Cbs
When sitting my F/Nav. examination, one of the questions was " You are the Chief Navigator of a Trans Atlantic Airline. What radio equipment would you require and why?"
I specified pretty well everything...
I asked another candidate what he had replied. He said that he had written " I have been in this position myself. I would require 2 ADFs. Two for reliabilty. With them I could get time checks for Astro. I have flown across the Atlantic 90 times with just this equipment and am quite satisfied with it." ( He had held this position with a South American airline. This would have been pre Weather radar being around.)
It might be helpful to look at what had happened to some of the other airlines' experiences with loss of airspeed. NWA, near Tokyo were some 25 miles from a Cb which was off to one side and went into some cirrus. It was daylight. I think that they lost their Pitot etc on two occasions in quick succession, both recovered in a few minutes. TAM was over the Caribbean, at night. Again the ASI came back after a few minutes. Both of the flights were prior to AF. Jetstars episode came after AF.
More details must be available of these (and others ?) from places other than my armchair.
What went right ? ( for them)