More Ways to Help ...

More News ...

More Info ...

Learn More ...

Visit our
Web Discussion Forum

Today is

General Aviation Info: Aviation Definitions

Privately Owned Airport: An airport which is owned by a private individual or corporation.

Public-Use Airport: An airport that is open for public use without prior permission, and without restrictions within the physical capabilities of the facility. It may or may not be publicly owned.

Reliever Airport: An airport designated as having the function of relieving congestion at a commercial service airport (Newark, Kennedy, LaGuardia, Philadelphia) and providing more general aviation access to the overall community.

Optimum Runway Length: That runway length that will enable an aircraft at gross weight with zero wind to accelerate to takeoff speed and to abort the takeoff and decelerate to a safe stop on the runway with a small amount of runway remaining as a safety margin. This length can be determined by adding the ground roll length for an aircraft at gross weight with it's landing roll length over a 50 foot obstacle at the airport's approximate highest density altitude.

VFR - Visual Flight Rules: Operating under visual flight rules, you are governed by specific regulations which include minimum cloud clearance and visibility requirements, and procedures for conducting flight under visual conditions.

IFR - Instrument Flight Rules: When you are operating under instrument flight rules, you can fly in the clouds with no reference to the ground or horizon. Instrument flight rules govern flight operations in weather conditions below VFR minimums.

Density Altitude: Pressure altitude that has been corrected for nonstandard temperature. In other words, decreases in air density due to temperature, pressure and humidity reduce the performance of an aircraft's wings, propeller and engine. When the air is less dense, it will take longer for the plane to accelerate to a takeoff speed. It will also take more runway to reach takeoff speed.

REIL - Runway End Identifier Lights: Runway end identifier lights are designed to help pilots spot the approach end of a runway at night, in poor visibility conditions, in an area with a great deal of other lighting, or anywhere that the runway is exceptionally difficult to identify. REIL are two synchronized, flashing lights located one on each side of the runway threshold. They may be visible from only one direction, or they may be omnidirectional. REIL can generally be seen from the air for several miles, even in marginal visibility.

Observing System: ASOS is a surface weather observing system being implemented by the National Weather Service (NWS), the Federal Aviation Administration (FAA), and the Department of Defense (DOD). ASOS is designed to provide minute-by-minute observations and perform the basic observing functions necessary to generate a surface weather observation and provide other aviation weather information. The information provided includes, among other things, wind direction and speed, visibility, runway visual range, weather phenomena, sky condition, temperature/dew point, altimeter setting and remarks. This information can be accessed by pilots during their flight planning to be aware of the local weather conditions at their destination airport or at an enroute airport before they depart on their flight. Access is through dial-in telephone numbers and ground-to-air radio.

ILS - Instrument Landing System: A precision approach navigational aid which provides highly accurate course, glide slope, and distance guidance to a given runway. The typical ILS installation is made up of several components, a localizer to align the aircraft with the centerline of the runway, a glide slope transmitter which creates a three degree slope for the aircraft to descend on the approach to the runway, and distance measuring equipment (DME) for the pilot to determine distance from the runway threshold. The ILS can be the best approach alternative in poor weather conditions for several reasons. First, the ILS is a more accurate approach aid than any other widely available system. Secondly, the increased accuracy generally allows for lower approach minimums. Third, the lower minimums can make it possible to execute an ILS approach and land at an airport when it otherwise would not have been possible using a nonprecision approach. A recent study completed under the auspices of the Flight Safety Foundation concluded that an increase in approach and landing safety can be obtained through the use of precision approach and landing guidance facilities.

ILS Marker Beacons: Usually there are two marker beacons associated with an instrument landing system (ILS) -- the outer marker (OM) and middle marker (MM). The placement of the OM varies from four to seven miles from the runway, depending on the installation. It usually is placed inside the just point where an aircraft flying the ILS intercepts the glide slope. The MM is usually located 3,500 feet from the landing threshold, with its signal array intercepting a 3 degree glide slope at approximately 200 feet above the touchdown zone for the runway.

Localizer: A transmitter used in an instrument landing system which provides the pilot with information on a display in the aircraft regarding his alignment with the runway centerline during a landing approach.

Glide Slope: A transmitter used in an instrument landing system which provides the pilot with vertical navigation information on a display in the aircraft for descent to the lowest authorized decision height for the associated approach procedure.

DME - Distance Measuring Equipment: On many instrument landing system procedures, a DME transmitter is placed at or near the localizer or glide slope transmitter to provide runway distance information for the pilot. The pilot has a DME receiver on board the aircraft which displays the distance from the DME transmitter.

Runway Markings: Markings vary between runways used solely for operations under visual flight rules (VFR) and those used for operations under instrument flight rules (IFR). A visual runway usually is marked only with the runway number and a centerline. Runways used for instrument operations have additional markings. A non precision instrument runway is used with an instrument approach that does not have an electronic glide slope for approach glide path information. This type of runway has the visual runway markings, plus the threshold and aiming point markings.

Runway Approach Lighting: Airport lighting systems range from the simple lighting needed for visual night landings to sophisticated systems which guide you to the runway in poor weather or instrument conditions. The approach lighting system (ALS) helps pilots transition from instrument to visual references during the approach to landing. It makes the runway environment more apparent in low visibility conditions and helps the pilot maintain correct alignment with the runway. Some approach light systems include sequenced flashing lights (SFL) or runway alignment indicator lights (RAIL) SFL and RAIL consist of a series of brilliant blue-white bursts of flashing light. From your viewpoint, these systems give the impression of a ball of light traveling at high speed toward the approach end of the runway.

VASI - Visual Approach (Glide) Slope Indicators: Once you have the runway environment in sight, visual glide slope indicators help the pilot maintain a safe descent path to the runway. Their purpose is to provide a clear visual means to determine if you are too high, too low, or on the correct glide path. These indicators are extremely useful during low visibility, or at night, when it may be difficult to judge the descent angle accurately due to a lack of runway contrast. Staying on the VASI glide path assures the pilot of a safe obstruction clearance within plus or minus 10 degrees of the extended runway centerline and out to 4 nautical miles from the threshold. VASI lights are visible to the pilot from 3 to 5 miles during the day and up to 20 miles at night.

Runway Edge Lights: Runway edge lights are used to outline the runway during periods of darkness or restricted visibility. They are classified according to their brightness -- high intensity (HIRL), medium intensity (MIRL), and low intensity (LIRL). HIRL and MIRL have variable intensity controls which may be adjusted by the pilot using the aircraft radio.

Bi-Directional Threshold Lights: Bi-directional threshold lights mark the ends of each runway. As you approach for landing, the lights are green, indicating the beginning of the runway. As you take off, the lights are red indicating the departure end of the runway. These lights are inside of the runway edge lights and are perpendicular to the runway centerline.

SOURCE: Furnished by a compilation of FAA, Jeppesen, and Pilot Materials.

Top of page 

If you are interested in joining PARTNERS @ Solberg or are interested in helping us educate and inform area residents about the benefits of general aviation, please contact us for information about joining our group that is dedicated to finding effective reasonable solutions!

Top of page