CAS = Close Air Support. Tactical aviation bombing and strafing targets, direct fire support to the gound forces.
Those three essential elements of the blitzkrieg offensive as that term understood during the Great War [WW1] to include:
* The use of infiltration tactics [Hutier tactics].
* Poison gas delivered on target by artillery shell.
* The use of ground attack aircraft.
With regard to the latter, pursue the enemy in a relentless manner to the greatest extent possible, no surcease or refuge allowed.
GROUND ATTACK BY DEDICATED WARPLANES ALBEIT RECOGNIZED AS VERY DANGEROUS DUTY.
"losses of the unarmoured fighters proved to be extremely high, reaching up to 30% per day when aircraft were deployed in such attacks. Most losses were due to ground fire, although low-flying aircraft also proved vulnerable to attacks from above by enemy fighters"
Ad hoc measures taken to ameliorate these excessive and even catastrophic losses camouflage detail as applied, distinct and different patterns for the underneath and top portions of the aircraft.
"Field-Expedient Camouflage for Trench Strafing"
"Such attacks [aircraft in the ground attack mode] could be devastating, particularly against troops caught retreating or deploying. Strafing by Bristol fighters and Camels single-handedly routed and destroyed a Turkish army surprised in a defile in Palestine."
"The Sopwith TF.2 Salamander was a British ground-attack aircraft of the First World War designed by the Sopwith Aviation Company which first flew in April 1918. It was a single-engined, single-seat biplane based on the Sopwith Snipe fighter but with an armoured forward fuselage to protect the pilot and fuel system from ground fire during low level operations."
The Salamander. Did not see action during the Great War. But was in the works.
Within a period of only four years the warplane went from being a novelty and a contraption for which there was thought to be little if any purpose into a great feared [and with good reason] weapon of war.