VivaColombia Airbus A320-200N, registration HK-5378 performing flight VH-8332 from Cali to Riohacha (Colombia), was descending towards Riohacha Airport when the crew aborted the approach at about FL180 and entered a hold for about 30 minutes. The aircraft subsequently climbed to FL370 and was enroute to divert to Medellin when the crew again needed to abort the approach to Medellin at about 15,000 feet. The aircraft climbed back to FL210, the crew declared emergency, and diverted to Monteira (Colombia) where the aircraft finally landed on runway 32 about 2:15 hours after aborting the approach to Riohacha and about 3:20 hours after departure from Cali. The aircraft had about 100kg in its left fuel tank and about 110 kg of fuel in its right hand tank, the totalizer showed 200kg of fuel remaining.
The airline reported the aircraft needed to abort the approach to Riohacha due to bad weather and diverted to Medellin (Rio Negro). While the aircraft was approaching Medellin weather also impacted the aircraft and made a landing impossible. The crew therefore diverted to Monteira where the aircraft landed safely. The aircraft had more than 180 minutes of fuel available for the 80 minutes flight.
On Oct 27th 2022 Colombia's DIACC reported: "During the arrival to MDE terminal area, the flight crew listened to other aircraft on the frequency reporting missed approaches at MDE due to meteorological conditions; after a couple of circuits in holding, the flight crew decided to proceed to Los Garzones Airport (MTR) in Monteria (SKMR) as alternate. While enroute to MTR, at approximately 18:40 UTC, the flight crew declared MAYDAY FUEL EMERGENCY - SQUAWKING 7700. The flight landed at approximately 19:07 UTC in MTR and it taxied to the assigned parking position without further incident. According to information retrieved from FDA, the flight landed with 282 kg of fuel and it had 236 kg remaining when engines were shut-down." The occurrence was rated a serious incident and is being investigated by Colombia's DIACC.
I wonder how much fuel was actually onboard as the gauging has its own inbuilt design errors?For an A320 Family aircraft, the instrumental tolerance on the ground is calculated as follows:
± (1% of current FOB + 1% max possible FOB for this aircraft)As an illustration, for an A320 aircraft, if there are 5 tons left in the aircraft, the maximum normal tolerance value is:
± (5000kg (current FOB) * 1% + 20000kg (max FOB)* 1% ) = ± 250kgNote: The FQI system is designed in such a way that the lower the fuel quantity in the tank, the more accurate the fuel indication.
The FQI system is calibrated on ground during manufacturing and its accuracy (as per the formula above) will remain the same throughout the operational life of the aircraft.