I posted an answer once but it disappeared into lala land.

It sounds like your blooms have been pollinated. If a bloom is damaged for whatever reason, they fall off.

Brooke

Pollinated? Really? This sounds exciting - but how? They are inside and I hope we don't have bugs crawling around! How can I tell for sure?

I am curious to hear the reply as I also have two Phals that did this to me. The one had a full inflorescence of 4 flowers fully opened and then one shriveled but did not fall, it didn't even lose it's color. It just hung there like it was under watered, but the other three were fine.

I cut it off as I was displeased with how it looked, but then my other Phal did the same thing. All 6 flowers open on the inflorescence, then one goes saggy.

My suspicions were some sort of trauma to the individual flower, but I too have mine on a windowsill and it has been awfully cold up here in PA these last two months. So cold damage seems completely logical.

Curiosity peeked. Thanks in advance !

My initial reaction is the same as Brooke, but I have a nagging doubt. When polinated the flowers will droop within a couple of days, stay on the plant and gradually dry off and go crispy.

The doubt is how so many of your flowers are being polinated so quickly, this does not usually happen.