Sadly, this is one of the few legal loopholes in the current labour law; probation.
A probation period is mandatory under the law, not less than three months and not more than six months.
Article 37
A worker may be employed on probation for a period not exceeding six months, during which the employer without notice or severance pay may terminate his services. A worker shall not be placed on probation more than once with the same employer. Where a worker successfully completes the period of probation and continues in employment, the said period shall be calculated as part of his period of service.
Also,
Article 83
1- A worker shall not be entitled to any paid sick leave during the probationary period.
During this time (or at the culmination of this period) the employer may terminate the services of the employee under article 120 of the labour law, without any recourse for the employee.
Article 120
An employer may dismiss a worker without notice if and only if the worker:
b- Is engaged on probation and is dismissed during or at the end of the probationary period;
With regards to the ticket; if you are recruited from a foreign country, and are not resident in the UAE (on a visit or other visa), by law the employer is responsible for ALL recruitment costs – including that of the initial airfare. However. If you are already resident in the country (on for example a visit visa), and are lucky enough to find employment you are not entitled to try and claim your entry airfare from your employer.