NTSB issues safety recommendations following B737 tailwind landing accident

December 11, 2011

The NTSB has issued four safety recommendations and reiterated one older recommendation to prevent runway excursion accidents following tailwind landings.

On December 22, 2009, American Airlines flight 331, a  Boeing 737-800, N977AN, ran off the departure end of runway 12 after landing at Kingston-Norman Manley International Airport (KIN), Jamaica. The aircraft landed approximately 4,000 feet down the 8,911-foot-long, wet runway with a 14-knot tailwind component and was unable to stop on the remaining runway length. After running off the runway end, it went through a fence, across a road, and came to a stop on the sand dunes and rocks above the waterline of the Caribbean Sea adjacent to the road. No fatalities or postcrash fire occurred.

The investigation, being conducted by the Jamaica CAA, is still ongoing. The NTSB, being part of the investigation, decided to issue the following recommendations to the Federal Aviation Administration (FAA):


Require principal operations inspectors to review flight crew training programs and manuals to ensure training in tailwind landings is (1) provided during initial and recurrent simulator training; (2) to the extent possible, conducted at the maximum tailwind component certified for the aircraft on which pilots are being trained; and (3) conducted with an emphasis on the importance of landing within the touchdown zone, being prepared to execute a go-around, with either pilot calling for it if at any point landing within the touchdown zone becomes unfeasible, and the related benefits of using maximum flap extension in tailwind conditions. (A-11-92)

Revise Advisory Circular 91-79, “Runway Overrun Prevention,” to include a discussion of the risks associated with tailwind landings, including tailwind landings on wet or contaminated runways as related to runway overrun prevention. (A-11-93)

Once Advisory Circular 91-79, “Runway Overrun Prevention,” has been revised, require principal operations inspectors to review airline training programs and manuals to ensure they incorporate the revised guidelines concerning tailwind landings. (A-11-94)

Require principal operations inspectors to ensure that the information contained in Safety Alert for Operators 06012 is disseminated to 14 Code of Federal Regulations Part 121, 135, and 91 subpart K instructors, check airmen, and aircrew program designees and they make pilots aware of this guidance during recurrent training. (A-11-95)

The National Transportation Safety Board also reiterates the following recommendation to the Federal Aviation Administration and reclassifies it “Open—Unacceptable Response”:
Require all 14 Code of Federal Regulations Part 121, 135, and 91 subpart K operators to accomplish arrival landing distance assessments before every landing based on a standardized methodology involving approved performance data, actual arrival conditions, a means of correlating the airplane’s braking ability with runway surface conditions using the most conservative interpretation available, and including a minimum safety margin of 15 percent. (A-07-61)

This recommendation, A-07-61, was issued following the December 2005 runway excursion accident involving a Boeing 737-700 at Chicago-Midaway Airport.

More information:

NTSB issues recommendations on accessibility of flight deck fire extinguishers

August 15, 2011

Fire damage on the captain's windshield of this Boeing 757 (photo: NTSB)

The National Transportation Safety Board (NTSB) issued three safety recommendations on flight crews’ ease of access to fire extinguishers while oxygen masks are donned.

These recommendations were made following the Boards investigation into an incident in which the crew of a Boeing 757 were face with a fire at the windshield heat terminal connection in the cockpit. The flight crew diverted to Washington Dulles International Airport, VA, and landed without further incident. No evacuation was conducted, and none of the 7 crewmembers or 105 passengers sustained injuries.
In addition to the factors that led to the fire, NTSB’s investigation of this incident revealed a safety issue concerning 14 CFR Part 121 flight crews’ ability to readily access fire extinguishing equipment while wearing the oxygen masks and goggles that they are instructed to don at the first indication of smoke, fire, or fumes. During postincident interviews, the flight crewmembers of the incident flight indicated that they immediately donned oxygen masks and smoke goggles in accordance with the United Airlines Boeing 757 Smoke, Fire or Fumes checklist.
The captain reported that he left his seat because the flames were in front of him and he needed to immediately reach the fire extinguisher, located on the back wall of the cockpit next to the jumpseat.
The captain stated that, as he moved toward the fire extinguisher, his oxygen mask and smoke goggles were “torn off” because he had reached the end of the hose attached to the oxygen mask. He removed the fire extinguisher, put the mask and goggles back on, and discharged the extinguisher until it was empty. The captain reported that the fire was suppressed but reignited within seconds and that, as he moved toward the cockpit door to retrieve a second extinguisher from the cabin crew, his mask and goggles came off again. He retrieved the extinguisher, put his mask and goggles back on, and discharged the extinguisher, fully extinguishing the fire.

Therefore, the National Transportation Safety Board makes the following recommendations to the Federal Aviation Administration:

Require that the length of oxygen mask hoses in the cockpits of airplanes used in 14 Code of Federal Regulations Part 121 operations be increased, as necessary, to allow flight crews access to all required emergency equipment in the cockpit, as 6 well as to additional emergency equipment provided by the cabin crew via the cockpit door, while oxygen masks are donned. (A-11-79)

Amend Advisory Circular 120-80, “In-Flight Fires,” to provide clear guidance to flight crews concerning the type of breathing equipment to wear when combating a cockpit fire, taking into consideration the limitations of portable protective breathing equipment in both passenger and cargo operations. (A-11-80)

Amend Advisory Circulars 20-42D, “Hand Fire Extinguishers for Use in Aircraft”; 25-17A, “Transport Airplane Cabin Interiors Crashworthiness Handbook”; and 25-22, “Certification of Transport Airplane Mechanical Systems” to indicate that hand fire extinguishers in the cockpit must be reachable by at least one flight crewmember while wearing an oxygen mask. (A-11-81)

More information:


Indonesia: Investigators issue interim safety recommendations after Merpati crash

May 21, 2011

The Indonesian National Transportation Safety Committee (NTSC) issued three interim recommendations in the light of the May 7, 2011 fatal accident involving a Merpati passenger plane.

A Xian MA60 airplane crashed during a visual approach to Kaimana  Airport (KNG), Indonesia in weather conditions below VFR minima. All 25 on board were killed in the accident.

The investigation is still on-going, but the NTSC published three immediate safety recommendations based on their findings so far:

A. to Merpati Nusantara Airlines:
Ensure that visual flight is being conducted in accordance with VFR conditions, and conduct training on the MA60 Crew Simulator with an emphasis on CRM in the face of the bad weather.

B. to the Director General of Civil Aviation:
Monitor the implementation of the recommendations in point A , to be carried out  by Merpati Nusantara Airlines.

C. to Directorate General of Civil Aviation and Directorate of Airports:
Review the provisions of the use of facilities / equipment, especially the airport runway lights to enhance the safety of flight operations, especially in low visibility conditions.

More information:

Report: ATR-72 control difficulties following rudder maintenance

April 18, 2011

The U.K. AAIB published a Special Bulletin including three safety recommendations regarding control difficulties that were encountered by the crew of an ATR-72 during a post-maintance flight.

The aircraft had undergone routine maintenance at an engineering facility at Edinburgh Airport immediately prior to the incident flight.
Everything appeared normal during the crew’s pre-flight checks, which included a full-and-free check of the flying controls.
The aircraft took off at 21:22 from runway 24 at Edinburgh, with the co-pilot acting as the handling pilot.
After carrying out a standard instrument departure the crew climbed the aircraft to FL 230 at a speed of 170 kt with the autopilot engaged. As the aircraft levelled and accelerated through about 185 kt, the crew felt the aircraft roll to the left by about 5 to 10° and they noticed that the slip ball and rudder trim were both indicating fully right. The co-pilot disengaged the autopilot and applied right rudder in an attempt to correct the sideslip and applied aileron to correct the roll. He reported that the rudder felt unusually “spongy” and that the aircraft did not respond to his rudder inputs. Approximately 15° to 20° of right bank was required to hold a constant heading with the speed stabilised above 185 kt and a limited amount of aileron trim was applied to assist. Shortly after regaining directional control a FTL CTL caption appeared on the Crew Alert Panel (CAP) and the FLT CTL fault light illuminated on the overhead panel, indicating a fault with the rudder Travel Limitation Unit (TLU). The commander requested radar vectors from ATC for a return to Edinburgh, later declaring a PAN.

The crew carried out the required procedure from the Quick Reference Handbook (QRH). As part of the procedure they established that both Air Data Computers (ADC) were operating, before manually selecting the TLU switch to the LO SPD position. The aircraft had at this point temporarily slowed to below 180 kt. The co-pilot reported that on selection of LO SPD more roll control input was required to maintain heading and that roll authority to the right was further reduced. The commander therefore decided to return the TLU switch to AUTO and the required roll control input reduced. The green LO SPD indicator light did not illuminate.

An approach was made to runway 24, the aircraft was established on the ILS and was normally configured for a full flap landing. The crew added 10 kt to their approach speed, in accordance with the QRH. The co-pilot had to operate the control wheel with both hands in order to maintain directional control; the commander operated the power levers in the latter stages of the final approach. The co-pilot reported that the aircraft became slightly more difficult to control as the speed reduced, but remained controllable.

The aircraft landed just to the left of the runway centreline, whereupon the commander assumed control of the aircraft and applied reverse thrust. Despite the application of full right rudder pedal during the rollout, the aircraft diverged towards the left side of the runway. The commander re-established directional control using the steering wheel tiller. The aircraft was taxied clear of the runway and back to the engineering facility for inspection.

Th subsequent investigation and testing demonstrated that it is possible to incorrectly install the cams on the rear rudder quadrant shaft during maintenance. In this incident, the right hand cam was installed in the incorrect orientation and neither an independent inspection nor an operational test of the TLU system was performed. The incorrectly installed right hand cam was not detected prior to releasing the aircraft to service. When the TLU system automatically activated as the aircraft accelerated through 185 kt, the right hand roller encountered resistance as it came into contact with the upper lobe of the incorrectly installed cam, rather than slotting into the vee groove. This caused an uncommanded rudder input and associated control difficulties.

Three safety recommendations were made to the manufacturer, ATR.

The investigation is ongoing.

More information:

TSB critices Transport Canada on slow implementation of safety recommendation

April 11, 2011

A TSB investiation into a cabin smoke and passenger evacuation incident revealed that Transport Canada had not yet implemented an actual regulatory change after accepting a safety recommendation dated December 2007. The recommendation called for passenger safety briefings to include clear direction to leave all carry-on baggage behind during an evacuation.

On March 23, 2010 an Air Canada Airbus A320-211 (registration C-FTJO), operating as flight AC433, departed Montréal/Pierre Elliot Trudeau International Airport, Québec, for Toronto/Lester B. Pearson International Airport, Ontario, with 98 passengers and 6 crew members on board.
In cruise, 1 of the 3 hydraulic systems failed. The flight continued toward destination where the flight made an uneventful landing. While stopped on the runway awaiting a tow, smoke entered the cabin and an evacuation was ordered. Two crew members and 2 passengers received minor injuries during the evacuation.

The TSB concluded that:

  1. A leak from the number 1 yaw damper caused fluid to be ingested into the auxiliary power unit and sent through the air conditioning system, resulting in smoke entering the cabin.
  2. When the crew ordered the evacuation as a result of the smoke, several persons received minor injuries while exiting the aircraft via the emergency slides.

It appeared that many passengers deplaned with their carry-on luggage. It could not be determined whether this was due to the fact that they were not aware of the instructions given by the flight attendants and included in the safety card, or if they were aware, but chose to disregard them. Passengers would have been more aware of this restriction if information was included during the pre-takeoff and pre-landing passenger briefings, as per TSB recommendation A07-07.

The few injuries that did occur may have been aggravated by the fact that the slides were wet from the rain, and the resultant speed of the exiting persons was higher than normal. While the baggage did cause some minor injuries and delays at the bottom of the slides, it did not appreciably increase the evacuation time. Were this a higher level of threat or emergency, however, even a slight delay could have resulted in more serious consequences.

Transport Canada agreed with the Board’s recommendation (A07-07) that called for passenger safety briefings to include clear direction to leave all carry-on baggage behind during an evacuation. However, to date, no regulatory change has been implemented. Due to the extensive delay between TC’s acceptance of this recommendation and the implementation of actual regulatory change, identified safety dificiencies continue to persist.

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NTSB issues safety recommendations to prevent B737 elevator jam due to FOD

February 14, 2011

The U.S. National Transportation Safety Board (NSTB) issued five safety recommendations to the Federal Aviation Administration (FAA) to prevent the elevator of certain Boeing 737 models to become jammed as a result of foreign object damage to the elevator power control unit input arm assembly.

The recommendations were issued as a result of an incident involving a Boeing 737-400 in June 2009.

On June 14, 2009, a Boeing 737-400, registration number TC-TLA, operated as Tailwind Airlines  flight OHY036, experienced an uncommanded pitch-up event at 20 feet above the ground during approach to Diyarbakir Airport (DIY), Turkey. The flight crew performed a go-around maneuver and controlled the airplane’s pitch with significant column force, full nose-down stabilizer trim, and thrust. During the second approach, the flight crew controlled the airplane and landed by inputting very forceful control column inputs to maintain pitch control. Both crewmembers sustained injuries during the go-around maneuver; none of the 159 passengers or cabin crewmembers reported injuries. The airplane was undamaged during the scheduled  commercial passenger flight.

An investigation found that the incident was caused by an uncommanded elevator deflection as a result of a left elevator power control unit (PCU) jam due to foreign object debris (FOD). The FOD was a metal roller element (about 0.2 inches long and 0.14 inches in diameter) from an elevator bearing. During  its investigation of this incident, the NTSB identified safety issues relating to the protection of the elevator PCU input arm assembly, design of the 737 elevator control system, guidance and training for 737 flight crews on a jammed elevator control system, and upset recovery training.

The National Transportation Safety Board recommends that the Federal Aviation Administration:

Require Boeing to develop a method to protect the elevator power control unit input arm assembly on 737-300 through -500 series airplanes from foreign object debris. (A-11-7)

Once Boeing has developed a method to protect the elevator power control unit input arm assembly on 737-300 through -500 series airplanes from foreign object debris as requested in Safety Recommendation A-11-7, require operators to modify their airplanes with this method of protection. (A-11-8)

Require Boeing to redesign the 737-300 through -500 series airplane elevator control system such that a single-point jam will not restrict the movement of the elevator control system and prevent continued safe flight and landing. (A-11-9)

Once the 737-300 through -500 series airplane elevator control system is redesigned as requested in Safety Recommendation A-11-9, require operators to implement the new design. (A-11-10)

Require Boeing to develop recovery strategies (for example, checklists, procedures, or memory items) for pilots of 737 airplanes that do not have a mechanical override feature for a jammed elevator in the event of a full control deflection of the elevator system and incorporate those strategies into pilot guidance. Within those recovery strategies, the consequences of removing all hydraulic power to the airplane as a response to any uncommanded control surface should be clarified. (A-11-11)


ATSB: Manufacturing problem potential factor in recent A380 engine failure

December 2, 2010

The ATSB has issued a safety recommendation about potential engine problems in some Airbus A380 aircraft.

The ATSB is investigating an occurrence involving a Qantas A380 aircraft that experienced engine failure over Batam Island, Indonesia on 4 November 2010. The aircraft landed safely in Singapore having returned with the aircraft’s No 2 engine shut down. There were no injuries.

The ATSB has now issued a safety recommendation (AO-2010-089-SR-012) about potential engine problems in some Airbus A380 aircraft.

The safety recommendation identifies a potential manufacturing defect with an oil tube connection to the high-pressure (HP)/intermediate-pressure (IP) bearing structure of the Trent 900 engine installed in some A380 aircraft.

The problem relates to the potential for misaligned oil pipe counter-boring, which could lead to fatigue cracking, oil leakage and potential engine failure from an oil fire within the HP/IP bearing buffer space.

In response to the recommendation Rolls Royce, affected airlines and safety regulators are taking action to ensure the continued safe operation of A380 aircraft. The action involves the close inspection of affected engines and the removal from service of any engine which displays the suspected counter-boring problem.



NTSB concerned about training for mechanics and inspectors

May 28, 2010

Based on preliminary findings from the investigation of a partial gear up landing of a CRJ200 in December 2008, as well as prior investigative findings, the U.S. NTSB voiced its concerns about training for mechanics and inspectors. Two safety recommendations were issued and three older recommendations were re-iterated.

On December 14, 2008, about 17:00 local time, Air Wisconsin Airlines flight 3919, a Canadair CL-600-2B19 (CRJ-200), N407AW, landed at Philadelphia International Airport, PA (PHL), with the left main landing gear in the retracted position. The aircraft was being flown as a repositioning flight from Norfolk International Airport, VA (ORF) to PHL. There were no injuries to the two flight crew and one flight attendant on board the aircraft.

The flight crew received indications of a left main landing gear problem prior to landing and stated that they completed the applicable Quick Reference Handbook (QRH) procedures, but were unable to lower the left main landing gear. They elected to land with the nose and right main landing gear in the down and locked position and the left main landing gear up.

Maintenance had been performed on both the left and right main landing gear systems prior to the incident flight. Post-incident inspection of the aircraft revealed that, the upper attachment bolt for the left main landing gear uplock assembly, which is designed to be attached to both the uplock mechanism and the structure, was attached to the airplane structure only.

The NTSB concludes that the incident mechanic was not properly trained or supervised when he replaced the uplock assembly on the incident airplane for the first time, which led to the error in installation. Further, the error was not detected by the inspector. The NTSB is concerned that the Federal Aviation Administration (FAA) does not currently require mechanics to receive on-the-job training (OJT) or be supervised while performing required inspection item (RII) tasks for the first time.

Problems with untrained or unsupervised mechanics performing maintenance tasks for the first time have also been found during the NTSB’s investigation of the January 8, 2003,  fatal accident involving a Beechctaft 1900D  which crashed shortly after takeoff at Charlotte-Douglas International Airport, NC. The accident airplane underwent a detail six maintenance check.  One of the mechanics assigned to check the elevator control cable tension was receiving OJT under the supervision of a quality assurance inspector who failed to adequately supervise and direct the mechanic.

Therefore, the NTSB recommends that the FAA:

Require that mechanics performing required inspection item and other critical tasks receive on-the-job training or supervision when completing the maintenance task until the mechanic demonstrates proficiency in the task. (A-10-96)

Require that required inspection item (RII) inspectors receive supervision or on-the-job training on the proper inspection of RII items until the inspector demonstrates proficiency in inspection. (A-10-97)

AAIB: Flight director mode confusion cited in serious DHC-8 incident

March 12, 2010

FDR parameters of the approach of G-JECI (AAIB)

An investigation into a serious incident involving a DHC-8-400 on approach to Edinburgh Airport, UK revealed that Flight Director mode confusion led to a descent to within 800 ft of local terrain approximately 5 nm from the runway threshold.

On December 23, 2008 a de Havilland Canada DHC-8-402Q Dash 8, registered G-JECI, was being operated on a scheduled passenger service from Southampton to Edinburgh as BEE247S. As it commenced its final approach to runway 24 at Edinburgh the approach controller (APC) instructed the aircraft to turn onto a heading of 280° to intercept the ILS localiser, descend from 3,000 ft to 2,100 ft and maintain a speed of at least 160 kt until 4 nm from touchdown. During the descent the aircraft accelerated to approximately 200 kt with flap and landing gear up.

The aircraft did not level off as intended at 2,100 ft but continued to descend at a constant vertical speed such that it remained at all times below the ILS glideslope. At an altitude of approximately 1,800 ft, apparently without having noticed that the aircraft had descended below the cleared altitude before intercepting the ILS, the APC instructed the pilots to contact the aerodrome controller (ADC). At about this time Flap 5 was selected and the aircraft decelerated to approximately 180 kt.
The ground movement controller (GMC), who sat beside the ADC in the visual control room (VCR), saw the aircraft when it was approximately 5 nm from touchdown and noticed that it looked “substantially below the glidepath”. He mentioned this to the ADC. When shortly afterwards the co-pilot called, “tower jersey two four seven sierra is five and a half miles two four”, the ADC responded “jersey two four seven sierra roger and we’ve got you five miles out showing nine hundred feet is everything ok”.

The co-pilot replied “err affirm jersey two four seven sierra”. Not content with the response the ADC replied “jersey two four seven sierra how low are you planning on descending at the moment”. The co-pilot responded “err we’re gonna level now actually our glideslope capture obviously failed jersey two four seven sierra”. The controllers in the VCR saw the aircraft climb slightly and continue an apparently normal approach.

Attempting to regain the correct flight path manually, the commander initially experienced some difficulty disconnecting the autopilot and found that the aircraft tended to adopt a pitch attitude 8° below the horizon. When able to resume full control, at approximately 700 ft agl, he called for Flap 15 and landing gear down. The landing was completed without further incident.

A similar incident occurred on 8 May 2009 involving a DHC-8-400 on approach to Glasgow Airport.

Both incidents appear to have been initiated by Flight Guidance Control Panel (FGCP) selections which resulted in Flight Director modes other than those intended by the pilots. In the case of G-JECI, recorded data indicates that the altitude select mode was not armed after selection of a lower altitude. This problem would be alleviated if the altitude select mode was automatic upon selection of a new altitude and vertical mode, as is the case on several other aircraft types and as envisaged by the aircraft manufacturer in its discussions with operators.

The AAIB issued two safety recommendations:

Safety Recommendation 2009-005
It is recommended that Bombardier Aerospace enable automatic arming of the altitude select mode of the flight director fitted to Dash-8-400 series aircraft upon selection of a new altitude and vertical mode.

Safety Recommendation 2009-006
It is recommended that Flybe consider amending its standard operating procedures to require an altitude check whilst on final approach even when the pilots are in visual contact with the runway.

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