'Glacier' was a US programme of air operations against targets in Japan from bases in the Aleutian islands group of the North Pacific area (1943/45).

More than a month before the US and Canadian 'Cottage' landing of 15 August 1943 to retake Kiska island from the Japanese, who had in fact already evacuated their garrison, Major General William O. Butler’s 11^th AAF began a new phase of operations against the Japanese when, on 10 July 1943, six North American B-25 Mitchell medium bombers of the 11^th AAF flew to Paramushiru island in the Kurile islands group to deliver the first direct attack on the Japanese home islands since the 'Conceal' raid ('Doolittle raid') of April 1942. From Alexai Point AAF on Attu island, eight Mitchell bombers of the 77^th Bomb Squadron of Lieutenant Colonel Ralph W. Rodieck’s 28^th Bombardment Group attacked bases on Paramushiro. All the US aircraft returned safely.

A week later, Consolidated B-24 Liberator heavy bombers from Attu bombed targets in the Kurile islands group and returned with reconnaissance images of the Japanese installations: these were the first pictures taken of the defences of Japan’s northern islands. The next raid on the Kurile islands group, carried out on 11 August, was a diversionary raid before the 'Cottage' landing on Kiska. On this mission, the first aeroplane was lost over the Kurile islands group, and Lieutenant James C. Pottenger and his crew made a forced landing in the USSR.

These operations led to a joint mission on 11 September, when the 11^th AAF despatched eight B-24 Liberator and 12 B-25 Mitchell machines. The Japanese were alert, however, and had reinforced their defences, and as a result 74 crew members in three B-24 and seven B-25 bombers failed to return: 22 were killed in action, one taken prisoner and 51 interned after landing on the Kamchatka peninsula of the eastern USSR. Though it had been shown by this time that attacks on the Kurile islands group could be made, it had also become clear that new methods had to be devised as the raid had lost the 11^th AAF more than half of its offensive power. No more combat missions were flown in 1943.

Several changes took place following the occupation of Kiska. The 11^th AAF became a component of Task Force 'Y', still under US Navy control. Vice Admiral Frank Jack Fletcher was named as the commander, North Pacific Ocean area, and Major General Davenport Johnson replaced Major General William O. Butler as commander of the 11^th AAF on 13 September. One of Johnson’s first acts, reflecting the nature of the weather and over-water flying typical of the north Pacific theatre, was the establishment of an 11^th AAF instrument flying school and the promotion of an intensive training programme of navigation and instrument flying, as well as the accelerated development of radio and navigation aids in the Aleutian islands group.

The major improvement brought about by intensive instrument training and the increased aids to navigation and radio now meant that aircraft which would formerly have been grounded by adverse weather were now flying regular schedules. Aircraft of Troop Carrier Command and Air Transport Command were now able to operate into and out of the Aleutian islands group with airline regularity.

In November 1943 a second airfield, Casco Cove Army Airfield, was constructed on Attu island for long-range bombing operations. The 11^th AAF carried out another bombing mission against targets in the northern part of the Kurile islands group on 5 February 1944, when six B-24 bombers of the 404^th Bomb Squadron of Colonel Robert H. Herman’s 28^th Bombardment Group and 16 Lockheed P-38 Lightning fighters of the 54^th Fighter Squadron of Colonel Robert H. Jones’s 343^rd Fighter group flew a mission. March 1944 saw bombers of the 11^th AAF over the Kurile islands group on daylight armed reconnaissance missions. These were not numerous, but were nonetheless sufficient to convince the Japanese that there were a growing number of US warplanes in the Aleutian islands group and that the Kurile islands group was in constant danger of air attack. During the crucial period, while other US forces were advancing in the South Pacific, the Japanese were forced to keep much-needed aircraft in the Kurile islands group and on Hokkaido island in the home islands as defence against possible attack from the north-east.

Operations against the northern part of Japan had thus become the new mission of the 11^th AAF, which was successfully carrying out its limited but significant role. Except for July, when the weather was especially bad, each month of 1944 showed a steady increase in operations against targets in the Kurile islands group. However, the nature of the North Pacific theatre, and especially its weather, was reflected that each month’s record showed aircraft which were compelled to turn back short of their targets. Even so, the B-24 bombers which did manage to reach their target areas were able to drop their bomb loads with good accuracy through the typical undercast by use of the newly installed radar bombing equipment: this was altogether more effective than the older system in which timed runs were made on a bearing from a nearby geographical feature such as a mountain protruding through the undercast. June 1945 was the month in which the 11^th AAF dropped its record tonnage of bombs dropped.

The B-24 Mitchell medium bombers were also contributing usefully to the operations against the Kurile islands group. These lighter warplanes had been kept on anti-shipping alert since the abortive raid of 11 September 1943, but in May 1944 two aircraft on a fuel consumption test to the west of Attu island located and sank two Japanese armed trawlers. From that time on, the Mitchell bombers made sweeps against shipping when the weather permitted, and by the autumn of 1944 were bombing land targets in the Kurile islands group.

Although the 11^th AAF was engaged most directly in the war against the Japanese, it also supported the Lend-Lease transport of aircraft though Alaska to the USSR by Lieutenant General Harold L. George’s Air Transport Command from September 1942. Lend-Lease aircraft were ferried from Great Falls Army Air Base, Montana to Ladd Army Airfield near Fairbanks, Alaska, by the 7^th Ferrying Group (later the Alaskan Wing) of the Air Transport Command. The US-built aircraft was transferred to Soviet crews at Ladd Army Airfield, and from there the Soviet crews flew to Marks Army Airfield, near Nome in alaska, as a final refuelling and maintenance stop en route to Uelkal in eastern Siberia. From Siberia, the aircraft were flown westward across the USSR via Krasnoyarsk to the combat areas of the Eastern Front. Aircraft of the 11^th AAF were also ferried up the North-West Staging Route to Elmendorf from RCAF Station Whitehorse. More than 8,000 aircraft were delivered along this route, the majority of them Bell P-39 Airacobra and P-63 Kingcobra tactical fighters, although significant numbers of Douglas A-20 attack aircraft, B-25 medium bombers and Douglas C-47 Skytrain transport aircrafts. To support these operations, Air Transport Command personnel were based at Edmonton as well as other Canadian bases.

A lesser-known part of the ferrying mission for Air Transport Command pilots was search and rescue for General Robert Olds’s Ferrying Command pilots and crews who had been forced down in the remote wilderness. The Air Transport Command’s Alaska Wing was equipped with a number of Noorduyn C-64 Norseman single-engined light transports, which could operated on wheels, skis and pontoons depending the season. The C-64 aircraft were also used to resupply stations along the Canadian pipeline as well as for search and rescue work.

The Air Transport Command developed two transport routes to Alaska during the war to support the 11^th AAF. The first was from McChord Field, near Seattle, Washington, to the north along the coast of British Columbia to Annette island, and thence to Yakutat and into Elmendorf AFB. The second was developed to support the Aleutian islands campaign and was built as US forces moved to the west along this island chain. The route started in Anchorage and went through Nannek Airfield then to Point Heiden, Cold Bay and thence along the Aleutian islands chain until reaching Shemya and Attu islands in 1944. These transport routes ferried personnel, along with high-value equipment and supplies which could not be shipped by normal cargo sealift.

This route eventually extended to Hokkaido in northern Japan after the end of the war, the route becoming part of the Great Circle route between the USA and Japan. Much of the transport along the routes was entrusted to airlines, with Northwest Airlines and Western Airlines operating the routes under US government contract.

In overall terms, more than 1,500 sorties were flown by the 11^th AAF on the northern parts of the Japanese home islands and the Kurile islands group. The targets included the army and navy bases on Paramushiro in the northern part of the Kurile islands group just to the south of the tip of Kamchatka, and this led to the Japanese to divert 500 warplanes and 41,000 ground troops for the air and surface defence of the islands.

The headquarters of Lieutenant General Takashi Tsutsumi’s 91^st Division, responsible for defence of the northern part of the Kurile islands group within Lieutenant General Kiichiro Higuchi’s 5^th Area Army, was established at Kashiwabara, and numerous coastal artillery positions and fortified bunkers were constructed in various locations around the island. In addition, the army constructed airfields at Kashiwabara in the north-east, Kakumabestu on the south-west coast, Kitanodai on the north-east coast, and Suribachi as an auxiliary base in the centre of the south coast. The navy had an airfield at Musashi on the south-western tip of the island, and this also included an early warning radar.