Northwest Orient Airlines Flight 705
Encyclopedia
Northwest Orient Airlines Flight 705 was a scheduled passenger flight operated on 12 February 1963 by a Boeing 720
aircraft which broke up in midair and crashed into The Everglades
shortly after take-off from Miami International Airport
in a severe thunderstorm. The plane was destined to Portland, Oregon
, via Chicago
, Spokane
and Seattle.
After the jet lifted off from runway 27L, the jet made a left turn based on radar vectors from Miami Departure Control, to avoid areas of anticipated turbulence associated with thunderstorm activity. Another flight had followed the same guidance shortly before the jet took off.
While maintaining 5,000 feet and a heading of 300 degrees, Flight 705 contacted controllers and requested clearance to climb to a higher altitude. After a discussion between the flight and the radar departure controller about the storm activity, and while clearance to climb was being coordinated with the Miami Air Route Traffic Control Center, the flight advised "Ah-h we're in the clear now. We can see it out ahead ... looks pretty bad."
At 13:43, Flight 705 was cleared to climb to flight level 250. They responded, "OK ahhh, we'll make a left turn about thirty degrees here and climb..." The controller asked if 270 degrees was their selected climbout heading, and they replied that this would take them "... out in the open again..." Controllers accordingly granted the jet clearance. Following some discussion about the severity of the turbulence, which was described as moderate to heavy, the flight advised, "OK, you better run the rest of them off the other way then."
At 13:45, control of Flight 705 was transferred to Miami Air Route Traffic Control Center. There were communication difficulties, although after the jet was provided with a different frequency to tune to, the flight crew established contact with Miami ARTCC. Several minutes after contact was established, the jet's altitude began increasing with a rate of climb gradually increasing to approximately 9,000 feet per minute. Following this rapid ascent the rate of climb decreased through zero when the altitude peaked momentarily at just above 19,000 feet. During this time the jet's airspeed decreased from 270 to 215 knots and as the peak altitude was approached, the vertical accelerations changed rapidly from 1G to about -2G.
In the next seven seconds the negative acceleration continued to increase at a slower rate, with several fluctuations, to a mean value of about -2.8G, the jet began diving towards the ground with increasing rapidness. As the descent continued with rapidly increasing airspeed, the acceleration trace went from the high negative peak to 1.5G, where it reversed again.
Below 10,000 feet the forward fuselage broke up due to the forces of the dive. The main failures in both wings and horizontal stabilizers were in a downward direction, and virtually symmetrical. The forward fuselage broke upward and the vertical stabilizer failed to the left. All four engines generally separated before the debris of the aircraft fell in unpopulated area of the Everglades National Park, 37 miles west-southwest of Miami International Airport.
Boeing 707
The Boeing 707 is a four-engine narrow-body commercial passenger jet airliner developed by Boeing in the early 1950s. Its name is most commonly pronounced as "Seven Oh Seven". The first airline to operate the 707 was Pan American World Airways, inaugurating the type's first commercial flight on...
aircraft which broke up in midair and crashed into The Everglades
Everglades
The Everglades are subtropical wetlands in the southern portion of the U.S. state of Florida, comprising the southern half of a large watershed. The system begins near Orlando with the Kissimmee River, which discharges into the vast but shallow Lake Okeechobee...
shortly after take-off from Miami International Airport
Miami International Airport
Miami International Airport , also known as MIA and historically Wilcox Field, is the primary airport serving the South Florida area...
in a severe thunderstorm. The plane was destined to Portland, Oregon
Portland, Oregon
Portland is a city located in the Pacific Northwest, near the confluence of the Willamette and Columbia rivers in the U.S. state of Oregon. As of the 2010 Census, it had a population of 583,776, making it the 29th most populous city in the United States...
, via Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...
, Spokane
Spokane
Spokane is a city in the U.S. state of Washington.Spokane may also refer to:*Spokane *Spokane River*Spokane, Missouri*Spokane Valley, Washington*Spokane County, Washington*Spokane-Coeur d'Alene-Paloos War*Spokane * USS Spokane...
and Seattle.
Accident
Prior to departing from Miami, the flight crew questioned the ground controller at the airport about the departure routes being used, and he replied that most flights were departing "either through a southwest climb or a southeast climb and then back over the top of it."After the jet lifted off from runway 27L, the jet made a left turn based on radar vectors from Miami Departure Control, to avoid areas of anticipated turbulence associated with thunderstorm activity. Another flight had followed the same guidance shortly before the jet took off.
While maintaining 5,000 feet and a heading of 300 degrees, Flight 705 contacted controllers and requested clearance to climb to a higher altitude. After a discussion between the flight and the radar departure controller about the storm activity, and while clearance to climb was being coordinated with the Miami Air Route Traffic Control Center, the flight advised "Ah-h we're in the clear now. We can see it out ahead ... looks pretty bad."
At 13:43, Flight 705 was cleared to climb to flight level 250. They responded, "OK ahhh, we'll make a left turn about thirty degrees here and climb..." The controller asked if 270 degrees was their selected climbout heading, and they replied that this would take them "... out in the open again..." Controllers accordingly granted the jet clearance. Following some discussion about the severity of the turbulence, which was described as moderate to heavy, the flight advised, "OK, you better run the rest of them off the other way then."
At 13:45, control of Flight 705 was transferred to Miami Air Route Traffic Control Center. There were communication difficulties, although after the jet was provided with a different frequency to tune to, the flight crew established contact with Miami ARTCC. Several minutes after contact was established, the jet's altitude began increasing with a rate of climb gradually increasing to approximately 9,000 feet per minute. Following this rapid ascent the rate of climb decreased through zero when the altitude peaked momentarily at just above 19,000 feet. During this time the jet's airspeed decreased from 270 to 215 knots and as the peak altitude was approached, the vertical accelerations changed rapidly from 1G to about -2G.
In the next seven seconds the negative acceleration continued to increase at a slower rate, with several fluctuations, to a mean value of about -2.8G, the jet began diving towards the ground with increasing rapidness. As the descent continued with rapidly increasing airspeed, the acceleration trace went from the high negative peak to 1.5G, where it reversed again.
Below 10,000 feet the forward fuselage broke up due to the forces of the dive. The main failures in both wings and horizontal stabilizers were in a downward direction, and virtually symmetrical. The forward fuselage broke upward and the vertical stabilizer failed to the left. All four engines generally separated before the debris of the aircraft fell in unpopulated area of the Everglades National Park, 37 miles west-southwest of Miami International Airport.