you to specify a route and the distance either side of the route that needs to be
CHUMed. The work of chumming the chart is still there, but the CHUM retrieved through
ECHUM is limited to only what is requested.
It is recommended that you enter all the points found in the two routes that you are
building. Many routes overlap and requesting the routes separately will cause you to re-CHUM
many points. Save yourself time and get all the points at one time. Use the picture provided on
NIMA to make sure that what you entered looks like the route are building! Do not forget to
include the escape routes in the CHUM searches.
If you have checked out an older chart and you need to update the CHUM, then use
ECHUM. Go the page and enter the information as you would normally, but check the Specify
Additional Query Criteria box at the bottom of the page. This will present a page with a
number of options. The option Specific Publication Query will allow you to select, for
FLIGHT PREPARATION D-3