It looks like there are a number of airports placed in the exact same spot, some with minor differences such as runway length or material.
| HKIM | HKIL | |
|---|---|---|
| HSPH | HSPL | |
| HADA | HAHU | |
| VTOK | VTOG | |
| VAKA | VOKP | |
| MGTK | MGMM | |
| SLCH | SLHI | |
| SJQI | SWCT | |
| YDEY | YDEC | |
| WAPX | WAPW | |
| SWNN | SWPD | |
| OEAD | OE55 | |
| FYOR | FYOZ | |
| VAOK | VAOH | |
| VAAI | VAAB | |
| FYHJ | FYIT | |
| VAMD | VAMA | |
| 7FD6 | FD38 | |
| HESR | HESA | |
| GMAG | GM47 | |
| GMTB | GMTC | |
| T90 | KT90 | |
| HUAJ | HU0A | |
| FZLM | FZLP | |
| 0FL8 | KNIP | |
| TX45 | 40TS | |
| 11TE | TX78 | |
| 43LA | 0LA3 | |
| 58T | 58TA | |
| 0GA7 | 27GA | |
| 2CA8 | 51CA | |
| 6TS0 | H81 | |
| KTHA | TN38 | |
| 7NC9 | 1NC0 | |
| 04NV | NV42 | |
| 6AR1 | 3AR7 | |
| 2AR1 | AR11 | |
| NZWP | NZHB | |
| 2V1 | KPSO | |
| K15 | 19T | |
| 31KY | 52KY | |
| LGME | LGMS | |
| 3VA1 | 2VA9 | |
| 12CO | 44CO | |
| KRJD | 5MD0 | |
| 3LF | 1LL4 | |
| 58M | 1C4 | |
| 3PN2 | W73 | |
| 3I1 | 2II3 | |
| 0II0 | II77 | |
| PA36 | 1PA3 | |
| ZULL | ZULA | |
| ZKKP | ZKKF | |
| 1IN3 | 3II9 | |
| KBTA | K46 | |
| 0C7 | IL22 | |
| LEBJ | LEAA | |
| 3T7 | 3W9 | |
| 02PS | 57PA | |
| ZSAI | ZSAA | |
| UGMS | UGME | |
| 2MI7 | 7MI | |
| K8V3 | 8V3 | |
| 11OR | 60OR | |
| VT29 | VT49 | |
| 0MN0 | 35MN | |
| 4WI9 | 2H3 | |
| KEKS | 5U3 | |
| 25MN | KPEX | |
| 21M | 3B1 | |
| 28OR | OR50 | |
| 19MT | 09MT | |
| MN13 | KBJI | |
| LF07 | LF09 | |
| 2MN5 | KORB | |
| 22MT | MT95 | |
| UA33 | UAUR | |
| EGTT | EGVQ | |
| EPSR | EPSK | |
| UBOV | UBOF | |
| PAEE | EEK | |
| 38AK | 89AK | |
| 16AK | AK65 | |
| 4AK6 | AK79 | |
| AK32 | AK7 | |
| BIOL | BIOA | |
| WAPZ | WAQA | |
| HSDF | HSCY | |
| HSDA | HSDG | |
| SBGY | SDQU | |
| 27CL | 38CL | CA22 |
| OTUS | OTUD | |
| FD10 | 1FA9 | |
| GMMM | GMMG | |
| LS43 | LS21 | |
| 0LS1 | LS18 | |
| MD35 | 11MD | |
| MO51 | 40MO | |
| II52 | 01II | |
| 49N | 1N2 | |
| 24OH | 26OH | |
| 6WN5 | WI75 | |
| 5OR2 | 91OR | |
| MT83 | MT06 | |
| MY59 | 45MN | |
| EGCP | EGCI | |
| EGCG | EGYI | |
| EGDF | EGCA | |
| HSGY | HSGJ | |
| HSAN | HSAO | |
| HSAB | HSAD | |
| HSHU | HSHT | |
| CYOX | CYOV | CYOT (one of these 3 is a duplicate) |
I have submitted these to Zendesk.