If they looked at the FDR several times it tells me that something is possibly confusing them. what would be on the FDR for them to extend the search area's. would this be pressure spikes, or the fact of them not knowing exactly where the plane was during these readings on the FDR?
The document above suggest a distance of over 25 miles of possible jump times....that's north of the Lewis river all the way down to the Columbia...
It is a mystery to me why they would try to reconstruct the flight path from the data on the FDR. Much more accurate data would be in the Seattle ATC radio transcripts.
Take a look at the Oakland ATC and Reno tower radio transcripts to see what should be in the Seattle ATC radio transcripts, but had been deleted.
So the pressure spike time would be about the only useful thing available from the FDR.
From the context of the document, it looks more like they were using the FDR to try to time the jump, they were not trying to reconstruct the flight path since they already had it from the radar. What's interesting is that they couldn't get a precise time for the jump from the FDR; in the document they are relying on the cockpit testimony to shorten the window of the jump.
I think that is exactly right - timing is their issue. Is it even possible that FDR did not record things in 'clock time'?
See the attached. Supposedly a three channel pressure recording for a 727 showing stairs open (oscillations) and bump. The time scale is not in clock time! My question to the Rockwell-Boeing guy that supplied this was: 'well what time is this? How do you know the time of an event?' His reply: 'Oh. We would have to correlate this with the clock recorder or flight comms then.' 
The Rockwell guy noted further: "oh that was pretty common back in the day". Can this possibly be true!? (dumbfounded)
Is it possible Rataczak's attempt to nail down a time of departure ("about 5 to 10 minutes after we last talked to him...") was the best they could do technically, data-wise? I find that very difficult to believe. But if you take R's statements at face value then they perhaps did not know and have no straightforward way of determining the exact time of Cooper's departure? And what blows my mind about this is the Boeing guy Ive talked to countless times about this finds nothing strange in any of it. He basically is saying: 'well we didn't build the plane to keep time of hijacker's actions'.
This ambivalence is an open hole to hell. But it has plagued this case, apparently since the beginning. I almost dread to post this graph.
First, a bit of history. Flight Data Recorders and Cockpit Voice Recorders were mandated by the FAA/NTSB with a lot of opposition from the pilot's unions, airlines, and manufacturers. Cost and what the data would be used for (such as enforcement actions against pilots, etc.) were hotly contested matters, legally and otherwise. The main reasons given for mandating these recorders was the information they would provide for accident investigators.
Also, the early recorders, which were probably introduced in the early 1960s, had quite limited capability compared to today's recorders. Perhaps only about 20 or 30 parameters were recorded by the first FDRs and they were recorded on foil drums.
Todays FDRs can record probably hundreds of parameters and save them on solid state equipment. In fact, the overall system can also send such things as engine performance parameters to the airline and/or engine manufacturer ever minute, or less, in real time. It was this type of information that was used in trying to locate MH370.
As I have pointed out several times over the years, one of the advantages of getting the actual Seattle ATC radio transcripts is that they have the GMT embedded in the voice tapes. They could give the times of each radio transmission by ATC or the airliner crew down to the second.
But redacting those Seattle ATC tapes to remove pertinent transmissions is an excellent CYA action.
