Recent Posts

Pages: 1 ... 8 9 [10]
DB Cooper / Re: General Questions About The Case
« Last post by 377 on May 24, 2023, 04:51:15 AM »
Are you sure the 727 autopilot maintained AOA? I see only altitude hold in a casual look through my manuals. It would respond to the lowered stair but only by sensing a change in baro altitude and pitching up to maintain the set value. I may be incorrect. I have not looked at it in depth yet.

DB Cooper / Re: General Questions About The Case
« Last post by snowmman on May 22, 2023, 06:26:23 PM »
good thoughts by Edwards on the oscillations
You are not allowed to view links. Register or Login
Edwards: (this is 8/16/22 so Edwards is musing post-book, and with new knowledge from newly released fbi files)

As mentioned in earlier posts, I discussed Boeing report D6-7771, on the Boeing tests 100-1 and 100-3 of the 727-22 in 1964, with an aerospace engineer who knows the Boeing 727 well.

He advised that on the Boeing tests, given the frequent references to manual trim, the autopilot was probably not engaged. However, with regard to Flight 305 between Seattle and Reno, I had reached the conclusion that the autopilot was almost certainly engaged most of the time.

This represented a significant difference between the configuration of the Boeing tests and that of Flight 305. With the autopilot engaged, any excursions in the control axes would be quickly corrected. Consequently, I would have expected any oscillations on Flight 305 to be much smaller than those on the Boeing tests.

I therefore asked my correspondent:
"... on Flight 305, given that the autopilot was engaged and that (probably) "altitude hold" was on, is there a way to estimate the maximum altitude excursions from 10,000 feet AMSL resulting from deployment of the airstair? I'm wondering: plus or minus 100 feet? More, or less?"
His reply was as follows [with my comments in square brackets]:
"... I would expect that [on Flight 305] the altitude fluctuation due to airstair deployment was less than 100 feet, especially with the autopilot engaged. The pilots would have needed to add some power to maintain airspeed. I am inclined to say that any altitude deviations of significance, if they existed, were more likely due to the weather of the evening [of November 24, 1971] than to the airstair deployment."
We recall that the crew's report of the oscillations on Flight 305 led to an estimate of the place and time of the hijacker's leap, which led to the delineation of a search area, where the FBI found nothing. We may wonder whether the oscillations on Flight 305 led the FBI down a wrong track, from which they were unable to return.
DB Cooper / Re: General Questions About The Case
« Last post by snowmman on May 22, 2023, 06:13:03 PM »
robert edwards commentary on the details of the boeing air stairs tests is reasonable, and here:
with discussion about hydraulics

You are not allowed to view links. Register or Login
also a later update
You are not allowed to view links. Register or Login
this second post has images showing oscillations in airplane altitude. I think he made the graphs from the data in the fbi files?

Edwards makes an interesting point:
"If on Flight 305 the autopilot was engaged (as the FBI assures us was the case) and "altitude hold" was switched on (which I think probable), it would compensate for the pitch-up without any intervention by the pilot, and would return the airplane to the desired angle of attack and to the desired altitude. There would surely have been some oscillations in the airplane's altitude, in the cabin's equivalent altitude, and in the cabin rate-of-climb (rate of change of cabin pressure), as there were in Boeing Test 100-1, summarized in the graphs below.]"

"[I believe that there were at least three relevant differences between the Boeing tests and Flight 305.
* In the Boeing tests, the landing gear was up. On Flight 305, the gear was down.
* In the Boeing tests, according to my correspondent, the autopilot was probably disengaged. On Flight 305, according to two statements to the FBI by Northwest's Director of Flight Operations (Technical), the autopilot was engaged throughout most of the segment between Seattle and Reno. A former senior FBI agent advised me that the FBI had no reason to question these statements.
* In Boeing Test 100-1, all the interior panels in the stairwell were removed. to avoid possible damage. I do not know what the aerodynamic effects might have been, but I suspect that this condition would have created more turbulence in the stairwell. In Boeing Test 100-3, the panels were re-installed. On Flight 305, all the panels were in place."

He has a nice pic of N727000 doing a test drop over the Pacific with the stairs removed. Interestingly, the payload and parachute descend at a more vertical angle from the plane, then I've seen in other test drops. (in other tests)

interestingly Edwards said
"Back on March 5, 2020, I had submitted a FOIA request for all reports relating to the Boeing test flights. The FBI replied on July 6, 2020, to the effect that they had searched for the reports and found nothing."

and then the FBI released the files with the detailed test reports.
DB Cooper / Re: Suspects And Confessions
« Last post by snowmman on May 22, 2023, 05:54:02 PM »
in 1973, Allen Tyre (buckshot31 at says Braden was driving a "18 wheeler for Pittsburg Glass Co, Pittsburg" based on the random meet at a truck stop.

"In 1973 Ted was driving an 18 wheeler for Pittsburg Glass Co, Pittsburg, PA. I think his primary route was between Pittsburg and Nashville. The only markings on the tractor were the DOT numbers. The trailer was well marked with Pittsburg glass logos and etc. He appeared to be very content driving an 18 wheeler. Have a great day. Al"

so that's odd, given the letter to Pauline in 1973 talking about Consolidated Freightways.

And the supposed FBI investigation of an insurance scam in the "early '70s?"
could there be a relationship?

I was wondering if the FBI faked the story, when they interviewed Pauline...really looking to dig up info about possible hijack connection
Since Braden didn't go to jail or anything?

I'm also wondering why there is no mention of Braden anywhere in the FBI files released. That's odd.

Did no one drop a dime on Braden in all these years to FBI? FBI has zero paperwork on Braden. Hard to believe. Especially when you see all the obvious "not" suspects in the files.

Be nice to do a FOIA on Braden to see what the FBI has.
DB Cooper / Re: General Questions About The Case
« Last post by snowmman on May 22, 2023, 03:56:24 PM »
I read an extended description of Al Tyre's reconnect with Ted in the famous truckstop breakfast in 1973

I hadn't noticed this before
"During the encounter in the service area in 1973, Tyre and Ted had breakfast together. Ted also asked him if he had followed the DB Cooper hijacking case. Tyre said he hadn't."

wonder if that's true.
DB Cooper / Re: General Questions About The Case
« Last post by snowmman on May 22, 2023, 03:34:01 PM »
The timing of the test in 1964 is interesting.

Braden entered Vietnam in 1964 with Special Forces Project Delta.  That's when he was teaching? some HALO

the official us navy seals site has some mention of those days

You are not allowed to view links. Register or Login

[RT] Colorado was also unique because of its team leader, Ted Braden. Among the many larger-than-life characters in the program, Braden was a complete enigma. Formerly an active-duty commissioned officer from the Army Reserve, he had arrived in South Vietnam in late 1965 as part of the second increment of special forces noncommissioned officers slated for the cross-border teams. At times, he was a quiet, almost professorial model, walking around camp in a sweater and puffing on a pipe. At other times, however, Braden displayed uncontrollable rage. “He punched a Vietnamese lieutenant in Kontum,” said Hetrick, “and was banished to Dak To.”

There, troubles followed. After a tense exchange with Lieutenant Colonel Arthur “Bull” Simons, one of the senior SOG planners, Braden was punished by having Colorado’s intended long-term unconventional mission scrubbed. Instead, Colorado would be tasked with reconnaissance missions like any other Shining Brass team.

Despite such outbursts, there was no denying Braden was something of a pioneer. “He had the idea of mixing different ethnic groups in a single team in order to foster competition,” noted Hetrick. Braden also had his team train in native civilian garb. After this led to protests from SOG superiors—who apparently disliked the complete departure from military norms—he then became the first SOG team leader to have his men wear combat fatigues dyed black, reflecting existing Vietcong apparel.

Perhaps the most mysterious aspect about Braden was his close ties to the CIA. “He spent a lot of time with the agency representatives in Saigon,” noted Shattuck, who joined the team in the fall of 1966. “We were told not to ask questions when he was gone for a week at a time.”

Not only did Braden go missing for extended periods, but he would return from his CIA trysts with cutting- edge hardware. “We were the first SOG team to get a Starlight scope (an early-model night-vision device) and a wiretapping kit,” said team member James “J. D.” Bath. Braden also procured a seismometer to test its applicability for use in conjunction with the automatic detonation of Claymore mines.

After a single in-country reconnaissance mission at the behest of the U.S. Marine Corps during the second half of September—which turned up no evidence of an NVA presence—Colorado was ready for its first major outing in early October.

A few days before its scheduled infiltration, the team gathered at the SOG compound in Phu Bai, the town north of Danang. To ease tension, Braden arranged for a tour of the nearby ancient imperial capital of Hue. Halfway to their destination, however, their truck ran into a Vietcong ambush. Careening off the road into a ditch, the team jumped from the vehicle and hugged the rise formed by a railroad track running parallel to the road.

Noticeably cool under pressure, Braden leapt to his feet, carbine in hand. Urging his teammates to fire, he sprinted ahead across a rice paddy toward the source of the ambush in a neighboring village. When it soon became apparent that the enemy weapons had fallen silent and the Vietcong had fled, the other Americans followed. Before reaching the village, however, they came across a body wearing the uniform of the South Vietnamese Regional Forces militia. The corpse was face down in the paddy, a bullet hole at the base of the skull.

When they finally arrived in the village, their team leader was interrogating the locals and made no mention of the dead militiaman. Already, U.S. Marine reinforcements had arrived and brought the situation under hand. Braden, however, apparently was still on an adrenaline high. When the team suggested they return to Phu Bai before nightfall, he waved his weapon and labeled them cowards, then commandeered a bus for Hue.

By the time the team regrouped at Phu Bai, a cloud already was starting to form over the execution of the South Vietnamese militiaman. While it was apparent that Braden would face some kind of disciplinary hearing, it was decided to go ahead with the scheduled mission. For this, they would be equipped with both the Starlight scope and a West German-made wiretap—both firsts for the Shining Brass program. Their target was the extreme western edge of the Demilitarized Zone, just inside the Laos-Vietnam border.

In keeping with plans, Colorado would not be the only team to be deployed in that vicinity. Seven kilometers south of the intended landing zone, a second SOG spike team, Arizona, was gearing for a simultaneous infiltration. Richard Ray—who previously had accompanied Ohio on a single mission—was originally scheduled to accompany Arizona on this outing. Two days earlier, however, he contracted malaria and was convalescing at the SEAL compound on the Son Tra peninsula. Five Vietnamese members of the team also remained behind, giving Team Arizona a light complement of just three Americans and four indigenous commandos.

Late on 2 October, both spike teams headed for the forward SOG launch site at Khe Sanh. The next morning, Colorado departed first aboard South Vietnamese-piloted H-34 choppers. Already thick with tension, the team focused on Braden with added concern. “He was carrying very little ammunition,” recalls Shattuck, “and we feared he had no intention of coming back.”

According to the original plan, they were supposed to install the wiretap, then pull back three kilometers and wait for a B-52 bomber strike before recovering the tapes. After further consideration, however, the planners felt it was not worth the risk of detection to have the team move three kilometers. Revising their plan, then, the B-52 strike went in first, immediately followed by the team’s insertion.

Once they landed, the situation intensified. In short order, Colorado located a suitable telephone cable running along the slope overlooking the Houei Nam Se River from the north. The entire valley, they found, was crawling with North Vietnamese troops, who had carved steps into both slopes and even had a simple ferry shuttling supplies across the river.

The heavy NVA presence extended all the way to Arizona’s area of operations, this entire pocket of Laos essentially having been annexed and treated as territorial North Vietnam since December 1958. Almost as soon as this second team landed to the south, it was in deep trouble. “We made contact with the NVA next to the landing zone,” said ethnic Chinese team member Tran Hung Quang. Pleas from the U.S. radioman came over the airwaves, followed by an eerie silence. One member managed to escape and return to friendly lines. Tran and one other ethnic Chinese were captured the following morning; the remainder of the team, including the three Green Berets, were listed as missing and presumed dead.

Colorado was more fortunate. Remaining sheltered in a bomb crater near the summit of the slope, the team waited patiently until sundown. Intending to use their Starlight scope, they unpacked the device and aimed it along the river. To their disappointment, however, the scope refused to work. Not wanting to be burdened with broken gear, Braden buried the night vision device on the spot. “We later caught hell for not bringing it home,” said Bath.

The team had better luck with the wiretap, which it managed to install without complications. Waiting nearby for the tapes to record several hours of telephone traffic, Colorado then recovered the device and was successfully exfiltrated by chopper.

DB Cooper / Re: General Questions About The Case
« Last post by snowmman on May 22, 2023, 03:06:20 PM »
some of the tabulated data

DB Cooper / Re: General Questions About The Case
« Last post by snowmman on May 22, 2023, 02:57:51 PM »
we had been looking for this. I randomly was looking at fbi file 71 and on page 333 there it was

There is a lot of detail in the test. Way more than the FBI test ...the exact details of how the door and stairs were managed.
"A Pulse Duration Modulation (PCM) magnetic tape system and a photorecorder were used to record performance and calibrated data. Airspeed and altitude were measure using the pilots' production pitot-static system. The aft airstair was instrumented to measure position in degrees from the up and locked position. The static pressure in Section 48 was measured by a pick-up that was located on the LR side of the airplane, outboard of the LH cavity side panels. Airplane cabin pressure and rate of climb were recorded on the photorecorders"

They include pictuires of airstair extended with and without hydraulic power, on pages 340 and 341

Flight Test Summary Report Commercial Transport Model 727-22
Test Item Title "Flight Characteristics with Aft Airstair Down - B"

Prepared by C.M. Clark 5-6-64

What's nice is it gives detail on the dates, documentation, airplane etc. Gives detail on the nose trim with stairs extended. Hydraulics extended the stair to 13.5 degrees.   "No excessive cabin pressure transients were noted with the aft entry door open and the stair extended". "125 knots and flaps at 25 degrees"

Very interesting to see the full report. I ocr'ed the summary and references, but the whole thing is interesting
detail on the document received 6/1/72 from Boeing and written up on 8/3/72 by FBI, has names of people investigated as a result of the document. (some redacted) all starts on page 332 of file 71

Interesting they did free-fall test of the stair, and hydraulic assisted. So the stairs did have some hydraulic assist, at least on the airplane in this test?

23 pages
References 5 other documents with details around the test


This report presents the results of tests conducted on the Model 727 airplane to evaluate the characteristics of the aft airstair when extended inflight and the associated effects on airplane performance and handling.

The airstair was extended both by allowing it to freefall and by utilizing normal hydraulic power. 

These extensions were made with the airplane trimmed for level flight at 125 knots and flaps at 25 degrees.

The airstair extended a nominal 8.5 degrees when allowed to free-fall and it required only approximately one-tenth unit of nose-down trim to compensate for the stalr.

The stair extended a nominal 13.5 degrees with hydraulic power and this caused approximately a three-tenth unit nose-down trim change.

The airplane was also accelerated to Vmo with fleps up and the airstair free-floating.

The airstair was quite stable when it was down and no airplane control problems were experienced.

No excessive cabin pressure transients were noted with the aft entry door open and the stair extended.

The environment near the aft entry door allowed it to be safely opened and the stair retracted at speeds up to 300 knots.

At 300 knots, it was also found that the airstair would not free-fall when unlatched.

DB Cooper / Re: Suspects And Confessions
« Last post by snowmman on May 22, 2023, 02:21:39 PM »
page 212 of fbi file 80 has a section of the "radar trace" from Boeing
has the well known markers (time) that we have from the Larry-provided color map
DB Cooper / Re: Suspects And Confessions
« Last post by snowmman on May 22, 2023, 02:16:55 PM »
this note on page 208 of fbi file 80 ..followed by the well known radar trace map, seems to say that the "address of contributor" was Boeing Co.

so did Boeing get data from ??? and make the trace map?

Pages: 1 ... 8 9 [10]