Immersion is generally not permissible until after the seven clean days have been completed.

In your case, that means that you cannot immerse prior to flying out, unless the timing works out in your locale and you can slip away to a mikveh in close proximity to the airport after nightfall, before your flight. Otherwise, you could either explore the possibility of arranging a late-night immersion at your destination (the wee hours of the morning before dawn work fine for this as well) or plan on delaying immersion by one night.

In some very extenuating cases, as when there are major issues of fertility or shalom bayit, there may be room for a special ruling to immerse earlier on the seventh clean day, on condition that the couple are not alone together prior to nightfall. If your situation may fall into this category, please get back to us with more details.

Please let us know if we can be of further assistance.