I'm submitting this as a bug because it is driving me nuts when the route map doesn't display or displays incorrectly due to another issue.
The following airports have IATA codes and ICAOs that GCM does not map:
Unplottable with IATA or ICAO Code with GCM
AnShun HuangGuoShu
Bose
Davis Station
Dongying
Handan
Jinggangshan
Jiuzhai Huanglong
Kanasi
Liancheng - Longyan GuanZaiShang
Lincang
Liping
Manzhouli
Mirny Station
Muan Airport
Nalati
PanZhiHua BaoAnYing
Redang Airport
Sari
Torres Islands
Wenshan Puzhehei
Wuhai
Xingyi
Yancheng-China 50,674
Yucheng GuanGong
Zhijiang
The following airports need to use the ICAO code to get any type of relavant map:
Agostinho Neto
Albacete Los Llanos
al-Jouf al-Jawf Domestic Airpo
Amundsen-Scott Station
Aracati
Arak
Araripina - PE
Arcoverde - PE
Asaloyeh
Bakki
Ban Huoeisay Airport
Bonito
Brisbane Archerfield
Caernarfon
Campos Sales - CE
Chemnitz
Chu Lai Airport
Con Dao Co Ong Airport
Dezfool
Egelsbach
Eisenach Kindel
Feira de Santana
Fort Nelson Airport
Gachsaran
Galle Koggala Airport
Gera Leumnitz
Gorgan
Gyor Per International
Hengchun
Herzlia Airport
Iguatu
Ilam
Iranshahr
Itaperuna
Jena Schongleina
Jiroft
Kahramanmaras
Katiu Airport
Khanty Mansiysk
Khoy
Lamard
Llanbedr
Madrid Cuatro Vientos
Magdeburg Cochstedt
Maria Reiche Neuman
Marshall- Don Hunter
Memmingen Allgau
Neuhausen
Nevsehir Kapadokya Airport
Nha Trang Cam Ranh Airport
Obidos - Tirios
Oudomsay Airport
Pai Airport
Passau Vilshofen
Patos de Minas
Polokwane International Airpor
Punta del Este
Raivavae Airport
Ravensthrope
Rio Turbio
Sabzevar
Sahand
Sao Paulo - Campo de Marte
Sarakhs
Serra Talhada - PE
Sirjan
Speyer
Spremberg Welzow
Stendal Borstel
Strausberg
Takume Airport
Tanjung Manis Long Banga Airpo
Tokat
Trat Airport
Ventspils International
Videira
Wirawila Airport
Yangyang Int`l
Yasuj
Zanjan
Special cases:
Abu Dhabi International Airport – Incorrect ICAO, it is listed at OMAR should be OMAA. Source – GCM
Agostinho Neto – Use ICAO code instead of IATA, more accurate date and plotting with GCM
Araripina – PE – Use ICAO code when submitting to GCM. GCM see IATA code for this airport in Arkansas, United States.
Arica – Chacalluta Airport – Incorrect ICAO, it is listed at SCAP should be SCAR. Source – GCM
Van Huoeisay Airport – Use ICAO code instead of IATA, more accurate date and plotting with GCM
Ciudad Bolivar – Tomas de Here – Incorrect ICAO, it is listed at SVBC should be SVCB. Source – GCM
Fort Nelson Airport – Incorrect IATA, it is listed at YEE should be YYE. Source – GCM
Hyderabad Begumpet Airport – General aviation airport in India. Presume you actually want Rajiv Gandhi International Airport in Hyderabad, India. This airport has the IATA code of HYD and the ICAO code of VOHS. Coordinates are 17.254, 78.431.
KKC Hafar Al-Batin Domestic Ai - Incorrect ICAO, it is listed at OEKK This is for a military base approx 47 miles away. GCM lists no ICAO code for that airport. Source – GCM
Lambasa Airport – Incorrect ICAO, it is listed at NFNS should be NFNL. Source – GCM.
Llanbedr – Use ICAO code when submitting to GCM. GCM see IATA code for this airport in California, United States. GCM lists this as a military airfield. Source – GCM
Madrid Cuatro Vientos - Use ICAO code when submitting to GCM. GCM see IATA code for this airport in Australia. Source – GCM
Marshall – Don Hunter - Use ICAO code when submitting to GCM. GCM see IATA code for this airport in South Pacific. Source – GCM
Nanaimo Airport – Use IATA code. GCM lists ICAO code belonging to a seaplane terminal with an IATA code of ZNA.
Neuhausen – Use ICAO code. GCM lists IATA code belonging to a marker in Algeria. Airport does not have an IATA code.
Nevsehir Kapadokya – Use ICAO code. GCM lists IATA code belonging to a marker in 14 miles away. Airport does not have an IATA code.
Nyala Airport – Incorrect ICAO, it is listed at HSNL should be NSNN. Source – GCM.
Olpoi Airport – Incorrect ICAO, it is listed at NVSC should be NVSZ. NVSC is an airport approx 100 miles away from this one. Source – GCM.
Palmerston North – Incorrect ICAO, it is listed at NZQN should be NZPM. Source – GCM.
Punta del Este – Incorrect ICAO, it is listed at SUPE should be SULS. Source – GCM.
Qui Nhon Phu Cat Airport – Incorrect ICAO, it is listed at VVPC should be VVQN. Source – GCM.
Saarbrucken – Incorrect ICAO, it is listed at EDDN should be EDDR. Source – GCM.
Saint Lucia – Hewanorra Intern – Incorrect ICAO, it is listed at NWWV should be TLPL. Source – GCM.
Sao Paulo – Campo de Marte – Use ICAO code instead of IATA, more accurate date and plotting with GCM
Tambacounda Airport – Incorrect ICAO, it is listed at GOTS should be GOTT. Source – GCM.
I did go through all 3034 airports...I don't think I missed any but it is possible.