Airports without a control tower are classifies as "uncontrolled". As such, operations at airports without operating control towers require the highest degree of vigilance on the part of pilots to see and avoid aircraft while operating to or from such airports. Pilots should stay alert at all times, anticipate the unexpected, use the published CTAF frequency, and follow recommended airport advisory practices. There are many airport lighting and visual aids that are available at St. Mary’s County Airport. These systems are intended to aid the pilot in locating the airport environment.   Precision Approach Path Indicators (PAPIs) A PAPI is a system of lights that provide visual descent guidance information during the approach to a runway. This system provides a visual glide path that allows for safe obstruction clearance from the start of descent to the threshold. Both Runway 11 and Runway 29 are equipped with 2-box PAPIs installed to the left of the threshold. Runway End Identifier Lights REILs are installed at many airfields to provide rapid and positive identification of the approach end of a particular runway. They are effective for: a. Identification of a runway surrounded by a preponderance of other lighting; b. Identification of a runway which lacks contrast with surrounding terrain; and c. Identification of a runway during reduced visibility. These lights consist of a pair of synchronized flashing lights located on each side of the runway threshold facing the approach area. Both Runway 11 and Runway 29 have omni-directional REILs.  In June  2005 the REIL system was replaced with funding assistance from the Maryland Aviation Administration to allow for  improved pilot control. Pilots may now adjust the intensity of the lights as they approach for landing by keying or “clicking” the aircraft’s microphone in accordance with the Pilot Control Lighting Operating Procedures outlined below.   Runway Edge Lights Runway edge lights are used to outline the edges of runways during periods of darkness or restricted visibility conditions. These light systems are classified according to the intensity or brightness they are capable of producing: they are the High Intensity Runway Lights (HIRL), Medium Intensity Runway Lights (MIRL), and the Low Intensity Runway Lights (LIRL).Runway 11-29 at St. Mary’s County Airport is equipped with MIRLs. In addition, the Airport is equipped with runway threshold lights at each runway end.   Taxiway Edge Lights Taxiway edge lights are used to outline the edges of taxiways. Similar to runway edge lights, these light systems are classified according to the intensity of light they are capable of producing. Limited quantities of MITLs have been installed at St. Mary’s County Airport to delineate the taxiway turnoffs as well as the midfield connector. Obstruction Marking and Lighting In administering Title 14 of the Code of Federal Regulations CFR Part 77, the prime objectives of the FAA are to promote air safety and the efficient use of the navigable airspace. To accomplish this mission, aeronautical studies are conducted based on information provided by proponents on an FAA Form 7460-1, Notice of Proposed Construction or Alteration. Advisory Circular 70/7460-1K, Obstruction Marking and Lighting, describes the standards for marking and lighting structures such as buildings, chimneys, antenna towers, cooling towers, storage tanks, supporting structures of overhead wires, etc. A new Part 77 final Rule was published on July 21, 2010, and will become effective on January 18, 2011. Who Needs to File an FAA Form 7460-1 CFR Title 14 Part 77.13 states that any person/organization who intends to sponsor any of the following construction or alterations must notify the Administrator of the FAA: any construction or alteration exceeding 200 ft above ground level any construction or alteration: within 20,000 ft of a public use or military airport which exceeds a 100:1 surface from any point on the runway of each airport with at least one runway more than 3,200 ft within 10,000 ft of a public use or military airport which exceeds a 50:1 surface from any point on the runway of each airport with its longest runway no more than 3,200 ft within 5,000 ft of a public use heliport which exceeds a 25:1 surface any highway, railroad or other traverse way whose prescribed adjusted height would exceed the above noted standards when requested by the FAA any construction or alteration located on a public use airport or heliport regardless of height or location. Runway and Taxiway Edge Markers   In 2010, the County received special grant funding from the Maryland Aviation Administration to purchase retroreflective  markers to delineate the edges of the runway and taxiway. The markers are a safety enhancement intended to benefit the users of the St. Mary’s County Regional Airport. The markers are 2.25-inch diameter colored flexible polyethylene tubes with bands of colored retroreflective material which were FAA Tested & Certified per FAA AC 150/5345-39. The colored bands provide daytime marking,  improve ground navigation and also function as snow markers for aircraft and plows during the winter months. Control of Airport Lighting Systems The St. Mary’s County Airport does not have an operating control tower. Therefore, radio control of lighting is provided via airborne control of lights by keying the aircraft’s microphone. This eliminates the need for pilots to change frequencies to turn the lights on and allows a continuous listening watch on a single frequency. At St. Mary’s County Airport, the MIRLs and REILs can be activated using the designated Common Traffic Advisory Frequency (CTAF), 123.0. At this airport, the CTAF is a UNICOM frequency. In addition, the MIRLs and REILs are controlled by a photo cell and are automatically turned on at dusk and during adverse weather. Pilot Control Lighting Operating Procedures Runway Lights: The runway lights are controlled by a photo eye and via the CATF by “clicking” the microphone. From dusk until dawn, the runway lights are turned on to the Low setting by the photo eye. The runway lights can be changed to the High setting by clicking the mic 5 times. They can be set back to Low by clicking the mic 3 times. During times of heavy overcast, the photo eye may allow the runway lights to come on during “daylight hours”. Runway End Identifier Lights (REIL) Strobes: The REILs are controlled via the CATF by “clicking” the microphone, a set timer and by a photo eye.  Radio Control System Key Mike Function 3 times within 5 seconds Highest intensity available 5 times within 5 seconds Medium or lower intensity (Lower REIL or REIL-off) 7 times within 5 seconds Lowest intensity available (Lower REIL or REIL-off) NOTE: At any time in the sequence the pilot has the option of sending three, five, or seven pulses to command the intensity level to his/her requirements. The system will remain at the intensity level of the last command received. The solid state timer will continue to operate for 15 minutes after which it will cause the system to revert to the original “off” condition. The timer is reset by the receipt of any command at anytime, reinitiating the 15 minute “run” cycle. A photo eye keeps the REILs from operating during the day, but may allow them to operate during periods of heavy overcast. Airport (Rotating) Beacon The airport beacon is used to aid pilots in locating the airport using a rotating green and white light. The ten (10) inch airport beacon at the Airport is located on top of the County Hangar. A photo eye controls the rotating beacon. It operates from dusk until dawn and may come on during periods of heavy overcast. Wind Cone and Segmented Circle The lighted wind cone and segmented circle is used to aid pilots in determining takeoff and landing information at an airport. St. Mary’s County Airport’s lighted wind cone and segmented circle is located to the north of Runway 11-29 and is in good working condition.   INSTRUMENT APPROACH PROCEDURES            An Instrument Approach Procedure (IAP) is a flight procedure that provides a transition from the en-route flight environment to a point from which a safe, normal landing can be accomplished. U.S. Civil Standard Instrument Approach Procedures are designed and approved for public use by the Federal Aviation Administration (FAA) and are unique to each airport. While these procedures can be flown during good weather conditions, the instrument approach procedures are especially important during Instrument Meteorological Conditions (IMC). When the cloud ceilings are low and visibility is minimal, all flights must follow Instrument Flight Rules (IFR), and therefore must utilize published instrument approach procedures when transitioning to the landing environment. The FAA has established ceiling and visibility minimums for each individual instrument approach procedure. Currently, there are two (2) published instrument approach procedures for St. Mary’s County Airport. These procedures are listed below with the corresponding landing minimums:   LANDING MINIMUMS APPROACH PROCEDURE CEILING VISIBILITY VOR OR GPS RWY 29 600 FT 1 MILE GPS RWY 11 500 FT 1 MILE Standard instrument approach procedures are primarily based upon either an on-airport or nearby electronic navigational aid (NAVAID) or the Global Positioning System (GPS). Therefore, the type of instrument approach procedure is determined by what the procedure is based upon. One of the instrument approach procedures at St. Mary’s County Airport is a VOR type procedure. This procedure is based on the Patuxent VORTAC (PXT, frequency 117.6) located at the Patuxent River Naval Air Station. A VORTAC is a navigation aid providing VOR azimuth, TACAN azimuth, and TACAN distance measuring equipment (DME) at one site. VOR, TACAN and DME are briefly defined and described below: VHF Omni-Directional Range (VOR) - A ground-based electronic navigation aid transmitting very high frequency navigation signals, 360 degrees in azimuth, oriented from magnetic north. VORs operate within the 108.0 to 117.95 MHZ frequency band and have a power output necessary to provide coverage within their assigned service volume. There are subject to line-of-sight restrictions, and the range varies proportionally to the altitude of the receiving equipment. Tactical Air Navigation (TACAN) - A navigational system developed for use by the military and naval forces. Distance Measuring Equipment (DME) - Equipment (airborne and ground) used to measure, in nautical miles, the slant range distance of an aircraft from the DME navigational aid. Operating on the line-of-sight principle, DME furnishes distance information with a high degree of accuracy. DME is typically collocated with other NAVAIDS. In addition, two of the instrument approach procedures can be flown using the Global Positioning System (GPS). GPS is a system of 24 satellites, orbiting the earth, which emit signals to receivers below. By measuring the travel time of a signal transmitted from each satellite, a receiver in the aircraft can calculate its distance from that satellite. When receiving the signals from at least four (4) satellites, a receiver can determine latitude, longitude, altitude and time. The basic GPS service provides users with approximately 100 meter (328 feet) accuracy 95% of the time anywhere on or near the surface of the earth. When the civil aviation community first began using the Global Positioning System (GPS), many existing instrument approaches were modified to allow pilots with GPS capabilities to fly a published approach using their approved GPS capabilities instead of the more traditional NAVAIDS. This type of approach is referred to as a GPS Overlay approach and is published as an "OR GPS" approach. This type of procedure did not require any modifications to the existing "base" published procedure. St. Mary’s County has one GPS Overlay approach procedure, VOR OR GPS RWY 29.Please note the following FDC NOTAM that makes the VOR 29 Approach NOT AVAILABLE. The GPS 29 is still active. FDC 7/6353 2W6 FI/T ST. MARY'S COUNTY REGIONAL, LEONARDTOWN, MD. VOR OR GPS RWY 29, AMDT 6A... VOR PORTION NA. In addition to the GPS Overlay approaches, in recent years GPS Stand Alone approaches have been developed as well. This type of approach is not related to any traditional NAVAID. St. Mary’s County has one GPS Stand Alone approach procedure, GPS RWY 11. NOTAMS (Notice To Airmen) In the event that conditions at the Airport are determined to be unsafe for landings or takeoffs, the airport owner is responsible for providing warning to users, such as adequate marking and issuing a Notice To Airmen to advise pilots of the condition. Where climatic conditions render the airport unsafe, the owner will promptly notify airman by proper notices and, if necessary, close the Airport, or any portion thereof, for a reasonable period of time or until those unsafe conditions can be corrected or no longer exist. Additional information can be obtained from the following Aircraft Owners and Pilots Association web-site Current NOTAM's are required by the Federal Aviation Administration and are available from Flight Services Stations at 1-800-WX-BRIEF. Notices restrictions, and advisories may be changed at any time and without notice. Do not attempt any operation in the National Airspace System without first obtaining and understanding a thorough pre-flight briefing. Pilots may also wish to view current NOTAM's for St. Mary's Regional Airport at the FAA website and by typing in "2W6" in the Flight Safety Notams box. UNICOM Communication The airport is served by a UNICOM radio. All pilots of aircraft having radio equipment permitting two-way communications should contact the Airport UNICOM to obtain advisory information and announce their intentions when within ten (10) miles of the Airport. Pilots are also encouraged to maintain a listening watch on the frequency when operating within a ten mile radius of the Airport. All departing aircraft shall announce on the UNICOM their intention and runway to be used for departure. In communicating with a UNICOM station, the following practices will help reduce frequency congestion, facilitate a better understanding of pilot intentions, help identify the location of aircraft in the traffic pattern, and enhance safety of flight: Select the correct CTAF frequency. State the identification of the UNICOM station you are calling in each transmission. Speak slowly and distinctly. Notify the UNICOM station approximately 10 miles from the airport, reporting altitude, aircraft type, aircraft identification, location relative to the airport, and whether landing or over-flight. Request wind information and runway in use. Report on down-wind, base, and final approach. Report leaving the runway. GCO (Ground Communications Outlet) The ground communications outlet (GCO) is a radio transmitter/receiver with a telephone interface. The GCO allows pilots to communicate directly with air traffic controllers located at the Patuxent River Naval Air Station. The GCO at the Captain Walter F. Duke Regional Airport @ St. Mary’s  was provided by the Maryland Aviation Administration and installed and commissioned in 2004 as a part of a cooperative effort between Naval Air Station, the Airport Advisory Committee, and County Airport staff.  The system is an affordable way to access ATC from the ground. By making such remote access available, pilots won’t have to chose between climbing out of the airplane to make a phone call or launching into marginal conditions to gain the altitude needed for radio contact. Pilots must obtain a clearance to depart, prior to entering clouds or areas of poor visibility (instrument conditions). Pilots needing a clearance can tune in aviation frequency 121.725 MHz and key their microphone four times. The GCO recognizes the clicks and automatically dials a restricted number. The pilot then has the ability to communicate directly with the controller.  How to Use the system: 1)  Pilots on the ground at St. Mary’s should tune a COM radio to Frequency 121.72 MHz and slowly click the microphone FOUR times ( ie. one click per second). 2)  You will hear approximately two rings of the phone line. 3)  A controller from Pax River NAS will answer - you can then begin your communication. 4) After you complete your communications, the controller will hang up and the system will automatically disconnect.  Note: If there is no communication for more than approximately 30 seconds, the system will automatically disconnect.   PIC (Pilot Information Center) The Maryland Aviation Administration is initiating a statewide Pilot Information Center Program for all public use airports. The PIC will provide on-line services for flight planning, and, flight plan filing. Pilots will have the ability to access destination airports, file flight plans, check weather throughout the country, access navigational maps and other local interest information. Computer terminals will be in the new terminal building and available for use by everyone in the general aviation community. AWOS (Automatic Weather Observation System) AWOS is a system for automatic acquisition, processing and presentation of sensor data and is used to generate, edit and distribute meteorological reports. The AWOS will provide information on wind speed and gusts, wind direction, air temperature, dew point, precipitation, barometric pressure, visibility, cloud/ceiling height etc. The sensor data is processed in accordance with ICAO and WMO regulations. The data is displayed as instant values in a monitoring window, formatted and automatically assembled into various reports. The operator can switch the system into a semiautomatic mode and supplement the automatic data with his/her own observations. All parameters are stored in a direct access database and can be displayed graphically. The generated reports (METAR, SYNOP, METREPORT, SNOWTAM, CLIMATE) are transmitted to a meteorological network (AFTN, METCOM) and distributed locally (workstations, CCTV). AWOS sends coded messages to other systems such as the ATIS speech synthesizer or radar processing units. The AWOS system also allows also for remote control, monitoring and surveillance of sensors WEBSITE: http://www.faa.gov/air_traffic/weather/asos/?state=MD or http://weather.noaa.gov/weather/current/K2W6.html  Frequency: 119.575 MHZ    Phone:(301) 373-6514   Data Transmission Network (DTN) The DTN is designed to provide pilots, airports, and FBO’s with unlimited access to comprehensive satellite aviation weather maps and flight planning information.  METARs, Terminal Area Forecasts (TAFs), Airmen Meteorological Information (AIRMETs) / SIGMETs, satellite imagery, weather radar imagery, surface weather imagery, upper air imagery, 12 & 24-hour significant weather imagery, and city forecasts are several of the services provided by the system.    The system, located in the Piedmont Flight Center, has full color graphics, is equipped with NOAA warnings and alert module, is AOPA certified, and is automatically updated. Feel free to access the on-line Help segment for further information and assistance. Localizer Performance with Vertical Guidance (LPV) Wide Area Augmentation System (WAAS) - capable equipment can be used to improve navigation. It is used primarily by private general-aviation pilots, business and regional aircraft, and some cargo aircraft. The system includes two geostationary satellites and a network of ground reference stations that monitor GPS satellite signals. WAAS corrects for the GPS satellite position errors, ionosphere delays, and other disturbances in the GPS signals and warns pilots when the satellites are not functioning correctly and should not be used for navigation. In addition to the supporting IFR operations, WAAS provides for both more flexible approach and departure routings and more direct, fuel-efficient routings through the air traffic control system. It also provides an improved navigation source for other aviation innovations such as terrain avoidance warning systems and automatic dependent surveillance-broadcast (ADS-B). Using GPS, an ADS-B–equipped aircraft determines its own position and periodically broadcasts this position and other relevant information to air traffic control stations and other aircraft with ADS-B-in equipment flying in the area. Like the GPS SPS standard, the WAAS PS defines the WAAS signal-in-space (SIS) characteristics, navigation message, and performance requirements. Many view WAAS-LPV as being more economical for piston, turboprop and smaller jets such as those planned for the St. Mary's Regional Airport. WAAS-supported LPV approach procedures now surpass the number of approach procedures of the its ground-based predecessor, the Category-I instrument landing system (ILS). LPV takes advantage of the very high performance of the GPS signals when corrected by WAAS. LPV enables pilots to use instrument flight rules for approach and landing operations down to a decision height of 200 feet. LPV approach ceiling minimums are generally 250 feet, with visibility minimums of 3/4 or 1/2 mile, depending upon runway lighting and markings. LPV is also designed to provide 16-meter horizontal accuracy and 20-meter vertical accuracy 95 percent of the time. LPV status can also calls for a 6.2-second time to alert when the system is not meeting specified requirements. An LPV approach should be published by the FAA for the St. Mary's Regional Airport by September 2010.