Monday, June 23, 2025

Hexamer Digital Surveys

 
"The Hexamer General Surveys were prepared by Ernest Hexamer (and, it is suspected, with the assistance of diverse hands) between 1866 and 1895 and consists of, as near as can be determined 2855 numbered plates depicting various industrial and commercial properties.


Industrial properties are such companies as breweries, textile mills and print works, sugar refineries, petroleum yards, dye and chemical works, sawing and planing mills and meat houses. Commercial properties are large farm estates, freight yards, grain elevators and warehouses, movie theatres and concert halls, office buildings, stores, hotels and trolley barns.

Other properties include a university, newspaper building, a racetrack, a prison, an insane asylum and a hospital and almshouse.

By far the overwhelming majority are industrial and of these the textile mills predominate." - From A Consolidated Name Index to the Hexamer General Surveys by Joyce A. Post, Philadelphia, 1974

Surveys for buildings in and around the Central Susquehanna Valley Include:

COLUMBIA COUNTY


MONTOUR COUNTY:

 

Montour Iron & Steel Co
1892

 

North Branch Steel Co
Galvanized Iron
1891

 


There are a lot of great details & drawings on these surveys

NORTHUMBERLAND COUNTY:

 


 


 



The Steam Tannery in Milton Pa
Located along Elm Street
Opened in 1795, Burned in 1880, rebuilt.  

UNION COUNTY:

 


 



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Ernst Emil Julius Ferdinand Hexamer (Koblenz, 29 May 1827 - Philadelphia, 3 December 1912) was a German-born American civil engineer. He was known as originator of a system of fire insurance maps, which by the time of his death were used by fire insurance companies in all parts of the world.




Saturday, June 21, 2025

A Search For Supplee Mill

 

Periodically I get a request to find a photo of Supplee Mill, in Union County Pa. From the oral accounts, this mill stood until about 1950, on Turtle Creek, south of Lewisburg.  At one time, the area was called "Turtleville".

In 1873, when up for sale, the property was described as:
New Mill House, 36x43 feet, three stories high, with three run of barrs, all necessary gearing, an machinery for doing first class work.
Water Power
The 12 acre property also included a mansion house, a tenant house, a new barn 30x60 feet.

With the mill existing as long as we believe it did - there really should be a photo of it out there somewhere?  But so far, none of us have turned one up.  Every year or so I run new searches - and I realized I am repeating a lot of my work over and over again.  So although I have no photo, here's the time line/history that I have pulled so far.  Perhaps someone with a bit more time and dedication may wish to track down descendants of those who ran the mill - one of the family members may have a photo.


There was at the very least, one saw mill, one fulling mill, and one flour mill on Turtle Creek.  At times, when a mill is mentioned, I cannot be certain which mill is being referred to.  For that reason, I have included all of the mill information I have come across, and I will leave it to others to sort out which is which.


Lippincott's Gazetteer of the World, 1880:
"Turtleville, A hamlet of Union County.  3 miles from Lewisburg.  It has a flour mill and a saw-mill.  "

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In 1770 A Connecticut Yankee named William Speddy in 1770 followed a claim on land in Pennsyvania and settled along Turtle Creek on the site where the mill would later be built.  Eventually his deed was deemed defective and he left the area.  "He is remembered in the area by a geographical feature, Speddy's Gap"  https://amzn.to/4l5e4VS  

====================
1772-1773   
Aurant, John - Jenkins Mill, Turtle Creek 
An 1874 article in the Lewisburg Chronicle lists the mill on Turtle Creek as Jenkins mill, run by John Aurant.

John Dietrich Aurand (afterward Reverend) enlisted in Colonel Stewart's Regiment, General Wayne's brigade. He had been learning milling at his father's mill, on Turtle creek. His father sold the mill this year, and, possibly, going down the country in search of employment, he fell in with the recruiting officer. - Buffalo Valley Annals 
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1833
Cornelius, Jesse 
Jesse's  daughter Jane Cornelius Himmelreich was born at Supplees Mill [1925 birthday announcement, repeated in 1931 obit]


Lewisburg Journal:
Jesse Cornelius, 31 May 1833
Mr. Jesse Cornelius who was attending the mill on Turtle Creek was accidentally killed by falling into the works of the mill...violent pain in the head. Mr. Cornelius was a sober, honest and industrious man, and was generally respected and esteemed by those who knew him. We understand he has left a wife and six children to mourn his meloncholy exit.

1833. May 31, Jesse Cornelius, miller, at Trester's old mill, on Turtle creek, was caught in the machinery. Ribs, breast bone, &c., broken. He died immediately. - Annals of the Buffalo Valley by John Blair Lynn


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1850-1864
Brown, Michael
1850 & 1856 Map of Union County 
& in 1864 Newspaper]

1850 Map, Snyder County Pa


1864 newspaper mentions a sale "near Michael Brown's mill on Turtle Creek"
In the 1850 and 1860 census, Michael's occupation was "Farmer".  In 1870, "retired farmer".


March 1876, Lewisburg Chronicle

Note - The Jefferson School is also recorded as having been named Brown's School, or Supplee's Mill School.

---------------------------------
1865 - Wolfe

William Wolfe, according to his 1922 obituary, was born on "the homestead farm at Supplee's Mill.  He was the 3rd son of Michael R. & Jane Wolfe."

Michael Wolfe 1832-1892
married Rachel Gundy
Son - William

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Supplee Mill


Supplee, G & Co [1868 Map - shown between 2 branches of the creek]

In the 1868 map, business directory
A. Kneuss Grain Dealer, Lumberman

An 1888 article in the Northumberland Press mentions Kneuss - 
"Turtle creek flows into the west branch of the Susquehanna four miles above Northumberland and the above named village is located at its confluence. The Burgmeister of the village appears to rest in the hands of Col. Alf. Kneass, whose tall commanding form can be seen supervising his mills together with about one mile square of land. He is the inventor, architect and mechanic of his mills, and book-keeper and sweeper of his office, and how he manages all and continues to stand straight up all time is not altogether explained in modern physiology. "


Rodenbaugh, J & Son - Supplees Keystone Mill ran by  1872-1877

March 1873, Brown Mill For Sale, listed by  Jacob Rodenbaugh
[Rev. Jacob Rodenbaugh 1812-1894]

In 1873, when up for sale, the property was described as:

New Mill House, 36x43 feet, three stories high, with three run of barrs, all necessary gearing, an machinery for doing first class work.
Water Power

The 12 acre property also included a mansion house, a tenant house, a new barn 30x60 feet.

1873

=====================
1881 - A. H. Supplee [Born 1834]

In 1881 newspapers across the state carried the news that A.H. Supplee Jr, of Supplees Mill, had run off with Mrs. Jere Yeager, the wife of the man who was in charge of the mill, while Yeager was away on business.  Mrs Yeager, who reportedly "eloped" with Supplee, left her young son [age 3 or 4] with a neighbor.  Her parents arrived and took custody of their grandson.

 A.H. Supplee was not yet 21 years of age, Mrs Yeager was "about 24 and is said to be quite good looking."  Supplee had taken some $3,000  [close to $100,000 in 2025] out of his account, before leaving with the woman.  The mill books were examined and found to be in good condition.  

In the 1870 Census, Johnathan and Eliza Suplee were in East Buffalo Twp, with 9 year old Alexander.  [Also Howard 12, and Jennie 5].  Alexander Howard Supplee, born Aug 2 1860

In the 1880 Census, Alexander, age 20, was listed as a "boarder", and a miller, in East Buffalo Twp. In the same household were Jeremiah Yeager, his wife 22 year old wife Elinore [Barner], and their 3 year old son Benjamin.

Although I can't be certain, it does appear that Elinore returned to her husband Jeremiah before too long.



-------------------------------------------
1876 Leedam & Robert's

1876


On March 26th 1877, "Mill stock and Personal Property Of Leedom and Robert's Supplee Mill" sold at public auction.

-------------------------
1883- A.H. Supplee

A. H. Supplee

[Alexander Henderson Supplee died in 1882  - but I am uncertain how he is related to the A.H. Supplee who ran off with Yeagers wife]
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1885
Overhauled Flour Mill now under the efficient management of 
Mr. J.W. Zeller

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1886 - S. S. Meyers


Samuel S. Meyers 1839-1921, wife Phebe

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1892 - M.R. Supplee


From Abrams, Montgomery County
Owns Mill, visits to check on it about once a year.

Possibly Mark Rambo Supplee  1836-1901?

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1894 Mr. S. Potter


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1910 - Potters Mill, Jacob Fetzer

1920 Postal Map - which I have not yet located myself

Jacob K. Fetzer, genial miller at Potters Mill East Buffalo Twp

In 1922, "Mrs Emma Fetzer, wife of Jacob Fetzer, died at the age of 62 at their home at Supplee's Mill, East Buffalo Township" - The Miltonian

Jacob Fetzer 1854-1924
Wife Emma Watson Fetzer, Adopted daughter Hazel
1920 Census - Miller, Chop Mill East Buffalo, Union, Pennsylvania.  Also there in 1910. 

--------------------------
1936 - part of a historical tour


-----------------------
Torn Down About 1950

Local resident reported that the mill was taken down in 1950
According to Water-Powered Gristmills of Union County Pennsylvania by  Rich Thomas P and David W Del Testa:

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Turtle Creek Mentions in Lynn's Annals Of Buffalo Valley: 

Turtle creek was so called before 1769, and in the latter year I found the stream below it, traversing Dry valley, called Lee's run, after John Lee, the first settler of the site of Winfield.

He [William Speddy] chose for his residence the prettiest little dale in Buffalo Valley. It is on Turtle creek, near what is now Supplee's (formerly Treaster's) mill. Jacob Brown now owns the place. 

On the 3d of October, John Aurand bought the " Jenkin's mill " property, on Turtle creek, and it went by the name of " Aurand's mill," when he sold it to Morgan Jenkin. It is still owned by the Jenkin's family. Doctor Harbaugh, in his " Fathers of the German Reformed Church," states, upon the authority of John Aurand, of Yellow Springs, Blair county, a grandson of John Aurand, that the latter built both flour and saw-mill at Turtle creek. Wilson, however, had some sort of a mill there as early as 1771. John Wilson died during the year 1772, according to my researches — Miss Sandford, ante, says in 1774.

John Dietrich Aurand (afterward Reverend) enlisted in Colonel Stewart's Regiment, General Wayne's brigade. He had been learning milling at his father's mill, on Turtle creek. His father sold the mill this year, and, possibly, going down the country in search of employment, he fell in with the recruiting officer.

Improvements of this year — Wendell Baker's saw-mill, (at Cowan;) Alexander Beatty's tan-yard, at New Berlin ; Christopher Weiser's fulling-mill, on Turtle creek, now Peter Wolfe's.  [Note, a fulling mill is a cloth mill ]

Dietrich Aurand, who had followed milling at different places down the river, removed, with his family, into the Valley, and settled on a farm on Turtle creek, midway between its source and outlet, about five miles above Jenkins' mill. The farm he was on had a reserved water right, and was given to him by his father, with the design that he should build a merchant mill on it, and he intended so to do ; but the Hessian fly having proved very destructive to the wheat crops for upwards of ten years, he lost severely in purchases of wheat for the French, and lost by bailing, so he could not build the mill, and had to sell and remove to an adjoining farm, in 1801.


1838 - In the fall, the iron ore below the mouth of Turtle creek was found to be of a superior quality, and its development was commenced by Napoleon Hughes, of Franklin county, a short distance above the site of the present furnace of Beaver, Marsh & Co., a few hundred yards from the river bank. 

1846 - Friday evening, March 13, Thomas Follmer and his son Henry and William Gundy, son of Major John Gundy, who were managing the Farmers' company store at Turtle creek, were drowned at the mouth of that creek. They were going in a boat, about ten, p. m., to visit the store-house on the opposite side of the creek, and were on their return, when the mill dam gave way, and the boat struck a timber raft. William Gundy's body was found in the boat under the raft, the next day; the others were carried down the river, and their bodies were found three weeks afterward, some miles below. The flood in the river at this time exceeded that of 1810, being six and one half inches above the mark of that date on Kremer's store-house. The canal was broken, mails stopped, the Milton bridge badly injured, the bridge on the North Branch, at Northumberland, carried away, as well as the one at Duncan's island, and the Harrisburg bridge in pa

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Tuesday, June 17, 2025

The crash of Flight 624, Wilburton, June 1948

On June 17, 1948, at 1:41pm,  United  Airlines Flight 624 enroute from San Diego, California to New York narrowly missed hitting the breaker at Wilburton.  The plane banked to the right to avoid the building, which brought the  right wing  in contact with a transformer sub station. With thirty nine passengers and 4 crew members were on board, the plane exploded.  There were no survivors.

===========

THE PLANE

United Airlines Flight 624, a Douglas DC-6 airliner, registration NC37506, was a scheduled passenger flight that originated in San Diego, California with stops in Los Angeles and Chicago en route to LaGuardia Airport in New York City. 


The four-engine propeller-driven airplane crashed at 1:41 p.m. Eastern Daylight Time on June 17, 1948 outside of Aristes, Pennsylvania, killing all 4 crew members and 39 passengers on board


============
THE LOCATION

A Modern Map, showing Wilburton in relation to Centralia, Mt Carmel, and Ashland
Aristes is located above Centralia, to the right of Wilburton on this map.  


"NC-37506 crashed approximately three miles east-northeast of Mt Carmel, Pa., in a power line clearing on wooded mountainous terrain 


The airplane struck a 66,000 volt transformer and severed power lines. The time at which this occurred was automatically recorded at the Culpment [Kulpmont], Pa. steam electric station at 1241.



An explosion just after impact scattered the wreckage over an area 580 feet long and 175 feet wide. A flash fire followed, scorching and smudging parts of the wreckage throughout the entire area."

Newspapers published the map above, in 1948.


"The breaker, incidentally 265 feet high.  Eighty men were inside at the time of the crash.  Miners in the Continental mine were unable to be brought to the surface, since the power operating the cage was suspended.  They had to walk up a nearby slope."


The Republican and Herald reported that Midvalley,  Continental, and Germantown collieries planned to resume on Saturday the 19th.  Raven Run would remain idle due to lack of coal supply.

==========
THE CRASH



The plane “limped at half-speed into a valley dotted with anthracite collieries.” as the pilot  “guided his ship four miles between two hills. He was scarcely 30 feet above ground.” 


It would later be determined that the trouble began as the plane began its initial descent just west of Centralia PA. "This was in preparation for arrival in New York City. During this time, a warning light illuminated indicating that the forward cargo hold was on fire. Believing there was a fire, the crew discharged carbon dioxide into the cargo hold to suppress it.


Per operating procedure, the crew should have opened the pressure release valves on the cabin to vent excess carbon dioxide gas away from people. However, it is believed that this step was not taken.

As a result, carbon dioxide gas began seeping into the cabin and cockpit. This caused the crew to become partially incapacitated. Realizing something was wrong, they began an emergency descent.


As the aircraft dropped in altitude, it accidentally came in contact with a high voltage power line. The aircraft burst into flames and crashed into the wooded hills to the north of Centralia Pennsylvania. Without a doubt, the residents of the town would have been able to see the wreckage burning."

Two telephone repairmen were working on a nearby hillside.  One, William Davis, was former Air Corps.  He said he knew something was wrong when he saw the plane bank at a 45 degree angle.  "A moment later, we saw smoke rising a few miles away."


"We heard an awful roar in the sky" said railroad worker Joseph De Melfi.  "We glanced up as the plane seemed to be coming down in a glide and then it struck the high tension wire.  It was terrible."

“Stunned miners saw the nose of the plane veer upward too late. It shattered against a 60,000 volt power line and exploded.” 


Harry Stibitz, employee at the breaker said:
 "I was standing near the corner of the warehouse with Harry Kreisher. when we saw the plane coming from the west, only about forty feet above the ground. Me buddy said 'dig' because we thought the plane was going to hit us. Gosh, the plane was only a few hundred feet away when we saw it. We were almost frozen to the ground. Suddenly the plane curved into the mountainside.  


In what seemed but a second there was the crash; the explosion. Flames leaped up. They must have been ninety feet. I could see nothing but smoke and fire. The first impulse was to get some help, so we ran into the office. You couldn't tell if the landing gear down or anything else it all happened so fast." 


 John D Carey, of Lost Creek, along with Superintendent Mike Wascovich, were looking out the window, toward the west.   "We heard the explosion and rushed outside. The flames were shooting into the sky.  Some of our men ran up the bank but everything as burning in a wide area.


 Immediately we called the Midvalley ambulance and notified the State Police, the Mt. Carmel fire companies and the P. P. and L. "In a matter of a few minutes another large plane' came along, and it must have circled five minutes before going on." 



Harry Carey, of Lost Creek, a clerk at the Mid-Colliery, saw the horrifying crash from the office porch, just across the road. "It all happened so suddenly it's hard to explain," he recalled.  "There was a mighty roar when the plane exploded. As the wreckage dropped all around us, those of us at the office dashed for fire extinguishers and ran to the scene. At first we couldn't get through the flames to the wreckage, and the danger of high tension lines knocked to the ground held us back. But we knew instantly that no one lived through the sickening disaster."


Cpt. Earl Bach, a 32 year old pilot for United Airlines, flew over the scene several minutes after the crash and made the first official report of the tragedy.  "I've sighted Flight 64.  It looks demolished, " he radioed in.   He later said "The plane was demolished in a hillside. Nearby woods were on fire.  You could see a clearing nearby.  Smoke made it hard to distinguish things in the are, but there appears to be no survivors."  Bach kept a "wing in the passengers view" and none of his passengers were aware there had been a crash.  "The few who noticed a disturbance thought it was just another fire". 



============
RECOVERY


The accident scene was roped off, and "coal miners from a colliery that barely missed being hit by the plummeting plane helped searchers comb the area for body fragments."


The charred scene covered an area the size of three city blocks.  "Bodies, baggage, and plane parts were strewn everywhere."


"A tattered steamer robe atop a burning tree fluttered as a bleak ensign of the destruction.  Underneath, workers poked awkwardly into the debris on the side of a coal mountain, in a search for the bodies."


Capt Thelma Peirce, "a Salvation Army lassie", distributed sandwiches and coffee to scores of persons digging in the wreckage.


 Many of the remains were flown by helicopter to Centralia where a helicopter landed on a flat space about a quarter mile from the  Joseph Stutz Funeral Home.


 Stutz had charge of arrangements.


United flew relatives in on special planes, to make identifications.   Family members  stayed at the McGinley Hotel directly across from Stutz, The Marble Hotel in Mt Carmel, and The Hotel Loeper in Ashland.  The McGinley in Centralia had  17 rooms,  a bar and restaurant.
[McGinley's burned down in 1935, so whether the photo above is the original, or the later rebuild, I am not certain]


 Bell Telephone set up extra phone banks at each of the hotels for the use of families of victims and news media.


 A wallet was found with Earl Carroll's identification, and $1024 cash.  [That's roughly the equivalent of $13,600 in 2025].  Also found was a baby's purse with a penny inside.


Jack Herlihy, vice president of operations for United, set up an emergency office on one of the collieries.


The plane had been carrying mail, which was, as was custom, stored in the tail, where much of it survived the crash.  


The  recovered mail was  packed into cardboard boxes supplied by the Marsden Potato Chip Co. of Pottsville.

  It was  then taken to the  Pottsville post office to be sent on it's way.


Each piece  included a slip identifying it as  being aboard an aircraft that was involved in a crash.

On Wednesday the 23rd, the Morning Press reported that an air Force reserve Helicopter had arrived at Bloomsburg Airport, and would be used to search for parts that may have fallen from the plane before it crashed.

==============
THE VICTIMS


"Victims included famed Hollywood-Broadway theatrical producer Earl Carroll; Mrs. Jack Oakie [Venita Veriden], divorced wife of the motion picture actor, Actress Beryl Wallace, star of Carroll's theater restaurant show, and Henry L. Jackson, men's fashion editor of Colliers magazine.


Carroll was headed to the MacArthuer headquarters at the Republican National Convention.  "A hero pilot in the sketchy air force of World War I, Carroll was long a friend of Gen. Douglas MacArthuer, and an untiring worker in the Mac-Arthur-For-President campaign"

Albert William Stampel, of Stratford Connecticut, had just been discharged from the Navy and was on his way home.

Two infants were also on board.

"The passengers aboard the United Airlines plane which crashed in Pennsylvania yesterday, killing all aboard were:

Earl Carroll, Hollywood producer.
Mrs. Jack Oakie, Hollywood , divorced wife of the motion picture actor.
Beryl Wallace, star of Carroll’s theater restaurant show.
E. George Von Sebo, New York City, official of Devoe & Reynolds, Inc., paint firm.
Parker W. Silzer, 48, Metuchen, N. J…son of…late former Gov. George S. Silzer of NJ.
Mrs. Alta Gwinn Saunders, professor of business English…Univ. of Illinois, Urbana.
Hugh McCloskey, the Texas Company, New York City.
Lt. Com. C. S. Avery, San Francisco.
Nathan Berke, Berke Bakeries, Brooklyn.
Ernest Winckoff, Berke Bakeries, Brooklyn.
Rowland Brown, auditor, Brown Brothers, Harriman and Company, New York City.
Arthur B. Smith, department head, Brown Brothers, Harriman and Co., New York City.
Frank Campi, San Jose, Calif.
H. Jackson, Crowell & Collier Company, publishers, New York City.
W. A. Kendall, Scarsdale, N. Y.
D. Marcus, Chicago.
Mrs. D. Marcus, same address.
The Marcus Infant.
Mrs. L. O. Weiser, Chicago.
The Weiser Infant.
A. S. Angus, the Texas Company, New York City.
A. G. Devito, Brooklyn.
Hans Joachim, San Francisco.
R. Harvey, Recotron Corp., New York City.
H. L. Slater, New York City.
Miss Kay Thorpe, NBC announcer in Chicago.
E. Hinchliff, Bursen Knitting Mills, Rockford, Ill.
G. W. Rogers, Lamond Corliss Company, New York City.
Y. Lecorre, Paris, France.
T. J. Gallagher, Bryn Mawr, Pa.
L. Dleringer, Comstock Electric Co., New York City.
R. B. Stewart, Comstock Electric Co., New York City.
N. V. Pessin, Los Angeles.
Mr. and Mrs. G. Harries, Boyertown, Pa.
Remo Bufano, nationally famous marionette producer, New York City.
William Casmer, New York City.
Albert W. Stempel, Stratford, Conn.
Paul March, 32, Sacramento, Calif.

Members of the airliner’s crew:
Capt. George Warner Jr., Westmont, Ill., pilot.
Richard Schember, 26, Elgin, Ill., first officer.
Nancy L. Brown, 23, R. D., Fort Meyers, Fla., stewardess.
Lorena R. Berg, 28, Woodstock, Ill., stewardess.”





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Crew on board: 4
Crew fatalities: 4
Pax on board: 39
Pax fatalities: 39
Other fatalities: 0
Total fatalities: 43
Captain / Total flying hours: 7310
Captain / Total hours on type: 30
Copilot / Total flying hours: 3289
Copilot / Total hours on type: 129
Aircraft flight hours: 1245

Circumstances: The airplane arrived in Chicago at 0952LT, en route from Los Angeles to New York City. At Chicago, the airplane was given a routine station inspection, serviced, loaded, and the flight departed for New York with a new crew at 1044. Aboard were 39 passengers, a crew of four, 2,568 pounds of cargo and 1,800 gallons of fuel, all properly loaded. The resulting total airplane weight was within the certificated gross weight. The airplane climbed en route to its planned altitude of 17,000 feet, proceeding on course, and at 1155 the captain reported to the company radio at LaGuardia Field, that the airplane was mechanically "okay” for a return trip. A routine report was made over Phillipsburg, PA, approximately 500 miles east of Chicago, at 1223, and at 1227 the crew made a routine acknowledgment of a clearance to descend en route to an altitude between 13,000 and 11,000 feet. Four minutes later, at 1231, the company radio operator at LaGuardia Field heard a voice which did not identify itself calling loudly and urgently. Another United crew in a DC-3, flying over the same route behind Flight 624 and at a different altitude, heard what they termed “screaming voices” calling "New York." Then, after an unintelligible transmission, “This is an emergency descent." Inasmuch as all other air carrier flights in the vicinity at this time were accounted for, this transmission undoubtedly emanated from Flight 624. The airplane was first observed by ground witnesses 31 miles northwest of the scene of the accident flying a southeasterly heading toward Shamokin, PA. The airplane flew over the Sunbury Airport, at approximately 4,000 feet above the ground on a southeasterly heading. Immediately north of Shamokin the airplane, then only 500 to 1,000 feet above the ground, described a shallow left turn. The course was toward constantly rising terrain, the hills around Sunbury being 900 feet in elevation and the hills around Shamokin being approximately 1,600 feet in elevation. Five miles east or beyond Shamokin the airplane, flying only 200 feet above the ground, entered a right climbing turn. As it passed to the north of Mount Carmel, the climbing turning attitude increased sharply. The airplane then struck a hillside at an elevation of 1,649 feet. The aircraft disintegrated on impact and all 43 occupants were killed.

Probable cause: The Board determines that the probable cause of this accident was the incapacitation of the crew by a concentration of CO2 gas in the cockpit.

The following factors were considered as contributing:
- A fire warning caused the crew to discharge at least one bank of the CO2 fire extinguisher bottles in the forward cargo pit (the forward underfloor baggage compartment),
- Six 15-pound CO2 bottles and six discharge valves were found in the wreckage, however, both the bottles and the valves (which had become separated from their respective bottles upon impact) were so damaged that no conclusions could be drawn as to how many of such bottles had been discharged prior to impact,
- At the time of impact, the emergency cabin pressure relief valves were closed, and the control mechanism for such valves was in the closed position,
- Except for the apparent failure of the fire detection instrument referred to in finding No. 5, supra, the investigation revealed no mechanical failure of the aircraft or fire in flight,
- The emergency procedure for the operation of the DC-6 fire extinguisher system was established after flight tests were conducted in a descent configuration of 300 miles per hour, with landing gear and flaps up, no flight tests were conducted prior to the accident in a descent configuration of 160 miles per hour with gear and flaps down, which configuration was also approved for DC-6 operations,
- At the time of impact the landing gear was in the “up" position, thus indicating that the aircraft had descended in the configuration of 300 miles per hour. The extensive breakage of the aircraft precluded any positive determination as to the position of the flaps,
- After the release of CO2 gas hazardous concentrations of the gas entered into the cockpit,
- Due to the physiological and toxic effects of high concentrations of CO2 gas in the cockpit, which would probably not have occurred had the cabin pressure relief valves been open, the members of the flight crew of the aircraft were rendered physically and mentally incapable of performing their duties.


The following comment was added to the conclusion:
A fire in flight permits little opportunity for the exercise of detached and thoughtful consideration of emergency procedure. Immediate action is required if a fire is to be controlled. Too little consideration has been given to the psychological and physical limitations of crew members in time of stress and danger as related to the complexity of emergency fire procedure. It is not safe to assume that the pilot and co-pilot, under emergency pressure, will always adhere rigidly to the sequence of steps outlined in the CAA Approved Airplane Operating Manual. The possibility of human error under great mental stress is well documented in air transport experience and the design of aircraft controls, especially those of an emergency character, should take into consideration the natural limitations of human nature. These limitations argue against involved procedures applicable in emergencies. In harmony with this objective, the Douglas Aircraft Company has designed and is testing a modified fire extinguishing system which will permit all necessary steps to be executed by the movement of one control. An additional vent is also being designed to reduce CO2 concentration in the cockpit. Seven days after the Mt Carmel accident, the Director of Aviation Safety of the CAA directed telegrams to all CAA regional administrators calling attention to his telegram of June 10, 1948, referred to above, and advising that further investigation had disclosed the existence of the CO2 concentration condition found in Constellation aircraft by the Chillicothe tests in other makes of aircraft. The telegram concluded "Hence, flight crews of all aircraft should be advised to wear oxygen masks and utilize emergency cockpit smoke clearance procedures when carbon dioxide is released into any fuselage compartment from other than portable extinguishers.” All scheduled U S air carriers operating DC-6s have equipped the airplanes with demand type full face oxygen masks for the use of the crew.

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