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Author Topic: Landing Gear and Bevington Object shadow study  (Read 13959 times)

Greg Daspit

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Landing Gear and Bevington Object shadow study
« on: January 11, 2017, 10:04:16 AM »

I need help to verify if Eric Bevington’s time entries in his Diary are coordinated correctly with time settings used in AutoCAD.
In 1937 would Gardner Island be under Daylight savings time?
I need to verify if the annotated settings in the attached PDF are correct (for 1937).
In his Diary Bevington writes:
“We got in by 11.30, both somewhat foot-sore – constant walking in the lagoon softens one’s feet. On return to camp, water reports were excellent, so we had a meal and pushed off to Nimanoa, having first raised the flag on the mast”
Based on this entry, I've done shadow studies starting at 11:30am but I’m not sure if Daylight savings comes into play.

Bevington seems to be at least trying to keep track of the correct time in this entry:
“ we crossed the date line this evening (180 degrees) at 6 p.m. so it will be Sunday again tomorrow as the clocks go back 24 hours. At 7 p.m. when time had really gone back to Saturday”

I also need help on C/n 1005. (For practice and test of methods) Any aerials showing its orientation? I saw someone recovered the tail section but does the wreck still show up on google earth, or archived images of google earth?
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Ric Gillespie

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Re: Landing Gear and Bevington Object shadow study
« Reply #1 on: January 11, 2017, 11:17:11 AM »

In 1937 would Gardner Island be under Daylight savings time?

I don't know, but I would be VERY surprised if the Gilbert & Ellice Islands Colony was using Daylight Savings time.

I also need help on C/n 1005. (For practice and test of methods) Any aerials showing its orientation? I saw someone recovered the tail section but does the wreck still show up on google earth, or archived images of google earth?

Attached are the original images I have.  I don't know where the thing is so I don't know where to look for it in Google Earth.
« Last Edit: January 11, 2017, 12:02:59 PM by Ric Gillespie »
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Greg Daspit

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Re: Landing Gear and Bevington Object shadow study
« Reply #2 on: January 11, 2017, 12:49:57 PM »

These exhibits show the shadows for the hard parts only and hard parts with the tire. A fully inflated tire casts a shadow on the worm gear or the left side of the fork at various times of the day. At no time are both of them in light. In the Bevington Photo both areas are in light. For the shadows of the tire to not cover those areas, the tire has to be deformed similar to the tire in the Luke Field Crash. Attached is a concept study I did last year with a big gash in the tire and exhibits for the shadow study of the inflated tire.
Edit:
The image of the tire with a gash in it is from a camera 15' away so the perspective is different than the Bevington Camera
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« Last Edit: January 11, 2017, 12:52:15 PM by Greg Daspit »
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Ric Gillespie

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Re: Landing Gear and Bevington Object shadow study
« Reply #3 on: January 11, 2017, 12:53:32 PM »

That's pretty compelling.
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Greg Daspit

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Re: Landing Gear and Bevington Object shadow study
« Reply #4 on: January 16, 2017, 04:38:36 PM »

Regarding the AutoCAD lighting study of just the hard components.
The time of the day that the worm gear is in sunlight and does not have a shadow on it cast by either the axle, hub or brake falls within a somewhat small window. The worm gear first gets sunlight at about 11:45am, although not lit brightly at all. It gets brighter and brighter afterwards as the sun angle changes, and then the brake starts to cast a shadow on it at 1:15pm. By 1:45pm the axle starts to cast a shadow. In my opinion what may be the worm gear in the Bevington Photo is well lighted except for area which may be underwater.

From his diary, the only time Bevington could have taken the picture was when they departed the island. He said he arrived back at camp at 11:30, had lunch, raised the flag and headed off. I’m not sure how long it takes to cross the reef but the ocean seems very calm in the photo.
  I would be interested to hear from expedition members on the forum regarding how much time they typically spent crossing the reef in calm waters and loading the skiff, or an estimate for loading a small boat.   What would be a reasonable time or window?
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Greg Daspit

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Re: Landing Gear and Bevington Object shadow study
« Reply #5 on: January 16, 2017, 04:51:26 PM »

Attached is an exhibit to illustrate something interesting observed after positioning the components.
If the worm gear section has the same diagonal struts still attached like in the Luke Field Accident,  there is a physical constraint for moving that section right. A strut on the worm gear section can clash with the brake or hub on the fork section. Moving the worm gear left much starts to conflict with the tire as dimensioned in the study Mr. Glickman in the The Object Formerly Known as Nessie.
 Moving it forward conflicts with both the strut and with what may be the axle tip in front of the worm gear. Moving it back buries it in the tire. There is a very small range to position these 2 components.

Note that what is shown in the attachment has the rear part of the fender/ mud flap at the bottom. Different than the 2D illustrations in “The Object Formerly Known As Nessie” (larger part of the fender part on top).   The intent is to study the fenders in both configurations. Also note the worm gear in the 2 D illustrations is a different shape than what I have modeled in 3D based on 40650 . I suspect the 2D illustrations are based on a modified landing gear version that Mr Harney may have used as a guide in his drawings. If it helps in the future I may be able to provide graphics for these parts.

Here is where I could use some help:  It would be helpful if I had a picture of either fender part, where it is not attached to the fork. I’m interested to see if it is notched to fit the contours of the reinforcing on the fork or not. And if so how much.
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Ric Gillespie

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Re: Landing Gear and Bevington Object shadow study
« Reply #6 on: January 16, 2017, 05:11:28 PM »

  I would be interested to hear from expedition members on the forum regarding how much time they typically spent crossing the reef in calm waters and loading the skiff, or an estimate for loading a small boat.   What would be a reasonable time or window?

Except on rare occasions we use the landing channel so we don't have to cross the reef.  During the Maude/Bevington visit there was, of course, no landing channel. RCS Nimanoa was tied off to Norwich City.  Walking from the beach out to the shipwreck takes, at most, ten minutes but breaking camp, loading the whaleboat, and conveying stuff out to Nimanoa is going to be done by the Gilbertese, not the white guys.
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Jerry Germann

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Re: Landing Gear and Bevington Object shadow study
« Reply #7 on: January 16, 2017, 10:12:48 PM »

These exhibits show the shadows for the hard parts only and hard parts with the tire. A fully inflated tire casts a shadow on the worm gear or the left side of the fork at various times of the day. At no time are both of them in light. In the Bevington Photo both areas are in light. For the shadows of the tire to not cover those areas, the tire has to be deformed similar to the tire in the Luke Field Crash. Attached is a concept study I did last year with a big gash in the tire and exhibits for the shadow study of the inflated tire.
Edit:
The image of the tire with a gash in it is from a camera 15' away so the perspective is different than the Bevington Camera

Greg,

Really enjoy your study and images!
 In trying to grasp all that you are saying, I have a question. In your image I believe you portray the tire as having become separated or gashed to create the dark shadowed area, and reference the luke field accident.The tire would therefore appear too have differing tread heights, with each separated end,out of the norm. In the bevington image, it appears to me that there is a reflection in that shadowed area, and is similar to the reflection on either side of the remaining tire. Would there be a refection there if the tire was separated? It may be possible that a gash was cut in two places, some few inches apart and allowed that small section of tire to collapse inward and still allow a reflection from the side of the tire....but that reflective area also appears out of plane with what would be the sides of the tire. What are your thoughts?
« Last Edit: January 16, 2017, 10:24:03 PM by Jerry Germann »
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Greg Daspit

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Re: Landing Gear and Bevington Object shadow study
« Reply #8 on: January 16, 2017, 11:16:13 PM »



Greg,

Really enjoy your study and images!
 In trying to grasp all that you are saying, I have a question. In your image I believe you portray the tire as having become separated or gashed to create the dark shadowed area, and reference the luke field accident.The tire would therefore appear too have differing tread heights, with each separated end,out of the norm. In the bevington image, it appears to me that there is a reflection in that shadowed area, and is similar to the reflection on either side of the remaining tire. Would there be a refection there if the tire was separated? It may be possible that a gash was cut in two places, some few inches apart and allowed that small section of tire to collapse inward and still allow a reflection from the side of the tire....but that reflective area also appears out of plane with what would be the sides of the tire. What are your thoughts?
For the sunlight to cover the worm gear and light the upper part of the fork, the part of the tire closer to the camera has to be lower than inflated height.  Dropping this section of tire down also creates a cave of darker area under the rear part of the tire. The shape of the tire needed is Very similar to the Luke Field Accident. The image attached was just a concept study to determine what was happening with the shadows. In that 1-16-16 study I just sliced the tire with a clean strait cut and lowered one section. I didn't get detailed in making it jagged. (yet) . Regarding the center arrow you annotated. The tire cut may be jagged and what your see may just be an edge, also note the inside of the tire appears light colored in the Luke Field image. It may be part of the inside tire not in shadow. I don't see that as very bright.

Regarding the left arrow you annotated. That area may be the brake or part of the fender overlapping the area of the brake. Still studying that spot.

Regarding what the arrow to the right is pointing to. I intend to model the larger fender on top. The larger fender has a brace on either side. I think with the small fender on top(the concept study I attached), there is not enough area reflecting. I also did studies where I modeled what I call the Harney fender which he drew about 2" longer than what the installation drawing showed. It was very close to matching the area reflecting but I don't think its dimensions were accurate. Preliminary studies suggest the larger fender needs to be bent down into the tire to reflect lighted area to equal that of what is seen in the Bevington Object. In the Luke Field Accident, the worm gear is holding down the tire.  I suspect that in the Bevington Object, the fender is bent down on top of the tire and the fender's brace may be holding down the tire. So what I intend to study is if the line you annotated to the right could be the fender brace.
3971R
 
« Last Edit: January 16, 2017, 11:26:48 PM by Greg Daspit »
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Greg Daspit

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Re: Landing Gear and Bevington Object shadow study
« Reply #9 on: March 19, 2019, 12:30:17 PM »

A question on another string came up about if the landing gear failed and consideration of that in tidal studies.

Based on the sun analysis of the Bevington photo, at least the upper part of the tire was significantly pushed in right next to the wheel hub. The deformity in the tire could be caused by the landing gear failure but it could also be caused by the tire being flat and the plane being pushed and twisted around on the reef. Then the landing gear failing after this and the worm gear getting stuck in the tire opening.
https://tighar.org/Projects/Earhart/Archives/Research/Bulletins/82_BevingtonAnalysis2/82_BevingtonObjectNewAnalysis.html


The possible “tire” in the Debris Field video from 2012 appears to show what might be the hub significantly extending up from what would be the tire. The proportions of what would be  the tire and hub in this object are right.
If this was the case it could be the tire was cut around the hub’s rim like paper being cut on the edge of the table.  If the tire was flat and the plane was pushed by tides sideways and also forward/back sharp coral might cut the tire from the hub like that. The coral almost acting like a can opener. The tire being the can and the hub the lid. Another analysis of the tides could include an assumption where a tire or both tires were flat.
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« Last Edit: March 19, 2019, 12:46:17 PM by Greg Daspit »
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Jim Zanella

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Re: Landing Gear and Bevington Object shadow study
« Reply #10 on: March 19, 2019, 03:22:41 PM »

Would it be worth it to evaluate the Luke Field broken landing gear using your methods? I am assuming we know when the pics were taken at Luke field. This would help validate your
Gardner island analysis.
« Last Edit: March 19, 2019, 03:25:30 PM by Jim Zanella »
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Greg Daspit

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Re: Landing Gear and Bevington Object shadow study
« Reply #11 on: March 19, 2019, 07:04:45 PM »

Would it be worth it to evaluate the Luke Field broken landing gear using your methods? I am assuming we know when the pics were taken at Luke field. This would help validate your
Gardner island analysis.

I don’t know the camera angles and distances at Luke Field. Jeff Glickman did a detailed analysis of the camera location and the object location and how they are oriented at Gardner Island. I used that data for my study but don’t have it for Luke Field.

I think to validate the study more it might be better to build an actual full size model and use a real camera just to validate the angles and positioning of the components. In the full size real model study you would not be studying shadows but just the angles of the components, specifically the fork. Once the components angles are validated you could then go back and check them again with the autocad model. This method would also allow you to do an “overlay” of an enlarged real photograph with the enlarged Bevington Photo to check the angles and sizes.

In Autocad you typically “zoom in” to see something better. It’s like you walked closer to the object. An “enlarged” Bevington Photo and the “zoomed in” Autocad image of the landing gear have different perspectives so you can’t do an overlay.


FYI for the autocad study multiple cameras were used. One to check the fork’s angles using a camera from where Bevington took the photo, hundreds of feet away. Using this camera, extension lines projected from the different angled parts of the fork had to be added just to see the angles from about 300’ away. You can actually see one of these leftover extension lines in an image in the report. (The one taken above the entire model including the Norwich City and shoreline.) Another autocad camera was set closer to the components to be able to more easily adjust their position. This was the “working camera”. Images from this camera are what you see in the computer rendered images. 

If the positioning is right then the rendering of the shadows would not need to be validated. (edit others have asked me this):  It’s not me guessing where the shadows are by “drawing” or “sketching” any of it. It’s a computer rendering of  a “model” based on the actual location, day and time the photo was taken. 
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« Last Edit: March 19, 2019, 08:08:15 PM by Greg Daspit »
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Leon R White

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Re: Landing Gear and Bevington Object shadow study
« Reply #12 on: March 20, 2019, 12:37:37 PM »

Could someone refresh me on the details of how TIGHAR thinks the landing gear got into the nessie position?  If the tire is deflated, it didn't float with the gear part hanging below it.  If the tire deflated and some part of the gear caught on the reef, would it stay fast in the "tire showing" position? If the tire is torn, it isn't floating, but if the tire is OK it could be floating when the pic was taken? Did the entire assembly get dragged across the reef and then get stuck in a crevice in an upright position?  Understanding the story should explain, or at least not contradict, the theoretical position of the remains.  thanks to all.
Leon
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Greg Daspit

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Re: Landing Gear and Bevington Object shadow study
« Reply #13 on: March 20, 2019, 03:51:41 PM »

Could someone refresh me on the details of how TIGHAR thinks the landing gear got into the nessie position?  If the tire is deflated, it didn't float with the gear part hanging below it.  If the tire deflated and some part of the gear caught on the reef, would it stay fast in the "tire showing" position? If the tire is torn, it isn't floating, but if the tire is OK it could be floating when the pic was taken? Did the entire assembly get dragged across the reef and then get stuck in a crevice in an upright position?  Understanding the story should explain, or at least not contradict, the theoretical position of the remains.  thanks to all.
Leon
It’s my understanding the object is on the edge of the reef in very shallow water, in a few inches or less. It’s right next to where the reef starts to slope down and it gets deeper. There is also a hole in the area as seen in the video Tighar has on YouTube. I don’t know if an exact tide analysis was done for the window of time the lighting works. That window is around 1pm, give or take about ½ hour. There are several sharp edges that could get stuck in a groove or hole. Some broken struts could still be attached to the mounting bracket which may have broken off with the worm gear / oleo strut assembly. These parts would be hidden by the tire or under water.

A few possibilities for why it’s there:
1.   It’s not stuck and has been moving from somewhere else, maybe even kicked back up from a storm.
2.   It’s stuck in a groove, crack or hole. Maybe the same hole that might have contributed to the gear failing.
3.     The crew, in attempt to save the plane, somehow found a way to secure it, via the landing gear, to the reef. Contributing to it's failure.
4.   My favorite: It’s tangled up with something heavier that could survive the dynamic conditions there.  For example a length of one of the several control cables which ran to the engine located just above the landing gear. The other end of the cable still tied to the engine in the deeper water next to it. The engine being easily identifiable as an airplane part by Emily’s father and rusty as she remembered. Possibly it's the same aircraft cable John Mims saw a fisherman using as a fishing leader. This line may have held the gear there a while, flopping around a bit, sometimes lower in the water, until the fisherman cut it lose and it eventually tumbled down to the debris field ledge.
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« Last Edit: March 20, 2019, 04:25:55 PM by Greg Daspit »
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Jon Romig

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Re: Landing Gear and Bevington Object shadow study
« Reply #14 on: March 21, 2019, 06:26:12 PM »

Would it be worth it to evaluate the Luke Field broken landing gear using your methods? I am assuming we know when the pics were taken at Luke field. This would help validate your
Gardner island analysis.

I think to validate the study more it might be better to build an actual full size model and use a real camera just to validate the angles and positioning of the components. In the full size real model study you would not be studying shadows but just the angles of the components, specifically the fork. Once the components angles are validated you could then go back and check them again with the autocad model. This method would also allow you to do an “overlay” of an enlarged real photograph with the enlarged Bevington Photo to check the angles and sizes.


Hi Greg,

Nice work!

It might be possible to get AutoDesk’s help building a model. Their CAD/CAM BUILD Space is in my building in Boston and they accept applications for protects to utilize it, I think for free if non-commercial. See https://www.autodeskbuildspace.com/

They have an amazing array of robotic fabrication tools that can work with a variety of materials. In this case we might want to use something easy like high density foam - I am not sure we could create a “working” model (with moving parts) without a lot of difficulty.

The BUILD Space studio has huge windows to the promenade and I have seen lots of fascinating projects fabricated there. I also notice that it is fairly underutilized and they appear to like projects that capture the imagination of passers-by.

I can reach out to them if you think it is worthwhile.

Alternately, it could be built on a standard 3-d printer but it would have to be a large one - most design firms like mine have printers that are too small, although the model could be scaled down and still work, I think.

Jon
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