Diverse Vector Area  Noise Abatement Procedures  Visual Climb Over Airport (VCOA)  ATC may establish a minimum vectoring altitude (MVA)  around certain airports. This altitude, based on terrain and  obstruction clearance, provides controllers with minimum  altitudes to vector aircraft in and around a particular  location. However, at times, it may be necessary to vector  aircraft below this altitude to assist in the efficient flow of  departing traffic. For this reason, an airport may have an  established Diverse Vector Area (DVA). This DVA may be  established below the MVA or Minimum IFR Altitude (MIA)  in a radar environment at the request of Air Traffic. This  type of DP meets the TERPs criteria for diverse departures,  obstacles and terrain avoidance in which random radar  vectors below the MVA/MIA may be issued to departing  traffic.  The existence of a DVA will be noted in the Takeoff  Minimums and Obstacle Departure Procedures section of  the U.S. Terminal Procedure Publication (TPP). The Takeoff  Departure procedure will be listed first, followed by any  applicable DVA. Pilots should be aware that Air Traffic  facilities may utilize a climb gradient greater than the  standard 200 ft/NM within a DVA. This information will be  identified in the DVA text for pilot evaluation against the  aircraft's performance. Pilots should note that the DVA  has been assessed for departures which do not follow a  specified ground track, but will remain within the specified  area. ATC may also vector an aircraft off a previously  assigned DP. In all cases, the minimum 200 ft/NM climb  gradient is assumed unless a higher is specified on the  departure, and obstacle clearance is not provided by ATC  until the controller begins to provide navigational guidance  (vectors). Lastly, pilots should understand ATC instructions  take precedence over an ODP [Figure 1-35].  A visual climb over airport (VCOA) is a departure option for  an IFR aircraft, operating in VMC equal to or greater than the  specified visibility and ceiling, to visually conduct climbing  turns over the airport to the published "climb-to" altitude  from which to proceed with the instrument portion of the  departure. A VCOA is a departure option developed when  obstacles farther than 3 SM from the airport require a CG  of more than 200 ft/NM.  These procedures are published in the Take-Off  Minimums and (Obstacle) Departure Procedures section  of the TPP. [Figure 1-36] Prior to departure, pilots are  required to notify ATC when executing the VCOA.  As the aviation industry continues to grow and air traffic  increases, so does the population of people and businesses  around airports. As a result, noise abatement procedures  have become commonplace at most of the nation’s airports.  14 CFR Part 150 specifies the responsibilities of the FAA to  investigate the recommendations of the airport operator in  a noise compatibility program and approve or disapprove  the noise abatement suggestions. This is a crucial step in  ensuring that the airport is not unduly inhibited by noise  requirements and that air traffic workload and efficiency  are not significantly impacted, all while considering the  noise problems addressed by the surrounding community.  While most DPs are designed for obstacle clearance and  workload reduction, there are some SIDs that are developed  solely to comply with noise abatement requirements.  Portland International Jetport is an example of an airport  where a SID was created strictly for noise abatement  purposes as noted in the DP. [Figure 1-36] Typically, noise  restrictions are incorporated into the main body of the  SID. These types of restrictions require higher departure  altitudes, larger climb gradients, reduced airspeeds, and  turns to avoid specific areas. Noise restrictions may also  be evident during a radar departure. ATC may require you  to turn away from your intended course or vector you  around a particular area. While these restrictions may seem  burdensome, it is important to remember that it is your  duty to comply with written and spoken requests from ATC.  Additionally, when required, departure instructions specify  the actual heading to be flown after takeoff, as is the case in  Figure 1-37 under the departure route description, “Climb  via heading 112 degrees...” Some existing procedures specify,  “Climb runway heading.”Over time, both of these departure  instructions will be updated to read, “Climb heading 112  degrees....” Runway heading is the magnetic direction that  corresponds with the runway centerline extended (charted  on the airport diagram), not the numbers painted on the  runway. Pilots cleared to “fly or maintain runway heading”  are expected to fly or maintain the published heading that  corresponds with the extended centerline of the departure  runway (until otherwise instructed by ATC), and are not to  apply drift correction (e.g., RWY 11, actual magnetic heading  of the runway centerline 112.2 degrees, “fly heading 112  degrees”). In the event of parallel departures, this prevents  a loss of separation caused by only one aircraft applying a  wind drift.  1-42 