This past weekend I was sitting here wandering what the distance would be if you were on the line 157/337 and the next minute we hear Amelia broadcasting 158/338 according to Betty's notebook.
Betty did not hear Amelia say 158/338. Betty heard her say "158 miles." It would appear to have no relationship to "We are on the line 157 - 337" which are compass directions, not miles.
Little did I know you answered that question back in 2010 with the answer of 6 miles. My question is if this be the case...Travelling at 1000 feet from the surface of the water...can you see clearly six miles in either direction?
Yes, assuming the visibility is good.
If so...how long would it take to go those six miles?
It depends on how fast the airplane is going. At 130 kts it would take the airplane about 3 minutes to go six nautical miles. At 100 knots it would take about 3.5 minutes.
but does the Electra have the capability to glide if either engine may fail. If this be the case, how long could she keep the Electra gliding at 1000 ft above the water
If one engine quits she can continue to fly. If both engines quit the airplane will glide. I'm not sure what rate of descent the Electra would have at it's best glide speed but I would guess it's about 300 ft/min. If so, from 1000 feet she would be on the surface in about 3 and a third minutes - but I don't see what this has to do with anything.
However, your mention of "158 mi." in Betty's Notebook got me thinking. Betty said the reference to 158 miles was among the first things she heard and was part of other things Earhart was saying before Betty started transcribing. Why would Earhart say 158 miles? We know she was trying to describe where she was but apparently did not know the name of the island. We also know that she hit the advanced LOP where she thought Howland was, but it wasn't;t there ("We must be on you, but cannot see you.") We know she then ran north and south on the LOP.
Could 158 miles be the distance she ran south from where she thought Howland should be? That's something Noonan could calculate. If they hit the LOP 158 nm from Gardner, they hit it 192 nm southeast of Howland, which puts them right where Bob Brandenburg's propagation model gives Itasca the best chance of hearing Earhart at Strength 5 on 3105.