"When you run an airline, for reasons which are both economic reasons and prestige, you want a new kit, so you order an aircraft. And if your neighbour orders aircraft, so you order aircraft," said Bertrand Grabowski who heads German bank DVB's aviation and land transport finance divisions.
"I wouldn't call it irrational exuberance but clearly everybody in Asia is ordering aircraft more than they really need," Grabowski told Reuters in an interview.
Most of the aircraft orders come from the region's two fastest growing airlines - Malaysia's AirAsia Bhd, run by entrepreneur Tony Fernandes, and Lion Air, co-founded by Indonesian businessman turned politician Rusdi Kirana.
(Read more: AirAsia stock poised to take off: CEO)
Both carriers have placed orders for hundreds of Boeing and Airbus aircraft valued at tens of billions of dollars as they race to get Asians flying in a region set to overtake the United States as the biggest aviation market.
Others ordering aircraft include Cebu Pacific, Tiger Airways, 40-percent owned by Singapore Airlines, Garuda Indonesia's low-cost unit Citilink, and the Qantas Airways Ltd-owned Jetstar and its affiliates such as Singapore-based Jetstar Asia.
In the event that any airline cannot complete an order, there are others waiting in the wings to take their slot.
(Read more: 'Full-fledged war' awaits India's airline sector)
While Fernandes has dismissed speculation of an aircraft order bubble in Asia, AirAsia's profits have taken a knock due to a gruelling price war in its home market, stoked by Lion affiliate Malindo and competition from Malaysian Airlines.
AirAsia has termed competition in Malaysia and Thailand as "irrational".
Kirana, the head of Lion Air which does not disclose profits, believes consolidation in the sector is "inevitable" given the large number of companies in the low-cost market.
(Read more: Airbus considers A380revamp to lift sales, sources say)
Recently, Tiger Airways agreed to sell its Philippine operations to dominant carrier, Cebu Pacific, and AirAsia's Philippine unit bought into smaller Zest Air.
Such concerns are unlikely to get much of a public airing at this week's aerospace event, where deals may be signed for between 100 and 200 jets worth $10-20 billion - albeit far below the record $200 billion seen in Dubai in November.
Manufacturers are perennially upbeat and Boeing is expected to reiterate confidence in long-term Asian demand this week.
"Nobody is going to place a future order unless they know that whatever they are taking in today is being absorbed in the market at a reasonable yield and a reasonable load factor level," said Dinesh Keskar, Boeing Commercial Airplanes' vice president, Asia-Pacific and India sales.
"I wouldn't say the party is ending in the near-term but the rate of growth will slow down."