On the 9th of July, 1964, United Airlines Flight 823 took off from Philadelphia International
Airport, bound for Huntsville International Airport in Alabama.
Neither it, nor any of the passengers or crew, ever reached the intended destination.
The exact details of what happened on board that flight remain a mystery to this day – one
that, despite much patient investigation – may never be definitively solved.
The Vickers Viscount airliner was first produced in Britain in 1953.
With World War II over, there was less need for military aircraft, and governments around
the world were looking to develop passenger air travel.
The Viscount was designed with this in mind – it was the first aircraft to be powered
by turboprops, and was designed to carry a relatively small number of passengers on frequent
short haul flights.
This profile made the Vickers Viscount 745D the perfect aircraft to fulfil United Airlines’s
regularly-scheduled Philadelphia to Huntsville route.
Flight 823 would take off from Philadelphia at 3:15pm, and make intermediary stops in
Washington DC and Knoxville Tennessee, before arriving in Huntsville late in the evening.
The first leg of this journey on the 9th of July was routine, and the aircraft arrived
in Washington DC at 3:54pm.
The crew reported nothing unusual, and no maintenance other than basic servicing was
required before it took off once again for Knoxville at 4:36pm.
There were 35 passengers and 4 crewmembers on board.
The flight continued to operate normally, with crew reporting in to Atlanta Air Traffic
Control as they approached Knoxville Airport, on track for a landing at 6:21pm.
They reported that they had passed Holston Mountain, and requested clearance to descend
to a lower altitude.
Clearance was granted.
A few minutes later they made contact again, and were cleared to switch to visual flight
rules.
Both of these manoeuvres were normal and expected for a plane descending towards Knoxville.
What happened next, however, was not expected.
The plane stopped responding to communications from Air Traffic Control, and deviated from
its expected route.
Witnesses on the ground reported the plane passing overhead at an extremely low altitude,
the engines labouring.
Some noted a bright red light on the side of the plane, while others reported brown
spots on the outside of the fuselage, which looked to them like burn damage.
Two local residents were also alarmed to see what appeared to be a person fall from the
aircraft and land in an area of woodland.
Just moments after this, the plane crashed into a hillside, with spilled fuel starting
a raging fire.
Residents from nearby towns converged on the crash site, and were joined by the emergency
services just minutes later.
Fire-fighting equipment was brought to the scene, and the flames were extinguished using
a combination of foam, water and carbon dioxide.
Despite an extraordinarily rapid response, it became apparent that there were no survivors.
All 39 people on board Flight 823 had perished.
The recovery operation which followed lasted for several days.
Debris had been scattered over an area of around 2.5 square kilometres, (or one square
mile).
Very little of the aircraft remained in one piece – no intact bodies nor any intact
pieces of luggage were found.
A temporary road was built out to the crash site, and hundreds of people worked there
night and day.
On site were local police, National Guardsmen, paratroopers, aviation investigators, firefighters
from several different jurisdictions, and volunteer rescue workers from several local
organisations.
Investigators removed, pieced together and forensically examined thousands of individual
pieces of wreckage, while bodies were taken to a makeshift morgue in a nearby National
Guard Armory.
The body of the individual who had fallen from the plane before the crash was located
and retrieved after an extensive search.
Local resident Mae Trentham, whose house was closest to the crash site, allowed workers
to use it for the duration of the painstaking clean-up.
What exactly had happened to cause the crash was something of a mystery.
The crew had been fit and well.
Captain Oliver Sabatke had a great deal of flight experience, including making a successful
emergency landing in a military aircraft during the war.
Co-pilot and First Officer Charles Young had more than 7,000 flight hours, with at least
2,000 hours in the Vickers Viscount.
Both had recently passed medical exams, were fully rested, and were proficient and respected
pilots.
The weather had been clear.
The plane itself had performed completely normally during previous flights, and there
was no sign at all that there were any mechanical faults with it.
So what had caused it to deviate from its route, to lose a passenger, and then to crash
into a hillside?
The investigation was hampered by the fact that the flight data recorder (or black box)
had been destroyed during the crash.
This was one of the first times in the history of civilian aviation that this had happened,
and was testament to the force of the impact and the destructive power of the ensuing fire.
By examining smoke damage on recovered pieces of the plane, investigators were able to piece
together a partial narrative.
They concluded that the crash had been caused by a fire on board the plane – a fire predominantly
based in the passenger cabin.
It appeared that the fire had developed extremely quickly, giving the crew and passengers very
little time to react.
The condition of on board firefighting equipment suggested that one crewmember had left the
cockpit and attempted to extinguish the flames, but had been unsuccessful.
It also appeared that the cabin had been intentionally depressurised, cockpit windows had been opened,
and fire suppression devices in the baggage hold activated by crew, even though the fire
was not in the baggage hold.
These actions were not part of the normal protocol for dealing with a fire in the passenger
cabin, but investigators concluded that they were carried out in a desperate attempt to
expel smoke or improve the situation.
The final report stated: “It is considered likely that as the situation
aboard the aircraft became very grave, precise checklist items were supplemented by any action
that offered even a remote possibility of being helpful.”
As the fire developed, the crew may have been overwhelmed by smoke, or mechanisms for steering
the aircraft might have been damaged.
Either would explain the loss of control of the aircraft in its final moments.
The passenger who fell from the aircraft was more difficult to explain.
It was concluded that he exited the plane intentionally via an emergency exit when conditions
in the cabin became unbearable.
He was identified as a lawyer who was known to have a fear of flying.
He had previously said to friends that he always made sure to sit on the emergency exit
row of any flight he took, and that in the event of an emergency he would rather attempt
to jump to safety than go down with the aircraft.
It appears, in the end, that this is exactly what he did.
Several possible sources of ignition were investigated.
A reservoir of flammable hydraulic fluid was examined, but was determined to have broken
open only after the crash.
Similarly a can of paint thinner that was on board was examined, but no conclusive evidence
that it was the cause of the fire was found.
A radio fire, malfunctioning batteries, or a passenger bringing flammable materials on
board (either innocently or with malicious intent) were all considered as possibilities.
Ultimately, though, it was not possible to determine the source of ignition.
Even though the starting point of the disaster could not be identified, several changes were
made in the wake of the accident.
The design and positioning of the flight data recorder used on board the Viscount was improved
to make it more durable, with some changes applied to flight data recorders in other
aircraft as well.
Additionally, a deficiency with the fire extinguishing equipment on board was also uncovered, and
subsequently rectified.
It was a fault that had not caused or worsened this particular accident, but one that was
highlighted by it, and fixed before it could cause problems on other aircraft in the future.
The crash had a profound effect on the area, and is remembered by many local residents
who witnessed it.
A memorial stands in Union Cemetery in Newport, Tennessee, where unidentified body parts retrieved
from the crash site are interred.
Meanwhile, the site of the crash has been deliberately left undisturbed as a mark of
respect to the dead.
On some anniversaries of the disaster, residents welcome the families of those lost in the
crash to their community, and hold memorial services.
One local resident, Tom Dier, has dedicated many hours to documenting the history of the
crash, and keeping the memory of it alive.
The exact cause of the fire that lead to the crash of Flight 823 remains a mystery.
Despite this, the crash and those who were impacted by it have not been forgotten.