Aeronautical Information Manual (AIM), page 560
7110.65R AIM AIM CHG 2 3/15/07 11/10/16 12/10/15 6. Helicopter Route Charts. A three-color addition, pictorial symbols, roads, and easily chart series which shows current aeronautical identified geographical features are portrayed. information useful to helicopter pilots navigating in Helicopter charts have a longer life span than other areas with high concentrations of helicopter activity. chart products and may be current for several years. Information depicted includes helicopter routes, four Helicopter Route Charts are updated as requested by classes of heliports with associated frequency and the FAA. Scale 1 inch = 1.71nm/1:125,000. 34 x 30 lighting capabilities, NAVAIDs, and obstructions. In inches folded to 5 x 10 inches. (See FIG 9-1-4.)FIG 9-1-4 Helicopter Route Charts b. IFR Navigation Charts. communications; minimum en route and obstruction clearance altitudes; airway distances; reporting 1. IFR En Route Low Altitude Charts points; special use airspace; and military training (Conterminous U.S. and Alaska). En route low routes. Scales vary from 1 inch = 5nm to 1 inch = altitude charts provide aeronautical information for 20nm. 50 x 20 inches folded to 5 x 10 inches. Charts navigation under IFR conditions below 18,000 feet revised every 56 days. Area charts show congested MSL. This four-color chart series includes airways; terminal areas at a large scale. They are included with limits of controlled airspace; VHF NAVAIDs with subscriptions to any conterminous U.S. Set Low (Full frequency, identification, channel, geographic coor- set, East or West sets). dinates; airports with terminal air/ground (See FIG 9-1-5 and FIG 9-1-6.) 9-1-4 Types of Charts Available
Page 560 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures