Here is what the Fleet Air Arm link I gave above has listed on its Battle Honors link for Operation Avalanche.
Salerno 1943
Operation Avalanche, support of landing forces at Salerno on the Mainland of Italy, 9 September to 6 October 1943.
Awarded to Squadron numbers: 807, 808, 809, 810, 820, 834, 878, 879, 880, 886, 887, 888, 890, 893, 894, 897, 899.
Awarded to HM aircraft carrying ships: Attacker, Battler, Formidable, Hunter, Illustrious, Stalker.
I had to research each squadron on the same site to find what aircraft they flew during the time period of Operation Avalanche.
Hopefully Warloc can shed more light on this.
This statement.... "Operation Avalanche, support of landing forces at Salerno on the Mainland of Italy, 9 September to 6 October 1943."
could very well mean nothing more than U-Boat patrol for some of the units. Sometimes unit participation in an operation can be painted with a pretty broad brush.