SINGAPORE -- Singapore on Tuesday kicked off Asia's biggest air show - the first in six years unaffected by pandemic restrictions - as the global aviation industry grapples with a full rebound in travel demand in the face of severe supply constraints. Russian companies like Russian Helicopters and Irkut that attended past editions of the show are not participating this year amid Russia's attack on Ukraine. However, Israeli companies Israel Aerospace Industries and Rafael Advanced Defense Systems which dropped out of the Dubai Airshow in November amid the Israel-Hamas conflict in Gaza have come to Singapore. Airbus this month announced a further delay in entry to service of its long-range A321XLR single-aisle jet to the third quarter from the second. Suppliers told Reuters that Airbus is producing around 50 A320neo family jets a month compared to a production plan that had foreseen 58 by end-2023.