a Stirling Pathfinder was shot down over the Netherlands, on only H2S's second operational use. Harris made similar objections to supplying the American-created 3 cm-wavelength H2X radar units to Coastal Command (which knew it as ASV.IV), again got higher priority, and again saw it fall into German hands, almost exactly a year later, in February 1944. As Coastal Command predicted, the Germans captured the damaged H2S, which would have been next to impossible from a Coastal Command aircraft downed at sea, rather than over land, and Telefunken produced the Rotterdam Gerät (Rotterdam Device, named for where it was captured). Coastal Command's first ASV.III-equipped patrol took place over the Bay of Biscay 1 March. ASV.III made its first U-boat contact on the night of 17 March, but unfortunately the carrier Wellington suffered a malfunction of its Leigh Light and was unable to press home the attack. The first attack using the system occurred the next night. When ASV.III did enter service, German submariners, right up to Dönitz, began to mistakenly believe British aircraft were homing on emissions from the Metox receiver, which no longer gave warning. Meantime, German scientists were perfecting the Rotterdam Gerät to create a submersible version for U-boat defense, of the aviation-utilized FuG 350 Naxos radar detector for night fighters, the submersible version getting the FuMB7 Naxos U designation. While fragile, Naxos worked. However, it entered service the same day as the 10 GHz-emissions H2X (which Naxos could not detect) became operational in Coastal Command. Naxos was replaced by FuMB36 Tunis in May 1944, and was supplemented by Stumpf, what today would be called radar absorbent material, under the codename Schornsteinfeger ("Chimneysweep"). Just before the TRIDENT Conference, Admiral Ernest J. King got control of A/S aircraft from the Army Air Force, arranging a trade of B-24s for comparable types. This enabled Slessor to make a deal with him to "borrow" one squadron. After attacks on ONS 166, the number of VLRs in Newfoundland finally increased. "Canadians had been pressing hard for Liberators since autumn 1942, against British doubts that the RCAF could employ them effectively, while RCAF, for its part, opposed RAF taking over a job RCAF saw as its own. The commanding officer of 120 Squadron, Squadron Leader Bulloch, confirmed RCAF's ability, and in early March 1943, the number in Newfoundland belatedly increased (though it was not enough to constitute 10 Squadron, RCAF, before 10 May), while