<p>The brilliantly conceived and executed raid on the Son Tay prison compound took place on 21 November and, even though its primary purpose failed, it stands as a classic among rescue operations. On the same day, a heavy retaliation strike was flown to avenge the loss of a single RF-4C. About 200 USAF and USN aircraft struck targets along the trail, doing heavy damage without suffering any loss.
</p>
<p>Operation Louisville Slugger, named after a widely used American baseball bat, hit SAM sites in the Ban Karai pass during February 1971. The USAF and USN joined forces for Operation Fracture Cross Alpha against SAM sites on 20 and 21 March.
</p>
<p>The first blind-bombing attack using LORAN was on 21 September against POL storage areas that were south of Dong Hoi, a few minutes north of the DMZ. The 196 aircraft destroyed about 350,000 gallons of fuel.
</p>
<p>By late in the year, the NVAF had strengthened its inventory of MiG-21s and was coming up to fight more often and more aggressively. Working in an advantageous environment, controlled by ground radars and operating from bases that were still withheld as potential USAF targets, the MiGs managed to inflict real damage on both Air Force and Navy flights. The air combat odds that had favored the Americans by almost two and one-half now dropped closer to even.
</p>
<p>Back came the EC-121D College Eye aircraft to take up their positions to warn of MiG intercepts in the making. The USAF, trying once more to be allowed to attack the NVAF bases, finally got authorization.
</p>
<p>They struck on 7 and 8 November, pounding the runways and installations of Dong Hoi, Quan Lang and Vinh. With those bases essentially impotent, heavy strikes were mounted against targets south of the 20th parallel that had been in the defense area of those three fields. During the four-day period between 26 and 30 December, the Americans dispatched more than 1,000 attack sorties.
