They ARE illegal
Sorry AAIGUY, cannot agree. Below is what my lawyer wrote, what did yours write?
"Bonds are not unlawful in Hong Kong. Put simply, a bond is a term in a contract between an employer and an employee in the same way as, for example, hours of work, rates of pay, amount of leave etc. In aviation a bond is usually linked to an amount of money equivalent to the cost of training which a newly joining pilot agrees to reimburse over a period of time, either by a 'real' monthly deduction from salary or a 'notional' amount per month so long as the pilot remains in employment at the end of the agreed period. Therefore, if an airline states that a job offer is dependent upon reimbursement of training costs by an amount of money or a period of employment (the bond) and the pilot accepts the offer, a contractual relationship is made that is enforceable and is not unlawful."