Table:
text: Singapore Changi Airport
Airlines based in Changi
Airlines based in Changi
Airline IATA ICAO Callsign Commenced_operations
Jetstar Asia Airways 3K JSA JETSTAR ASIA 2004
Scoot TZ SCO SCOOTER 2012
SilkAir MI SLK SILKAIR 1976
Singapore Airlines SQ SIA SINGAPORE 1947
Singapore Airlines Cargo SQ SQC SINGCARGO 2001
Tiger Airways TR TGW GO CAT 2003
Valuair VF VLU VALUAIR 2004

Question: What callsign at Singapore Changi Airport has an IATA of tr ?

Question: What operations has a Valair airline started under Singapore Changi Airport?

Question: What operations has a Valair airline started under Singapore Changi Airport?

Question: Which IATA has an ICAO of slk under Singapore Changi Airport?