TIGHAR
Amelia Earhart Search Forum => Aircraft & Powerplant, Performance and Operations => Topic started by: Heath Smith on June 10, 2012, 01:24:05 PM
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I have found several references to the Electra tire size being 35 inches (2000 article) to 36 inches. Glickman's photo analysis suggested that the tire size was also 36 inches.
Some time ago, there was a reference to the size of the hub being 8 inches. Is this the case?
If the hub is about 8 inches in diameter, according to my crude attempt to measure the tire, this would suggest that the tire is only about 26 inches in diameter.
Does anyone have a definitive answer?
If you have better photos, please pass them on.
Thanks in advance.
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Does this help?
Wheel Of Fortune / Electra wheel details (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/41_WheelofFortune/41_Wheel.html)
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Chris,
That does show a hub about 8 inches in diameter but that is not the actual Electra from AEs plane.
That tire also ends up being about 26 inches in diameter.
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The diameter of the tire doesn't change no matter what the size of the hub, it is still a 35 inch diameter tire measured from side to side across the middle, the hub simply takes up the center section and fills the "hole" in the tire.
Looking at the material in the WOF link Chris provided, the standard Electra tire was a Goodyear "Airwheel" - "Goodyear Airwheels and heavy duty tires were standard equipment on all Lockheed Model 10 Electras. The size was 35x15-6. The 35 refers to the uncompressed height of the tire, the 15 refers to the width across the face of the tire, and the 6 is the diameter of the opening in the middle of the tire, all in inches. Lockheed publication EE1135 revised 5/1/36."
So if the hub is 6 inches across, you'd have 14.5 inches of rubber sidewall on either side of the hub for a total of 35 inches in diameter.
Andrew
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As you can see in the 1st photo (below), the rim is measured at 8 inches. Although it is not a perfect picture, the rim is certainly not 6 inches. The diameter of the rim where it meets the tire might be 6 inches, but the outer rim is 8 inches.
If we assume the outer rim is 8 inches as shown, picture #2 shows that the shown tire is not 36 inches. It is more like 26 inches.
Along with these photos is the description "As shown in this photo of the Goodyear Airwheel on Lockheed 10A c/n 1052 at the New England Air Museum".
So the question is, is the tire and rim shown in these photos supposed to be the exact same as those on the Electra?
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From the catalog in the link Chris posted the hub is 6". The rims on the outboard side is probably 8" and the inboard rim looks even bigger, with a disk brake. The donut shaped balloon tire likely ordered by the hub, not the rim size.
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I think the 1936 Lockheed publication is more accurate for the configuration of AE's Electra. it Clearly states that the standard issue was the 35x15-6 Airwheel.
The Aircraft at NEAM has had many years to be modified, and it is not unlikely that Goodyear offered an 8 inch Airwheel with a smaller tire sometime during the past 75 years, particularly as airport runways improved. I would not take the NEAM aircraft configuration as exactly like AE's, but at least a good example of the Goodyear Airwheel.
Andrew
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I believe this photo is after the Hawaii crash as it has the sector gear for retracting the landing gear. This shows the inboard hub and the brake line. This should be a pretty good reference for measuring the tire size.
Just doing a quick experiment with a wood yard stick, crouching like Earhart was, I am already inclined to believe that the tire shown is also not 36 inches. I am 5'11 and I believe she was 5'7.
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And, respectfully, this is sliding into Jeff Glickman territory. He's the pro from Dover on all things photographic when TIGHAR wants to know something definitive about a picture.
LTM, who knows an expert is someone who knows when to bring in the experts,
Monty Fowler, TIGHAR No. 2189 CER
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Heath, If you look closely at the "guy" behind the tire in your picture he is not sitting but rather crouching just as AE is. When you look at a picture it is very difficult to compare the scale of two items unless they are next to each other and in the same plane.
I am 5'8" tall and tried your experiment with the yardstick. I crouched down and leaned forward slightly as AE is doing in the picture. The top of the yardstick came up to my mouth.
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Heath, I concur that the diameter of the tire shown is probably 28 inches. However the caption with the picture in your reference further states "This photo shows a Goodyear Airwheel on Lockheed 10A c/n 1052 at the New England Air Museum with a 4-inch obstruction."
On 5-19-37 the Department of Commerce, Bureau of Air Commerce, re-certified NR-16020 for flight after the repairs necessary from the Luke Field accident. The Aircraft Inspection Report ,which is attached below, says on page 2, that the tires on the aircraft were 35x15-6, 8 Ply Goodyear 6HBA.
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The page that I posted in reference to the 28 inch diameter was not in reference to the one that the museum. You can approximate the museum tire to about around 30 inches just using the tape measure in the foreground.
Landing on the Reef? (http://tighar.org/wiki/Landing_on_the_Reef%3F)
"NR16020 was equipped with low-pressure, 28 inch, Goodyear Airwheels. These tires were designed for operations from unimproved airfields. The aircraft should be able to land safely on a hard surface with perturbations not exceeding four inches in height or depth."
Note that this specifically mentions Earhart's plane (NR16020), and is not a generic statement about L10Es nor is it a reference to the one at the museum.
That is interesting about the inspection report declaring a 35 inch tire, that is not what I estimate and seems to be in conflict with the TIGHAR's statement above.
Despite the report, I would say that photographic evidence trumps a document. There are plenty of photographs to analyze as they made their way across Africa, Indonesia, Australia, and Lae.
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According to this page (http://tighar.org/wiki/Landing_on_the_Reef%3F):
"NR16020 was equipped with low-pressure, 28 inch, Goodyear Airwheels. These tires were designed for operations from unimproved airfields. The aircraft should be able to land safely on a hard surface with perturbations not exceeding four inches in height or depth."
I concur with that measurement.
I am the person who placed that page in the wiki.
I can't find my original source. It may have been an older research paper that is now no longer available on the Forum--perhaps from the Eighth Edition (http://tighar.org/wiki/The_Earhart_Project_Book_%28Eighth_Edition%29) of the Earhart Project Book.
I've revised the article (http://tighar.org/wiki/Landing_on_the_Reef%3F), given that the list of standard equipment (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/41_WheelofFortune/lockheedspecs.gif) as well as the last inspection (http://tighar.org/Projects/Earhart/Archives/Documents/Reports/AircraftInspection.pdf) confirm the larger tire size.
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The Lochheed 10A was a smaller aircraft than the 10E and used a smaller tire.
I believe all models of the Lockheed 10 series were the same size, the difference between the models being engine make and HP. The Lockheed 12's were smaller. Of course, this doesn't mean that all model 10's used the same size tires. There were probably options available determined by the projected use of the aircraft.
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I can only say that it is good that we have lots of photographs to analyze.
For anyone interested, I believe Earhart was about 5'7", figure a 1 inch heel, she would be about 5'8". The cowling opening is about 37" and I believe the prop is about 9ft.
The drum is more than likely a standard oil drum about 22.5 inches in diameter and 33.5 inches high.
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The following is from a retired Navy submariner... who is not an engineer.. so, be kind and gentle.. This is nothing more than a guess (swag).
Based on the 55 gal drum (actually 44 gallons), divide the drum into 6 sections. You can then say the tire is approx. 5/6 the height of the drum.
The tire is also squatting approx 3-4" (swag), this needs to be added to the total.
5/6 height of tire = 28"
tire squat = 3-4"
total = 31-32"
Now, the drum is not beside the tire. If you move the drum back, you could add 2-3" (swag), which would be around the 34-35" size... See attached (crude) dwg... Please share your thoughts...
John
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John,
No worries about swags, that is all we are doing here.
If you look closely, there is a tiny sliver if light behind the drum and before the shadow (lower-right) suggesting that the back of the drum is very close to the tire.
If you measure the drum at it's left edge, you would need to add approximately 22.5 / 2 inches to the distance of the drum to put the left edge of the barrel next to the tire.
Just roughly calculating a 9% reduction in the barrel height, I would still say that the barrel is 2-3 inches taller than the tire if they were on the same plane.
Just as an experiment, if you assume that the rim in 8" in diameter, what is the height of the tire not attempting to correct for deflection?
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It’s viewing examples like this video (http://www.youtube.com/watch?v=hCV2Ba5wrcs) that makes me realize that inferring relative size of various objects in a photograph is best left to those who have mastered the very complicated science of photogrammetry (http://en.wikipedia.org/wiki/Photogrammetry).
From what height was the picture taken? Was the photographer down on one knee? That’s what it looks like to me ... and that could help form a mental image of the 55 gallon drum looking “obviously” taller than the tire.
John Kirk’s cogent explanation (http://tighar.org/smf/index.php/topic,721.msg14424.html#msg14424) of how the perspective in the picture containing the 55 gallon drum could be misleading about size comparison is compelling to me ... along with the splendid reminder of “tire squat” (which Andrew McKenna alluded to (http://tighar.org/smf/index.php/topic,721.msg14325.html#msg14325) when he spoke of "the uncompressed height of the tire") for the tire accounting for some of the measurement discrepancy that Heath is fixated on.
My money is on the aircraft inspection report (http://tighar.org/Projects/Earhart/Archives/Documents/Reports/AircraftInspection.pdf), combined with the training of persons professionally trained and working in the field of forensic photo analysis.
Talking about tires, and making inferences from flawed premises, reminds me of a favorite saying of a famous person (http://books.google.com/books?id=bSAChoqpnHUC&pg=PA358&lpg=PA358&dq=goizueta+bicycle+grandmother&source=bl&ots=JuRokWgmji&sig=j6ZsTOaLmx0AIO3Jtded2pfmtn8&hl=en&sa=X&ei=25LXT8W4J8Pg0QG1zP3zAg&ved=0CJICEOgBMAA#v=onepage&q=goizueta%20bicycle%20grandmother&f=false) who ran the company I spent my career with: "Si mi abuela tuviera ruedas seria bicicleta."
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Bruce, based on your comments, me having to refer to Webster, the photo, and the inspection report, my final answer is 35", I believe I came close to the 35". My swag was 34". So, this means I could possibly go on the next excursion??? lol. I am very good with a metal detector..
You guys, keep up the good work.. Very nice site, and very informative.
jk
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Heath's photo doesn't show the bottom of the drums or the tire, so it is not useful to judge relative sizes.
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Heath,
good catch, I missed seeing the barrel with the 3 guys until I opened the photo. Now if we could only see the bottom of the tire. The camera angle/altitude relative to the drums and tire appears to be fairly high, making judging heights difficult. The drum is roughly on the aircraft centerline (the hose appears to touch the nose), making the port landing gear about 6 feet closer to the camera. That should make the port tire appear larger than an equally tall barrel, but to be sure the tire and barrel image dimensions need to be measured from top to bottom, not just comparing the tops. The barrel looks unusually large/tall, relative to the 3 guys. Maybe they're quite short?
Is the tall man standing on the wing, wearing dark clothes, Fred Noonan? Wasn't he about 6 feet tall? A standard 55 gallon barrel is 35 inches tall, or about equal to a tall man's trouser inseam.
The paint on the leading edge is clearly visible in the photo, which might interest some folks over in the artifact thread.
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According to The Wreck Photo (http://tighar.org/Publications/TTracks/14_1/Wreck_Photo.html), the cowling is about 54 inches diameter. Since it's fully visible, and on nearly the same plane as the tire, and not greatly forshortened by goofy angles, they're rather easy to measure and estimate the tire diameter. On my screen I measure the cowling as 33 mm, and the tire as 20-1/2 mm, for a tire/cowling ratio of 0.62. Times 54 inches = 33-1/2 inches diameter for the tire.
There's obviously some margin of error with my method. For example, my plastic measuring stick is only useful for measuring to the nearest 1/2 mm, so each measurement has a potential error of +/- 1/4 mm, giving a potential range from 32.9 to 34.2 inches. There are additional potential errors that make the possible range a bit greater, but I think it is safe to say the tire is more than 30 inches in diameter.
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Instead of trying to compare the tire with the barrel, why not work it backwards from the wheel hub?
We know that the 6 inch hub was "standard" issue, and if so, what do you guys calculate the tire diameter to be? How much "uncompressed" rubber is there above the hub?
We also know that there was also an 8 inch hub, as seen in the NEAM photo, and if that is what we see in the AE photo, what would the diameter be?
AMCK
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Andrew,
Assuming that the visible part of the rim is 8 inches, I would estimate the red line shown on this photo would measure 14 inches.
If the tire is deflated as on some of the other photos, it could be a 30 to 32 inch tire.
It not the greatest photo because we cannot see the bottom of the tire.
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Here is the shot with the somewhat deflated tire. I estimate the red line to be 27.6 inches assuming the outer rim is 8 inches.
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I worked out the wheel rim diameter a little differently, again using Heath's photo, blown up on my screen to allow better resolution when reading my mm scale, and again using the 54 inch cowling diameter as a reference for comparison. I obtain a tire diameter of 33.3 inches +/- about a half inch, and a visible hub diameter of 9.6 inches, +/- about the same half inch. Just how deep is the edge of the rim on an 8-inch, and on a 6-inch hub? The "8-inch" or "6-inch" measurement is the diameter of the hole in the tire, not the edge of the wheel rim.
Somewhere there must be a record of the actual outer diameter of the 6-inch and 8-inch wheel hubs.
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Double checking Johns work, I came out with the exact same numbers if the hub is 9.6 inches.
The hub that meets the tire is smaller than the outer visible rim. The museum tire for example possibly has a 6 inch diameter hub where it meets the tire and an 8 inch visible outer rim.
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Here is something else that we can compare. I do not have time today but perhaps tomorrow.
On the museum wheel, my estimate for the axle tube is 2", the outer rim is 8". Keep in mind that the face the 2" tube is about 6" closer than the rim.
Now if a different rim were used to for larger tires, and that rim was say 9.6 inches, the axle tube should still measure around 2" unless the entire fork was swapped out.
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I was under the impression that AE's Electra was fitted with the oversize tires, requiring custom forks. I don't know if that would also change the axle tube diameter. I'll look for a reference...
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Re-reading this thread a bit, it is clear, as Woody pointed out, that the aircraft was equipped with Goodyear 35x15-6 tires and a Goodyear 6HBA Airwheel when it left the Lockheed repair shop, as indicated in the inspection report.
The photo of the Airwheel assembly found here may help explain the apparent diameter of the hub vs the 6 inch designation.
(http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/41_WheelofFortune/catalog.jpg)
I'm not sure why we're still speculating on the size of the tires given the inspection report.
Andrew
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I'm not sure why we're still speculating on the size of the tires given the inspection report.
I think the question arose from Jeff Glickman's use of the tire diameter in his analysis of the Anomaly Formerly Known as Nessie (AFKaN). It's not clear to me whether Heath is trying to contradict or confirm Jeff's interpretation.
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I tried to rotate the Mobil Oil photo about 1.9 degrees counter clockwise to compensate for the camera tilt.
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"...If we assume that Earhart was about 5'7", and she is about 4ft away from the tire, can you approximate the tire diameter on the vertical?...
Assuming the vertical distance from the top of AE's (bent) head, down to the bottom of her right shoe (not accounting for heel lift), I measure 71-1/2 mm on my screen. Note that each pixel is about 3/4 cm, so there's a LOT of potential error here. The tire appears to be about 37-1/2 mm across the diameter, at an angle from the vertical that includes both completely rounded edges. Since it is at a moderately oblique angle, there will be some distortion, and since the tire is not spherical, some additional distortion. Ignoring those distortions gives an apparant and relative tire diameter of 35 inches.
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Heath
I don't think anyone is getting uptight about this thread, it has been an interesting exercise.
You say you found something that you didn't agree with, and at this point I'm not sure I understand exactly what it is that you feel points to anything other than the 35x15-6 tires, which are both indicated by the standard equipment list for the L-10, and the inspection report as it came out of the repairs from Lockheed. I don't believe there is any documentation that the tires were changed after this point, and we can probably calculate the number of T/Os and landings made after that point.
If anything, this thread seems to confirm that the tires are approximately 35 inches in diameter.
Is there something that still indicates otherwise in your mind?
Andrew
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Andrew,
The museum wheel clearly is not what would be a standard 35x15-6 tire. It is a 30 inch tire at most. The outer rim is 8". If you only assume the outer rim was the same size on Earhart's Electra, the tire size ends up being nearly identical as the museum piece. While it is possible that the tire on the museum piece is non-standard, it is also possible that the hub and tire on the piece became a standard. This also is surely not a case of someone hacking on some old tire where a 36" tire belonged as a 36" tire would not fit in the forks. It is logical to assume then that the forks and tire sizes were either optional equipment or Lockheed produced several incarnations of all of the above, fork, tire, and hub.
There are at least a couple of photos of Earhart squatting next to a tire. If she is a foot or two away from the tire, and she is 5'7" tall, it is not plausible in my opinion that the tire is 36 inches.
I have measured other objects in some of the photos like the standard oil drum that is 33.5 inches tall near the tire and after adjusting for distance, the tire is not 36 inches tall. It is at most the same diameter as the museum tire.
There are many other photographs out there yet to be look at and I will continue to do so. So far, everything that I have looked at does not indicate a 36" tire but a much smaller tire.
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Ignoring those distortions gives an apparant and relative tire diameter of 35 inches.
John,
Attached is the photo with a red line where I peg her height at 5'7". Is that about what you had selected? Note that he her head is slightly tilted downward so I am slightly above where you would consider the top of her head.
If you do nothing else but assume the same pixels per foot, the tire as shown by the red line is about 32 inches. This is of course not adjusting for perspective, since the tire is closer than Earhart, it's actual size is less than 32 inches.
Once you adjust for perspective, say approximately 4 feet (which is just a guess of course) the tire is much less than 32 inches, more like 28 inches. Interestingly enough, the size of the outer rim is 8 inches, the same as on the museum wheel.
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It's an interesting excercise, Heath, and something that I do not claim to have even the remotest expertise in. I would gently suggest, though, that since you have to keep using words and phrases like assume, approximately, adjust for, not plausible, etc., in all of your posts, it causes me, at least, to question your results.
I am not a photo interpreter or forensic photo analyst. I push paper for a living. I have, however, been kicked in the head enough times to know when I don't know something, and to leave those things to people with greater expertise than mine. It's interesting speculation, but at the end of the day, it's the paperwork that carries the weight, as far as I'm concerned. That, again, is just my opinion. ;D
LTM, who will now resume his regularly scheduled pushing,
Monty Fowler, TIGHAR No. 2189 CER
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Heath, here is a picture of the AE Electra being serviced in Karachi. Notice that one of the mechanics is actually bent over the tire under the port side engine.
http://earchives.lib.purdue.edu/u?/earhart,510 (http://earchives.lib.purdue.edu/u?/earhart,510)
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I know next to nothing about photogrammetry except to know that it’s a lot more complicated than anything I or anyone else has tried to use in this thread to reconcile the difference in opinion about the diameter of AE’s tires. That’s why I posted earlier the link to the video that shows perspective playing such a large role (http://www.youtube.com/watch?v=hCV2Ba5wrcs) in complicating the determination of the relative size of two objects in a single photo. Then John Kirk pointed out the role of “tire squat” (http://tighar.org/smf/index.php/topic,721.msg14424.html#msg14424) in complicating any comparison with the tire diameter versus the height of a 55-gallon drum (which, incidentally, is cited to be both 33.5” and about 34.5” in the same Wikipedia article (http://en.wikipedia.org/wiki/Drum_%28container%29)).
Many such critical considerations (can you say “trompe l’oeil"?) come to mind: How high is the camera above the ground? Is the ground level? That is, is the photographer standing on a small rise or in a slight depression, so that the lens may not be in the same plane as the objects being compared? Are the two objects being compared equidistant from the lens? Are shadows distorting important detail? What are the lens characteristics of the camera? And there are myriad other considerations that require the expertise of a person like Jeff Glickman to investigate and reconcile to obtain a reliable answer. After all, how much time and energy went into trying to measure the length of AE’s shoe (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/31_ShoeFetish2/31_ShoeFetish2.html) by comparing it to the rivet spacing on the aircraft?
That said, I’m just as intrigued as others with this matter of tire size, and cannot hold back in trying to apply my own amateurish hand and eye and naïve knowledge to the problem. It’s shaping up to be a lot like those witness accounts of a crime that differ substantively, leaving it to a jury to choose.
Let’s take the two pictures below for comparison purposes. The first one shows a Lockheed 10A at the New England Air Museum (NEAM) and is from Earhart Project Research Bulletin #58 (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/58_NessieHypothesis/58_NessieHypothesis.htm). As has been remarked in this thread, the tape measure shows that this tire is clearly 28” in diameter — well, except for one person (http://tighar.org/smf/index.php/topic,721.msg14417.html#msg14417), who assures us that the tape measure gives the tire’s indicated diameter to be 30”.
No, I say that museum tire is indeed 28” high: the photographer has used the détente on the measuring tape to lock it with the marking for 28” showing at the very bottom of the visible tape. But I see the first 2 inches of the tape extending up above the horizontal plane across the top of the tire by two inches.
Why did the photographer extend the tape those 2 additional inches? Well, because the body of the case for the measuring tape is exactly 2”, and the two extra inches at the top come from the case’s two additional inches at the bottom. It’s likely that the photographer ran the tape out 28” so that the end of the tape touched the floor and the 28” marking was level with the top of the tire; then he set the détente and inverted the tape, standing the tape on its case as shown to take the picture, thereby causing the end of the tape to be seen to be 2 inches above the top of the tire. Either way, I say that the tire shown is indeed 28” in diameter — and certainly not the claimed 30”.
Notice two other things about that picture and the landing gear shown. First, the top of the tire appears to come about midway up that oval surface at the top of the fork. And second, there is quite a bit of space showing between the top of the tire and the mud guard. Neither of those would be affected by "tire squat."
Now look at the second picture, which is NR16020 being refueled in Bandoeng. I think that the two things I pointed out in the previous paragraph support the notion that this aircraft’s tires are of a larger diameter than 28”, perhaps even as much as 35”.
First, the top of this tire is showing significantly higher than the middle of the oval surface at the top of the fork. And second, there appears to be significantly less space between the top of the tire and the mud guard above it than for the plane at NEAM. Assuming that the fork assembly on AE’s plane is the same size as that of the plane photographed at NEAM, then the miserable little 3.5” of radius that is consuming so much attention in this thread is easy for me to reconcile in my mind’s eye. But are those perceptions the result of varying perspective between the two pictures? There’s no telling. How to reconcile this difference in amateur photo analysis? Leave it to those trained in photogrammetry.
So, I continue to believe in the integrity and correctness of the Aircraft Inspection Report (http://tighar.org/Projects/Earhart/Archives/Documents/Reports/AircraftInspection.pdf) that was signed the day before AE began the second world flight in her repaired airplane. I’m comfortable in trusting that the main tires were indeed of the 35” diameter size. But then, I keep hearing Ronald Reagan’s voice: “Doveryai, no proveryai – trust, but verify.” And I hope that the Bureau of Air Commerce inspector who signed that form (Lake? Duke? Dike?) did likewise.
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Bruce, take a look at the picture that I just posted of the Electra being serviced in Karachi. Note the one mechanic leaning over the port side tire and compare his size to the size of the tire and then measure 35 inches on your own leg.
Also I have been doing a little research on the "oil drums" used to store fuel. It appears that the size of the drums was not standardized until sometime during WWII so we can't be absolutely sure of the size of the drums in the pictures. See writeup below.
http://en.wikipedia.org/wiki/Drum_%28container%29 (I changed your link -- those drums you pointed to were too loud! --BT)
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Bruce, take a look at the picture that I just posted of the Electra being serviced in Karachi. Note the one mechanic leaning over the port side tire and compare his size to the size of the tire and then measure 35 inches on your own leg.
Also I have been doing a little research on the "oil drums" used to store fuel. It appears that the size of the drums was not standardized until sometime during WWII so we can't be absolutely sure of the size of the drums in the pictures. See writeup below.
http://en.wikipedia.org/wiki/Drum
Well, since I don't know how tall that fellow in the picture was, and you don't know how tall I am, I'm not sure what conclusion can be drawn there. I do know that 28" comes to mid-thigh for me, and 35" falls a lot short of my hip. :)
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Well Bruce, I am 5' 8" tall and 35" comes to right at my hip joint, just about where the top of the tire appears to be on the fellow in the picture.
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I believe we should keep in mind that you are measuring one tire from very clear shots with other items in the foreground/background to get a scale from it. Jeff Glickman has no such luxury when he says it is "Approximately: 36" diameter. He has quite a fuzzy picture with nothing to give an easy reference to. His estimate is based on a triangulation of landmarks from a photo in 1937 with approximate measurements from lst year's expedition.
As an exercise this is a lot of fun to work out and speculate about but I think you cannot say definitively that the "Bevington Object" is a 36" versus 28 tire". Even Jeff isn't willing to come out 100% and say its a wheel or tire never mind saying its 36" for sure. He only says that it "could" be a wheel assembly.
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This post is to pose some questions for you guys out there who are, or have been, aircraft mechanics.
1. I have noticed that the tire in the picture of the Electra landing gear from the "museum picture" appears to be new.
2. Can a 35x15-6 tire that fits the Goodyear 6HBA wheel be purchased today?
3. Can a different sized tire that will fit the Goodyear 6HBA wheel be purchased today?
4. Could a modern wheel, with an 8" flange, and a modern 28"-30" tundra type tire be fitted to the Electra landing gear?
5. Does anyone know how to get a drawing with dimensions of the Goodyear 6HBA wheel?
Just some questions that have come to mind after looking at the museum tire picture.
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Woody,
I finally had a chance to look at the photo you posted. It is a bit tricky because the tire is a bit further away than the guy standing in front of it. See the attached picture. The red lines approximate the height. I estimate the height to be 28 inches.
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An excellant photo for analysis - the camera is directly on a parallel line, with minimal parallax. I get a tire radius 17.9 inches, for an apparent diameter of about 35-3/4 inches. There remains some error from the remaining angles, but the obvious conclusion is that the tire is pretty close to 36 inches in diameter, just as reported in the Luke field inventory.
Heath's redlines don't quite line up with the fuzzy top and bottom of the tire, and I don't know what he used for a relative dimension. The cowling is closer to the camera than the tire, so it appears bigger, and the tire smaller. There are enough bits of the aircraft visible to allow more thorough analysis by computing angles and using trig, but why?
Is there any point in continuing to analyze more photos?
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Heath asks "Out of curiosity, which photo were you looking at when you measured nearly 36 inches?"
answer: the "June 2 Venezuela 1937" photo. The only clear edges to take dimensions from are the center of the nearest hub, and the forward edge of the nearest tire. The bottom of the nearest tire is squashed out of shape, and the top is obscured as well as undifferentiable from the far tire, so I used the distance from hub center to foward edge to measure. The cowling was measured across the major diameter of the forward ring (54 inches), and assumed to be on nearly the same plane as the nearest tire. There isn't enough tire showing to get an undistorted diameter measurement.
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John,
After studying the photo I agree that it is not as good as it first appeared. The tire appears to be very under inflated making the measurements difficult. As you mentioned there are no real great reference points however I do think we can make a pretty good estimate.
Could you do a couple more measurements if you do not mind?
Can you verify your measurement / coordinate scheme by measuring the rim flange in multiple areas, taking multiple measurements perpendicular to each other to verify that any distortions in the X-Y plane are accounted for? After doing so, can you please tell me your estimate for the diameter of the rim? It will be interesting to see if we can concur on that diameter. If any modifications are made, please re-verify the cowling diameter. I measured at the thin black line on the cowling. Reading up a bit on the cowling on TIGHAR, an L10E cowling was found to be exactly 53.5 inches.
Next, please take a measurement from the center of the axle to the edge of the tire as shown in the attached picture. Although the camera is not perfectly square to the axle, it should give us the ability to compare measurements.
I do believe that we are both attempting to the best of our ability to take these measurements. It will be interesting to see if we can find a consensus on the measurements.
Thanks.
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Heath, Jeff Glickman has done an analysis of the picture in question, and of the analysis in question. He presented the verbal summary of that at the just-completed Earhart 75 symposium, in which he stated that the round object appeared to have a diameter of about 36-inches. Which would make it consistent with the main landing gear of a certain Lockheed Electra 10E Special according to all published and written records. Jeff uses, among other things, proprietary software that he developed to complete that analysis.
Just for what it's worth, "Mr. Glickman provides expert witness testimony and expert reports for the enhancement, reconstruction and recovery of photographic and video imagery. Mr. Glickman is a Board Certified Forensic Examiner, a Fellow of the American College of Forensic Examiners, and a Senior Member of the Institute of Electrical and Electronics Engineers. Mr. Glickman previously served Governor Gregoire on the Washington State Forensic Investigations Council which supervises the State's crime labs. He is President-Elect of the American Society for Photogrammetry and Remote Sensing, Puget Sound Region."
He's staking his professional reputation on saying that that "thing" in that image has a round shape and that appears to be 36-inches in diameter. And that that is consistent with the last know tires and wheels as installed on our favorite Electra.
LTM, who usually trusts the paper he pushes,
Monty Fowler, TIGHAR No. 2189 CER
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Here is a good photo allowing you to compare the cowling, believed to be 54" with the tire. Taken in 1937, Venezuela.
Okay, Heath, I decided to go ahead and play amateur photo sleuth, since that picture you posted of NR16020 being serviced in Venezuela (http://tighar.org/smf/index.php/topic,721.msg14658.html#msg14658) was pretty much side-on from the photographer's point of view. It's to be hoped, therefore, that problems with perspective will be greatly minimized.
First (see the first attachment below) I brought one of the Harney drawings -- the one that shows both the engine cowling and the main gear (raised) -- into Photoshop. In red, I drew a vertical line for that portion of the engine cowling that is supposed to have been 53.5" in diameter, and another vertical line from the center of the tire hub out to the edge of the tire.
There is a nice measurement scale in the lower-left corner of the Harney drawing. I used Photoshop to create a copy of that ruler, rotated it 90 degrees clockwise, and laid copies up against the two vertical red lines I made. I hope you'll agree that the one for the cowling shows its length to be just shy of 4'6" (54"), so I call that 53.5" . Then, the vertical red line for the tire's radius is looking to be something just shy of 1'6" (18"), so I call that 17.5" -- which doubles to 35", of course. So I feel comfortable that the Harney drawing is faithful to the tire diameter of 35" that the Aircraft Inspection Report documents.
Next, I brought the Venezuela picture into Photoshop, rotated it slightly counter-clockwise (similar to what you had done earlier) so that the place on the cowling is vertical, and drew a red line for the cowling, and another for the tire radius (but I took a horizontal radius so that the "tire squat" would not distort things). In the first version of the Venezuela picture attached below, I also show the same vertical ruler that I copy-and-pasted from the other photo, off to the left edge and resized appropriately.
So, in the second variant of the Venezuela picture, I have moved the vertical ruler up against the red line for the cowling, and you can verify that the ruler shows the same length as in the Harney drawing: 53.5". Now, a horizontal copy of that same ruler is laid against the red line that runs from the hub of the gear to the edge of the tire. Voila. That's clearly 17.5" in radius, and therefore the tire is 35" in diameter.
So, even though I said I'd trust the Aircraft Inspection Report (http://tighar.org/smf/index.php/topic,721.msg14555.html#msg14555), and I am not a forensic photo analyst, I do come from a long time of Doubting Thomases, and I couldn't resist this exercise. I'm hopeful that it'll help to show that the tires truly were 35" in diameter -- at least in Venezuela :D.
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The 'museum picture' and the 'Bandoeng picture' (both appearing elsewhere in this string so I won't repeat posting them) show a rather definite difference in tire diameter if you compare them side-by-side visually - the museum tire leaves noticably more 'gap' in the mud guard, and for what it's worth, seems 'indexed' to a smaller radius compared to the strut fork as well. The NR16020 tire in the Bandoeng picture rather more closely fills the mud guard arc and rises a bit higher (visually, for what worth) against the reinforced weldment where the vertical strut-fork 'shoulders' into the sloping strut-fork member. I think the mud-guard arc proximity consideration is probably rather accurate as-viewed; the strut / tire relationship would appear more subjective, but perhaps is still meaningful for comparison.
LTM -
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I believe the inference here is that it was analysts at the State Department that made this claim. This is by definition a blind study, when you are not told what you are looking at.
I doubt very much that it was a "blind study." Parts of it may have been, but I don't see any way that completely independent analysts could exclude all other airplanes other than the Electra as the source for the landing gear, if it was a landing gear. What they could do would be to check the steps in Jeff's work to see if there were any obvious errors.
- Is it a picture of a real object or is it a defect in the negative or the print?
- Is the image part of the original picture or is it a hoax?
- Did Glickman scale and rotate the components of the Electra landing gear properly?
- When scaled and rotated, do the components of the Electra landing gear really fit the image?
Glickman of course has made no such claim and has stated that the Bevington object is "consistent with" the landing gear and tire from the Electra.
Agreed. I'm pretty sure that's all that the government analysts agreed to as well. That is very different from the garbled claim that the peer reviewers worked in the dark and selected the Electra landing gear as the only possible match for the image.
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The tire in the photograph at the museum is from an L10E that was donated to the museum. The plane was manufactured a few months prior to Earhart's Electra. You can investigate that yourself if you are so inclined.
Heath, I want to take you up on your gracious offer to let me investigate that by myself. Please provide me with the specifics of which museum has the L10E and where that museum is located. It's okay if you just provide a link to the museum's website. I hope you'll also provide details of how you ascertained the manufacture date for that specific aircraft. Oh, I pray you're not going to tell me that it's the New England Air Museum, and that their Lockheed L10A, c/n 1052 (http://www.neam.org/aircraft_inventory/airprofile.php?ID=70) (just 3 numbers before AE's L10E, so obviously "manufactured a few months prior to Earhart's Electra"), is really an L10E! We'll just have to demand a change in their signage and the disciplining of their curator! Regardless, how dare they display any Lockheed Electra with tires more suitable to today's paved runways! Don't they know we're depending on them to help us discover the facts about something that happened 75 years ago? Sheesh!
Maybe a pretty comprehensive list of museums and other places where the remaining Lockheed Electras (http://tighar.org/smf/index.php/topic,577.msg8467.html#msg8467) are would be of help.
The photographs of the Electra as it made the journey around the globe trump speculation, documentation, and or any other paper evidence that can be produced. This is of course something that can be studied by those with the capability going forward although I doubt there is much interest to do so. I have already done the measurements and am convinced that the tire was not 35 or 36" in diameter.
I'm glad that you're convinced that Amelia pulled a fast one on the inspector from the Bureau of Air Commerce who certified that the tires on NR16020 were 35" in diameter (http://tighar.org/Projects/Earhart/Archives/Documents/Reports/AircraftInspection.pdf). Where do you think they secretly swapped the tires? Miami? Puerto Rico? Obviously, I'm still convinced that they were what the inspector said they were.
Concerning the results shared by Jeff Glickman at last month's Earhart75 Symposium, you wrote:
I have had the 4800 dpi image for a couple of months. Personally I do not see anything that resembles an Electra landing gear, tire, and mangled versions of either.
Could you share that 4800 dpi image with the rest of us? All I've seen is a hand-held shot of Jeff's PowerPoint image on a projection screen, taken by Irv Donald from 50-75 feet away (Thanks, Irv! Love your camera. I still owe you for dinner.), and if that's all you've got to look at, too, I agree that it is quite difficult to interpret -- but then, neither of us is highly trained in photogrammetry, right? (Gee, do you think it might just be a weird piece of coral? :D ) But I've got a good excuse -- according to you, I'm challenged to even make enough sense of a clear picture of AE's L10E sitting on the ground in Venezuela to correctly judge the size of its tires. ::)
... but I would like to see Glickman's analysis of the Bevington oject if he ever decides to publish it.
Wouldn't we all!
"... not having any idea of what they were looking at ..."
I think that in court, that would be known as "hearsay" evidence. When I heard Dr. Ballard say that in his remarks at the State Department meeting, I smiled and wished for a TV camera to have been focused on the faces of those unnamed photo analysts. I remember thinking to myself, "Now, Bob, let's not get carried away."
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Perhaps there was a bit of mis-communication going on there as to the actual events at the State Department but he did make his statement at the podium.
I am attributing the garbling to Ballard himself or to the person who described the peer review of Jeff's work.
I'm not denying that it was said in the Press Conference. I'm denying that it was a credible statement. Ballard or someone who spoke with him overstated the conclusion that someone could reach from a "blind" review of the image.
To have declared that the landing gear as being from a 1937 Electra would be incredulous to put it kindly.
That's why I don't believe that the statement Ballard made at the Press Conference is true. It is incredible, i.e., not worthy of belief. (People are credulous or incredulous, not propositions.)
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Heath, I want to take you up on your gracious offer to let me investigate that by myself. Please provide me with the specifics of which museum has the L10E and where that museum is located. ...
Maybe a pretty comprehensive list of museums and other places where the remaining Lockheed Electras are would be of help.
The plane is an L10A, the tire is from an L10E that was donated. Please do check it out for yourself. Feel free to contact the museum and discuss it. I am sure they will confirm where it came from.
I'm glad that you're convinced that Amelia ...Obviously, I'm still convinced that they were what the inspector said they were.
Your evidence of a 36" tire relies on one document, the inspection report. Human being make all kinds of errors, especially when they are lazy. Just look at the Earhart telegrams and radio logs. As an example of clerical errors, how many different times were reported for when Earhart left the ground in Lae? Lights that were 5,600ft high on an atoll? The list goes on and on. To suggest that the inspection report typed up by who know who (likely a secretary) is iron clad evidence is wishful thinking. There was no conspiracy, it was just a simple error. As I stated before, the photographs of the plane during the 2nd attempt do not lie. I leave it to others to analyze the photos, those with the proper tools to do so.
Could you share that 4800 dpi image with the rest of us?
As Ric and others have pointed out, part of the agreement with the Oxford library is that you can not publish it or share it. That is their agreement you sign. They want to make a couple of bucks, hey, it is their gig and they own it. The total cost is $50-$60 USD (put a few extra bucks on for currency conversion) for a 4800dpi (be sure you specify that resolution). Run down and get a pre-paid Visa and file the application over the Internet. It takes about 3 weeks for them to scan it and send you a link. Why they are re-scanning it instead of just keeping the image on the FTP server is a bit strange. It is about a 150MB image. See attached application form to request the image.
Personally, looking at the image, I see a contiguous circular object that is part of the object. I have no idea what it is, but I cannot see separate pieces like the sector gear, fender, etc. It could be anything from a droplet of water on the lens, a tiny defect, or some real object. I cannot declare that it is identifiable as anything. What is interesting is that there appears to be another object, whitish in color, slightly to the right of the Bevington object, that also appears to be in the photo.
I think that in court, that would be known as "hearsay" evidence.
Surely someone told Ballard that this Bevington object was a 1937 Electra landing gear identified in a blind study. Who that was only Mr. Ballard could say. It is interesting that such a fundamental point to the photo story was somehow missed by Ballard and repeated.
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I believe the only one qualified to judge the Bevington object in the photo is someone with photo analysis qualifications. In our case it's Jeff Glickman. I asked Jeff at the Washington conference how a blind study could be done where State Dept experts identified the object as possible landing gear from an Electra. Jeff very clearly stated it was NOT a blind study. The State Dept experts were told what Jeff suspected could be seen in the photo. He said they performed their own analysis and agreed that it "could" be an Electra landing gear but also agreed with Jeff that there was no guarantee that it was. When I pressed Jeff to give me his own personal opinion and not the official line he said it was his personal opinion that it "might" be landing gear but it also may not be. He cannot and will not guarantee what that object is. This means two groups of experts looked at the photo and both agree it may be landing gear and it might not be. BUT this evidence was strong enough for thHe State Dept to talk with some people and ask them to help TIGHAR with an underwater search. No money but just good old fashioned encouragement.
On another subject....
I, personally, have become quite disenchanted with many forum contributors who make statements that are based on their own opinions and that are not backed up by scientific research. I have been quieter on this forum lately than I really want to be during these exciting few weeks. Why? Because it has not been enjoyable to come here and read about new ideas and theories without bumping into so many posts about how Tighar believers are sheep being led down the garden path blindly by unscrupulous leaders. I know of NO TIGHAR member who has stated the hypothesis is true for sure. Not one. Yet several forum contributors feel compelled to argue or at least act as though TIGHAR has claimed this fact when they know better.
I'm sorry but until evidence is found that proves the hypothesis is true then we, TIGHAR members, will insist that it is an unproven hypothesis. We will continue to believe in the hypothesis until we don't. Let's stop the accusations, the falsehoods and the constant misleading statements. Let's agree that some people believe the hypothesis will be proven true and others who don't. TIGHAR only has to work at proving our hypothesis. We don't have to prove anything else. Those who believe our hypothesis is false should spend their time and energy in proving what they believe. That's what free speech and democracy is all about.
And don't ever let it get personal. That's inexcusable when we are all entitled to our opinions.
Remember that just saying something out loud doesn't make it a fact. Proof makes it a fact.
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Is there any reason now that the expedition is underway why the enhanced picture and the steps in the enhancement process cannot be made public?
They were already made public at the symposium. Jeff Glickman gave an excellent presentation of his qualifications, methodology and technics, and then shared his thoughts. I personally believe Jeff showed himself as an unbiased researcher using known and accepted photo analysis techniques to reach an expert opinion. It could be landing gear and it might not be.
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Your suggesting by the use of the phrase "be released" that the information is being "held" or "unreleased".
The information was made public at the initial State Dept announcement and at the symposium. I even have photographs of every slide presented by Jeff Glickman. I published a cross section of those on a free web site and posted the link in this forum. No one ever suggested the information could not be distributed.
The information is public. TIGHAR has no reason to be cautious with the information. The information a original photograph and two expert opinions that it "might" be landing gear.
Are you suggesting that you are as expert,or more expert, than the two groups who ventured their opinions after using modern analytic equipment and techniques where the end result was the opinion that it "might" be landing gear?
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Malcolm
My understanding is that Oxford University who now owns the photo, wanted more money than TIGHAR had available to obtain the full publication rights, so in the deal that was struck with Oxford, TIGHAR was granted only the rights to use them for research purposes, hence the restriction from our Publishing or otherwise making the hi resolution images publicly available. Presumably anyone including yourself, willing to pay Oxford enough for the rights to publish and distribute the hi resolution photo can have them.
Your insinuation that TIGHAR is somehow withholding the images from being released serves no purpose other than to cast aspersions on the organization. Given your professional relationship to archaeology, it seems beneath you. Why continue to fan the flames? What purpose does it serve?
I'd like to see all the inflammatory statements cease. Do the rest of you folks think we could make some progress in that direction?
You can see Jeff Glickman's analysis presentation on YouTube at
http://www.youtube.com/watch?v=iLxjEU1VJHA
At best, Jeff is willing to say that it MAY be a Lockheed 10E landing gear. Not proven by any means, but he does estimate the tire-like component at about 36".
Andrew