R99: You and I have chatted on here about the ground speed vs air speed.  As I understand, if a car's speedometer says 60MPH, then in an hour it will have traveled 60 miles, regardless of wind. That's because it measures ground speed. If an aircraft's speedometer says 60MPH, then it will only have traveled 60 miles if there is no wind.  If there is a 10MPH headwind, then it will only have traveled 50 miles.  Am I in the right ballpark here?

If so, any idea how the flight path was calculated using this info?  Or, what was the average wind speed against the plane, or with the plane?

Granted on such a short flight, the air speed vs ground speed may not have made a huge difference.  Thanks.

R99: You and I have chatted on here about the ground speed vs air speed.  As I understand, if a car's speedometer says 60MPH, then in an hour it will have traveled 60 miles, regardless of wind. That's because it measures ground speed. If an aircraft's speedometer says 60MPH, then it will only have traveled 60 miles if there is no wind.  If there is a 10MPH headwind, then it will only have traveled 50 miles.  Am I in the right ballpark here?

If so, any idea how the flight path was calculated using this info?  Or, what was the average wind speed against the plane, or with the plane?

Granted on such a short flight, the air speed vs ground speed may not have made a huge difference.  Thanks.

You have the general idea correct.  This has been discussed at length on both DropZone and here over the years.  I suggest you look up those detailed calculations that I have posted on this subject for a better explanation.  I would also suggest that you go to the FAA's website and download their free publications on navigation and such.

But here is the basic idea of how things work for aircraft navigation.  And we will keep airspeed and ground speed separate initially.  The airspeed indicator in an aircraft measures a pressure that is calibrated by a standard atmospheric model to read speed.  Since the pressure/airspeed as measured is a function of temperature and altitude, the pilot must use a flight calculator to determine the actual (or true) airspeed as indicated by the cockpit instrument.

The calculated true airspeed is the speed of the aircraft through the air mass in which it is flying.  Generally, the air mass is moving over the earth and must be allowed for in determining the aircraft's flight path over the ground.  The winds aloft (or the direction and speed of movement of the air mass) are generally predicted by the National Weather Service and provided to aviators for flight planning purposes.  In actual flight, the pilot can determine the direction and velocity of the wind to a reasonably accurate degree.

Assuming that the pilot is trying to track down the centerline of an airway or to fly a direct line between two points, he will probably need to calculate a wind correction angle unless he has a direct headwind or tailwind or no wind at all.  Typical flight calculators can be used to determine the wind correction angle and the component of the headwind or tailwind that he is experiencing.  If it is a headwind or tailwind component, it must be subtracted from or added to the true airspeed, as determined above, to determine the ground speed.  And ground speed is what is needed to determine the time required to get from point A to point B.

There is considerably more to aircraft navigation than what I have mentioned above.  So again, I suggest that you get the FAA publications on the subject and give them a very thorough reading.

On the subject of radar, posts on this site have indicated that in the Portland/Vancouver area, the McChord radar (which is about 80 miles or so from Portland) has an error of several miles.  The VOR equipment in the airliner is more accurate than the radar in this case.  And there are a lot more VOR stations (which are used to determine airways) than radar stations.  So I will give priority to the VORs over the radars here.

   

"This line of position is called the VOR "radial". The intersection of radials from two different VOR stations can be used to fix the position of the aircraft, as in earlier radio direction finding (RDF) systems."


okay pre-gps, I guess location could be determined by the intersection of two VOR stations.

but again, that determination of location is independent of any speed determinations.

I'm not sure any determination of speed feeds into location determination?
Robert99, does it? I suppose it's a crosscheck for information , but not a primary contributor to location determination.

I forget, did Flight 305 record any such location info from two or more VOR signals at any time? Did the flight recorder record that at intervals? Could the flight path have been determined from the flight recorder? (we don't know how the flight path maps were generated? is that still right?)

Snowmman, I'm not sure what you are getting at here but I assume it relates to the last paragraph in my post above which does not involve speed.  The intersection of radials from two different VORs determines a location as does a radial and DME distance from one VORTAC.

I doubt if the Flight Recorder on NWA 305 was accurate enough to determine the actual flight path.  The flight recorder was apparently the same one installed on the 727 when it was manufactured in about 1965.

As has been discussed at length over the last 11 years, the only positions given in the Seattle ATC radio transcripts for the airliner on the flight to Reno are two points on V-12 just south of SEATAC.  These two points are also identified in the ARINC teletype transcripts.  There are 19 redactions in the Seattle ATC radio transcripts to remove all additional information as to when and where the airliner was.  And the FBI refuses to release these unredacted transcripts.

However, the airliner was handed off to the Oakland ATC center in northern California and the Oakland ATC radio transcripts have not been redacted.  The first entry in those transcripts covers the hand-off from the Seattle ATC center and includes comments from Seattle controllers.  They give the location and time of the handoff and Oakland and Reno Tower transcripts include relevant times and locations when the airliner was under their control.   

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thanks. I'm not really pursuing any thought, just wondering about it
you said
"as does a radial and DME distance from one VORTAC."

I didn't realize the DME could determine distance accurately from a single VORTAC
if it does, that still doesn't guarantee a fixed location by itself, right?
I suppose a collection of such measurements would be pretty good, from a single VORTAC though.

exact location is a tricky thing. A lot of times, planes just need to know direction and I guess distance to a point, right?

There are 19 redactions in the Seattle ATC radio transcripts to remove all additional information as to when and where the airliner was.  And the FBI refuses to release these unredacted transcripts.

yeah, that's crazy.

A radial and DME distance from the same VORTAC does in fact determine a valid navigation fix (a precise geographical point) and such fixes were in use in 1971.

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thanks. I'm not really pursuing any thought, just wondering about it
you said
"as does a radial and DME distance from one VORTAC."

I didn't realize the DME could determine distance accurately from a single VORTAC
if it does, that still doesn't guarantee a fixed location by itself, right?
I suppose a collection of such measurements would be pretty good, from a single VORTAC though.

exact location is a tricky thing. A lot of times, planes just need to know direction and I guess distance to a point, right?

There are 19 redactions in the Seattle ATC radio transcripts to remove all additional information as to when and where the airliner was.  And the FBI refuses to release these unredacted transcripts.

yeah, that's crazy.

A radial and DME distance from the same VORTAC does in fact determine a valid navigation fix (a precise geographical point) and such fixes were in use in 1971.

Let's get specific for a change! 'There are 19 redactions in the Seattle ATC radio transcripts to remove all additional information'. You compare the SEA to PDX transcript with the Oakland transcript saying the Oakland to RNO transcript is UNREDACTED, while the SEA to PDX transcript is redacted. To remove all info that could direct people to precisely when and where Cooper jumped and landed.

Give us an example. Give an example of what precisely is redacted ? 

What line or  lines (information) in the Oakland-RNO transcript should be in the SEA-PDX transcript that have been redacted.

Or is this like Martha's breakfast, where she cooked waffles instead of pancakes, and you come along saying: Martha redacted breakfast? You wanted pancakes but she gave you waffles instead?

Get specific! What kind of pancakes did Martha redact! ? Give us examples of the information that should be, or must be, in the SEA-PDX transcript that will keep you satisfied and happy! ?

Georger, this has been discussed for the last 10+ years.  All you need to do is read the post here on Shutter's site and on DropZone.  The radio transcripts are posted here and on Sluggo's site.

Read the Oakland and Reno radio transcripts, which are textbook examples of air traffic control in the 1971 time frame.  That same type of information should be in the Seattle radio transcripts but is not.

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thanks. I'm not really pursuing any thought, just wondering about it
you said
"as does a radial and DME distance from one VORTAC."

I didn't realize the DME could determine distance accurately from a single VORTAC
if it does, that still doesn't guarantee a fixed location by itself, right?
I suppose a collection of such measurements would be pretty good, from a single VORTAC though.

exact location is a tricky thing. A lot of times, planes just need to know direction and I guess distance to a point, right?

There are 19 redactions in the Seattle ATC radio transcripts to remove all additional information as to when and where the airliner was.  And the FBI refuses to release these unredacted transcripts.

yeah, that's crazy.

A radial and DME distance from the same VORTAC does in fact determine a valid navigation fix (a precise geographical point) and such fixes were in use in 1971.

Let's get specific for a change! 'There are 19 redactions in the Seattle ATC radio transcripts to remove all additional information'. You compare the SEA to PDX transcript with the Oakland transcript saying the Oakland to RNO transcript is UNREDACTED, while the SEA to PDX transcript is redacted. To remove all info that could direct people to precisely when and where Cooper jumped and landed.

Give us an example. Give an example of what precisely is redacted ? 

What line or  lines (information) in the Oakland-RNO transcript should be in the SEA-PDX transcript that have been redacted.

Or is this like Martha's breakfast, where she cooked waffles instead of pancakes, and you come along saying: Martha redacted breakfast? You wanted pancakes but she gave you waffles instead?

Get specific! What kind of pancakes did Martha redact! ? Give us examples of the information that should be, or must be, in the SEA-PDX transcript that will keep you satisfied and happy! ?

Georger, this has been discussed for the last 10+ years.  All you need to do is read the post here on Shutter's site and on DropZone.  The radio transcripts are posted here and on Sluggo's site.

Read the Oakland and Reno radio transcripts, which are textbook examples of air traffic control in the 1971 time frame.  That same type of information should be in the Seattle radio transcripts but is not.

Yes you have recited this sermon for 10+ years.

If I read the Harrison notes for Oakland and Reno and compare them to SEA-PDX will that yield the examples you are referring to ?   

No.  With the possible exception of the first two mentions of the airliner's location on V-23 within 5 minutes of its takeoff from SEATAC, the Harrison notes are based only on information received through the ARINC phone patch and teletype system. 

Harrison did not have access to the Seattle or Oakland ATC radio communications.  Those communications were strictly between the air traffic control people and the airliner crew.  However, the air traffic control people apparently did pass one piece of information from NWA to the airliner.  And that was to switch to a frequency for the ARINC site in the San Francisco area sometime after they had been handed off to the Oakland ATC center.   

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thanks. I'm not really pursuing any thought, just wondering about it
you said
"as does a radial and DME distance from one VORTAC."

I didn't realize the DME could determine distance accurately from a single VORTAC
if it does, that still doesn't guarantee a fixed location by itself, right?
I suppose a collection of such measurements would be pretty good, from a single VORTAC though.

exact location is a tricky thing. A lot of times, planes just need to know direction and I guess distance to a point, right?

There are 19 redactions in the Seattle ATC radio transcripts to remove all additional information as to when and where the airliner was.  And the FBI refuses to release these unredacted transcripts.

yeah, that's crazy.

A radial and DME distance from the same VORTAC does in fact determine a valid navigation fix (a precise geographical point) and such fixes were in use in 1971.

Let's get specific for a change! 'There are 19 redactions in the Seattle ATC radio transcripts to remove all additional information'. You compare the SEA to PDX transcript with the Oakland transcript saying the Oakland to RNO transcript is UNREDACTED, while the SEA to PDX transcript is redacted. To remove all info that could direct people to precisely when and where Cooper jumped and landed.

Give us an example. Give an example of what precisely is redacted ? 

What line or  lines (information) in the Oakland-RNO transcript should be in the SEA-PDX transcript that have been redacted.

Or is this like Martha's breakfast, where she cooked waffles instead of pancakes, and you come along saying: Martha redacted breakfast? You wanted pancakes but she gave you waffles instead?

Get specific! What kind of pancakes did Martha redact! ? Give us examples of the information that should be, or must be, in the SEA-PDX transcript that will keep you satisfied and happy! ?

Georger, this has been discussed for the last 10+ years.  All you need to do is read the post here on Shutter's site and on DropZone.  The radio transcripts are posted here and on Sluggo's site.

Read the Oakland and Reno radio transcripts, which are textbook examples of air traffic control in the 1971 time frame.  That same type of information should be in the Seattle radio transcripts but is not.

Yes you have recited this sermon for 10+ years.

If I read the Harrison notes for Oakland and Reno and compare them to SEA-PDX will that yield the examples you are referring to ?   

No.  With the possible exception of the first two mentions of the airliner's location on V-23 within 5 minutes of its takeoff from SEATAC, the Harrison notes are based only on information received through the ARINC phone patch and teletype system. 

Harrison did not have access to the Seattle or Oakland ATC radio communications.  Those communications were strictly between the air traffic control people and the airliner crew.  However, the air traffic control people apparently did pass one piece of information from NWA to the airliner.  And that was to switch to a frequency for the ARINC site in the San Francisco area sometime after they had been handed off to the Oakland ATC center.

Thats what I thought/assumed ? So why do you keep referring to the WSHM work that found 'redactions' using the Harrison notes?  If the Harrison rolls dont even apply, whats the overlap btwn his rolls and the ATC radio communications? You keep bringing up the WSHM redactions work! WSHM redaction work in what transcripts?

Georger, please get someone who is fluent in English to explain posts on this site to you.  I have never said that the Harrison notes were redacted.  But the WSHM digital group determined that the ARINC teletype transcripts had been redacted.

Repeat "The Harrison Notes and the ARINC teletype transcripts are two, repeat t-w-o, different things." 100 times before you go to bed tonight.

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thanks. I'm not really pursuing any thought, just wondering about it
you said
"as does a radial and DME distance from one VORTAC."

I didn't realize the DME could determine distance accurately from a single VORTAC
if it does, that still doesn't guarantee a fixed location by itself, right?
I suppose a collection of such measurements would be pretty good, from a single VORTAC though.

exact location is a tricky thing. A lot of times, planes just need to know direction and I guess distance to a point, right?

There are 19 redactions in the Seattle ATC radio transcripts to remove all additional information as to when and where the airliner was.  And the FBI refuses to release these unredacted transcripts.

yeah, that's crazy.

A radial and DME distance from the same VORTAC does in fact determine a valid navigation fix (a precise geographical point) and such fixes were in use in 1971.

Let's get specific for a change! 'There are 19 redactions in the Seattle ATC radio transcripts to remove all additional information'. You compare the SEA to PDX transcript with the Oakland transcript saying the Oakland to RNO transcript is UNREDACTED, while the SEA to PDX transcript is redacted. To remove all info that could direct people to precisely when and where Cooper jumped and landed.

Give us an example. Give an example of what precisely is redacted ? 

What line or  lines (information) in the Oakland-RNO transcript should be in the SEA-PDX transcript that have been redacted.

Or is this like Martha's breakfast, where she cooked waffles instead of pancakes, and you come along saying: Martha redacted breakfast? You wanted pancakes but she gave you waffles instead?

Get specific! What kind of pancakes did Martha redact! ? Give us examples of the information that should be, or must be, in the SEA-PDX transcript that will keep you satisfied and happy! ?

Georger, this has been discussed for the last 10+ years.  All you need to do is read the post here on Shutter's site and on DropZone.  The radio transcripts are posted here and on Sluggo's site.

Read the Oakland and Reno radio transcripts, which are textbook examples of air traffic control in the 1971 time frame.  That same type of information should be in the Seattle radio transcripts but is not.

Yes you have recited this sermon for 10+ years.

If I read the Harrison notes for Oakland and Reno and compare them to SEA-PDX will that yield the examples you are referring to ?   

No.  With the possible exception of the first two mentions of the airliner's location on V-23 within 5 minutes of its takeoff from SEATAC, the Harrison notes are based only on information received through the ARINC phone patch and teletype system. 

Harrison did not have access to the Seattle or Oakland ATC radio communications.  Those communications were strictly between the air traffic control people and the airliner crew.  However, the air traffic control people apparently did pass one piece of information from NWA to the airliner.  And that was to switch to a frequency for the ARINC site in the San Francisco area sometime after they had been handed off to the Oakland ATC center.

Thats what I thought/assumed ? So why do you keep referring to the WSHM work that found 'redactions' using the Harrison notes?  If the Harrison rolls dont even apply, whats the overlap btwn his rolls and the ATC radio communications? You keep bringing up the WSHM redactions work! WSHM redaction work in what transcripts?

Georger, please get someone who is fluent in English to explain posts on this site to you.  I have never said that the Harrison notes were redacted.  But the WSHM digital group determined that the ARINC teletype transcripts had been redacted.

Repeat "The Harrison Notes and the ARINC teletype transcripts are two, repeat t-w-o, different things." 100 times before you go to bed tonight.

So what are the the Harrison TTY printout rolls produced by ARINC?     

No one is saying the HARRISON NOTES were redacted. But the public version of the TTY rolls were redacted ?

BTW, a full OCR version of the TTY roll is available. Have you ever seen it? Huh?