The Rutherford Appleton Labs ionospheric thingamybobs website seems to have been playing up for about 3 days now, and in particular, I have not been able to retrieve ionograms. I have been able to find foF2 plots here:
I’m not aware of another site that publishes the Chilton ionograms but until the RAL system is up & running again you could refer to the Belgian equivalent http://digisonde.oma.be/
Click on Public:Latest Ionogram
As Belgium is at a lower latitude I have generally found that the FoF2 is slightly higher at any particular time than it is on the RAL ionogram, but it is certainly a useful guide.
Seems to me that the Chilton site has been quite unreliable over the last few weeks. I did have a script running to periodically download them, but that has had various hiccups over the last few weeks, it seems to have stopped working completely since 12 April.