The public would recall that Alhaji Asoma Banda of Antrak Air addressed a press conference to comment on the cause of the damage to the Kumasi airport runway that led to the closure of Kumasi airport for repair works to be carried out.Following consultations with our lawyers, Antrak wrote to the Ghana Civil Aviation Authority on October 4, 2012. Although we are yet to receive even an acknowledgement of our letter, we deem it necessary to share with the public relevant information that underpins our claims.We have attached for the information of the media and the general public documents from the International Civil Aviation Organisation (ICAO), Boeing and Airport Consultants Council (ACC) that clearly explain the key issue Alhaji Asoma Banda raised during the press conference, to the effect that bigger aircraft with Aircraft Classification Number (ACN) higher than the Pavement Classification Number (PCN) of the runway are responsible for the damage to the runways in Kumasi (as well as Tamale and Takoradi).In the attached ICAO report on the GCAA in 2006, please refer to pages 86 & 167. You can also go through the Boeing and ACC documents as well for further information. The ACC document is summarized below for your reference.As you would see from the documents and summary provided, the BAe 146-300 has an ACN of 24 whereas the PCN of the Kumasi runway is 15. The standard of ICAO, FAA and all civil aviation authorities across the world is that the ACN should be less than or equal to the PCN. In simple layman's terms, the BAe 146-300 is 60% heavier than the Kumasi runway is meant to handle.Summary of ACC document:PCN and ACNEstablished by ICAO in 1981 and presented in Aerodrome design manual, part 3: PavementsGhana is a member of ICAO and is bound by treaty agreements to comply with their requirements to maximum extent practical.ACN is the Aircraft Classification Number, a single unique number to express effect of an individual airplane on different pavements, given by manufacturer.PCN is the Pavement Classification Number, a single unique number to express the load carrying capacity of a pavement, without specifying a particular airplane.A pavement with a given PCN can support, without weight restriction, an aircraft with ACN rating equal to or less than the pavement PCN.Overload guidanceFor flexible pavement which is what we have here in Ghana: ACN should not exceed 10% of the reported PCNOccasional overloads should not adversely affect the pavementOverloads should not be allowed:If pavement is exhibiting signs of distress During periods of thaw When pavement/sub-grade is weakened by waterACN of current aircraft operating in Ghana:ATR 72-500 ACN 11 ATR 42-300 ACN 09 BAE 146-300 ACN 24 Fokker 100 ACN 25 Embraer E170 ACN 20 Embraer E145 ACN 14Major airports & their corresponding runway PCN:Accra PCN 60 Kumasi PCN 15 Takoradi PCN 10 Tamale PCN 15 Sunyanni PCN 15