Airport Reference Code / Explained

The design of an airport is based on criteria selected by the airport sponsor, the owners in the case of Solberg. A standard known as the Airport Reference Code together with a Design Aircraft are used to establish characteristics such as runway size, seperation from taxiways and runway protection zones.

cheyenne iiia piper2_01

Cheyenne III A Turboprop Jet

The existing facilities at Solberg use the reverence code “B-I (small only)” and the design aircraft, “Cheyenne III A“. What does this mean? 

The reference code is made up of a letter and a roman numeral sometimes with the additional designation “small only.”

The letters, A to E, designates the landing speed of the aircraft in knots. A knot is the measure of speed based on a nautical mile which is 6,076 feet, or just a bit longer than the statute mile at 5,280 feet. One knot is about 1.15 mile per hour. The roman numeral designates the aircraft wingspan and “small only” appears to afford smaller dimensions for some characteristics (runway width, etc.) for lower visibility conditions.

Landing Speed Wingspan
A < 90 knots I up to 48 feet
B 91 – 120 knots II 49 to 78 feet
C 121 – 140 knots III 79 to 119 feet
D 141 to 165 knots IV 118 to 170 feet
E 166 knots or more V 171 to 213 feet
VI 214 to 262 feet

The design aircraft is a common production aircraft that is withing the definition of the reference code and offers characteristics for acceleration (take off) and braking (landing) that are applicable to specifying a safe runway length for its operation. Additionally other characteristics of its operation are used to define safe dimensions for various airport facilities.

The Solberg Airport Master Plan reconfigures the airport for a Reference Code of B-II with a Design Aircraft being a Cessna 550 which is a turbojet, employing jet thrust as opposed to propellers for propulsion. The picture in our masthead is a Citation 550 taken at Solberg Airport.

You may ask how does the design aircraft for a B-II airport use an airport designated B-I (small only)? The airport designation does not establish hard and fast limits on what aircraft can use a facility. It is intended as guidance, however, a pilot can review that airport’s specifications with respect to the specific plane she or he is flying and make a determination if the facility can accommodate the plane under the specific load and weather conditions to be encountered. This “B-II” aircraft already uses the B-I (small only) Solberg Airport!

So what if Solberg is built out according to the current Solberg Airport Master Plan? One thing is clear, aircraft larger than the “B-II” designation can and will be using the facility. Further, if appropriate design is employed in when drafting the build plans from the concepts of the Master Plan (increasing runway width from 100′ to 150′ and moving further from taxiways) the airport designation could easily be upgraded to D-II or even D-III. This scenario has been ongoing at Hayward Airport in California in recent years where facilities similar in size to those planned for Solberg are recommended for “redesignation” to a higher classification! Build it and they will come…

The important thing to take away is the Airport Designation and Design Aircraft simply establish guidelines, can be easily upgraded if appropriate design is used in build out and are frequently only an indication of the type of aircraft with 500 or more operations (take offs OR landings) at a facility. Creeping expansion can and will happen!


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