Category Archives: NTSB

NTSB issues recommendations to the FAA for the evaluation and certification of lithium-ion batteries on Boeing 787s

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The National Transportation Safety Board (NTSB) (Washington) has issued a series of recommendations related to the evaluation and certification of lithium-ion batteries for use in aircraft systems, as well as the certification of new technology.

The five safety recommendations, all addressed to the Federal Aviation Administration (FAA) (Washington), are derived from the NTSB’s ongoing investigation of the January 7, 2013, fire event that occurred in a lithium-ion battery on a Boeing 787 that was parked at Boston Logan Airport.

Investigators found that the battery involved in the Boston 787 fire event showed evidence not just of an internal thermal runaway but that “unintended electrical interactions occurred among the cells, the battery case, and the electrical interfaces between the battery and the airplane.”

The 12-page safety recommendation letter said that the processes used in 2006 to support the certification of the lithium-ion battery designed for the 787 were inadequate, in part, because there is no standardized thermal runaway test that’s conducted in the environment and conditions that would most accurately reflect how the battery would perform when installed and operated on an in-service airplane.

Further, the NTSB said that because there is no such standardized thermal runaway test, lithium-ion battery designs on airplanes currently in service might not have adequately accounted for the hazards associated with internal short circuiting.

In its examination of the challenges associated with introducing newer technologies into already complex aircraft systems, the NTSB said that including subject matter experts outside of the aviation industry “could further strengthen the aircraft certification process” by ensuring that both the FAA and the aircraft manufacturer have access to the most current research and information related to the developing technology.

To address all of these issues, the NTSB asked the FAA to do the following:

1. Develop an aircraft-level thermal runaway test to demonstrate safety performance in the presence of an internal short circuit failure
2. Require the above test as part of certification of future aircraft designs
3. Re-evaluate internal short circuit risk for lithium-ion batteries now in-service
4. Develop guidance for thermal runaway test methods
5. Include a panel of independent expert consultants early in the certification process for new technologies installed on aircraft

“The history of commercial aviation is one in which emerging technologies have played a key role in enhancing flight safety,” said NTSB Acting Chairman Christopher A. Hart. “This is why it’s crucial that the process by which these technologies are evaluated and certified is as robust and thorough as possible. These recommendations will take us further in that direction.”

The final report on the January 2013 Boston 787 battery fire investigation is estimated to be completed in the fall.

Read the full report: CLICK HERE

Read about the original Boston JAL Boeing 787 incident: CLICK HERE

 

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NTSB Chairman Hersman’s briefing on the Asiana Airlines Boeing 777 crash at San Francisco

National Transportation Safety Board’s Chairperson Hersman briefs the media at yesterday’s hearing in Washington on the Asiana Airlines Boeing 777 crash. The main theme of the investigation is centered around the overuse of automation.

Read the analysis by Reuters: CLICK HERE

NTSB: The captain took over Southwest flight 345 seconds before its hard landing at New York LaGuardia Airport on July 22

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The National Transportation Safety Board (NTSB) (Washington) has issued this statement regarding the investigation of the hard landing of Southwest Airlines (Dallas) flight 345 at New York (LaGuardia) on July 22, 2013:

In its continuing investigation of the July 22 accident in which Southwest Airlines flight 345, a Boeing 737-700, landed hard at New York’s LaGuardia Airport (LGA), the National Transportation Safety Board has developed the following factual information:

  • The captain has been with Southwest for almost 13 years and has been a captain for six of those years. The captain has over 12,000 total flight hours, over 7,000 of which are as pilot-in-command. In 737s, the captain has over 7,900 hours, with more than 2,600 as the pilot-in-command.
  • The first officer has been with Southwest for about 18 months. The pilot has about 5,200 total flight hours, with 4,000 of those as pilot-in-command. In 737s, the first officer has about 1,100 hours, none of which are as the pilot-in-command.
  • This was the first trip the flight crew had flown together and it was the second leg of the trip. The first officer had previous operational experience at LGA, including six flights in 2013. The captain reported having flown into LGA twice, including the accident flight, serving as the pilot monitoring for both flights.
  • The en route phase of the flight, which originated in Nashville, was characterized by the flight crew as routine. On approach into LGA, the first officer was the pilot flying and the captain was the pilot monitoring. SWA 345 was cleared for the ILS Runway 4 approach.
  • The weather in the New York area caused the accident flight to enter a holding pattern for about 15 minutes. The crew reported that they saw the airport from about 5-10 miles out and that the airplane was on speed, course and glideslope down to about 200-400 feet.
  • The crew reported that below 1,000 feet, the tailwind was about 11 knots. They also reported that the wind on the runway was a headwind of about 11 knots.
  • SWA 345 proceeded on the approach when at a point below 400 feet, there was an exchange of control of the airplane and the captain became the flying pilot and made the landing.
  • The jetliner touched down on the runway nose first followed by the collapse of the nose gear; the airplane was substantially damaged.

At this point in the investigation, no mechanical anomalies or malfunctions have been found. A preliminary examination of the nose gear indicated that it failed due to stress overload.

Investigators have collected five videos showing various aspects of the crash landing. The team will be analyzing these recordings in the coming months.

Parties to the investigation are the Federal Aviation Administration, Boeing Commercial Airplanes, Southwest Airlines, and the Southwest Airlines Pilots Association.

This is a factual update only and no interviews are being conducted.

Southwest Airlines’ landed nose wheel first at LaGuardia Airport

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Southwest Airlines‘ (Dallas) Boeing 737-700 involved in the crash landing at New York’s LaGuardia Airport on July 22 landed with the nose wheel striking the runway first (the aircraft did not flare fro landing) according to the NTSB. The NTSB issued this statement:

The National Transportation Safety Board released factual information from the July 22 accident involving a Southwest Airlines Boeing 737-700 landing at New York’s LaGuardia Airport. The airplane’s front landing gear collapsed on landing.

  • Evidence from video and other sources is consistent with the nose-gear making contact with the runway before the main landing gear.
  • The flight data recorder on the airplane recorded 1,000 parameters and contained approximately 27 hours of recorded data, including the entire flight from Nashville to New York.
  • The cockpit voice recorder contains a two-hour recording of excellent quality that captures the entire flight from Nashville to New York and the accident landing sequence.
  • Flaps were set from 30 to 40 degrees about 56 seconds prior to touchdown.
  • Altitude was about 32 feet, airspeed was about 134 knots, and pitch attitude was about 2 degrees nose-up approximately 4 seconds prior touchdown.
  • At touchdown, the airspeed was approximately 133 knots and the aircraft was pitched down approximately 3 degrees.
  • After touchdown, the aircraft came to a stop within approximately 19 seconds.
  • A cockpit voice recorder group will convene at NTSB laboratories in Washington to transcribe the relevant portion of the accident flight.

Southwest Airlines: AG Slide Show

Asiana Airlines’ pilot sees a bright light on the final approach

National Transportation Safety Board (NTSB) (Washington) has conducted its final press conference in San Francisco. The landing Asiana Airlines pilot reported a bright light source on his final approach (reflection of the sun on the water?). The pilot looked away and did not think it blinded him. The other pilot did not report any source of light. Here is the briefing from yesterday afternoon (July 11). The final accident report will probably take a year or longer before it is issued. If there are any recommendations, the NTSB will issue those recommendations sooner to the Federal Aviation Administration (FAA).

Meanwhile the remains of the Boeing 777 are slowly being removed.

The latest (July 10) NTSB briefing on the Asiana Airlines crash

The National Transportation Safety Board (NTSB) issued this briefing on the Asiana Airlines crash at San Francisco late yesterday (July 10). The briefing includes new information on the pilots.

NTSB to conduct teardown examinations on Boeing 787 batteries cells with CT scans

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The National Transport Safety Board (NTSB) (Washington), which is still investing the Boeing 787 battery fire at Boston, is seeking help in conducting teardown examinations of Boeing 787 battery cells. The NTSB is asking for help with the CT scans.

The NTSB issued this statement:

The NTSB is planning to conduct teardown examinations as soon as possible of several aircraft batteries similar to one involved in an aircraft incident. This urgent requirement is in support of accident investigation DCA13IA037 that occurred in Boston, MA. To facilitate those examinations, CT scans of these batteries and their subcomponents are required to non-destructively determine as much information as possible about those components. In addition, batteries and battery cells of the same type which have been subjected to known test conditions will also be scanned. These scans will be conducted both before and after the test conditions are applied. Since these batteries are of the lithium ion type and have substantial shipping restrictions (including a requirement for ground shipping only using specially qualified hazardous materials shippers which would cause a delay of several days to accommodate), these scans need to be conducted at a location close to Washington, D.C. to allow the NTSB to transport the battery to the contractor and thereby avoid shipping and other logistical complications. They must also be completed within the shortest timeframe possible to provide the fastest possible receipt of this information to avoid potential future accidents involving this type of aircraft battery. Since the FAA has recently approved a plan intended to result in the Boeing 787 being approved for a return to service, the information from these tests (and the CT scans required to support these tests) is needed as soon as possible. A scan report that documents items such as the x-ray source power used, x-ray focal spot size, detector used, integration time, number of views, image pixel size, slice thickness, total length scanned, number of slices, etc. is due no later than 10 days after the end of the scanning activity. The NTSB has a requirement for CT scanning services to begin on May 6, 2013. Therefore, this requirement is urgent.

 

The NTSB has a requirement for CT scans of eight (8) Boeing 787 batteries cells. In addition, the NTSB has a requirement for additional scanning work for up to 40 additional battery cells or their equivalent scanning effort to be used as needed at the discretion of the NTSB. The scanning work for the “up to 40 additional battery cells” will be conducted in two installments. The cells will first be scanned in a “before testing” configuration, and then scanned again after testing has been completed with the cells. Finally, the NTSB requires at least 2 digital radiographs per component (90 degrees apart).

Read the full report: CLICK HERE