Author Topic: Flight Path And Related Issues  (Read 762736 times)

Offline 377

  • Hero Member
  • *****
  • Posts: 1596
  • Thanked: 442 times
Re: Flight Path And Related Issues
« Reply #4320 on: March 22, 2021, 02:46:00 PM »
DBfan57 wrote: “... if he pulls the chords on either side, would it not give him at least some ability to alter the course of his landing spot?”

Not in an unmodified C9 or other round canopy. Without a steering vent mod, pulling on on side accomplishes very little. I’ve tried it on both a C9 and a Navy 26 ft Conical canopy. I think paratroopers called it “slipping”.

Cooper’s canopy might have had a four line release mod, which, if activated post deployment, would have given the canopy some useful forward speed and steerability. The chances of the so called “4 line cut” mod being activated successfully on a night jump without a flashlight is very low.

377
 
The following users thanked this post: andrade1812

Offline Robert99

  • Hero Member
  • *****
  • Posts: 1711
  • Thanked: 196 times
Re: Flight Path And Related Issues
« Reply #4321 on: March 22, 2021, 05:00:13 PM »
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
I'm assuming DBC jumped at 8:13. If the jet was 23 DME at 8:18 then DBC jumped 5 minutes earlier. Back tracking 5 minutes along the Western Flight Path from 23 DME is about 16 miles north and puts the jet very near Tena Bar.
Actually, EU, I thought the same thing but in regards to the FBI path. Backtracking 5 minutes along the FBI flight path, would put an 8:13 jump spot very near the Columbia.

Unless Cpr is an expert and drops then opens at about 1000ft feet, he is going to drift no matter the flight path. He will not land in the Columbia or at Tina Bar in any event even with a jump at 8:13. There is no scenario that drops money at the Ingram find location on Tina Bar. This isnt a murder where a body drops in place to be found 8 years later in the same place!  ;)
But if he no-pulls, then drift doesn’t become an issue. If he jumped near the Columbia then the plane is flying into the direction of the wind. That would negate the forward throw, correct?

Nope.  If Cooper was a no-pull, he would be on the ground within 40 to 60 seconds.  The general estimate is that his forward velocity would be canceled in about 1500 feet and he could have moved about 1000 feet laterally from the flight path under the existing conditions that evening.

If you have had a course in elementary physics, you will understand why the above numbers cannot be determined more accurately.  And this is no put-down. :(
 

Offline EU

  • Hero Member
  • *****
  • Posts: 1759
  • Thanked: 322 times
    • ERIC ULIS: From the History Channel
Re: Flight Path And Related Issues
« Reply #4322 on: March 22, 2021, 05:04:41 PM »
Western Flight Path

During one of my conversations with Cliff Ammerman he mentioned that the Oregon National Guard T-33 departed PDX heading WNW. It then turned north over Sauvie Island, then finally made a U-turn to the east (presumably around the northern part of Sauvie Island) and pulled in behind 305 some five miles back.

Additionally, I know from the ATC transcripts that Ammerman (R4) took over 305 at 7:59:15 from R2. This handoff would have been at the moment that 305 was turning around the Maylay Intersection.

Ammerman told me that he was having to toggle the radio back and forth as he communicated with the F-106's so as not to be heard over the radio in 305's cockpit just in case DBC happened to be listening in on the communications.

Ammerman told me that this was labor intensive and therefore he opted to hand over 305 to ATC controller R5 because his work load was too great handling 305, the two F-106's and the T-33.

The ATC transcripts show that this handoff to R5 took place at 8:13:14.

I believe the handover to R5 was precipitated by the T-33 entering the theater. Meaning, the T-33 pulled in behind 305 at approximately 8:13:14.

The 8:13:14 time stamp is also notable because it happens to be at the same time DBC jumped--assuming, of course, that 8:13 is the jump time as I have suggested.

In my mind this all makes sense because we know that the T-33 pulled in behind 305 five miles back. Therefore, if the T-33 made the U-turn in the northern part of Sauvie Island as mentioned earlier, this would put 305 five miles further down the track and, once again, very near Tena Bar at 8:13.

Needless to say, it also makes a lot of sense when you consider that the money was found at Tena Bar which is a place not at all easy to walk to from off the Tena Bar "island" considering DBC would be lugging 25 - 80 lbs worth of money, parachutes and/or attache' case.
Some men see things as they are, and ask why? I dream of things that never were, and ask why not?

RFK
 

Offline Chaucer

  • Administrator
  • Hero Member
  • *****
  • Posts: 1080
  • Thanked: 243 times
Re: Flight Path And Related Issues
« Reply #4323 on: March 22, 2021, 05:34:46 PM »
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
I'm assuming DBC jumped at 8:13. If the jet was 23 DME at 8:18 then DBC jumped 5 minutes earlier. Back tracking 5 minutes along the Western Flight Path from 23 DME is about 16 miles north and puts the jet very near Tena Bar.
Actually, EU, I thought the same thing but in regards to the FBI path. Backtracking 5 minutes along the FBI flight path, would put an 8:13 jump spot very near the Columbia.

Unless Cpr is an expert and drops then opens at about 1000ft feet, he is going to drift no matter the flight path. He will not land in the Columbia or at Tina Bar in any event even with a jump at 8:13. There is no scenario that drops money at the Ingram find location on Tina Bar. This isnt a murder where a body drops in place to be found 8 years later in the same place!  ;)
But if he no-pulls, then drift doesn’t become an issue. If he jumped near the Columbia then the plane is flying into the direction of the wind. That would negate the forward throw, correct?

Nope.  If Cooper was a no-pull, he would be on the ground within 40 to 60 seconds.  The general estimate is that his forward velocity would be canceled in about 1500 feet and he could have moved about 1000 feet laterally from the flight path under the existing conditions that evening.

If you have had a course in elementary physics, you will understand why the above numbers cannot be determined more accurately.  And this is no put-down. :(
Would this remain the same even if the plane was flying directly into the winds?

For example at approximately 8:17 305 was flying southwest and the winds were from the south-southwest at around 15mph. When Cooper jumped he would have continued forward due to his forward throw but eventually this would stop and he would face some drift in the opposite direction even if no-pulling. My point being that given those conditions, he would lawn dart into the ground almost directly underneath where he jumped. Correct?
“Completely unhinged”
 

Offline dudeman17

  • Sr. Member
  • ****
  • Posts: 325
  • Thanked: 100 times
Re: Flight Path And Related Issues
« Reply #4324 on: March 22, 2021, 05:46:29 PM »
You are not allowed to view links. Register or Login
But once again I will ask, as I have asked some others, if he pulls the chords on either side, would it not give him at least some ability to alter the course of his landing spot?  They have emphasized he had non steerable chutes.  But couldn't you have a bit of control because it would have to change your direction if you  pulled the chords?  Sir Isaac Newton if you will.  To some degree.  To avoid hitting the water, if he was near the water.

I have to laugh. Maybe you'll believe it now, but I should probably make a side bet with 377 about how long it will be before you ask that same question again. Not sure if Mr. Newton was a rigger, and no disrespect for his intellect, but I bet 377 and I both have more jumps than he does.

You are not allowed to view links. Register or Login
But if he no-pulls, then drift doesn’t become an issue. If he jumped near the Columbia then the plane is flying into the direction of the wind. That would negate the forward throw, correct?

Pretty much what R99 said. You are pretty much correct in that if Cooper no-pulls, then drift isn't much of an issue. The forward throw will still happen regardless of winds, but it dissipates pretty quickly. High upper winds can cause some freefall drift, but not a whole lot. His body position could cause some 'slide', but again not a lot. Someone who no-pulls (or streamers) will end up pretty close to their exit point. Unfortunately, I witnessed my first one of those when I was about six.
 

Offline Robert99

  • Hero Member
  • *****
  • Posts: 1711
  • Thanked: 196 times
Re: Flight Path And Related Issues
« Reply #4325 on: March 22, 2021, 05:49:26 PM »
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
I'm assuming DBC jumped at 8:13. If the jet was 23 DME at 8:18 then DBC jumped 5 minutes earlier. Back tracking 5 minutes along the Western Flight Path from 23 DME is about 16 miles north and puts the jet very near Tena Bar.
Actually, EU, I thought the same thing but in regards to the FBI path. Backtracking 5 minutes along the FBI flight path, would put an 8:13 jump spot very near the Columbia.

Unless Cpr is an expert and drops then opens at about 1000ft feet, he is going to drift no matter the flight path. He will not land in the Columbia or at Tina Bar in any event even with a jump at 8:13. There is no scenario that drops money at the Ingram find location on Tina Bar. This isnt a murder where a body drops in place to be found 8 years later in the same place!  ;)
But if he no-pulls, then drift doesn’t become an issue. If he jumped near the Columbia then the plane is flying into the direction of the wind. That would negate the forward throw, correct?

Nope.  If Cooper was a no-pull, he would be on the ground within 40 to 60 seconds.  The general estimate is that his forward velocity would be canceled in about 1500 feet and he could have moved about 1000 feet laterally from the flight path under the existing conditions that evening.

If you have had a course in elementary physics, you will understand why the above numbers cannot be determined more accurately.  And this is no put-down. :(
Would this remain the same even if the plane was flying directly into the winds?

For example at approximately 8:17 305 was flying southwest and the winds were from the south-southwest at around 15mph. When Cooper jumped he would have continued forward due to his forward throw but eventually this would stop and he would face some drift in the opposite direction even if no-pulling. My point being that given those conditions, he would lawn dart into the ground almost directly underneath where he jumped. Correct?

Nope again.  According to the people listening in on the phone patch, the airliner crew said at 8:18 PM that they were 23 DME nautical miles south of the Battleground/Portland VORTAC.  They would be on the western edge of V-23 and flying almost straight south (actually about 178 degrees true).  The wind velocity at 10,000 feet was about 35 knots from the southwest (225 degrees true).  You can do some trig calculations to determine the headwind component and side component.  But the point is Cooper is going to continue on down the flight path for a short distance and move laterally by an even shorter distance.

And again, have you had a course in elementary physics? ???
 

Offline dudeman17

  • Sr. Member
  • ****
  • Posts: 325
  • Thanked: 100 times
Re: Flight Path And Related Issues
« Reply #4326 on: March 22, 2021, 06:00:16 PM »
Robert, you're arguing against Chaucer's calculated reasoning, but you seem to be agreeing with his basic point, which is that if Cooper goes in, he's pretty close to his exit point, which is correct. No, I don't have a degree in physics, but sadly, I've watched a number of people do it.
 

Offline Robert99

  • Hero Member
  • *****
  • Posts: 1711
  • Thanked: 196 times
Re: Flight Path And Related Issues
« Reply #4327 on: March 22, 2021, 06:00:57 PM »
Not sure if Mr. Newton was a rigger, and no disrespect for his intellect, but I bet 377 and I both have more jumps than he does.

Quote

Not only was Newton not a rigger, he made a mistake in some early aerodynamic calculations that reportedly delayed or discouraged the development of flying machines for a few years.  But his mistake was caught fairly early and, in any event, aerodynamics wasn't much of a science in the early 1700s anyway.
 

Offline andrade1812

  • Hero Member
  • *****
  • Posts: 624
  • Thanked: 144 times
    • My Website
Re: Flight Path And Related Issues
« Reply #4328 on: March 22, 2021, 06:04:47 PM »
You are not allowed to view links. Register or Login
DBfan57 wrote: “... if he pulls the chords on either side, would it not give him at least some ability to alter the course of his landing spot?”

Not in an unmodified C9 or other round canopy. Without a steering vent mod, pulling on on side accomplishes very little. I’ve tried it on both a C9 and a Navy 26 ft Conical canopy. I think paratroopers called it “slipping”.

Cooper’s canopy might have had a four line release mod, which, if activated post deployment, would have given the canopy some useful forward speed and steerability. The chances of the so called “4 line cut” mod being activated successfully on a night jump without a flashlight is very low.

377

Approximately 10:50 is the slipping technique



Video alse includes technique for getting down from a tree with reserve.

 

Offline Robert99

  • Hero Member
  • *****
  • Posts: 1711
  • Thanked: 196 times
Re: Flight Path And Related Issues
« Reply #4329 on: March 22, 2021, 06:36:36 PM »
You are not allowed to view links. Register or Login
Robert, you're arguing against Chaucer's calculated reasoning, but you seem to be agreeing with his basic point, which is that if Cooper goes in, he's pretty close to his exit point, which is correct. No, I don't have a degree in physics, but sadly, I've watched a number of people do it.

You are absolutely correct that a no-pull is going to land close to his exit point even from 10,000 feet.

The point about the physics and the comment that the the jump calculations for a no-pull are approximate needs some further explaining.

As Georger can attest, it is highly unlikely that any college physics textbook, either undergraduate or graduate, includes horizontal movement in the atmosphere without making gross assumptions, such as assume there is no atmosphere.  At least I have never seen one.

Vertical movement in the atmosphere can be handled easily.  But when you add the horizontal component to the vertical component, you end up with something like a fourth order nonlinear differential equation.  And solving that is where the rubber really hits the road and it is basically unsolvable in a realistic time frame even with a Cray super computer.
 

Offline dudeman17

  • Sr. Member
  • ****
  • Posts: 325
  • Thanked: 100 times
Re: Flight Path And Related Issues
« Reply #4330 on: March 22, 2021, 06:53:56 PM »
You are not allowed to view links. Register or Login
As Georger can attest, it is highly unlikely that any college physics textbook, either undergraduate or graduate, includes horizontal movement in the atmosphere without making gross assumptions, such as assume there is no atmosphere.  At least I have never seen one.

Vertical movement in the atmosphere can be handled easily.  But when you add the horizontal component to the vertical component, you end up with something like a fourth order nonlinear differential equation.  And solving that is where the rubber really hits the road and it is basically unsolvable in a realistic time frame even with a Cray super computer.

All good and well, but real-world, seat-of-your-pants...    Spotting is an art form, and I've always maintained that I can put a pumpkin down a chimney from 12,500'. HA!
 

Offline dudeman17

  • Sr. Member
  • ****
  • Posts: 325
  • Thanked: 100 times
Re: Flight Path And Related Issues
« Reply #4331 on: March 22, 2021, 07:00:32 PM »
You are not allowed to view links. Register or Login
Approximately 10:50 is the slipping technique

But again, very minimal control. I've done it with a 35' T-10, a 28' flat, a Piglet, a Para-Commander, a 26' Navy Conical, and a 24' Preserve II, and I wouldn't count on it for any degree of accuracy. How wide is the Columbia?
 
The following users thanked this post: andrade1812

Offline andrade1812

  • Hero Member
  • *****
  • Posts: 624
  • Thanked: 144 times
    • My Website
Re: Flight Path And Related Issues
« Reply #4332 on: March 22, 2021, 07:32:09 PM »
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
Approximately 10:50 is the slipping technique

But again, very minimal control. I've done it with a 35' T-10, a 28' flat, a Piglet, a Para-Commander, a 26' Navy Conical, and a 24' Preserve II, and I wouldn't count on it for any degree of accuracy. How wide is the Columbia?

Wider than that truck...
 

Offline Chaucer

  • Administrator
  • Hero Member
  • *****
  • Posts: 1080
  • Thanked: 243 times
Re: Flight Path And Related Issues
« Reply #4333 on: March 22, 2021, 07:52:52 PM »
You are not allowed to view links. Register or Login
Robert, you're arguing against Chaucer's calculated reasoning, but you seem to be agreeing with his basic point, which is that if Cooper goes in, he's pretty close to his exit point, which is correct. No, I don't have a degree in physics, but sadly, I've watched a number of people do it.
Thank you.
“Completely unhinged”
 

Offline Robert99

  • Hero Member
  • *****
  • Posts: 1711
  • Thanked: 196 times
Re: Flight Path And Related Issues
« Reply #4334 on: March 22, 2021, 10:30:52 PM »
You are not allowed to view links. Register or Login
You are not allowed to view links. Register or Login
Robert, you're arguing against Chaucer's calculated reasoning, but you seem to be agreeing with his basic point, which is that if Cooper goes in, he's pretty close to his exit point, which is correct. No, I don't have a degree in physics, but sadly, I've watched a number of people do it.
Thank you.

"Pretty close" and "almost directly underneath" are two different things.