Nummer: 17209b
| Area : | Western Area |
| Sea area : | North Atlantic |
| Date of attack : | 23.09.1943 |
| Time of attack : | 01:56 |
| Nationality of U-boat : | German |
| U-boat : | U 666 |
| Commander : | Engel |
| Grid : | AK 7147 |
| presumed target type : | Destroyer |
| presumed result : | sunk |
| Used weapon(s) : | Acoustic homing torpedo (gnat) |
| Convoy : | ON.202 |
| Date of observation : | 22.09.1943 |
| Time of observation : | 21:55 |
| Nationality of target : | British |
| Actual type of target : | Fregate |
| Name of target : | Itchen (K.227) |
| Year of launch : | 1942 |
| Actual tonnage : | 1370 ts |
| Actual result : | sunk |
| Position of target : | 53.25n 39.42w |
| Footnote : | U-666 heard a gnat-detonation after 8:21 min; the torpedo detonated in the wake of HMCS "Morden". The second gnat hit "Itchen" after 1:10 min; debris from the ship was later found on the conning tower of the U-boat. |
| related attacks : | Angriff 1 |
| Convoy : | ON.202 |
| Route of convoy : | United Kingdom - North America |
| Remark to convoy : | 1st series: Jul 1941 to Mar 1943 ON and ONS combined, later ON mit continuing and ONS with new numbering (counter traffic HX and SC) |