1951年04月21日
April 21
★★★
与航母相连的海军陆战队飞机首次在朝鲜上空遭遇敌机。
两头牦牛被机长菲利普·C·德隆击落，另一名海军陆战队飞行员哈罗德·U·戴中尉击落一架飞机，并对另一架飞机造成损害。
Marine（陆战） planes attached to a carrier encounter enemy aircraft for the first time over Korea.
Two Yaks are downed by Captain Philip C. DeLong, while another Marine（陆战） pilot, 1st Lieutenant Harold U. Daigh, downs one plane and inflicts damage upon one other.
★★★
最后一步，美军也将以“无畏”号的最后一步行动开始。
美第1陆战师配合行动在其区域发动攻击。
向大坝上方驶去。
与此同时，自大约04月11日以来一直难以与之交战的难以捉摸的敌人在这一天发动进攻。
Also, The U.N. forces, composed primarily of U.S. troops, advance beyond the 38th Parallel as the final phase of Operation DAUNTLESS commences.
The 1st Marine Division（陆战师） launches an attack in its zone in coordination with the operation.
The Marines drive toward the area above the Hwach’on Dam.
At the same time, the elusive enemy that has been difficult to engage since about the 11 April initiates an offensive on this day.
★★★
在工兵区，第3师和第25师为各自的目标奋力前进。
25号公路向科尔原前进，24号公路驶向昆华，后者位于铁三角的尖端。
这两个师都越过了堪萨斯线，在某些地方获得了大约5英里的距离，以抵抗零星的小规模抵抗。
与此同时，第25师穿过波盖桑高地前往科尔原，但任务要困难得多，因为部队受到猛烈炮火的袭击。
天黑后，志愿军在33号公路的土耳其旅区域特别猛烈地攻击犹他线。
夜间（21日至22日），巡逻人员发现志愿军在伊姆金河设置了防御工事。
▲In the I Corps（美第1军）sector▲
3rd and the 25th Divisions push off for their respective objectives.
The 25th advances towards Ch’orwon while the 24th drives towards Kumhwa, the latter at the point of the Iron Triangle.
Both divisions move beyond the Kansas Line and gain, at some points, about five miles, against minor sporadic resistance.
Meanwhile, the 25th Division（师） moves across the Pogae-san heights en route to Ch’orwon, but the task is much more difficult, as the troops are hit by heavy artillery fire.
After dark, the Chinese attack the Utah Line particularly hard in the zone of the Turkish（土耳其） Brigade（旅） at Route 33. During the night (21st-22nd), patrols discover that the Chinese have fortified positions at the Imjin River.
★★★
在九军区，没有遇到敌人的反对。
韩第6师在光德山脊移动，与第24师（租借给第1军）并肩作战。
▲In the IX Corps（美第9军） sector▲
no enemy opposition is encountered.
The ROK 6th Division（师） moves in the Kwangdok-san ridges, alongside of the 24th Division（师） (on loan to I Corps).

经过三个星期的延迟，该师被指示从堪萨斯州线到线匡提科发动攻击。
攻击将于第2天开始。
In the 1st Marine Division（陆战师） zone, after a three-week delay, the Division（师） is directed to initiate its attack from the Kansas Line to Line Quantico.
The attack is to begin the following day.
★★★

第2师和第7师的巡逻队在和川水库以东地区遭遇了大量朝鲜军队的集结。
发现了各种集中的敌军部队，其中有些部队的兵力高达1000人，这是向第8军发出的一个信号，表明他们正在解除和加强部队，但仍然没有绝对的证据证明即将进行反击。
此外，海上航空集团12（前方梯队）开始在汉城机场运营。
▲In the X Corps（美第10军） sector▲
patrols of the 2nd and 7th Divisions encounter large concentrations of North Korean troops in the area east of the Hwach’on Reservoir（水库）.
The discovery of various concentrations of enemy units, some of which contain up to 1,000 troops, is a signal to Eighth Army that they are relieving and reinforcing units, but still, there is no absolute evidence to prove a counterattack is imminent.
Also,
Marine（陆战） Air Group 12 (Forward Echelon) begins to operate from the airport in Seoul（汉城）.

一架隶属于第3空中救援队的飞机（SA-16）起飞前往镇南浦附近被击落的敌方牦牛飞行员的现场，试图找回他，以便收集情报；然而，飞机降落并扑灭木筏后，敌人的火力变得过于猛烈。
任务中止，飞机起飞时没有受到伤害，也没有敌方飞行员。
▲In Air Force activity, ▲
a plane (SA-16) attached to the 3rd Air Rescue Squad takes off for the scene of a downed enemy Yak pilot in the vicinity of Chinnamp’o（镇南浦） to try to retrieve him for the purpose of gathering intelligence; however, after the plane lands and puts out a raft, enemy fire becomes too heavy.
The mission is aborted and the plane takes off without harm and without the enemy pilot.
★★★
另外，布莱克少校作为第13炮击中队的一员执行任务，当他的轰炸机接近目标时，受到高射炮的猛烈射击。
尽管他的B-26没有炮塔，布莱克还是低空通过，轰炸并扫射了宋川的编组站。
他的飞机对无线电天线造成了一些损坏，但是布莱克摧毁了一个机车，损坏了另一个，并损坏了大约15辆棚车。
在用尽了所有的弹药，包括机关枪的炮弹之后，布莱克选择呆在头顶上直到天亮，试图探测正在行驶的火车。
天亮后，他召集战士，把他们带到编组站。
Also, Major Blake, on a mission as part of the 13th Bombardment Squadron, comes under heavy fire from antiaircraft guns as his bomber approaches the target.
Despite the lack of gun turrets on his B-26, Blake passes at low levels and bombs and strafes the marshaling yard at Songchon.
His plane sustains some damage to the radio antennae, but Blake destroys one locomotive, damages another and damages about 15 boxcars.
After expending all of his ammunition, including machine gun shells, Blake chooses to remain overhead until daylight to try to detect moving trains.
After dawn he calls for fighters and guides them to the marshaling yards.
1951年04月22日至07月08日。
第5次指定战役：中国共产党春季攻势。
April 22–July 8 1951. FIFTH DESIGNATED CAMPAIGN: CCF SPRING OFFENSIVE.