However, the Luftwaffe jets were simply too few and too late to have any serious effect on the Allied air armadas, now sweeping over the Reich with near impunity. V-1 and V-2 rocket sites were gradually overrun and the lack of fuel and available pilots for the new jets had virtually driven the Luftwaffe from the skies. The Me-262 was an elusive foe in the skies for the P-47s and P-51s, outclassing the American fighters. Despite its great speed advantage. Allied bomber escort fighters would fly high above the bombers – diving from this height gave them extra speed, thus reducing the speed difference. The Me 262 was less maneuverable than the P-51 and trained Allied pilots could catch up to a turning Me 262. However, the only reliable way of dealing with the jets, as with the even faster Me 163 Komet rocket fighters, was to attack them on the ground and during takeoff and landing. Luftwaffe airfields that were identified as jet bases were frequently bombed by medium bombers, and Allied fighters patrolled over the fields to attack jets trying to land. The Luftwaffe countered by installing flak alleys along the approach lines in order to protect the Me 262s from the ground and providing top cover with conventional fighters during takeoff and landing. Nevertheless, in March and April 1945, Allied fighter patrol patterns over Me 262 airfields resulted in numerous losses of jets and serious attrition of the force.