Iberia Flight 933 was an international flight from Madrid Barajas International Airport bound for its destination, Boston-Logan International Airport in Boston that suffered a crash landing on December 17, 1973. As the

McDonnell Douglas McDonnell Douglas was a major American aerospace manufacturing corporation and defense contractor, formed by the merger of McDonnell Aircraft and the Douglas Aircraft Company in 1967. Between then and its own merger with Boeing in 1997, it ...

DC-10 operating the flight was approaching the airport, it collided with the

approach lighting system An approach lighting system (ALS) is a lighting system installed on the approach end of an airport runway and consisting of a series of lightbars, strobe lights, or a combination of the two that extends outward from the runway end. ALS usually ...

(ALS) 500 feet short of the runway threshold. The impact broke off the right main landing gear. The aircraft became airborne for about 1,200 feet, then landed on runway 33 Left, veered to the right off the runway and came to rest. All 168 onboard survived, but the plane was written off. This accident was the first

hull loss A hull loss is an aviation accident that catastrophically damages the aircraft beyond economical repair, resulting in a total loss. The term also applies to situations in which the aircraft is missing, the search for their wreckage is terminated ...

of the DC-10.

Aircraft and Crew

The aircraft operating was a McDonnell Douglas DC-10-30, manufactured in early 1973 by

at Long Beach Airport, California. At the time of the accident, it was nine months old and flown a total of 2,016 flight hours. It was registered as N54627 during a certification test but re-registered as EC-CBN when it was delivered to Iberia Airlines in August 1973. Once, it was photographed previously for Iberia Airlines postcards and merchandise. The cockpit crew consisted of

Captain Captain is a title, an appellative for the commanding officer of a military unit; the supreme leader of a navy ship, merchant ship, aeroplane, spacecraft, or other vessel; or the commander of a port, fire or police department, election precinct, e ...

Jesus Calderón Gaztelu (age 53), First Officer Alfredo Perez Vega (54),

Flight Engineer A flight engineer (FE), also sometimes called an air engineer, is the member of an aircraft's flight crew who monitors and operates its complex aircraft systems. In the early era of aviation, the position was sometimes referred to as the "air m ...

Celedonio Martin Santos (42), and Radio Operator/

Navigator A navigator is the person on board a ship or aircraft responsible for its navigation.Grierson, MikeAviation History—Demise of the Flight Navigator FrancoFlyers.org website, October 14, 2008. Retrieved August 31, 2014. The navigator's prima ...

Candido Garcia Bueno (51). Captain Calderón had 21,705 flight hours. First Officer Perez had 34,189 hours, Flight Engineer Martin had 15,317 hours of flight time, and Radio Operator/Navigator Garcia had 14,562 hours.

Investigation

The

National Transportation Safety Board The National Transportation Safety Board (NTSB) is an independent U.S. government investigative agency responsible for civil transportation accident investigation. In this role, the NTSB investigates and reports on aviation accidents and inci ...

(NTSB) investigated the accident. According to the aircraft's flight data recorder, the descent rate was increasing too rapidly during the approach, the result of a wind shear encounter. The investigation found that the captain and the first officer failed to recognize the rate change until the aircraft collided with the ALS piers. It was also discovered that the changes in weather had directed their attention away from monitoring the descent rate. Eleven months after the accident, the NTSB issued its conclusion on the probable cause of the crash. In its accident report the NTSB stated: "The captain did not recognize and may have been unable to recognize, an increased rate of descent in time to arrest it before the aircraft struck the approach light piers. The increased rate of descent was induced by an encounter with low-level wind shear at a critical point in the landing approach where he was transitioning from automatic flight control under instrument flight conditions to manual flight control with visual references. The captain's ability to detect and arrest the increased rate of descent was adversely affected by a lack of information as to the existence of the wind shear and the marginal visual cues available. The minimal DC-10 wheel clearance above the approach lights and the runway threshold afforded by the ILS glide slope made the response time critical and, under the circumstances, produced a situation wherein a pilot's ability to make a safe landing was greatly diminished." The DC-10 had eight emergency exits, but after the crash, only four could be operated. The number 1 right exit had a fault in the mechanism and could not be opened. Due to the weak floor at the end of the aircraft, the floor had become deformed, causing failures in multiple-seat tracks and restraints, and also destroyed the two emergency exits at the back of the aircraft. This meant that the passengers in the back had to climb out of the section through the roof that had broken and jump off onto the ground, causing even more injuries. Due to the floor disintegrating, rock and mud were thrown into the rear compartment of the aircraft. The parts of the floor that had broken apart were between fuselage stations (sections in the aircraft fuselage) 1530 to 1850. Compared to American Airlines Flight 96, stations 1801 to 1921 had failed. The same floor section had collapsed in both crashes.

Aftermath

The NTSB issued seven safety recommendations to the Federal Aviation Administration on September 6, 1974. All of them were closed and with acceptable action.

* A-74-77: RELOCATE AS SOON AS POSSIBLE ILS GLIDE SLOPE TRANSMITTER SITES IN ACCORDANCE WITH FAA ORDER 8260.24 TO PROVIDE A LARGER MARGIN OF SAFETY FOR WIDE-BODIED AIRCRAFT DURING CATEGORY I APPROACHES.

* A-74-78: AS AN INTERIM MEASURE, INCREASE DH AND VISIBILITY MINIMUMS FOR THOSE APPROACHES WHERE THE COMBINATION OF THE GLIDE SLOPE TRANSMITTER ANTENNA INSTALLATION AND THE AIRCRAFT GLIDE SLOPE RECEIVER ANTENNA INSTALLATION PROVIDE A NOMINAL WHEEL CLEARANCE OF LESS THAN 20 FEET AT THE RUNWAY THRESHOLD

* A-74-79: PENDING THE RELOCATION OF THE GLIDE SLOPE FACILITY TO COMPLY WITH FAA ORDER 8260.24, EXPEDITE THE MODIFICATIONS TO OFFICIAL U.S. INSTRUMENT APPROACH PROCEDURES SO THAT THEY DISPLAY GLIDE SLOPE RUNWAY THRESHOLD CROSSING HEIGHT FOR ALL APPROACHES HAVING A TCH OF LESS THAN 47 FEET.

* A-74-80: ISSUE AN ADVISORY CIRCULAR WHICH DESCRIBES THE WIND SHEAR PHENOMENON, HIGHLIGHTS THE NECESSITY FOR PROMPT PILOT RECOGNITION AND PROPER PILOTING TECHNIQUES TO PREVENT SHORT OR LONG LANDINGS, AND EMPHASIZES THE NEED TO BE CONSTANTLY AWARE OF THE AIRCRAFT\'S RATE OF DESCENT, ATTITUDE AND THRUST DURING APPROACHES USING AUTOPILOT/AUTOTHROTTLE SYSTEMS.

* A-74-81: MODIFY INITIAL AND RECURRENT PILOT TRAINING PROGRAMS AND TESTS TO INCLUDE A DEMONSTRATION OF THE APPLICANT\'S KNOWLEDGE OF WIND SHEAR AND ITS EFFECT ON AN AIRCRAFT\'S FLIGHT PROFILE, AND OF PROPER PILOTING TECHNIQUES NECESSARY TO COUNTER SUCH EFFECTS.

* A-74-82: EXPEDITE THE DEVELOPMENT, TESTING AND OPERATIONAL USE OF THE ACOUSTIC DOPPLER WIND MEASURING SYSTEM.

* A-74-83: DEVELOP AN INTERIM SYSTEM WHEREBY WIND SHEAR INFORMATION DEVELOPED FROM METEOROLOGICAL MEASUREMENTS OR PILOT REPORTS WILL BE PROVIDED TO THE PILOTS OF ARRIVING AND DEPARTING AIRCRAFT.

EC-CBN was damaged beyond repair and written off 2 months later. It was scrapped in 1974.

References

External links

NTSB accident reportAlternate

ASN Aircraft accident report
{{Aviation accidents and incidents in 1973 1973 in Boston Accidents and incidents involving the McDonnell Douglas DC-10 December 1973 events in the United States 1973 meteorology Disasters in Boston Iberia (airline) accidents and incidents Airliner accidents and incidents caused by pilot error Logan International Airport Aviation accidents and incidents in the United States in 1973 Aviation accidents and incidents in Massachusetts

Aircraft and Crew

Investigation

Aftermath

See also

References

External links