National Airlines Flight 193
Encyclopedia
National Airlines
Flight 193
, registration N4744NA, Donna, was a Boeing 727-235
en route from Miami, Florida
to New Orleans, Louisiana
on May 8, 1978. It was scheduled with stops at Melbourne
, Tampa
, Pensacola
and Mobile
, Alabama
. The accident occurred at night in low visibility from fog. During the descent into Pensacola Regional Airport
it impacted Escambia Bay
, sinking in 12 feet (3.7 m) of water.
reported breaking out of the overcast at 450 feet (137.2 m). The minimum descent altitude for this approach was 480 feet (146.3 m). This concerned the first officer who informed the captain in his opinion that plane had made an illegal approach. An Eastern Air Lines
jet ahead of them reported briefly having the runway in sight before losing it in the clouds and going around.
While established on the approach the first officer neglected to make altitude and approach fix call outs. The ground proximity alarm sounded and the first officer checked his altimeter. He read it as 1500 feet (457.2 m) and turned off the alarm. The flight data recorder
would later show their actual altitude at this point was only 500 feet (152.4 m). The flight crew may have been distracted by the alarm and failed to realize they passed through the minimum descent altitude. Shortly after this they impacted Escambia Bay. Barge traffic in the area assisted in the evacuation. Three passengers drowned attempting to exit the aircraft. The aircraft was intact after the accident and was removed to a hangar at Naval Air Station Pensacola
but written off due to extensive sea water corrosion.
visual approach slope indicator (VASI) light system
serving runway 25 was available and operational, but while the information was available to the flight crew, the flight crew was unaware of this alternate approach aid.
An additional contributing factor to the crash was an error on the part of the radar controller. Procedure for runway 25 was to direct flights to intercept the final approach at 8 nmi, with the approach gate at 6 nmi. The controller misjudged the aircraft's distance and turned it to final inside the recommended distance , resulting in the aircraft being on final approach vector at about 4.5 nmi , close to half the distance of a normal approach. The NTSB report concludes the controller "created a situation that would make it impossible for the captain to configure his aircraft in the manner specified in the flight manual".
A reluctance to declare a missed approach
pervaded the descent. Radar controller, captain, first officer and flight engineer all had indications of an out of the ordinary approach, producing a rushed and busy environment. An example of this that the captain failed to lower the landing gear immediately after lowering the flaps to 25 degrees, because he "wanted to
avoid placing a simultaneous demand on the hydraulic system while the flaps were in transit". Similarly, the first officer never made the required 1,000-ft
callout, because he never got to 1,000 ft mentally, because his "inner time clock" which was based on a normal descent rate. In addition, each person chose not to ask for or offer additional assistance or warnings, including recommended announcements and acknowledgments. The lack of crew communication and a "no problem here" attitude resulted in false awareness of altitude and descent rate on the part of all involved.
National Airlines (NA)
National Airlines was an airline founded in 1934 and was headquartered on the grounds of Miami International Airport in unincorporated Miami-Dade County, Florida, United States near Miami.- History :...
Flight 193
, registration N4744NA, Donna, was a Boeing 727-235
Boeing 727
The Boeing 727 is a mid-size, narrow-body, three-engine, T-tailed commercial jet airliner, manufactured by Boeing. The Boeing 727 first flew in 1963, and for over a decade more were built per year than any other jet airliner. When production ended in 1984 a total of 1,832 aircraft had been produced...
en route from Miami, Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
to New Orleans, Louisiana
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
on May 8, 1978. It was scheduled with stops at Melbourne
Melbourne, Florida
Melbourne is a city in Brevard County, Florida, United States. As of 2009, the population estimated by the U.S. Census Bureau is 78,323. The municipal area is the second largest by size and by population in the county. Melbourne is a principal city of the Palm Bay – Melbourne – Titusville, Florida...
, Tampa
Tâmpa
Tâmpa may refer to several villages in Romania:* Tâmpa, a village in Băcia Commune, Hunedoara County* Tâmpa, a village in Miercurea Nirajului, Mureş County* Tâmpa, a mountain in Braşov city...
, Pensacola
Pensacola, Florida
Pensacola is the westernmost city in the Florida Panhandle and the county seat of Escambia County, Florida, United States of America. As of the 2000 census, the city had a total population of 56,255 and as of 2009, the estimated population was 53,752...
and Mobile
Mobile, Alabama
Mobile is the third most populous city in the Southern US state of Alabama and is the county seat of Mobile County. It is located on the Mobile River and the central Gulf Coast of the United States. The population within the city limits was 195,111 during the 2010 census. It is the largest...
, Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
. The accident occurred at night in low visibility from fog. During the descent into Pensacola Regional Airport
Pensacola Regional Airport
Pensacola International Airport is a public airport located within the city of Pensacola in Escambia County, Florida.- Facilities :Pensacola International Airport covers and has two runways:...
it impacted Escambia Bay
Escambia Bay
Escambia Bay is a bay located mostly in Santa Rosa County and partly in Escambia County, Florida, in the far western Florida Panhandle. The city of Pensacola is located on the western side, and the town of Milton is located on the northeastern end of the two-pronged bay. Both places are the...
, sinking in 12 feet (3.7 m) of water.
Incident
The instrument landing system (ILS) for runway 16 had been out of service since January of that year for runway reconstruction. A non-precision approach to runway 25 was available instead. Prior to initiating the approach a twin engine BeechcraftBeechcraft
Beechcraft is an American manufacturer of general aviation and military aircraft, ranging from light single engine aircraft to business jets and light military transports. Previously a division of Raytheon, it has been a brand of Hawker Beechcraft since 2006....
reported breaking out of the overcast at 450 feet (137.2 m). The minimum descent altitude for this approach was 480 feet (146.3 m). This concerned the first officer who informed the captain in his opinion that plane had made an illegal approach. An Eastern Air Lines
Eastern Air Lines
Eastern Air Lines was a major United States airline that existed from 1926 to 1991. Before its dissolution it was headquartered at Miami International Airport in unincorporated Miami-Dade County, Florida.-History:...
jet ahead of them reported briefly having the runway in sight before losing it in the clouds and going around.
While established on the approach the first officer neglected to make altitude and approach fix call outs. The ground proximity alarm sounded and the first officer checked his altimeter. He read it as 1500 feet (457.2 m) and turned off the alarm. The flight data recorder
Flight data recorder
A flight data recorder is an electronic device employed to record any instructions sent to any electronic systems on an aircraft. It is a device used to record specific aircraft performance parameters...
would later show their actual altitude at this point was only 500 feet (152.4 m). The flight crew may have been distracted by the alarm and failed to realize they passed through the minimum descent altitude. Shortly after this they impacted Escambia Bay. Barge traffic in the area assisted in the evacuation. Three passengers drowned attempting to exit the aircraft. The aircraft was intact after the accident and was removed to a hangar at Naval Air Station Pensacola
Naval Air Station Pensacola
Naval Air Station Pensacola or NAS Pensacola , "The Cradle of Naval Aviation", is a United States Navy base located next to Warrington, Florida, a community southwest of the Pensacola city limits...
but written off due to extensive sea water corrosion.
Accident analysis
Contributing to the crash was poor preparation on the part of the flight crew. While the captain and first officer were aware that runway 16 was closed, they had both forgotten it . Avisual approach slope indicator (VASI) light system
Visual Approach Slope Indicator
The visual approach slope indicator is a system of lights on the side of an airport runway threshold that provides visual descent guidance information during the approach to a runway...
serving runway 25 was available and operational, but while the information was available to the flight crew, the flight crew was unaware of this alternate approach aid.
An additional contributing factor to the crash was an error on the part of the radar controller. Procedure for runway 25 was to direct flights to intercept the final approach at 8 nmi, with the approach gate at 6 nmi. The controller misjudged the aircraft's distance and turned it to final inside the recommended distance , resulting in the aircraft being on final approach vector at about 4.5 nmi , close to half the distance of a normal approach. The NTSB report concludes the controller "created a situation that would make it impossible for the captain to configure his aircraft in the manner specified in the flight manual".
A reluctance to declare a missed approach
Missed approach
Missed approach is an instrument flight rules procedure which is a standard component segment of an instrument approach. Generally, if the pilot flying or the pilot in command determines by the time the aircraft is at the decision height or missed approach point , that the runway or its...
pervaded the descent. Radar controller, captain, first officer and flight engineer all had indications of an out of the ordinary approach, producing a rushed and busy environment. An example of this that the captain failed to lower the landing gear immediately after lowering the flaps to 25 degrees, because he "wanted to
avoid placing a simultaneous demand on the hydraulic system while the flaps were in transit". Similarly, the first officer never made the required 1,000-ft
callout, because he never got to 1,000 ft mentally, because his "inner time clock" which was based on a normal descent rate. In addition, each person chose not to ask for or offer additional assistance or warnings, including recommended announcements and acknowledgments. The lack of crew communication and a "no problem here" attitude resulted in false awareness of altitude and descent rate on the part of all involved.