upgrade to business class on cathay at airport

you can use miles for an Instant Upgrade Award from economy class and experience the luxury of flying on First or Business Class on Cathay Pacific or Dragonair. Instant Upgrade Awards are available on:

All CX flights departing from worldwide destinations.
All KA flights departing from 15 destinations: Bangaluru (Bangalore), Beijing, Busan, Dhaka, Fukuoka, Hanoi, Kaohsiung, Kota Kinabalu, Manila, Phnom Penh, Phuket, Shanghai, Taichung and Taipei to hongkong.
For exact redemption amounts, please refer to the Asia Miles Award Charts.
If you do not have enough miles to redeem an Instant Upgrade Award and are flying from HKIA, you may purchase up to 30% of the remaining miles you require with Asia Miles Top-Up.
How to redeem your Instant Upgrade Award on Cathay Pacific

At Hong Kong International Airport (HKIA): You may request to redeem your Award at our service desk at Aisle B, Departures Hall, Terminal 1, or make your request when checking in for your flight.
At airports worldwide: Please make your request when checking in for your flight.
Dragonair

At HKIA: Request to redeem your Award at our service desk at Aisle H, Departures Hall, Terminal 1 before checking in for your flight.
At the other 14 airports: Bangaluru (Bangalore), Beijing, Busan, Dhaka, Fukuoka, Hanoi, Hong Kong, Kaohsiung, Kota Kinabalu, Manila, Phnom Penh, Phuket, Shanghai, Taichung and Taipei. Please make your request when checking in your flight.
To ensure quick processing, please have your membership card, booking reference number and ticket(s) ready.
Terms and conditions.
Instant Upgrade Awards are subject to adequate mileage in member's account. Asia Miles Top-Up is available only at Hong Kong International Airport and to members who have at least 70% of the required mileage in their account.
3.Instant Upgrade Awards are valid on eligible booking class J, C, D, I (Business Class) and Y, B, H, K (Economy Class).
4.Instant Upgrade Awards are subject to seat availability and airport conditions on departure.
5.Members can redeem Instant Upgrade Awards for their redemption group nominees when they travel together with members on the same flight.
6.Instant Upgrade Awards for ‘Redemption Group Nominees’ will not be accepted if their names have not been registered in advance. Please allow at least 24 hours for names to be updated.