You don't need reflective chaff to track a jumper on ATC radar but it would certainly make it easier.

I talked extensively with an ATC controller who was also a pilot and skydiver. He said they routinely painted freefalling skydivers and could even count the number which had exited a jumpship.

It's a total myth that radar only sees metallic objects. I routinely tracked Pelicans on my X band boat radar. Newer S Band bird radars are used by tuna boats to spot birds at ranges exceeding twenty miles in ideal conditions.

If we had the RAW radar echo tapes we could have seen Coopers exit. Sadly the SAGE system processed the echoes and blanked out a "data box" in their immediate proximity in which they could post info about the target.

377

From Wikipedia:

The accuracy of DME ground stations is 185 m (±0.1 nmi).[2] It's important to understand that DME provides the physical distance from the aircraft to the DME transponder. This distance is often referred to as 'slant range' and depends trigonometrically upon both the altitude above the transponder and the ground distance from it.

For example, an aircraft directly above the DME station at 6,076 ft (1 nmi) altitude would still show 1.0 nmi (1.9 km) on the DME readout. The aircraft is technically a mile away, just a mile straight up. Slant range error is most pronounced at high altitudes when close to the DME station.

Radio-navigation aids must keep a certain degree of accuracy, given by international standards, FAA,[3] EASA, ICAO, etc. To assure this is the case, flight inspection organizations check periodically critical parameters with properly equipped aircraft to calibrate and certify DME precision.

ICAO recommends accuracy of less than the sum of 0.25 nmi plus 1.25% of the distance measured.

377

If I don't have my tablet running with the navigation map I can't really tell when I'm exactly over a VOR. my DME clock doesn't roll to zero.

You really can't be certain when you are directly overhead of a VOR.  There is a small angular "cone of silence" (maybe 3 degrees or so wide) extending vertically from the VOR station.  The diameter of this cone is small at lower altitudes (and smaller distances from the VOR) and wider at high altitudes (and further from the VOR).

If you are tracking inbound on a specific radial to a VOR station and pass directly overhead of the station, the TO/FROM flag will switch from TO to FROM rapidly without hesitation.  With the same radial as above set on the VOR, and say tracking inbound parallel to that radial but one-half mile offset from that radial, the TO/FROM flag will be noticeably slower and maybe fluctuate a bit as you approach the VOR radial that is 90 degrees from the one selected on the VOR.

So other things being equal, you can estimate to some extent if you hit the VOR exactly or missed it slightly just from the way the TO/FROM flag reacts.  It is a good thing to be familiar with the idiosyncrasies of your equipment.     

Bruce Smith wrote: Okay, so it's not perfect. But could have DB Cooper used some sort of DME device to locate the Merwin Dam? Or other landmarks, such as the I-5?

Nope. DME in 1971 was big eqpt. Not suitable for jumper use.

Today you can buy a cheap handheld walkie talkie that will give you VOR radials, but DME gear, as far as I know, is still not small enough to carry. No need for a portable DME in modern times when handheld GPS gives you far more nav data for less money.

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377

 



Quote from: 377 on August 15, 2016, 03:40:47 PM

Georger wrote: Did he pull the cards on each chute - I presume each chute had one. Maybe he was looking for evidence of tampering or a tracking device ... and found the card(s).


Don't know. The account I read (as I recall it was in Tosaws book) just had him looking at the packing card in the rig he decided to wear.

Beacon transmitters are way too large to put in the tiny packing car pouch which is nearly flush with the container surface and tight fit for a small folded piece of paper. The beacons are normally installed between the pack tray and back pad.

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So the chute he chose to use was the only chute he inspected? Hmmm.

One rumor has it the AF wanted to put chaff in the chutes, to track him with radar.   


                     I would really love to hear more of your thoughts on that being the only chute he inspected.

Yeah, I remember Marla talking about a triangulation of Mt St Helens and Adams, but she seemed to be making the theory up on the fly as she was getting grilled in Portland. She is certainly quick on her feet. She always had an answer, even when her first answer was refuted, such as the "most similar of all the pictures you're showed me" comment about LD and Tina, then Flo.

I'm not a big triangulation fan, even though the skies above the clouds might have been clear and Georger has shown that the moon was more than half full.

R99's Flight Path Theory


This is my understanding of Robert99's theory that the Flight Path was over Tina Bar, or just to the west. His speculation is that the money find at Tina Bar requires that the money was deposited via the following scenario:

1. The money bag tied around Cooper's waist became separated, or part of the money was released, or all of Cooper and his money impacted in the environs of Tina Bar, possibly on Caterpillar Island, or just inland from T-Bar, such as in the ponds or levee area of the Fazio ranch.

2. Shortly afterwards, some hydrological event, such as heavy rains or flooding, transported the money bag into the Columbia River, and in 1974 the dredging operation did two things – first, it spit up the three bundles, and secondly it chewed up as few more bundles into the itsy-bitsy pieces that were later recovered in the fragment field.

3. All of the money was deposited onto the beach at T-Bar in a  huge mix of dredge spoils, which the Fazios then spread it around with their bulldozers. The fragments were buried several feet below the bundles, which were buried under only a few feet of sand.

4. The bundles were exposed in 1980, six years after the Army Corps of Engineers no longer placed dredge spoils on the shoreline of the Columbia. As a result, the sand at T-Bar began eroding. By the time of discovery, the sand layer above the three bundles had been stripped away sufficiently to nearly expose the bundles, which Brian Ingram found on Feb. 10. Two days later the FBI found the fragment field, which extended for a diameter of 40 feet, centered at the bundles' location.


R99's scenarios are supported by the following:

1. Captain Scott allegedly told Himmelsbach at his retirement party in 1980 that 305 was flying over Woodland, WA, which is west of Victor 23, the air corridor that the plane was presumably following.

2. The “believed Flight Path map,” supplied by the FBI is incorrect, as Shutter has shown in his flight simulation studies that 305 could not have hit the locations marked on the map at the times specified at the speed of 200 mph, approximately.

3. The work of Richard Tosaw generally follows R99's theories. Tosaw believed that DB Cooper and all of his stuff fell into the Columbia River, where the skyjacker drowned and all of the gear sunk to the bottom, including the money, later to be brought up by the dredging.

4. The many redactions of the flight transcripts suggest that 305 was not flying in Victor-23, where it was presumed to be, for reasons unknown.



R99's theories are not supported by the following:

1. Tom Kaye's theories, as expressed at the 2011 Symposium in Portland, fully supported the Victor-23 Flight Path. Kaye said that he had direct access to all the pertinent radar transcripts, such as SAGE, FAA Seattle Center, etc.

2. Bill Rataczak many pronouncements that he was flying east of V-23 (BAS interview), over the Washougal River Valley (Himmelsbach), or far to the east of V-23 and over the flanks of Mt. St. Helens, as intimated in his History Channel interview when he said that 305 was flying over terrain that was 5,000 foot in elevation at the time the skyjacker jumped.

3. Larry Carr's general acceptance of the Victor-23 scenario, as revealed in his DZ posts.

If I've got anything wrong, please let me know.