Aircraft Loading Error
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Aircraft Loading Error

December 2, 2019


On Tuesday 13th December 2016, a Virgin Australia
Boeing 737-800 aircraft was being prepared to operate flight 1393 from Adelaide, South
Australia to Brisbane, Queensland. At 9:27 Central Standard Time, the graphical
load instruction report was sent to the ramp staff allocated to load the aircraft. Virgin Australia used an electronic load control
system, which was accessed by the leading hand on a mobile tablet device to organise
the loading of the aircraft. The GLIR indicated the Brisbane bound bags
and all cargo (including seafood and four dogs) were to be loaded in the forward compartment,
and the bags which would be transferred to connecting flights and the priority Brisbane
bags were to be loaded in the aft compartment. While loading the aircraft, a member of the
loading staff advised the leading hand that the Brisbane bags would not fit into the compartment
with the cargo unless they were placed on top of the dog crates. If the bags were placed on the crates, the
loading staff thought the dogs may not have enough oxygen to breathe. To resolve this issue, the leading hand used
the LCS to move 55 bags into section 31, and saved the changes in the system. When the changes were made, the ‘Move Mode’
and the ‘Ramp Clear Mode’ buttons on the tablet’s screen greyed out and the load control status
changed to ‘LL’. The loading staff proceeded to load these
bags in section 31. When the leading hand refreshed the device
after the bags had been moved, the status returned to normal and the leading hand presumed
the changes had been accepted. At about 9:38, the load controller in Brisbane
noticed an approval request in the LCS (for the load to be redistributed). This request was for 55 bags (equal to 870
kg) to be moved from section 21 to section 31. The LCS will allow the leading hand/load supervisor
to move up to 500 kg of freight, provided the centre of gravity moment does not change
by more than 5 index units without the approval of the load controller only if the resultant
centre of gravity remains within operational limits. However, as this amount exceeded the limits,
the change needed to be approved by the load controller. Two indications were generated by the LCS
for the leading hand indicating the system was locked and the take-off index was exceeded. A high priority message was also shown on
the load controller’s screen stating the take-off index had exceeded the aft limit by 4.8 index
units. This meant the aircraft was no longer within
the required centre of gravity limits. In response, the LCS was locked for 7 minutes
while the load controller calculated the required changes to the load and approved the changes
in the LCS. The load controller calculated that moving
40 bags from section 31 of the aircraft back to section 21, or moving a number of passengers
forward, would be enough to return the aircraft to balance. Because the leading hand was using the mobile
application, the load controller thought they had a direct line of communication with the
leading hand so they used the in-built messaging system to send a message. The load controller received no response from
the leading hand and amended the LCS. The flight information was then unlocked so
the ground crew could continue to update the LCS. The leading hand did not receive these messages
and they subsequently finalised the flight, without making any changes or checking the
LCS, and the final documents were released by the LCS automatically. This indicated the changes had been accepted
and the aircraft had been loaded correctly. After the aircraft had departed, the leading
hand was re-checking the paperwork and saw the bags had been moved in the LCS back to
section 21 by load control. The leading hand then spoke to the airport
movement co-ordinator. The AMCO attempted to contact the aircraft
by radio, but received no response. The AMCO then contacted the load controller
to explain what had happened. The load controller determined the aircraft
was out of balance by 4.8 index units past the aft limit for take-off and the flight
crew should be advised 40 bags (equal to 626 kg) were in section 31, not section 21. To return the aircraft to balance, the load
controller advised the AMCO that three passengers would have to move forward from zone D to
zone B. When the flight crew rang for the departure call, the AMCO passed on this information,
however, when asked to confirm they had received this information, there was no response. Flight dispatch then contacted the flight
crew via satellite phone and confirmed the flight crew had received this information. The flight crew contacted the cabin supervisor
with the request to move three passengers forward. There were no control issues during flight. The first step for users in the LCS is to
subscribe and add themselves to the flight. This is undertaken to ensure the messages
are received by people within the network, such as AMCOs, load controllers, freighters,
and leading hands. This is not a compulsory page in the LCS and
can be skipped when opening a particular flight. The leading hand had not subscribed to the
system, meaning they did not receive the messages from the load controller about the aircraft
being out of trim due to the movement of baggage from section 21 back to section 31. When the baggage was initially moved to section
31 by the leading hand in the LCS, the system locked. This did not provide clear indications that
the load distribution change needed acceptance by the load controller before proceeding with
loading the aircraft. The leading hand was not sure what the load
control status meant. Furthermore, as the system returned to open
when they reset the system they did not realise that changes had been made in the LCS. The load controller received an error message
in the system because the number of bags moved by the leading hand meant that the aircraft
was out of balance. The load controller attempted to contact the
leading hand via the messaging system but was unaware the leading hand was not subscribed
to the system so the messages were not received. The operator had two procedures for load control
to notify the leading hand that changes have been made in the LCS. The ‘deadload change ramp tolerance’ in the
standard operating procedures for the flight management mobile application required that
load control make a phone call to advise the leading hand or the AMCO that they had denied
a change request through the LCS. The second procedure, which is in the controlling
document used by load control, for ‘out of balance operations’ required that load control
communicated the requirements to the leading hand (which was normally done through the
messaging system within the LCS). In this incident, the load controller used
the messaging system which was not effective as the leading hand was not subscribed to
the system. Once the loading is completed, it is the leading
hand’s responsibility to confirm that the LDR reflects how the aircraft has been loaded. Although the leading hand did check, they
did not detect the error until after the aircraft had departed. As a result of this occurrence, the aircraft
operator issued two safety bulletins, and updated their system functionality to ensure
that only one leading hand can allocate him or herself to an aircraft at a time.

Only registered users can comment.

  1. Very interesting information about how this work is done. Its not uncommon for people to have no proper skills in using specific pc or in this case, tables-based applications, sadly.

  2. Are you getting paid by the ATSB? If not, you should be? Great video even though it didn't really lend itself to a video.

  3. Fantastic videos. Always astonished by the quality! And I love the videos where you are talking, it‘s really interesting

  4. Computers … Garbage In -> Garbage Out; this incident reflects very poor training and software design. The airline instituted the new devices with inadequate testing, training, and preparation. By shear luck, no one was killed.

  5. I'm myself a loadcontrol manager and your video clearly showed how important is to always double check all the data, loading, communcation with the flightcrew and CLCs, people's life is not a game. +1 subscriber 🙂

  6. Excellent video. Small discrepancies could lead to adverse flight operations. Glad to see remedies were initiated.

  7. That's good information but I don't know how you can expect the loaders to get it correct when you can't get it correct the bags weren't supposed to be moved back to section 21 it clearly says on the sheet section 12 not 21 my dyslexic friend

  8. How would moving 3 passengers forward make a difference what happens when they get up and start moving around the cabin would that not change the balance of the plane just as much

  9. Encountered this exact scenario back in April 2018. UA outbound from LAX to HNL on a 37/800. Doors were all closed and the aircraft pushed back into the alleyway… mule detached – and the GE 56s fired up. We were just about to proceed down to the taxiway, and then —the turbofans spun down! There was a noticeable nervous pause, and complete silence in the cabin…. with everyone looking around puzzled until the Captain came over the PA and advised PAXs and cabin crew what had occurred. The aircraft was pushed back to the gate and the cargo load had to be rearranged from aft to forward. I’ve flown millions of miles. The only other time CG concerns came about was once on an RJ out of OAK. Similar situation, several PAXs were moved to alternate seats. I avoid RJ’s nowadays…

    Hats off to attentive Load Controllers!!!

  10. Great video. What if i tell you, because of lack of staff, at my airport, we have to load two airplanes at the same time… Safety first (my ass)

  11. the pits on the B738 arent very large up front. 100-110 bags max is the average. 120-130 bags is the rear pit…. i know this from being a ramp agent. If passengers wouldnt pack so much shit, bags wouldnt be that heavy.

  12. so what I got from this is that me and two of my buddies can take down an airliner if we sit in the wrong seats?!

  13. To remove 55 bags make space for 4 dogs in a cage is a bit too much. They could have put 20 bags in compartment #11 and 5 bags in #12the doorway.

  14. I hope the people that turns up late at the airport watch this so they will never complain about missing a flight by 10 minutes again.

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