Commercial INCIDENTS (general discussion)

Summary:

Post here any incidents that have occurred to you that do not have a specific thread yet. (They will be moved to a specific thread in your behalf as soon as possible)

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time pressure... system malfunction... A Commercial Incident

Anonymous (guest) 22 Jan 2009 06:46

This incident occurred in early 2007. On the day the Boeing 747 flight had already been delayed for 3 hours. When the crew had reported for briefing, the aircraft still had six malfunctions, one of them being Left Outflow Valve AUTO INOP. On board the airplane, the flight crew found that the left outflow valve was indicating fully open. The maintenance was questioned by the PIC as to why the left outflow valve had not been deactivated closed as described in the MEL. At the time, the maintenance engineer was busy trouble shooting a thrust reverser problem. The reply was that the aircraft had been dispatched with the same malfunction items for quite some time and since there were no relevant EICAS messages displayed, Therefore, it should be OK for dispatch with no need for any further verification. With the maintenance engineer being busy with his job at hand, the flight crew decided not to bother him further and started their ground preparation procedures.

After 2 malfunctions were cleared, the maintenance log was signed and the PIC endorsed it without verifying the outflow valve’s position. The aircraft took off and after passing 6000ft, unusual cabin altitude indication appeared. The crew attempted to level off the aircraft at about 9000ft. However, the jet overshot 10000ft and the CABIN ALTITUDE warning horn went off. A descent was made to 9000ft and the problem was investigated. The crew found that the outflow valve was still in the fully open position, when it should have been closed after takeoff. The crew checked the operations manual, however they misunderstood the note written on the manual for this malfunction item to be- ‘the switch (would allow the outflow valve to be close manually) should not be operated’. They then made an attempt to reach the maintenance department, however, this failed at low altitudes. At the same time, they were under pressure by the ATC that they would soon be out of his control airspace and that they have to decide whether to climb or to turn back. After a brief discussion, and with all the contingency fuel used, the crew followed the PIC’s decision to return to the departure aerodrome. They dumped the fuel down to maximum landing weight. During the fuel dumping, they were able to contact the maintenance again, and they were advised to manually close the left outflow valve. The valve was closed and they landed back at the departure aerodrome.

The threat in this incident is that this aircraft was dispatched with multiple malfunctions. The flight had already been delayed for a couple of hours, and time pressure was put on the maintenance department to complete fixing the two malfunctions as soon as possible. Improper handling of the required maintenance actions by the maintenance department was the primary factor that caused this incident. The resolution of the crew after the discovery of the malfunction was safe, but was somehow unwise. The crew showed insufficient Threat Management skills. The outflow valve was not positioned according to the operations manual, and the crew did not take any action to manually correct its position. The Quick Reference Manual (QRH) checks were not initiated. This incident also shows lack of communication with the maintenance department.

Last edited on 28 Jun 2009 22:40 by JDPerezgonzalez Show more

Re: time pressure... system malfunction... A Commercial Incident

*AvIaTrIx* 24 Jan 2009 10:05

More about the Reason's Swiss Cheese Model here.

Last edited on 25 Jan 2009 21:58 by JDPerezgonzalez Show more

Re: time pressure... system malfunction... A Commercial Incident

JDPerezgonzalez 28 Jun 2009 22:39

[In behalf of Anonymous user, originally posted on 22 January 2009]

There are quite a lot that can be learnt from this incident. Firstly, the maintenance department should not have dispatched any aircraft when they cannot guarantee the safe operation of that particular aircraft, even under time pressure. Secondly, the crew should always consult the manual before accepting the aircraft for the flight. In this case, the crew did not take the required measures to break the chain of errors at the beginning and then failed to insist that proper corrective action be taken by maintenance. Instead, they were rushed and accepted the response from maintenance and remained silent. Thirdly, more training on the pressurisation system would be beneficial. If the crew had full knowledge of the system and could understand what the ‘could not be operated’ statement really meant on the operations manual, then the required action after the detection of the fault could have been done correctly. Fourthly, always complete the QRH checklist first before making any decisions. Here when the warning sounded, QRH was not followed before the crews’ decision to dump fuel.

As is often the case, there was a lengthy error chain in this incident as can be identified by using the Reason’s Model. These include the upper strategic management department to not properly manage available resources, and the line management who had not implemented procedures for the safe dispatch of an aircraft. Together these create an unsafe precondition for when the aircraft was dispatched. The unsafe act of the crew when signing the maintenance log led to the productive failure of not breaking the error chains before the flight, hence this incident. Luckily, the last barrier in the crew coming to realisation of the problem prevented this incident from developing into a disastrous accident.

From the Crew Resource Management (CRM) point of view, there are also many lessons that can be learnt. How to manage threat under time pressure should be more emphasised. This includes both the crew and maintenance. The crew to comply with the policy of confirming the desirable configuration for signing the maintenance log for the dispatch of an aircraft, and the maintenance department for its correct compliance. The threat management should also include effective workload management and teamwork management. Threat management requires that the threat be identified, then assigned a level of risk, and lastly to allow decisions to be made to minimise or eliminate the threat. Acceptance of an undesired state and ‘hoping that things will work out’ is choosing to ignore the threat.

Communication is also crucial in aviation. CRM should help to build an environment where message is not only communicated, but communicated effectively and clearly. In this case, between the crew and the maintenance department. Also, communication within the crew should encourage everyone to have a say, not just allow the PIC to make his decision. In abnormal situations it is critical that every crew member thinks and speaks if deferring to the PIC. A team can only function at its optimal strength when every crew member shares their opinions and knowledge.

This incident allows us to learn a lot from both the operational perspective, as well as from the Human Factor perspective.

Last edited on 28 Jun 2009 22:52 by JDPerezgonzalez Show more

Gear retracted...with the main wheels on the ground!

Anonymous (guest) 25 Jan 2009 12:40

This incident happened in late 2008 when a commercial MD-90 aircraft was flying a domestic route, departing out of an international airport and heading for a smaller domestic airport. Everything went well until the aircraft was approaching the active runway for takeoff. The Air Traffic Control (ATC) issued a clearance “After takeoff, turn left heading 290 degrees then contact departure”. The Pilot Monitoring (PM), in this case the first officer, started to wander whether the turn should be made at 400 AGL or at the end of the runway. He got distracted. During the takeoff roll, the PM called “Rotate” and immediately moved his hand onto the gear lever to retract the landing gear. At that instant, the crew heard a big bang noise coming from the main landing gear. After airborne, the left and right “MAIN GEAR UNSAFE” red warning lights were illuminated with the gear lever in the retracted position. The tower informed the crew that there were smoke coming out of the main gear area during lift off.

After being established on a heading of 290 degrees, and without first consulting to the Quick Reference Handbook (QRH), the flight crew decided to lower the landing gear again. This time they found three “GEAR DOWN” green lights with “GEAR DOOR OPEN” light illuminated. They then tried retracting the gear again. And, the left and right “MAIN GEAR UNSAFE” red lights illuminated with “GEAR DOOR OPEN” extinguished.

The flight crew then decided that they would action the ‘Red Light Illuminated With Landing Gear Handle Up’ checklist and informed cabin crew of the current flight condition. However, they got distracted and did not complete the ‘Red Light Illuminated With Landing Gear Handle Up’ procedure checklist, but instead continued to perform the unrelated “Unable To Raise Landing Gear Handle After Takeoff” checklist. After considering the time it had already taken in handling the gear problem, they decided to continue to their destination.

At their destination, the crew made two low approaches to allow the gear condition to be viewed by the company maintenance and ATC. Their conclusion was that the no.4 tire was damaged and the left gear door remained in open position when the landing gear in the fully down position. Before the final landing, captain informed all passengers and cabin crew the possibility of high vibration in the landing roll. Cabin crew also assisted all passengers to prepare for the emergency landing. During the landing roll, no.1and 3 tires bursted. Aircraft stopped 6500’ down on the runway. The Pilot In Command (PIC) did not issue evacuation instructions as there was neither fire nor gear collapse detected. All passengers were safe and picked up by the shuttle bus. However, both the aircraft landing gear doors and assembly suffered from serious damaged.

Last edited on 28 Jun 2009 22:42 by JDPerezgonzalez Show more

Re: Gear retracted...with the main wheels on the ground!

*AvIaTrIx* 25 Jan 2009 12:57

More on the considerations for abnormal situations after takeoff here.

Last edited on 26 Jan 2009 05:20 by *AvIaTrIx* Show more

Re: Gear retracted...with the main wheels on the ground!

JDPerezgonzalez 28 Jun 2009 22:41

[In behalf of Anonymous user, originally posted on 26 January 2009]

There are some obvious errors that can be observed in this incident. One of this being the PM retracts the landing gear right after the “Rotate” call, before checking the altimeter VSI for “Positive Climb” and hearing “Gear Up” command from Pilot Flying (PIC). The flight crew also recycled the landing gear without firstly, referring to the QRH. There was another critical procedure the flight crew had done wrong. The PM did not complete calling the ‘Red Light Illuminated With Landing Gear Handle Up’ procedure, but had continued with the unrelated ‘Unable To Raise Landing Gear Handle After Takeoff’ checklist.

These errors can lead to many underlying threats. These include the PM not complying with Standard Operating Procedures (SOPs), the damage of the gear door upon impact with the runway, the tire burst condition after takeoff, the wrong QRH initiated, as well as landing with the landing gear assembly damage and in a tire burst situation. These threats have the potential, when linked together, allow incidents to develop into disastrous accidents!

The two air- to- ground sensors of MD-90 to prevent gear retraction on the ground are mounted only in the nose gear. There will be no protection of early retract landing gear under the case like this. Mistake as to what the crew made in this case will cause serious impact to the flight safety, especially that gear door were open and brake was automatically applied for de-spin.

There are several lessons that can be learnt from this incident. Firstly, pilots should ensure that they have a full knowledge of the SOPs and QRH for their aircraft. In this case, according to the Flight Operations Manual (FOM), turns after takeoff should not normally be made below 400’ AGL, and it is recommended to turn at or above 400’ AGL. It is to be noted that even though the airlines hold regular proficiency training and checks for their pilots, it is still each pilots’ responsibility to ensure that they are, at all times, familiar with the QRH checklists.

Secondly, each crew should ensure that they have a full understanding of Flight Crew Training Manual (FCTM) Abnormal Operation. In this case, landing with ‘Abnormal Landing Gear Configuration’. Different aircraft may have slightly different concerns in handling situations like this. Therefore careful judgment must be exercised by the crew, with the consultation of the operations manual as to what the appropriate actions should be. Thirdly, Crew Resource Management (CRM) sessions for the flight crew should emphasise on areas such as crew coordination and workload management. Pilots can all learn from this incident. After all, as it is said “Try to learn from the mistakes of others. You won't live long enough to make all of them yourself”.

"TRAFFIC"!!

Anonymous (guest) 26 Jan 2009 08:28

This was a near miss incident that occurred in 2006 to a commercial aircraft during its cruising phase of flight. On that day, this aircraft was cruising at Flight Level (FL) 360 to its international destination. At the time of the occurrence, the radar service they were under had been terminated. Nine minutes after the termination, the Traffic Collision Avoidance System (TCAS) displayed opposite traffic approaching at the same flight level. When the traffic was 15 miles away, the Pilot In Command (PIC) decided to avoid the traffic earlier by turning left and descending. Landing lights were switched on to attract attention of the traffic.

At a distance of 10 miles, TCAS called “TRAFFIC” alert. The traffic was visual and approaching fast at 5 miles. The crew noticed that the opposite bound traffic did not change heading or altitude during the event. Also, there was also no response from the other traffic to the landing lights the crew had switched on. During the breakout maneuver to avoid the opposing traffic, bank angle momentarily exceeded 30 degree bank. A Controller Pilot Data Link Communications (CPDLC) text message was immediately sent to Air Traffic Control (ATC) to report the event. However, there was no response from ATC.

The PIC filed an incident report which was sent to the ATC unit involved. The reply from the ATC unit was that since there was no report of TCAS Resolution Advisory (RA), the report was not considered urgent. Additionally, the ATC unit apologised for the error and will improve their procedures to avoid similar event in the future.

Last edited on 28 Jun 2009 22:48 by JDPerezgonzalez Show more

Re: "TRAFFIC"!!

JDPerezgonzalez 28 Jun 2009 22:47

[In behalf of Anonymous user, originally posted on 26 January 2009]

Here is a brief introduction to how TCAS operates.

Low Hydraulics... how?

Jordan_Ng 28 Jan 2009 14:42

I am writing this with permission of an anonyous user, the pilot in command (PIC) of a commercial Jet.

The PIC was scheduled for a routine flight onboard an Airbus jet which had just gone through some major maintenance work. The engineers had cleared the aircraft for flight prior to departure.

The flight commenced without indication of any problems. however, during the run up checks before leaving the apron, the PIC noticed that the level of hydraulic fluid was decreasing rapidly. However, since it was still within limits, he decided to proceed with the flight in hope that it stabilizes.

As the airbus reached the holding point, the PIC noticed that the hydraulics had dipped below the lower limits of the system and the primary resevoir was almost empty! The PIC immediately decided to cancel the flight considering the safety of the passengers on board.

On a basic note, the airbus hydraulic system is built to comprise 3 integrated systems running independently to provide triple redundancy, should one system fail. This system runs throughout the aircraft and powers the brakes, langing gear acessories and various flight controls. In this instance, the drop in fluid was indicated on the primary system and could have resulted in the inability to retract the landing gears after take off and the failure of the normal brake system.

On further investigation, it was discovered that there was no leak. Infact, it was due to human error that the fulid levels were so low.

The Airbus Jet was discovered to have a worn out brake assembly during the routine inspection. The maintenance crew decided that the brake system needed to be changed. This task was carried out in these steps:

1. The wheel was removed to expose the brake system.

2. The hydraulic system was drained before the removal of the brake system.

3. The brake system was replaced.

4. The fluid reservoir was re-filled with hydraulic fluids and pressurised, to ensure that the lines were filled with the fluid.

5. The fluid levels in the tank will drop after pressurisation, therefore, the system was topped up again so that the whole system would be filled with the maximum amount of hydraulic fluid.

6. The wheel was re-attached and the aircraft cleared for flight.

in the case above, there was a change of shift after step 4. During this change, the technicians on the first shift failed to inform the technicians on the 2nd shift that the hydrulic system was not pressurised. When the second shift technicians took over, they cleared the aircraft for flight, assuming that step 5 had been completed already as the hydraulic gauges indicated a full reservoir. Infact, all the hydraulic lines were still empty.

This situation resulted in the sharp drop in hydraulic fluid during the jet's checks before take-off.

The change of shift caused distraction, and the lack of teamwork and communication also contributed to the error.

Lessons to be learnt
1. The indication of a system abnormality may be a symptom of another cause
The drop in hydraulic pressure signified a leak, however, the drop was due to empty lines in the hydraulic system.
on the other hand, an electrical failure may be the sign of a faulty generator, however, it may also stem from an electrical fire in the system.

2. The signs mentioned above must be treated with urgency. This is part of good airmanship
The decision to cancel the flight due to low levels of hydraulic fluid was wise of the PIC. A simple symptom may develop into a major problem in flight. the leak may cause the loss of contol of the aircraft should it have been caused by something else other than a empty hydraulic lines.

3. Do not assume that everyone knows what has or has not been done. Communicate progress to everyone, esecially those involved in the task.
The technicians on the first shift failed to communicate work progress to those on the 2nd shift. Therefore, the explicit details of the task were left to assumption.

4. Do not assume that work has been done. Go back 2 steps, re-check then proceed
The technicians completed steps 1, 2, 3, 4, and 6, missing out step 5 as the 2nd shift wrokers assumed that step 5 had been completed by the initial shift.

Re: Low Hydraulics... how?

edmarlo 29 Jan 2009 15:10

This incident is in a sense similar to American Airlines Flight 191. Maintenance work on intricate parts of the aircraft (brakes, engine) always require tedious procedures and oft eat into different shifts of the engineers.American Airways Flight 191 (DC-10) encountered an entire engine getting blown off one wing. Firstly the engine was being overhauled but the procedure of reattaching that portside engine needed so much time that the initial group of engineers that had initiated and planned the engine installation had to hand over duty to the next team of engineers. This resulted in an improper procedure that caused fatigue in the pylon attach point (see picture ) causing the entire engine mount to break off after take off.
Lesson here is that complex procedures should not be 'handed over' as often there is complex planning and strict SOP that should be adhered to.
As mentioned by Jordan Ng, compromising shift time would compromise communication, teamwork and ultimately flight safety.

Re: Low Hydraulics... how?

Kiwispanner 28 Aug 2009 06:00

I find the description of the above incident intriguing, as a LAME rated on the A320. While I am sure that the sequence described is how the operated perceived the procedure. It departs markedly from the procedure used to change an A320 Brake assy. Firstly there is no requirement to drain the Hydraulic systems (two in the case of an A320 brake change , yes the brakes are supplied by two independent systems) due to a check valve in the systems. Post fitment the task would require the brakes to be bleed and the system to be replenished. If the reservoir was filled even with significantly empty lines I have never observed the level drop to the point that a warning would be generated. The normal elapsed time to change a Brake assy including bleeding and replenishment of the Hydraulics is about an hour. Brake changes due to the slow rate of wear are normally scheduled into an overnight (or down time)package which would normally be tasked to one shift. It is likely that the problem encountered by the crew in this case was far more complex than a missed step in a simple procedure such as a stand alone brake change.
Having addressed my ingrained engineers need for accuracy I have to agree with the points raised by Jordan. The loss of Hydraulics or any other system is of major concern, and crews should be cautious.

It also highlights some of the issues faced by maintenance personnel ever night around the world, Yes it is important that good communication is very important and in this example apparently failed. The fact that most aircraft maintenance, on in service commercial aircraft is preformed at night all these issue are compounded by fatigue, the maintenance staff are working when there bodies and the environment tell them they should be asleep.

Rejected takeoff...!

Anonymous (guest) 30 Jan 2009 01:44

This incident happened to a commercial Boeing 747 during 2003. This flight proceeded as normal until takeoff. During taxi out to the active runway, ground control gave this aircraft at least six different instructions during that short amount of time. These instructions include requesting them to give way to other inbound and outbound traffic, as well as a frequency change.

On the initial taxi, the Pilot In Command (PIC) ordered the First Officer (FO) to set the flaps to 20degrees. The flight crew then completed the flight control checks and taxi checklist. All the while, the weather was deteriorating fast, and heavy rain was present. Due to the presence of heavy rain, as well as the numerous traffic and changing taxi clearances, the flight crew was under high pressure. At that time, there were other five aircraft in the take-off sequence.

The take-off checklist was completed before lining up on the active runway. Due to the poor weather conditions, extra care was given to taxi while doing the line up checklist. Flap indication on the Engine Indicating and Crew Alerting System (EICAS) was missed out! After the take-off clearance was issued, thrust increased N1 70% and TOGA switch (TOGA is an acronym used in aviation, standing for Take Off/Go Around switch) pushed. EICAS “CONGIG FLAP” warning message appeared with a warning sound.

The flight crew realised that flaps were not at take-off position. As the speed of the aircraft was 20 knots below the Rejected Takeoff (RTO) speed, the flight crew immediately commenced the Rejected Takeoff (RTO) procedure. The aircraft cleared the runway safely. After clearing the runway, the crew checked the aircraft systems and brake temperatures. They were all indicating normally. The flight crew completed the rest of the checklist and set the flap. Succeeding take-off was uneventful.

The shortcomings in crosschecking taxi and before take-off checklist, as well as Air Traffic Control (ATC) interruption, ground traffic and weather were all contributory factors to the event. A rejected take-off, even if commenced at low groundspeeds, is considered as an “Irregular Event” and as such requires assessment and lessons that can be learnt drawn out.

It is obvious that the standard error traps did not function correctly. The first officer checks the ailerons and elevators, the PIC checks the rudders and should both do the taxi checklist. These are the normal error traps, but there some deviation from procedures that some pilots use to increase the chance of trapping these errors. For example, some PIC don’t call for the ‘flight controls check’ until the flaps are in the takeoff position. This traps the unusual case where flap extension interferes with or damages the flight controls.

There are some other useful tips that will assist the flight crew in trapping these errors. Some pilots don’t conduct flap extension and flight control checks until they are taxiing on a straight section of taxiway. This is workload management, avoiding extra tasks during high workload times of turning at intersections or crossing active runways. By leaving the flaps and control checks until a straight taxiway allows the crew more time to focus on a thorough check of controls. Another suggestion in error trapping is to leave the status page in view until the control checks have been completed. If the lower EICAS is still in view, it means that process is incomplete. Also, it is advisable for the captain to put his hand on the flap lever when the checklist is called. This gives a tactile confirmation that the flap lever is in the correct position.

Many of these error traps are learned on older types of aircraft which had more frequent problems, but they are still good technique today. If any one of these error traps had been effective on this takeoff, they would not have heard the final error trap/ warning, which is the ‘Configuration Warning’.

In this particular case, the flow pattern of the crew was interrupted by outside sources thereby missing setting of flaps. The threats were not recognised. The flight crew should be more diligent in the performance of their duties to avoid similar occurrence. In addition, “Line Oriented Flight Training (LOFT)” sessions should also be prepared by the Crew Resource Management (CRM) group of each airline to enable the flight crew to improve in threat and error management.

No airspeed...?!!?

Anonymous (guest) 31 Jan 2009 10:05

This incident occurred in a commercial McDonnell Douglas MD- 11 aircraft in 2004.

The ground preparation was normal and the airplane started pushing back for the engine start almost on-time. When the tower cleared the flight for take-off from the active runway, Pilot Flying (PF) advanced the thrust lever to stabilise the engine and then call “STABLE” allowing the engine to reach takeoff thrust. Just before the 80 knots procedural call, PF observed the airspeed tape was not displayed on his Primary Flight Display (PFD). PF called “STOP” at the same time 80 knots call was made. The Rejected Takeoff procedure (RTO) was initiated, and the aircraft vacated the runway and stopped at hold line.

The reason for RTO was discussed among crew followed by radio contact to company maintenance personnel. After giving them the details, maintenance suggested returning to ramp for thorough check. Both crew concurred this view and returned for inspection.

It was found during the inspection that there is a problem on the left angle of attack and a dead bug blocking captain’s pitot heat. A blocked pitot will cause an erratic airspeed indication. In flight, this condition will be accompanied by different warnings and alert, along with wrong airspeed indication. In this case, timely recognition of the problem followed by decision to abort the take off during the above event, demonstrated crew adherence to Standard Operating Procedure and quick decision making skills.

While the decision to abort usually rests with the Pilot In Command (PIC), other crew members have valuable information that will aid his decision making. This information includes a clear recognition of the primary threats based on knowledge of the aircraft systems, aircraft operating procedures and policy as well as regulations. The ability to ‘communicate the right amount of information at the right time with the right amount of urgency’ is at the heart of successful communication as seen from a Crew Resource Management (CRM) Skills point of view. Although a low speed abort has threats and challenges. An abort at high speed requires assertive threat management and decision making based on learned processes that equip the crew to make the right choices. Always assume that something WILL go wrong, be ready and on the alert at all times. With this kind of attitude, there will not be any ‘surprises’ that cannot be taken care of!

Re: No airspeed...?!!?

*AvIaTrIx* 31 Jan 2009 10:43

Here is an interesting fact I came across when browsing through the Aviation Safety Network website. It states that worldwide, there had been number of accidents contributed by blocked pitot, some ended up with fatalities and most of them resulted in substantial damage to the aircraft. Flight Safety Foundation recorded, from 1996 to 2006, seven accidents caused by blocked pitot involving different aircrafts with total fatalities of 339 (source: Aviation Safety Network – Aviation Safety database). Some larger aircraft’s pitot static system is too high for inspection by pilots. However on aircraft fitted with pitot static system that allows for pilot inspection, a thorough pre- flight including checking for blockage of the pitot static system can prevent similar situation from happening!

the cabin door...is missing?!!?

Anonymous (guest) 31 Jan 2009 13:52

This incident occurred during mid 2003. A Boeing 777-200 was scheduled to carry passengers from an international airport to another international destination.

The pilots carried out all normal pre- flight procedures and waited for passengers to board the plane. Everything was going well until a radio transmission. The ramp controller misunderstood the message “Missing Passengers under control” as “Boarding completed”, and assumed that he had authorisation to close the doors, release aircraft and retract the boarding bridge. When the last 2 passengers arrived (boarding bridge not retracted), the ramp controller requested to reopen one of the doors through chief flight attendant by hand signal. However, the chief flight attendant did not inform the Pilot In Command (PIC) that they would reopen the door for passengers. The door was left open. The PIC was not aware that the door had been left open. The maintenance, too did not notice the boarding bridge had not been retracted, as they were standing on the wrong side of the aircraft. During push back, this cabin door was torn off by the passenger boarding bridge. The flight was terminated and the crew and passengers deplaned safely after the incident.

This incident, although not fatal, was caused by the carelessness of the flight crew, the ground staff, and the maintenance personnel. It is vital for every airline company to ensure that all staff members clearly understand the meanings of the technical language being used around the aircraft, and ensures that it is being effectively communicated. In this incident, the difference between “Under control” and “Boarding completed” was not effectively communicated.

Another suggestion is that once all the cabin doors are closed, inform PIC, through maintenance, of any operation (including reopening the cabin door) that needs to be conducted, and obtain approval from PIC before taking any action. In this case, this extra procedure can allow the PIC to ensure that before reopening the cabin door, the parking brake will be set and the chocks in place.

Effective communication should also be maintained between the PIC and the cabin crew. If PIC receives a request from maintenance, the PIC has to inform the cabin crew and vice versa. It is also advisable that prior to putting each changes or request into action, the cabin crew double-checks and confirms this action with the PIC. And from there, the message can be passed to the ramp controller to reopen the door. The ramp controller must not operate the door by himself without notifying the PIC, or the cabin crew.

It is vital that to ensure that all doors are closed before initiating push back. This procedure should involve all flight crew, cabin crew and maintenances’ confirmation. The flight crew should especially, check the door secure lights on their instrument panel. This needs to be checked visually as there are no aural warnings when the doors are left open during pushback or taxi. It is also advisable that the maintenance, the key man to ensure the safety before push back operation, shall always be on the side of the aircraft which connects the passenger boarding bridges. All incidents are caused from chains of error. If all staff fully complies with the company policy and procedures, fully cooperate with each other, maintain good team work, pay more attention on every chain of operation, then the incidents can be prevented.

Turning right... oh no!!

Anonymous (guest) 01 Feb 2009 07:33

This incident happened in 2004 to an A330 commercial aircraft carrying passengers to an international destination.

The flight proceeded as normal until the approach at their destination. The crew conducted an ILS approach and it was flown by the Pilot In Command (PIC). At minimums there were no visual cues and a ‘Go-around’ was executed. On contact with the Tower Air Traffic Control (ATC) advised “XXX, follow the missed approach procedure…” and instructed them to contact control. The First Officer (FO) changed over to the new frequency.

At some point during the execution of the missed approach which required a left turn,
the PIC found that the lateral mode, “NAV”, had not engaged. During this time the aircraft was tracking out on the runway heading. The FO then made a request of approach control to maintain runway heading. ATC responded by assigning left turn 090 degrees and to contact ATC on another frequency.

By this time the aircraft was climbing through approximately 3800 feet for the missed approach altitude of 6000ft but still maintaining the runway heading. About this time, when the FO was making contact on the newly assigned frequency, the PIC pulled the heading select knob and dialed in a right turn to 090 degrees. The FO noting this requested a right turn from ATC rather than the left turn as instructed by ATC.
ATC restated “Left turn 090” and the FO acknowledged again “Left turn 090”. But the aircraft continued turning right to the heading 090.

After the control realised the aircraft was well into a right turn the flight crew was asked to confirm they were in fact in a right turn and not left turn. The FO replied in the affirmative. ATC then reissued the clearance to the flight to continue the RIGHT turn to the assigned heading. By this time the aircraft was climbing through approximately 4000 feet to the 6000 feet required in the missed approach.

At the time, the other parallel runway was being used for departures. Another B 747-400 was departing from this runway and also was climbing to 6000 feet. To avoid conflict with this B 747, the controllers immediately stopped the climb of this aircraft at 4000 feet. The flight crew on that flight raised an inquiry because of the violent manoeuvre that was required to arrest the climb and level off at 4000 feet. The flight crew of the A330 was then vectored for a second approach which was uneventful.

When analysing this incident, various threats can be identified. Threat One, the prevailing weather at destination airport was a major threat factor, where the runway visibility was restricted by fog. However, this threat was managed properly by the crew by executing a missed approach. Threat Two, the captain claimed that the lateral navigation did not go to “NAV” mode. This automation problem was mismanaged as the aircraft remained on its original flight path from the time the missed approach was executed instead of tracking the missed approach procedure as published. Threat Three, the transfer from one frequency to another as instructed by ATC caused a distraction, as well as additional workload to the crew. This threat too, was mismanaged as the crew failed to comply with the ATC instructions.

Threat one was properly managed. However, threat two and three were missed, inducing many errors. Error One being lack of automation knowledge of the flight crew. This automation problem appeared due to the flight crew not selecting a different mode or level of automation to correct the aircraft’s flight path. Error Two being navigational error, which was induced when the crew missed to crosscheck and monitor the flight path. Error Three is a communication error when the flight crew misinterpreted ATC Instructions. Instead of following the missed approach procedures as published and instructed, the flight crew maintained runway heading. Also, an instruction was given to turn left, but instead a turn to the right was made. Error Four was a procedural error, when the PIC selected 090° heading– by dialing a turn to the right. The crew failed to respond timely and appropriately to these errors, which led to an undesired aircraft state. This undesired aircraft state eventually lead to this incident.

Missed approach is a very busy procedure and increases cockpit workload substantially. Pilot Flying’s (PF) priority task is to FLY the appropriated missed approach path use all available sources (A/P is recommended), and only if time or workload permits, modification of the flight management system to meet the miss approach path may be only attempted by Pilot Monitoring (PM). ‘AVIATE’ the aircraft always comes first. In no circumstances, the pilot should try to fly differently than the missed approach path unless ATC clearance has received. PM’s function is more than just ATC communication. Monitoring the aircraft’s flight path, and supporting the PF with information required for the phase of the flight is essential. Many valuable lessons can be learnt from this incident. Let us learn from the mistakes of others… because you won’t live long enough to make all of them yourself!

Remember to remain...sterile!

Anonymous (guest) 01 Feb 2009 10:28

This incident happened in 2005 to a Boeing 747 aircraft bound for an international airport. The duration of the flight was 3 hours. Both of the flight crew were very experienced and have over 15,000 jet hours altogether, and had past operational experience to that international destination.

Both of the flight crew was well rested and all preflight duties and procedures were carried out normally. After push back, and completion of the after start check by the first officer (FO), somehow the lower Engine Indicating and Crew Alerting System (EICAS) was selected to OFF. Normally at this point it would be selected to display the status page after engine start.

Taxiing out to the active runway, the PIC decided to delay configuring the aircraft until it was clear of the congested area. The initial taxi instructions from Air Traffic Control (ATC) were to “turn right on XX, hold short of YY”. After reaching YY we were sequenced behind two other aircraft for take off. During the taxi sequence, the flight crew ignored the sterile cockpit rule and initiated a few superfluous conversations. After reaching the hold short line of the active runway, the flaps, flight control and taxi check was not accomplished.

ATC issued instructions to line up and wait after the landing aircraft had crossed the threshold. With this clearance, the PIC started to taxi into take off position while commanding for the Before Takeoff Check. While lining up, the PIC was mainly looking outside when FO was carrying out the before take off check. The PIC failed to visually confirm the flap position on the upper EICAS nor that the flap handle was in the take off position. After take off clearance was issued the PIC stood the throttles up which instantaneously triggered the ‘Take Off Configuration Warning’. The PIC immediately retarded the throttles to idle before the engine could spool up while the aircraft had just begun to roll. The aircraft taxied off the first taxiway and was brought to a complete stop. After a brief discussion with the FO, the flight crew decided to taxi back to the runway and continue the flight to their destination. The subsequent take off and ensuing flight were carried out normally without further incident.

The greatest threat in this event was complacency caused by familiarity with airport, route, crew and good weather as they were taking off from base airport. ‘Identical and repetitive flight’, even though it is not in the form of a threat being identified in ‘Threat Management’, it is a potential threat. Being too used to doing something can seriously lower flight crews’ situational awareness. In this case, the crew did not remain sterile below 10,000 feet. They allowed outside distractions to impede cockpit discipline. Therefore, this resulted in their failure to complete procedures at the correct time. The repetitive checklist also made the flight crew to rely on habitual and expected visual cues as memory aids, and not confirming settings visually.

‘CONFIG Warning Systems’ were being implemented as a mechanical error trap because many pilots were getting caught in similar circumstances as this event. The aircraft system and standard procedures are designed to provide a few error traps. In this case, the first error trap is physically extending the flaps. This requires two people, the PIC who decides when to set the flaps and the FO who actually performs the task. The second error trap is the taxi checklist. Doing this at a suitable time is important, preferably when taxiing in a straight line or when stopped with the park brake on. The third and last error trap is the ‘CONFIG warning’ and has in the past saved many lives. Another recommendation is to use another error trap in future by ‘touching and pointing’. This is a technique used by many pilots who want to reduce the chances of falling into an error.

However, some pilots increase their error traps by making no unnecessary conversation when taxiing. There is never an excuse for doing procedures in a rush and pilots should always manage their time properly. It is easy to get distracted during critical phases of flight especially if you enjoy flying with a friend and feel the need to have a good conversation. One method of getting all the crew to stop the conversation and return to disciplined operations is to say something like “Okay, back to business”. It is each and every flight crews’ responsibility to manage the climate within the cockpit.

This event showed how easily we can get distracted when performing repeated tasks. The error traps are built into our system and each time when we drift away from the Standard Operating Procedures (SOPs) we might remove one or more of those error traps! Therefore remember to remain sterile, especially during critical phases of flight!

Re: Remember to remain...sterile!

*AvIaTrIx* 01 Feb 2009 11:39

I came across some recommendations from a member of the Crew Resource Management (CRM) team (of a commercial airline) for ‘trapping and avoiding errors’ for similar type of incidents. The recommendations are,

1. Maintain cockpit discipline at all times
2. Remain sterile below 10,000 feet
3. Query non-typical visual cues in a timely manner
4. Standardise the timing of commanding the checklists and control check for each
and every flight
5. Verifying the checklist items by sight but also through tactile feedback by
placing a hand on the item being called and pointing to any applicable EICAS indication
6. Avoid using the EICAS (the manner in which it’s displayed) as a memory aid to
initiate a procedure or action

Watch out for flap 'maximum limit speed'...!

Anonymous (guest) 03 Feb 2009 02:07

This incident occurred to a commercial Boeing 747 during its approach phase into an international airport during 2003.

This aircraft was at a higher altitude than usual during radar vectors and approach to an international location. The descent profile was further complicated by heading deviations due to thunderstorms around the area. Descending through 13,000 feet, the Pilot Flying (PF), in this case the Pilot In Command (PIC) announced and selected Flight Level Change. The First Officer (FO), in this case the Pilot Monitoring (PM) was expecting him to reduce speed to 250 knots by 10,000 feet. Requests for heading changes for weather avoidance ensued.

Further clearance to descend was given, and as the aircraft was high and fast, the PF asked for Flap 1. While replying to Air Traffic Control (ATC) instructions, the PM glanced at the flap placard speed and selected Flap 1. After engaging ATC, PM noticed that their speed was above the flap limit speed. The flap lever was retracted immediately. The flight crew could not ascertain whether the flap had in fact extended as selected since the flap lever was retracted immediately. The flight crew informed maintenance of what had happened and wrote it up in the technical log as a defect.

Flaps are normally used to dissipate extra height and speed of an aircraft. However, for a large aircraft fitted with speedbrakes, if greater descent or deceleration rates are desired, extend speedbrakes. The flaps are not meant to be used as drag devices and normally not used for increasing descent rate. Extend the flaps only when conditions require a reduction in airspeed below flaps up manoeuvring speed. It is recommended that flaps are extended when speed is as close as possible to the clean or current flaps manoeuvring speed instead of near flaps maximum limit speed. Never extend flaps above its limiting speed. Extension above flaps maximum limit speed may cause structural damage to the flaps. Therefore it is crucial to always confirm that you are below flap extension speed before extending the flaps.

Also, in high workload conditions, crosschecking and monitoring should be carried out more intensely. ‘Monitoring and crosschecking’ is the best tool for preventing damage, violations or embarrassment. All professional pilots should admit that they can make errors, and should therefore appreciate that good monitoring and crosschecking is essential in modern cockpits.

Re: Watch out for flap 'maximum limit speed'...!

Ben Hoffman (guest) 14 Sep 2009 06:19

This situation could have been avoided by practicing better communication. There were two failings here

1) The pilot monitoring should have been assertive and voiced his concern about the 250kt below 10,000ft restriction (this restriction is commonplace internationally).
2) The pilot flying's use of flap instead of speedbrakes

The pilot monitoring has been made aware of a threat (threat detection) through his expertise (knowledge of procedure (speed restriction) and aircraft systems (speedbrake vice flaps)) but has failed to practice the throughput of communicating (communication/assertivness/teamwork).

The pilot monitoring was also busy speaking with air traffic control (ATC) which is in itself a stressful situation during the approach phase of the flight as there can be many frequency changes (various TMA sectors) and instructions to comply with.

Because of the poor communication between the flight crew; the flaps were extended above maximim manuvering speed.

Re: Watch out for flap 'maximum limit speed'...!

paperplane 25 Jul 2017 12:06

In every case of such situation, there are human errors. Not only the appropriate statistic is enough, was this deciphered from the black box?I usually do some reports about this, but from time to time.

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