There have been several amazing airfare deals in the past few weeks. Fares are down from a year ago, with fuel prices low and profitable airlines competing more vigorously against each other — at least on specific routes or for specific periods of time.

What we’ve seen a lot of is flash sales, with one airline going after another and then that airline responding like Delta offering super-cheap business class fares to and from United hub cities.

Now United and American are both offering coach roundtrips between several cities in the US and several cities in Europe for a little over $400. That’s amazing, considering a not insignificant portion of that cost winds up being taxes.

Sample cities:

• San Francisco – Zurich
  
• Newark – Dublin
  
• Washington Dulles – Paris
  
• Chicago – London (a bit higher thanks to UK taxes)

There are also fares to Shannon, Istanbul, Madrid, Barcelona, Athens, Rome, Munich, Lisbon, Prague and Budapest at least.

It’s a nationwide sale in the US, with most West Coast cities a bit pricier than East Coast cities and many destinations available. Given pricing, and number of destinations, this may be the best (non-mistake fare) Europe sale I’ve seen.

In fact, the ‘more expensive from the West Coast’ doesn’t always hold. Check out San Francisco – Zurich on American (note that it’s American flying out of a United hub, that’s often how these sales work).

This is actually a $50 base fare each way plus fuel surcharges and taxes.

This particular fare has rules which are typical of those being offered by American right now.

• Outbound travel must be August 23 through October 29 or December 16 to 23, or April 7 through May 12.

• 90 day minimum advance purchase required, so August 23 departures aren’t actually possible.

• Minimum stay is a return the first Sunday after arrival.

• Tickets must be issued today, the fare will expire after that.

• $300 change fee

American’s Executive Platinum members of course can confirm upgrades using their VIP systemwide upgrades. Most other members would find themselves using miles and a cost-prohibitive cash co-pay if space is available (and if it’s not available to confirm at booking, would waitlist and be above elites of a higher tier).

So anyone other than an American Executive Platinum should plan to fly these fares in coach.

Similarly United mileage upgrades will come with a prohibitive cash co-pay, and United’s 1K systemwide upgrades have minimum fare requirements that won’t be met by this sale.

(HT: The Flight Deal and Eric Goldner)