It was a training jet - I don't recall what kind.
There are plenty of hiking trails in the area, with maps, a pilot could easily
get out in a few days.
I have not seen the book, but I have not really been looking either.
The reason for suppressing the seismic information was that the suggestion
had been made that perhaps the pilot had unloaded some of the bombs
to make the plane lighter. There had been reports from the area of explosions
at about that time. The Air Force said they had no evidence this had happened,
and the USGS was trying to support the government position. The quake was
sufficiently near a quarry to appear to be a quarry blast, but was larger than
any other quarry blast in the area in several years. No one at the quarry, however,
would admit to any blasting at that time.
The press had asked a specific question - "Had there been any seismic
disturbances in the area at the time", Waverly had been briefed that no disturbance
had been noted. At the time the USGS was understaffed and were not locating
most earthquakes themselves, but were using the Nuclear Test Ban data and
adding bits and pieces here and there. This was not something they wanted
the public to know - that they were not locating most of the earthquakes anymore -
so when it was made public that the Nuclear Test Ban earthquake catalog had
recorded an earthquake at about the time of the crash, but the USGS had omitted
this from their catalog, there were questions regarding cover-ups etc.
In fact, it was a perfectly natural mistake. The procedure was to take the Test
Ban catalog and automatically remove any events from it which were located
within 50 km of active quarries. The law stated that the test ban catalog could
not identify which events were blasts and which were earthquakes, so this was
a technique that removed most quarry events even if it also removed some
earthquakes. The problem was that this was automatic, so USGS personnel
did not know the event had been removed from the catalog and the error
snowballed.