proved to be murderously effective. The attachment of tank destroyers to the artillery battalions also paid substantial dividends in the early days of the campaign. The most effective defense of beleaguered field artillery units, however, was that provided by prompt counterattack delivered by neighboring infantry or tanks, a tactic which turned on accurate local intelligence, unbroken communications, and the enemy inability to deflect the counterattack force with heavy supporting weapons or mines.
The Air Weapon
Postwar estimates of the Luftwaffe operational strength assigned to support the ground attack on 16 December set the number of first-line planes at about fifteen hundred.  But German planes never, in the course of the campaign, appeared over the battle area in any such number. OB WEST records 849 sorties dispatched to assist the ground attack on 18 December, the largest Luftwaffe attempt to intervene directly in the Ardennes battle. The tabulation of German sorties is somewhat misleading, however, because a relatively small proportion of these sorties ever reached the battlefield in a ground support role and most were engaged by the Allied air forces far to the east of the ground combat zone. On 24 December, for example, a day characterized by the IX Tactical Air Command as the heaviest Luftwaffe effort since D-day, the Third Army-whose counterattack obviously invited retaliation from the air-reported the sighting of only one enemy squadron.
During the first ten days of the campaign the Luftwaffe sorties sent into the air varied between six and eight hundred per day. In the last six days of December the Luftwaffe was driven back to the air space over the Third Reich and the number of planes actually reaching the battlefield numbered between sixty and eighty a day, most of which struck under cover of darkness, as in the case of the 73-plane raid over Bastogne on 30 December.
At no point in the story of the ground battle can any crippling impact of German air attack be discerned. Nor was the Luftwaffe notably successful in defending the supply lines west of the Rhine. The German fighters did exact a heavy toll from the Allied planes hammering at rail yards, bridges, and supply installations. Thus the 391st Bombardment Group, flying Marauders without escort to attack the Ahrweiler railroad bridge, was jumped by about seventy-five German fighters, and lost onehalf of its thirty-six planes, though it did knock out the bridge.
In the first week of the German advance the well-established Allied superiority in the air hardly made itself felt in the battle area, although two fighter-bomber groups from IX Tactical Air Command did intervene in the fighting around Stavelot and Malmedy on 18 December. But the adverse weather which denied the tactical air forces access to the fight on the ground did not halt the bombers and on 18 December bombers from the RAF, began an interdiction attack seventy-five miles or more to the east of the battle line. It is difficult to measure the damage done the German rail system west of the Rhine
 Office of the Director of Intelligence, U.S. Strategic Air Forces in Europe, Allied Air Power and the Ardennes Offensive (n.d.).