To the west of the Maleme runway and around the Tavronitis bridge, the contingents disembarked from the gliders made their junction with the paratroopers and entrenched themselves in the bed of the dry river. In the valley of the Prison, large numbers have succeeded in disembarking, without opposition, but they must now get out of this valley which can become a trap.
Reports from dismounted forces are, at first, vague and imprecise and Student must request aerial reconnaissance to get a clearer picture of the situation. The reports he receives from Malemè and Chania are not brilliant, but he is then too committed to question the second part of his plan.
The second wave of Assault therefore takes flight for Crete. The operations on Rethymnon and Heraklion are, however, on the verge of causing the definitive failure of the "Merkur" operation.
Two Australian infantry battalions hold the outskirts of Rethymnon firmly, entrenched on the hills overlooking the road and the runway.
On the afternoon of May 20, a third of the 1,500 paratroopers of the second assault wave were put out of action; the survivors were scattered into small, unorganized groups. The Australians control the airstrip, and the groups of paratroopers heading towards the less important objective of Rethymnon are attacked by the Greek military gendarmerie.
Heraklion is held by a mixed force of British and Australians. The preparatory bombardments did not give the expected result, as a number of units took up positions after the last German aerial reconnaissance, and were therefore not on their target lists. The paratroopers are immediately the target of English automatic weapons. The Black Watch snipers, well placed around the perimeter of the aerodrome, have a good game of concentrating their fire on each stick, from the start of the jump.
In addition, the timing of the operation was not respected and, instead of a massive drop by large air formations, isolated Ju.52s dropped their sticks individually on the drop zones. The surprise of the German paratroopers is complete when they realize that the enemy has tanks and Bren armored cars.
The Black Watch, who quickly grasped the importance of the containers of heavy armament, are hounding the paratroopers who are trying to recover them. Captain Burckhardt of the 2nd Battalion, 1st Parachute Regiment was later to write:"I had absolutely not expected such fierce resistance and we began to doubt whether we would ever achieve our objectives, or even simply survive. .
The paratroopers dropped west of Heraklion, however, reached the outskirts of the city:there, they were caught under heavy fire from the 2nd Battalion of the 4th Australian Regiment, 2nd Leicester and 2nd York and Lancaster. The Greeks and British threw part of it out of the city, forcing the others to seek refuge in the old Venetian fort which once defended the port.
In the afternoon of May 20 , Student finally reconnects with his men in Prison Valley and Maleme; a damaged transmitter could be repaired. He learns that General Meindl has been wounded at Maleme, where fierce fighting continues, and that the units having landed in the valley of the Prison have given up any attempt to emerge in the direction of Chania. At nightfall, he is informed of the failure of the attack on Heraklion. But there is no news from Rethymnon.
It has also been a long day for the defenders of the island. The information circulates by dispatch riders, a perilous and uncertain method because all the roads are under constant threat from the German fighter-bombers. Although the British command was aware of the need to counter-attack until the Germans received reinforcements, many officers still believed that a major sea landing was imminent and did not realize that the adversary has already committed almost all of its airborne forces.
As night fell on May 20, the New Zealanders were still holding Hill 107, which overlooked the Maleme track. At 5:00 p.m., Lieutenant-Colonel L.W. Andrew, commanding the 22nd Battalion, mounted a counter-attack to dislodge the German elements posted near the Tavronitis bridge. But his forces are so scattered that he can only unite a single section supported by two tanks. The two tanks break down and are destroyed, and if the attack confuses the enemy, it does not succeed in throwing him from his positions
Student begins from this moment to get an idea of the situation thanks to the restoration of radio transmissions with Maleme and the valley of the Prison. By contrast, New Zealanders in the area are isolated, even from their closest neighbours. However, after his counterattack fails, Andrew is informed that he will be attacked the following morning by vastly superior German ground and air forces. He sends couriers to ask for orders. Not having obtained any, he decided to withdraw his battalion from Hill 107.