|Title:||Tail strike during go-around, McDonnell Douglas MD-11F, September 19, 2004|
|Micro summary:||This McDonnell Douglas MD-11F experienced a tail strike during a go-around maneuver.|
|Event Time:||2004-09-19 at 1243 CDT|
|Publishing Agency:||National Transportation Safety Board (NTSB)|
|Site of event:||Memphis, TN|
|Departure:||Oakland International Airport, Oakland, California, USA|
|Destination:||Memphis International Airport, Memphis, Tennessee, USA|
|Airplane Type(s):||McDonnell Douglas MD-11|
|Flight Phase:||Missed Approach|
|Type of flight:||Cargo|
NTSB short summary:
The pilot's over-rotation during a go-around maneuver initiated because of a bounced landing. The go-around maneuver was initiated at a low speed and high pitch angle, and after reverse thrust was selected, contrary to Boeing and FedEx training guidance.
The approach to landing was normal, and the crew stated that the touchdown was firm but not categorized as a hard landing. The airplane pitched up and bounced after touchdown and the captain became concerned that the airplane would porpoise. The speed had decreased to 107 knots, and reverse thrust had been initiated. The captain elected to conduct a go-around maneuver, and rotated the airplane to a nose high attitude of about 12 degrees prior to achieving sufficient airspeed and a positive rate of climb. The rear fuselage of the airplane contacted the runway for about 3,000 to 4,000 feet causing substantial damage to the airframe. The airplane lifted off, and the crew completed a second landing on runway 36R without further incident. Boeing training material and FedEx guidance states that "after reverse thrust is initiated, a full stop landing must be made. Do not attempt a go-around." Additionally, the FedEx tailstrike awareness training states that "the [pilot flying] must not exceed 10 degrees of pitch or retract the landing gear until the aircraft is safely airborne with a positive rate of climb."
NTSB factual narrative text:
HISTORY OF FLIGHT
On September 19, 2004, at 1243 central daylight time, a Boeing McDonnell Douglas MD-11F, N601FE, operating as FedEx (FDX) flight 859, experienced a tail strike during a go-around maneuver from runway 09 at Memphis International Airport (MEM). The crew was executing a Category III autoland procedure for proficiency. Neither of the 2 crewmembers was injured. The airplane sustained substantial damage to the underside of the rear fuselage and the aft pressure bulkhead. Flight 859 was operating on an instrument flight rules flight plan under the provisions of 14 Code of Federal Regulations (CFR) Part 121 as a regularly scheduled cargo flight from Oakland, California (OAK) to MEM. Visual meteorological conditions prevailed at the time of the accident. Flight 859 departed OAK at about 0721 Pacific daylight time. According to the flight crew, the flight was uneventful until the landing on runway 9 at MEM.
Memphis air traffic control (ATC) provided radar vectors to a 14 to 15 mile final approach to runway 9. The pilots reported that the approach was stable and nominal. The calculated landing weight for the airplane was 370,000 pounds, with a calculated approach speed of 142 knots indicated. The captain took over flying responsibility for the airplane at about 300 feet above the runway, and he reported that the autoland system was working normally. Flight Data Recorder information showed the airplane was at an airspeed of 142 knots, there was less than ½ dot deflection on the glideslope indicator, the flaps were set at 50 degrees, and the airplane was at a pitch attitude of about 3 degrees airplane nose up.
The captain said everything appeared normal when the airplane entered the flare maneuver. Prior to touchdown, the airplane drifted slightly right of the centerline, touching down about 20 feet to the right of centerline. The captain said that the airplane touched down firmly, but not what he would consider a hard landing. After touchdown, he perceived that the airplane pitched further up, instead of pitching down as he expected. He applied forward pressure to the control column to bring the nose down, the sink rate rapidly increased and there was "a second touchdown." He was concerned that the airplane would begin to porpoise and felt it would be safer to go around.
FDR data indicated that the airplane remained centered on the ILS localizer and glideslope beams during the approach, with the nose pointed to the left of the runway heading in order to compensate for a 10 knot left crosswind. As the airplane yawed to the right to align the nose with the runway heading just prior to touchdown, performance calculations indicate it drifted to the right and touched down about 30 feet to the right of centerline. With the autopilot still engaged, the airplane bounced slightly, eventually reaching a radio altitude of 3 feet; about 3 seconds after the first touchdown. As the airplane ascended through a radio altitude of about 1 foot during the bounce, the autopilot disconnect warning was recorded on the CVR.
According to the FDR, following the autopilot disconnect the control column moved aft to 7 degrees, while the pitch angle decreased from 7 to 4 degrees before starting to increase. At this time the thrust reversers were "unlocked," indicating flight crew selection of reversers. The airplane touched down for the second time about 4.2 seconds after the first touchdown. The spoilers briefly deployed, in conjunction with aileron movement, then retracted concurrently with the go-around maneuver.
Almost immediately after the second touchdown, the captain called for maximum power and initiated the go-around maneuver. The FDR indicated that the airplane pitched up steadily until reaching a pitch attitude of about 12 degrees, and the speed decayed to 107 knots. The captain said that he applied aft control column pressure to raise the nose; the airplane did not pitch up to this attitude on its own. About seven seconds after the go-around call, the power on all three engines began increasing, and the flaps began retracting from the 50 degree position. The airplane accelerated in the approximately 12 degree nose up attitude until about 15 seconds after the go-around call, when it reached an airspeed of 115 knots and achieved a positive rate of climb. About 3,650 feet of available runway remained. Witnesses reported that the rear fuselage of the airplane scraped the runway for about 3,000 to 4,000 feet and produced a great deal of sparks. The crew then maneuvered the airplane to a landing on runway 36R without further incident.
Boeing documentation states that the airplane's aft body would strike the runway surface at a pitch attitude of about 10 degrees with main gear struts compressed, or about 13 degrees with the main gear struts extended.
INJURIES TO PERSONS
The 2 crewmembers were uninjured.
DAMAGE TO AIRPLANE
During the tailstrike, three skin sections were abraded over an area of at least 12 feet by 3 feet. A significant portion of the skin was abraded completely away. Five longerons exhibited abrasion damage as well as numerous shear clips and eight aft fuselage frames. The aft drain mast was fractured and the left aft tail cone hinge was damaged. The damaged area extended from the unpressurized portion of the fuselage across the aft pressure bulkhead to a point about 2 feet forward of the bulk cargo door. The T-cap on the pressure bulkhead exhibited some abrasion damage and there was a ½ inch buckle in the bulkhead web above the point of contact. The listed damage was considered substantial under 49 CFR, Part 830.
The captain, age 46, was hired by FedEx on July 18, 1988. He held a Federal Aviation Administration (FAA) airline transport pilot (ATP) certificate with a multiengine land rating and a flight engineer certificate for turbojet-powered airplanes. The captain's ATP certificate indicated type ratings in the MD-11 and DC-10 (issued December 20, 2003). According to company records, at the time of the accident he had 6,390 hours total time; with 235 hours in the MD-11, all as Captain. The captain's most recent FAA first-class airman medical certificate was issued on July 23, 2004, with a restriction that the holder must wear corrective lenses. The captain had no history of failures or re-tests for FAA pilot and flight engineer certificates and ratings. He completed an MD-11 proficiency check on June 8, 2004, and completed MD-11 tailstrike awareness training on December 9, 2003
The First Officer, age 43, was hired by FedEx on May 16, 1994. He held an FAA ATP certificate with a multiengine land rating and a flight engineer certificate for turbojet-powered airplanes. The First Officer's ATP certificate indicated a type rating in the MD-11 (issued April 18, 2004). According to company records he had 3,723 hours total time, with 133 in the MD-11. The First Officer's most recent FAA first-class airman medical certificate was issued on August 18, 2004, with no restrictions. He completed an MD-11 proficiency check on April 18, 2004, and completed MD-11 tailstrike awareness training on March 26, 2004. A review of FAA records indicated that on May 6, 1994, the first officer was issued a notice of disapproval of application for a Military Competency written test. He subsequently passed the test on July 5, 1994, and was issued a Temporary Airman Certificate for a Commercial Pilot Certificate, Airplane Multiengine Land and Instrument Airplane.
N601FE, an MD-11F, serial number 48401, was the first production MD-11. It was delivered new to Federal Express on June 27, 1991. The airplane had previously been involved in an incident involving a flight control malfunction on approach to Subic Bay, Philippines, on June 16, 2002 (NTSB # DCA02MA042).
The Memphis aviation surface weather observation taken at 12:53 local time reported winds from 080 degrees magnetic at 10 knots, with 10 miles visibility under clear skies. The temperature was 28 degrees Celsius, and the dewpoint was 6 degrees Celsius. Sea level barometric pressure was 30.17 inches of mercury. The Memphis Automatic Surface Observation Station (ASOS) also recorded a five-minute average wind at 12:40 of 080 degrees at 12 knots, and at 12:45 a wind of 050 at 11 knots. Additionally, the ASOS recorded an instantaneous wind reading at 12:43 of 070 degrees at 9 knots with a gust of 060 degrees at 14 knots.
Performance calculations indicated a crosswind component of approximately 10 knots. According to the Limitations section of the FedEx Express MD-11/MD-10 Flight Manual, the maximum MD-11 crosswind speed component during an Autoland is 15 knots. The manual directs flight crews to adjust approach speed by increasing VREF by a wind additive. The wind additive is the greater of 5 knots, ½ the steady wind in excess of 20 knots, or the reported gust factor. The maximum wind additive is 20 knots.
AIDS TO NAVIGATION
Memphis International Airport runway 9 was equipped with an instrument landing system capable of Category I guidance, i.e. to a landing minima of 200 feet above the runway with ½ mile visibility minima an ILS approach. The FedEx MD-11/MD-10 Flight Manual (page 4-4-1-1) states that "an Auto-Land approach can be performed to any runway (CAT I, II, or III) providing it has a minimum TCH [Threshold Crossing Height] of 47 feet. Because of the inconsistencies in ILS beam qualities from one airport to another it becomes imperative that flight crews monitor the Auto-Land system performance on every approach. Approach charts should be reviewed for restrictions i.e., 'Glideslope Unusable Below 100 ft.' In these cases an Auto-Land approach must not be conducted." The Memphis ILS Runway 9 approach chart indicated that the TCH is 55 feet, and there were no pertinent restictions noted.
Memphis International Airport is located about 3 miles south of the city of Memphis, Tennessee. Runway 9 is constructed of grooved asphalt and is 8,946 feet long, and 150 feet wide. The touchdown zone is at 253.2 feet above mean sea level (msl). It is not equipped with a visual approach slope indicator.
The airplane was equipped with a Honeywell Model 980-4700 Flight Data Recorder. The recorder was in good condition and the data were extracted normally. For further information see the FDR Specialist's Factual Report.
The airplane was equipped with a Smith Industries Combined Voice and Flight Data Recorder, (CVR/FDR). The unit contained a two hour digital voice recorder. A CVR group was convened and prepared a transcript of 20 minutes and 2 seconds of the total 2 hour, 8 second recording. The transcript is attached to the CVR Group Factual Report.
WRECKAGE AND IMPACT INFORMATION
MEDICAL and PATHOLOGICAL INFORMATION
Flight crew toxicological testing was not accomplished.
TESTS AND RESEARCH
An Aircraft Performance Study was conducted to determine and analyze the motion of the aircraft and the physical forces that produce that motion. This study describes the results of using the flight recorder and radar data in defining, as far as possible, the position of flight 859 relative to the MEM runway 09 threshold throughout the approach, landing, and go-around. The study introduces the aircraft motion data collected during the investigation, describes the methods used to extract additional aircraft motion information from recordings, and presents the results of these calculations. The aircraft performance information described in this Accident Brief is described in detail in the Performance Study.
After the accident, FedEx maintenance personnel removed the autoland system and conducted bench tests. No pertinent fault codes were found, and the equipment was found to be operating normally.
An NTSB systems investigator reviewed the MD-11 spoiler logic, and compared the accident go-around to the previous landing and the landing immediately after the go-around recorded on the FDR. The spoilers appeared to operate as designed.
ORGANIZATIONAL AND MANAGEMENT INFORMATION
FedEx was incorporated in June 1971 and, in April 1973, began operating 14 corporate-type jet airplanes from the airline's hub at MEM. After the deregulation of the air cargo industry in 1977, FedEx began to expand, acquiring more and larger airplanes (including Boeing 727s and McDonnell Douglas DC-10s) and using multiple airports for its operations. In recent years, FedEx has added various models of Boeing, Airbus, Fokker, ATR, and Cessna airplanes to its fleet, including McDonnell Douglas MD-11s/-10s and Airbus A300s and A310s. At the time of the accident, FedEx operated a fleet of 624 airplanes with about 4,200 pilots.
According to Boeing and FedEx tailstrike awareness training material:
If a high sink rate or low bounce occurs, the PF should establish a 7½° pitch attitude and increase thrust until the sink rate has been arrested and/or a normal landing is accomplished. If a high bounce occurs, a low level go-around should be initiated. Low-level go-arounds are dramatically different than normal go-arounds. During low-level go-arounds, main wheel touchdown may be unavoidable. The PF must not exceed 10° of pitch or retract the landing gear until the aircraft is safely airborne with a positive rate of climb.
Additionally, the Fedex Crew Flight Manual states:
After reverse thrust is initiated, a full stop landing must be made. Do not attempt a go-around.
|Learning Keywords:||Operations - Bounce|
|Operations - Crew Resource Management|
|Operations - Tailstrike|
|Operations - Unstabilized Approach|
|Consequence - Damage - Airframe or fuselage|
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