The past few weeks have been rife with speculation about whether Airbus will be able to fly its new widebody A350 to—or at least over—the Paris air show. But the European manufacturer and its competitors are facing much more important questions at the year's biggest industry gathering.

Airbus is under some significant pressure to collect more orders for its flagship, the A380. And while there still is a backlog of 160 aircraft, it cannot be considered secure. Some airlines are considering changing their orders or are no longer in operation (Kingfisher). Deliveries are also spread out over many years leaving Airbus with unfilled production slots in 2015. The manufacturer is adamant that the current demand weakness is a temporary phenomenon and there is talk of more orders being announced in Le Bourget. The big question, however, is what delivery slots those orders will encompass.

The A350 has also gained some more momentum after a long order drought for the -1000 in particular. Recently British Airways committed to taking the aircraft as a replacement for its Boeing 747-400 fleet. Airbus expects orders for the largest variant to pick up soon, although the -1000 is not due for first delivery until 2017.

Boeing will be busy discussing its 777X with customers, having received permission by its board of directors to offer the aircraft earlier this year. Middle Eastern airlines Qatar Airways and Emirates have been pressing Boeing to speed up and are prepared to order large quantities of the latest 777 version as launch customers. But Boeing activities go beyond the 777X: Airlines are still waiting for a decision to launch the 787-10. In this case, it is not just the Persian Gulf carriers that would like that aircraft. European majors such as Lufthansa have a need for higher capacity and not necessarily abundant range.

Bombardier will yet again come to an air show amid huge expectations to finally see the commercial breakthrough of its CSeries. The aircraft is expected to fly for the first time soon after the Paris gathering, but its sales success has been limited largely to regional airlines rather than the mainline carriers it has been targeting.

The industry also will keep a keen eye on China's Comac C919 to determine what partners might be needed to supply key components.