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Help researching 1961 Electra crash

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Help researching 1961 Electra crash

Old 27th Nov 2017, 19:51
  #161 (permalink)  
 
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As to first pic, I would say motor mount. The relief holes are needed because the casting is heavy, and the two "attach points" just seem consistent with motor mount.

The second pic looks like nacelle. The Electra nacelle is quite long, and the structure looks like longeron and skin structure.
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Old 27th Nov 2017, 20:00
  #162 (permalink)  
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I wasn't able to get a good enough view into a nacelle to see it. Motor mount makes sense. The reduction gearbox is supported by two struts on each side, but I don't know what's directly under the power unit.

If we can identify it as that, then it's proof engine four was left at the tracks and therefore the 35 degree bank.

Last edited by BRDuBois; 27th Nov 2017 at 20:11.
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Old 27th Nov 2017, 22:12
  #163 (permalink)  
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I uploaded an image from the LEAP program, showing the new engine mounts. I don't see anything that looks right, but this is not a real detailed illustration. The back upper mount seems like the best match.

https://ibb.co/c2Gh3R
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Old 27th Nov 2017, 22:47
  #164 (permalink)  
 
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The piece of debris being examined appears identical to that next to the standing man in your earlier pdf upload. I suspect it is part of a wing rib from near the wing tip. I appears heavily distorted and folded into three by impact and tearing forces.
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Old 27th Nov 2017, 23:05
  #165 (permalink)  
 
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From your image, I may want to revise. The structure being observed by the kneeling man might by one of the gear box side mounts. If first impact was made at the tracks, Right wing low, it is likely the propellor contacted first, tearing away the gearbox, mounts, and nacelle skin. I don't see a wing tip in the second image. Ribs and skin, but oriented in longitudinal, not horizontal aspect, suggesting nacelle, not wing (tip). Also, I see a robust, cast object that has a circular attach point showing, something I would associate with a torque link, amidst some torn skin. We might be looking at the ring that constitutes the forward (circular) frame, mounting the gear box/propellor assembly. With its mass, though, and energy, how could it have remained in the area it first struck at 150 knots?

The holes in the skin (in the second image) have a square shape, and are likely inspection panels, something I would associate with an engine bay/gearbox.

Last edited by Concours77; 27th Nov 2017 at 23:24.
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Old 27th Nov 2017, 23:59
  #166 (permalink)  
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Originally Posted by G0ULI View Post
appears heavily distorted and folded into three by impact and tearing forces.
I considered that too. If it's folded, it's an awfully symmetrical fold. The two legs (for want of a better term) appear to have ribs or folds in them as if to strengthen them without too much weight.

We really need an Electra/P3 airframe guy to weigh in here.
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Old 28th Nov 2017, 00:02
  #167 (permalink)  
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Originally Posted by Concours77 View Post
how could it have remained in the area it first struck at 150 knots?
Because it hit a sloped embankment, killing forward momentum and translating any remaining inertia into a more or less vertical bounce.
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Old 28th Nov 2017, 01:17
  #168 (permalink)  
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Originally Posted by megan View Post
Ok, what about the womans purse and stretcher on page 41, what is the source for those?
Good catch on the purse. I had originally included an image that I later left out. I've uploaded it.

https://ibb.co/gQ5aOR

It was probably done as a human interest shot.

The stretcher is the one on page 72.

I noted these images on the Site image just to give the reader some context, to help them relate the images to the overall surroundings.
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Old 28th Nov 2017, 03:14
  #169 (permalink)  
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Originally Posted by megan View Post
If I were to hazard a guess I'd say your first image in post #187 is a piece of spar with the partial remains of two ribs attached, the holes in the ribs being lightening holes. Anyone is just shooting in the dark trying to assess what such an object may be, and mine is similarly nothing but a wild ass guess on which I would not place money.
That was my initial thought. The ribs are 7.5" OC, and that looks about right to be the distance between those uprights. The only place in the ribs that has holes of any kind appears to be the leading edge, with holes for the de-icing piping. The remainder of the ribs have diagonal bracing all the way back. But the cutout for de-icing is much larger and not at all circular. It's really up for grabs, which is why I put it out for opinions.

Here's a drawing of the leading edge.

https://ibb.co/b1k1f6

Re the object on the tracks that you suggest is an engine - I'm in complete agreement with G0ULI that it definitely is not an engine, but a piece of wing skinning.
I understand that finding engine four there seems pretty unlikely; I don't fault anyone for thinking it's something else. Paraphrasing Sherlock, if you rule out the impossible you're left with the truth even though it seems improbable.

Looking at the impact scar (page 41) and the scar across the railway tracks could you please explain what it means in terms of angle of bank. The video supplied by cordwainer is illustrative in this regard as well.
Nothing on page 41 says anything to me about the bank angle. Proving the bank angle from the railroad track comes from solving the riddle of engine four. The speed was judged from prop strikes on the track. If engine four was lost at the track, the prop must have been number three. Since the right wing was intact nearly to engine four, prop three can't touch the ground at anything more than about 35 degrees.
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Old 28th Nov 2017, 04:31
  #170 (permalink)  
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I was corresponding today with Omar Hayat Khan in Pakistan, who has done some really nice T56/501D illustrations. He doesn't think this looks like a motor mount.
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Old 28th Nov 2017, 18:01
  #171 (permalink)  
 
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I utilize a device in forensics that promotes theory, no matter the fallout.

Investigations take too long. Why? Generally because they proceed based on fossilized methods of inquiry.

Instead of waiting until the conclusion is "inescapable", the use of imminent analysis encourages all present to think, quickly, and forensically.

The piece is quite obviously ribs, likely because of their proximity to each other, outboard on the wing, and may be in the leading edge domain.

The piece has other characteristics. The gross shape suggests a symmetry found in mountings, "U-shape". Relief of material to save weight, but depending on the resolution of the photography, it also appears heavier than rib material (thicker).

In considering and rejecting discussion, not only is progress attained, but an encouragement to think outside the "box" is instructive.

We do round tables, no opinion is judged, instead it is objectively evaluated.

Many opportunities to find the truth are lost in waiting for the solution to "appear". It is a process, not magic.
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Old 28th Nov 2017, 19:34
  #172 (permalink)  
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It's much too heavy for ribs. The only place that makes sense (to me) in the leading edge would be directly under the engine. The rest of the leading edge needs large cutouts to let de-icer air recirculate and exhaust. This object has one small hole below that large broken hole on each leg, too small for much air to move. Compare that to the material removed in the leading edge image I posted above.

Under the engine it might support the de-icing duct that makes a Y there, or support the overwing cooling duct. Neither of those feels right, as I said earlier, because the pipe would be passing through the hole.

Here's a head-on view of an Electra showing landing lights. It might be a bracket for those. That would be right at the edge of the wing destruction.

https://ibb.co/fvc4Hm

It feels like some kind of bracket or stand-off. Something related to ailerons perhaps, but I don't have the relevant manual sections.

Not sure whether you're funnin' us with your forensic theory diagnostic tool description. Got a name for that?
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Old 28th Nov 2017, 21:52
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On the LEAP image showing the new braces. Give the side mount for gearbox a long look. I can almost see the Delrin doughnuts. Look again, visualize the brackets and brace with snubbed bolted beds, and see if you don't like the similarities?
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Old 28th Nov 2017, 22:05
  #174 (permalink)  
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I see what you're saying; it's not a bad fit. Problem is, that's in the forward cowling and they don't open that for routine work. I can't find a picture anywhere. Got lots of pictures with the side cowl doors up.

ETA: Here's a fairly poor image from a training manual. The trainee drew in the LEAP modifications. I don't know if LEAP changed the mounts, never saw a mention of it. Anyway, you can see the structure is a possible fit.

https://ibb.co/etY8Sm

Last edited by BRDuBois; 28th Nov 2017 at 22:29.
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Old 28th Nov 2017, 22:45
  #175 (permalink)  
 
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I am thinking the debris is the forward vibration isolate. Are you saying it is aft? Also, isn't there a bottom cowl panel to allow drainage for gearbox servicing?

Something to consider also, whatever it is, the shorn remnants were subject to extreme loads. My supposition is that from the data, the impact was borne by the propellor and transmission? Is it your belief that the blade ruts were from number three?
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Old 28th Nov 2017, 22:50
  #176 (permalink)  
 
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What if the wing tip outboard of engine four was the object left lying across the railroad tracks and the prop strikes were from engine four before it too broke away?

Would that significantly affect your calculations of bank angle as the aircraft crossed and came into contact with the embankment?

That seems a more probable chain of events.
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Old 28th Nov 2017, 23:09
  #177 (permalink)  
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Concours77 - I was agreeing it looks sort of like the forward vibration isolator. They can get into the cowl from several directions. From the maintenance images I've seen, and from the manuals, the sides are what they always open up. Going further might require just some more quick screws, but the garden variety maintenance always shows the sides up. I've never seen the forward cowl off an engine that's sitting on its mounts.

I am strongly persuaded that the prop hits on the railroad track were from prop three. There is a bunch of circumstantial evidence that four was torn off at the railroad, and what I'm looking for now is the smoking gun. Evidence includes the missing engine puzzle referenced earlier, the amount of damage to the tracks which looks to my novice eye like more than a wingtip would do, the large object on the track, etc.

G0ULI - I frankly don't recall whether the engine four or the turning radius epiphany came to me first. Evidence for the 35 degree bank is in the Lockheed map of the path, in my attempts to reach anything higher that were fruitless with respect to that location on the field, and in the forward sliding scenario as opposed to the impossible CAB cartwheel. Finding engine four somewhere else, and finding that prop four made the divots, doesn't change the bank angle. But finding that engine four was torn off at the track would certainly be the kiss of death to the high bank.

The best evidence against the large object being wingtip is that it would have been featured in the papers. They went with the most spectacular bit they had, and that was something the size of a crumpled rug. If the wingtip were left on the track, a team of half a dozen guys could move it to the idle track and the RR would be back in business. If the engine were left on the track, the RR would have called in a crane and flatbed and loaded it up and rolled it away, leaving small stuff for the photog to find.
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Old 29th Nov 2017, 03:13
  #178 (permalink)  
 
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Which is kind of the point I was making. A largish object is photographed across the tracks and appears to have been removed from that location very quickly. There does not appear to be any photographic evidence of the type of heavy equipment used to lift rails, repair or realign the track being used. That would have taken a while to get to the scene and remained for some time while any work was completed. This does not appear to have happened, which suggests that the damage done to the track was insignificant as far as affecting trains running along the lines. Railway repair work and the heavy equipment involved generates some good photo opportunities which would not have been missed by journalists at the time.

So we are left with the conclusion that whatever was left lying on the tracks was fairly large, yet relatively light weight. The tracks suffered no damage sufficient to cause them to be relaid, so impact with the angine and gearbox can effectively be ruled out.

We can be certain that some part of the aircraft struck the embankment because of debris left on top. Prop marks show that at least one of the engines was turning and developing power.

I suggest that the evidence indicates that it was engine four that created the marks and that the force of the propellors striking the embankment in addition to stresses caused by the wing tip being torn away, caused the engine to separate from the wing in advance of the rest of the aircraft impacting the ground. That would account for the engine being found away from the rest of the aircraft. Everything else could be exactly as you have described it. The bank angle would have been significant, certainly in excess of 30, but likely less than 60 because the aircraft would have stalled into the ground earlier at that angle of bank.
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Old 29th Nov 2017, 03:35
  #179 (permalink)  
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Picking up a hunk of debris and hauling it away is a matter of twenty minutes or so for the RR guys. They do this kind of thing all the time. As for straightening the track, here's an example of what trains can manage:

https://ibb.co/cBrdUb

You've seen the picture of the Chicago and Western track after the crash. The distortion is about 6 or 9 inches to one side. Pretty trivial. It registers the amount of force involved, but as soon as the RR inspectors have had a look they realize this is navigable, if one can say that of a RR track. They'd tell the trains to reduce speed a bit until they fixed the track.

As long as they got the engine hauled away before the photog got there, what's to take pictures of? Alternatively, where are the pictures of the relatively intact wingtip?

The plane's stall angle in a bank was about 63 degrees that day, by the way. They were descending not because they were in fact stalled, but because they were feeling the shaking in the controls and knew a stall was near, and they were fighting to keep the speed up by keeping the nose down. Rolling left, close to recovery, they ran out of air.
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Old 29th Nov 2017, 12:23
  #180 (permalink)  
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It's far from incontrovertible, but I understand your point. There's not enough detail on that embankment to be sure where the wingtip hit.

If it was indeed prop four that left the tip strikes across the track, I agree the engine could not have been left lying there.
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