camino aragones

via the Marcadau, presumably. The Pyr-Atl Amis de SJ reckon 8 hrs for Pont d'Espagne to Balneario de Panticosa http://nfrance.com/~eq12690/spip/articl ... rticle=448
so a reasonably fit walker should be able to cross in a day, depending on where you spend the night either side. If you plan to overnight at the Marcadau refuge, see http://www.premiumwanadoo.com/clubalpin ... &Itemid=28
and also http://www.pyrenees-pireneus.com/refuge_wallon.htm
May is quite early; snow should all be gone, but the pass is quite high (2541m) so you can never be sure I don't know what you mean by 'safety gear' but be prepared for bad weather. Disadvantage of going this way is you will need warm clothing that you prob won't need for the rest of the trip.

From Panticosa the route along the Gallego valley was opened last year though the markings come to a halt at the border of Jaca province
http://vppyr.free.fr/pages_transversale ... _ossau.htm