A Qantas plane bound for Perth landed unexpectedly at Adelaide Airport with paramedics on standby after passengers and crew noticed a strong smell.Paramedics were on standby as the plane landed just before midnight, breaking city's curfew but landed safely at about 11.40pm yesterday.They were called to assess about 15 passengers who had potentially inhaled carbon monoxide but they were given the all clear.READ MORE: Wife breaks down after kind-hearted husband killed in 'vicious' shootingA Qantas plane bound for Perth landed