Our mystery prop needs I.D.

[Pete_Homer_AK]

Hi,

While surfing the web for information on our mystery prop I came upon a posting from a D. Hutchinson who worked for a company that did cleanup work on Amchitka Island over a decade ago. The company, Chris Berg Inc, was under contract to the US government. They brought the mystery prop back to Homer along with a lot of other salvage material, most of which went to the local dump. The prop was saved and put on display outside the Alaska Islands and Oceans center in Homer.

An important fact from this post is that some years earlier Jim Coffey, an employee of the government stationed on Amchitka, found the prop and set it up near the airport. One could assume he discovered the prop in an aircraft grave yard on the island. Apparently there was a lot of material left over from the war. If you check out the link to aircraft accident reports
on Amchitka in a previous post you will see that there were about 75 crashes, most at the height of the effort to take Kiska and Attu Islands back from the Japanese in 1943. Due to the remote location, many of those wrecks were written off and left on the island.

It would be great to ask Jim Coffey how he found the prop and what aircraft might have been in the area but... (sigh)I haven't been able to locate him on the internet. He also had his wife, Nancy Coffey, and daughter Tiffany Coffey along and they might be able to contribute to the history of our prop. It would be interesting to talk to D. Hutchinson to see if he could add information on the retrieval process. I believe he lives in Anchor Point, AK about 20 miles north of Homer, but again I failed to locate him.

Here is link to the site Amchitka Scrapbook Post which includes a remarkable photo of our mystery prop. near the air terminal on the Island way back in the late 1970's.

The mystery slowly unfolds...

Pete

Mystery prop near Amchitka terminal 1975-78

 

[nuuumannn]

Hi Pete,

Interesting information you have there. I'm thinking that if pilots were not feathering the props before the crash, that suggests whats commonly called controlled flight into terrain (CFIT), basically a crash that the pilots weren't aware was going to happen - as odd as that might sound, e.g. flying into the ground in fog. If an engine failed then the pilots would most certainly feather the prop to reduce drag on the unpowered engine, also if they knew the aircraft was in danger and was going to go down, then feathering the props is also something they would have carried out, as well as shutting the fuel supply off to the engines to prevent fire etc.

Am disappointed they couldn't relate the S/N to date of manufacture or destination.

Unfortunately this sort of information is very rarely kept and collated by firms; rough guesstimates can be made from records, but who's got the time to do that sort of thing in a firm like Hamilton Sundstrand? Their core business is building propellers; they aren't an archive. That's the sort of data that researchers have to go look for themselves.

Propeller manufacturers didn't keep records of what individual props went on which individual airframes; why would they? Propellers of a particular type are designed to be interchangeable for obvious reasons. Those Hydromatic props went on heaps of different types - they were also licence built by De Havilland in the UK - these were exactly the same as their American counterparts apart from the splines on the spider differing between British and American engines, but the hubs for the basic 23E50 can be used on any three bladed aeroplane that operates them. There's a Yak-3 that I know of that has a 23E50 hub from a DC-3 with blades that originally came off a PB4Y Privateer that had been trimmed to size (all done by hand and eye) - and they are being driven by an Allison V-1710 on a Russian fighter. I'd imagine this sort of thing might have happened a bit (not the American engine and prop driving a Russian designed fighter bit) during the war with blades being damaged for whatever reason, so the operators would get what they could in a war zone. Obviously specific blade types were required for specific applications and the distributor valves in the hubs often differed with different aplications, but the basic prop was the same throughout.

 

[Pete_Homer_AK]

Hi All,

Have been reviewing aircraft accidents from Amchitka and came across aviation terminology that I can't identify. What does "slow timing" mean as in "a pilot was slow timing his aircraft around the field before landing."

Also have a second question. Am told that accident reports were not written for aircraft with combat damage. The example for our scenario would be a battle damaged aircraft returning from a mission having an accident during landing. If no accident report is written, where would the incident be documented? Seems like there ought to be paperwork for the loss of an aircraft.

Thanks for your reply!

Pete

PS Haven't found anything new to report on our mystery prop but am in contact with several sources for information including the Air Force Historical Research Agency who have archive documentation that may help. The search continues...

 

[Pete_Homer_AK]

Hi,

Have received aircraft accident reports from the Air Force Historical Research Agency for aircraft that are candidates for our mystery prop. One pilot, Robert Fleischman, had three accidents in his career including the one of interest on Amchitka. The second two accident reports for this pilot were included for general interest by the agency.

I am providing these reports for review by our most expert forum participants in hopes that they will find something my inexperienced eyes missed. Also it maybe of interest to others doing research on the propeller.

From my inspection of the documents, none of the accidents seem to match the damage done to our mystery prop. Several appeared promising including C-47, 42-24276, that damaged a prop on takeoff, circled around the field and landed. The engine could very well have been shut down and prop feathered during the short flight which fits our mystery prop. scenario. The accident report was well written and included a part number for the damaged prop. It was a 5353A-18, and not a 6477A-0 which is for our prop, so not our bird. The B-24D accident report also looked like a possibility but it didn't mention a feathering of the prop and the accident time line didn't allow it.

You will notice many hand written marks on the documents indicating they were probably used to review details of accidents. Often you will see numerals from one to five scribbled next to a piece of equipment such as an engine or propeller. That is a rating of damage to the unit with one being minimal to five indicating damaged beyond repair. For our mystery prop we would be looking for a four or five.

Different forms were used to report accidents and I'm not sure why but it looks like they changed over the years. Some have a written addendum and others just the single form so a wide variation in information provided. Besides the value in researching our mystery prop., the reports offer interesting insight into air operations during the war. The pilots were young men right out of pilot school with minimal flying hours. As a result many relatively new aircraft were damaged or written off not to mention accidents caused by the frightful weather conditions and primitive landing fields at advanced bases in the Aleutians Islands.

Hope you will find them interesting reading.

Pete

 

[Pete_Homer_AK]

Found this answer to the question of "Slow Timing" on the web.


"It was running the engine at reduced power to break it in after maintenance
had been performed on it. It was done even after such simple measures as
cleaning and gapping the spark plugs. You did not want to introduce the
engine to the high stress of combat flying until it had been run in for a
few hours. Slow-timing was not necessarily done in flight; there are
paintings and photos of rows of B-17s all sitting on the ramp slow-timing
their engines.

The engine was not run at a constant speed, but varied, and sometimes run on
just one magneto for periods of up to one minute (you can get an argument
going about whether running on one mag is good or bad for the engine).
Although all airplanes needed slow-timing, temperamental aircraft such as
the P-51 needed it more.

Modern engines still require a break-in period, using mineral oil for the
first 50 hours or so. It is still a good idea to slow-time a new engine on a
trainer aircraft, avoiding maneuvers such as touch and goes for a few hours
until the engine is broken in."

It applies to the B-24D accident report attached above. Pilot W.V. Zartman was "slow timing" 42-40093 around the field for an hour before attempting a landing that resulted in collapsed landing gear and a belly landing. Props hit the ground and may have been torn off the engine as would be the case for our mystery prop. The aircraft was written off due to extensive damage. The accident report did not mention feathering.

 

[Pete_Homer_AK]

Have been checking on production of propellers and found some interesting facts. Over 2,000,000 propellers were manufactured during WW2 including 695,771 by Hamilton-Standard and its licensees, Frigidaire, Remington-Rand, and Nash-Kelvinator. Those H-S props were used on over 25 different US and British aircraft. Between January 1942 and August 1945 N-K produced 159,753 H-S props along with 85,656 spare blades. At their peak production in October 1943, 7,015 propellers were sent to the war effort.

Our mystery prop.'s serial number is SN-NK-S847(?). The "NK" indicates it was made by Nash-Kelvinator at their plant in Lansing, Michigan. They began producing the Hamilton-Standard props. in January 1942 and finished in December, 1945. Remington-Rand serial numbers have an "RR" and those manufactured by Frigidaire an "F".



Some political trivia... George W. Romney (Mitt's father) joined Nash-Kelvinator in1948 and eventually became chief exec.

 

[Pete_Homer_AK]

Have found a B-24D that was badly damaged by antiaircraft fire over Japanese held Kiska Island in February 1943 and forced to land on a newly constructed fighter strip on Amchitka Island. With #1 engine on fire, #4 shut down (feathered), hydraulics shot out (no brakes) the bomber rolled the full length of the runway onto soft tundra where it stopped nose up as illustrated in the attached photo.

The propeller on #4 engine and mystery prop have similar attributes:

Both are feathered.

Both have battle damage

Mystery prop make and model used on B-24D aircraft (23E50/6477A-0)

Location the same, Amchitka Island, AK

While it can't be said with certainty that this is aircraft that the prop came from, no other wrecks have been found to date that are better candidates. Only one other heavy bomber crash was discovered and it did not have an engine shut down or feathered. Will continue searching documentation to make sure a wreck hasn't been missed, but this one is looking pretty good.

Pete

 

[Pete_Homer_AK]

Props on the Feb 43 crashed B-24D in the photo above have been identified as "skinny or thin" (6353A or 6153A) blades. Production Liberator's weren't outfitted with the 6477A-0 (mystery prop) blades until later in 1941, after the crashed bomber was delivered. These thicker profile "paddle" blades" improved high attitude performance. Images illustrating the two different style blades are posted at this link:

Mystery prop - a set on Flickr

B-24D's with the new blades didn't arrive in the Aleutians until later in 1943, so the crash in Feb 1943 could not be the source of the mystery prop.

PS:

While no longer a candidate for our mystery prop, the B-24D crash photo above is pretty dramatic and deserves a bit more comment. In spite of the damage to the crew compartment, the only fatality on the aircraft was the bombardier who was killed by a flak burst prior to the crash and while over enemy held Kiska Island, about 60 miles away from Amchitka. The rest of the crew got away with cuts, bumps and bruises but no serious injuries as a result of the crash.

An odd twist to the story was an extra passenger along for the mission. A naval academy midshipman had begged a ride and got a lot more excitement than he expected. The midshipman along with several of the bomber crew got a ride back to Adak Island, the bombers home base, on board a navy PBY. The cadet was able to meet his liberty ship there and share quite a story with his crew mates. The rest of the bomber's crew followed several days later.

The bombardier was the first war casualtiyt on Amchitka and was buried in the new "Port of Amchitka cemetery." His remains were sent back to Texas for reburial after the war. We can thank an enlisted gunner from the bomber for having his camera onboard for this mission and taking the dramatic photo.

 

[Procrastintor]

I'm going to sound like an idiot, but what does "feathered" mean?

 

[A4K]

Not at all mate - no stupid questions, only stupid answers!

In case of engine failure props are rotated about 90 degrees, edge-on to the direction of flight - this is called 'feathering'. The reason is to cut down air resistance on the stationary prop, thus preventing drag and risk of 'windmilling' (prop spinning of it's own accord in slipstream)

Others here will be able to expand on that, but that's what it's about.

 

[Procrastintor]

Ok thanks, that actually clears up a lot.

 

[A4K]

No worries mate!

 

[Pete_Homer_AK]

These side and rear views of the mystery prop show some gears. Are they part of the propeller feathering mechanism or part of the engine that it came off of?

 

[A4K]

It's the reduction gear in what's left of it's housing (front part of the engine block), though personally I don't know which gear works what...

 

[Pete_Homer_AK]

Thanks for that information A4K. I have two follow on questions...in a catastrophic accident, do propellers typically break off with part of the engine as is the case for the mystery prop or is it more likely to break off and leave the engine intact? This might be a clue to link a particular crash with this propeller.

Second question...is it possible to identify the engine from the reduction gears?

 

[A4K]

1st question: no idea sorry! Would depend on alot I guess: angle and speed of impact, position of engine(s) on airframe, and what surface/ terrain it hits. Crashing on water is like hitting concrete, for example.

2nd question: Very possibly... especially if it has some visible markings. Even if not, though many engines are very similar, each has it's own little characteristics. If someone knows a certain type well enough, they may well be able to identify it. (Personally I think it looks like a Wright of some sort - R-1830 maybe?)

 

[Njaco]

May be a stupid question but it appears that the props were feathered AFTER the crash. They appear bent to the side in the pics. Could they have been feathered after a crash?

 

[A4K]

Good question Chris.... I reckon (though I'm no expert) that the props wedged into the ground would prevent the rest from moving also, being (I presume) connected to a single synchronized mechanism...
Joe or someone will know for sure...

 

[FLYBOYJ]

Two things to look at -

1. Was the prop feathered because of an engine failure prior to the crash?

2. Some propellers automatically go into feather when they loose oil pressure or electrical power, depending the type and make (hydraulic/ electrical)

 

[Pete_Homer_AK]

FLYBOY, I can't answer question 1. because we don't know the history of the prop but I am working on the assumption that it was feathered prior to a crash. As to 2., post #18 addresses functioning of the Hamilton-Standard Hydrodynamic propeller system. As I understand it, the mechanism needs oil pressure and manual activation of an electrical solenoid by the pilot to feather blades. If either is missing, the blades remain at what ever angle they are set.

From research, the prop could have come from a B-17, B-24 or C-47. Perhaps forum members familiar with those aircraft could comment on the procedures/conditions for feathering blades

The following photo shows the blade that seems to have taken the brunt of impact at crash. It appears to be bent back and twisted. The vertical blade in second photo has no crash damage. The third blade tip (left in photo) can't be seen is in the ground in both images, but the center to the hub appears to be slightly bent in the downward direction.

This damage suggests the propeller was not rotating at the time of the crash. One blade hit hard (possibly causing the prop to be torn from the engine), a second not so much and the third not at all.

The first photo is from 2000 when the prop was displayed in front of the air terminal on Amchitka, Island in the Aleutians. The second is present day in Homer, Alaska.

BTW...I had a conversation with a fellow stationed on Amchika in the mid 1970's when the prop was first put on display. He said it came from a scrap metal yard near the runway. There weren't any wrecks in the vicinity of the propeller so it wasn't associated with a particular aircraft. A photo of the prop on display right after it was found can been seen on post #21 of this thread.