This is all very interesting. I'm not a professional pilot myself (just a PPL!) but do do alot of employment law. The original question is: can an employer retire over 55s and then take them back on.
Employees who have passed "normal retirement age" for the job they do cannot claim unfair dismissal. So, what is the normal retirement age in professional flying? It will probably vary from company to company. If 55 is the normal retirement age then there is probably no claim. However, you have to be alive to the very real possibility that this is a bit of a smoke screen to enable the company to make redundancies without paying redundancy payments.
Assuming that the 'retirement' is lawful, then there is nothing wrong with re-employing pilots.
As regards redundancies, there not only has to be a redundancy situation, but the employers have to act reasonably in treating that situation as justifying dismissal, otherwise the dismissal is unfair. Creating redundancies and then reemploying staff in a new associated or subsiduary company to do the same job would be caught by the TUPE regulations. Under TUPE, any dismissal connected with a transfer of an 'undertaking' is automatically unfair. Under the regulations, the employees would have a claim against their new employers because on any transfer caught by TUPE all the rights and obligations under a contract of employment transfer to the new employer, including the right to claim redundancy or unfair dismissal.
Dan Winterland - I don't know on what basis you say an Employment Tribunal will not touch a claim!! The right to a redundancy payment and to claim unfair dismissal are statutory rights now contained in the Employment Rights Act. Not only will a Tribunal entertain such claims, they are the only body that can; the ordinary courts have no jurisdiction in these matters. By the way, you can no more understand the complex issues involved in these situations by reading a book than you can learn to fly from a book! Decisions emerge on an almost weekly basis from the Employment Appeals Tribunal and higher courts which have a profound influence on this area of law.
Anyone who finds themselves in this situation needs to consult an Employment lawyer immediately, and not onewho does a bit of employment now and again.