# Service difficulty reports: N300UB A list on [N300UB](https://openairdocs.org/aircraft/N300UB.md). Matched to this aircraft by N-number and event date, checked against the reported serial number, make and model. Newest first. - [SDR AALA202607278357](https://openairdocs.org/sdr/AALA202607278357.md): Light · inoperative · Jul 24, 2026 · N300UB · Boeing 7378 · Emergency Lighting > AIRCRAFT WAS NOT GROUNDED: AFT RIGHT EMERGENCY WING EXIT LIGHT INOPERATIVE. MAINTENANCE REPLACED OVERWING EXIT LIGHT ASSY IAW AMM 33-21-00. - [SDR AALA202508283445](https://openairdocs.org/sdr/AALA202508283445.md): Oven · smoke · Aug 24, 2025 · N300UB · Boeing 7378 · Buffet/Galleys > AIRCRAFT WAS NOT GROUNDED: LEFT OVEN IN FORWARD GALLEY STARTS SMOKING WHEN TURNED ON. REMOVED AND REPLACED NUMBER 1 OVEN AT FIRST CLASS GALLEY. PER AMM 25-32-00. OPERATIONAL CHECKS GOOD. - [SDR AALA202508253445](https://openairdocs.org/sdr/AALA202508253445.md): Oven · smoke · Aug 24, 2025 · N300UB · Boeing 7378 · Buffet/Galleys > AIRCRAFT WAS NOT GROUNDED: LEFT OVEN IN FORWARD GALLEY STARTS SMOKING WHEN TURNED ON. (OPEN). - [SDR AALA202508197813](https://openairdocs.org/sdr/AALA202508197813.md): Door · lack of lube · Aug 17, 2025 · N300UB · Boeing 7378 · Fixed Inner Doors > AIRCRAFT WAS NOT GROUNDED: FLIGHT DECK DOOR DIFFICULT TO OPEN FROM OUTSIDE DOOR (CABIN SIDE). LUBED COCKPIT DOOR. - [SDR AALA202504226310](https://openairdocs.org/sdr/AALA202504226310.md): Control Unit · faulty · Apr 16, 2025 · N300UB · Boeing 7378 · Drag Control System > AIRCRAFT WAS GROUNDED: DURING FLIGHT AT CRUISE AT FL 210 USING ALL AUTOMATION CONTROL, WHILE REDUCING SPEED THE AUTO THROTTLE REDUCES THE POWER THEN THE GEAR HORN GOES OFF AND THE 3 GEAR RED LIGHTS COME ON. REMOVED AND REPLACED SPOILER CONTROL UNIT (AALA20250 - [SDR AALA202504176310](https://openairdocs.org/sdr/AALA202504176310.md): Warning Horn · activated · Apr 16, 2025 · N300UB · Boeing 7378 · Landing Gear Position and Warning > AIRCRAFT WAS GROUNDED: DURING FLIGHT AT CRUISE AT FL 210 USING ALL AUTOMATION CONTROL, WHILE REDUCING SPEED THE AUTO THROTTLE REDUCES THE POWER THEN THE GEAR HORN GOES OFF AND THE 3 GEAR RED LIGHTS COME ON. (OPEN). - [SDR AALA202504170737](https://openairdocs.org/sdr/AALA202504170737.md): Antenna · faulted · Apr 14, 2025 · N300UB · Boeing 7378 · Localizer/VOR System > AIRCRAFT WAS GROUNDED: REPEAT RECURRING ISSUE WITH GEAR WARNING HORN GOES OFF WHEN THROTTLES PULLED BACK, ALONG WITH 3 RED GEAR LIGHTS. HORN CUTOUT WILL SILENCE THE HORN.HAD TO REDUCE SPEED IN CRUISE AND WHEN THRUST WAS REDUCED, THE HORN WENT OFF. REPLACED LR - [SDR AALA202504175893](https://openairdocs.org/sdr/AALA202504175893.md): Antenna · faulted · Apr 14, 2025 · N300UB · Boeing 7378 · Localizer/VOR System > AIRCRAFT WAS GROUNDED: REPEAT RECURRING ISSUE WITH GEAR WARNING HORN GOES OFF WHEN THROTTLES PULLED BACK, ALONG WITH 3 RED GEAR LIGHTS. HORN CUTOUT WILL SILENCE THE HORN.HAD TO REDUCE SPEED IN CRUISE AND WHEN THRUST WAS REDUCED, THE HORN WENT OFF. REPLACED LR - [SDR AALA202504165893](https://openairdocs.org/sdr/AALA202504165893.md): Warning Horn · false activation · Apr 14, 2025 · N300UB · Boeing 7378 · Landing Gear Position and Warning > AIRCRAFT WAS GROUNDED: REPEAT RECURRING ISSUE WITH GEAR WARNING HORN GOES OFF WHEN THROTTLES PULLED BACK, ALONG WITH 3 RED GEAR LIGHTS. HORN CUTOUT WILL SILENCE THE HORN.HAD TO REDUCE SPEED IN CRUISE AND WHEN THRUST WAS REDUCED, THE HORN WENT OFF. **SUPPLEMENT - [SDR AALA202504176493](https://openairdocs.org/sdr/AALA202504176493.md): Pseu · faulted · Apr 10, 2025 · N300UB · Boeing 7378 · Landing Gear Position and Warning > AIRCRAFT WAS GROUNDED: GEAR WARNING HORN COMES ON AND RED GEAR LIGHTS COME ON DURING DESCENT. **SUPPLEMENTAL REPORT FOR (AALA202504116493): FOUND POWER SYSTEM FAULTS ON PSEU. REMOVE AND REPLACED PSEU (AALA202504116493), PER AMM IAW 32-09-10. REMOVE AND REPLACE - [SDR AALA202504177012](https://openairdocs.org/sdr/AALA202504177012.md): Interface Module · faulted · Apr 10, 2025 · N300UB · Boeing 7378 · Landing Gear Retraction/Extension System > AIRCRAFT WAS GROUNDED: GEAR WARNING HORN COMES ON AND RED GEAR LIGHTS COME ON DURING DESCENT. FOUND POWER SYSTEM FAULTS ON PSEU. REMOVE AND REPLACED PSEU (AALA202504116493), PER AMM IAW 32-09-10. REMOVE AND REPLACED LANDING GEAR CONTROL MODUL (AALA20250417701 - [SDR AALA202504116493](https://openairdocs.org/sdr/AALA202504116493.md): Warning System · malfunctioned · Apr 10, 2025 · N300UB · Boeing 7378 · Landing Gear Position and Warning > AIRCRAFT WAS GROUNDED: GEAR WARNING HORN COMES ON AND RED GEAR LIGHTS COME ON DURING DESCENT. **SUPPLEMENTAL REPORT WILL BE SUBMITTED**(OPEN). - [SDR AALA202504087941](https://openairdocs.org/sdr/AALA202504087941.md): Altimeter · false indication · Apr 7, 2025 · N300UB · Boeing 7378 · Microwave Landing System > AIRCRAFT WAS GROUNDED: LANDING GEAR WARNING HORN AND GEAR UNSAFE LIGHTS ILLUMINATED MULTIPLE TIMES DURING DESCENT. REPLACED NUMBER 2 RADIO ALTIMETER. - [SDR AALA202504081451](https://openairdocs.org/sdr/AALA202504081451.md): Antenna · undertorqued · Apr 6, 2025 · N300UB · Boeing 7378 · Microwave Landing System > AIRCRAFT WAS GROUNDED: GEAR WARNING HORN AND RED LIGHTS ON INTERMITTENTLY ON DESCENT FROM FL230 TO ABOUT 15000. PERFORMED BITE TEST ON BOTH LRRA TRANSCEIVERS, PER AMM 34-33-00 BITE TEST PASS. FOUND ALL SCREWS ON ALL 4 LRRA ANTENNAS LESS THAN 30 INCH LBS. HALF - [SDR AALA202503201017](https://openairdocs.org/sdr/AALA202503201017.md): Shaft · out of rig · Mar 19, 2025 · N300UB · Boeing 7378 · Passenger/Crew Doors > AIRCRAFT WAS GROUNDED: AFT L2 DOOR HANDLE NOT OPERATING CORRECTLY. MUST BE TURNED 90 DEGREES TO ENGAGE OPENING MECHANISM. TROUBLESHOT AND FOUND SLEEVE FOR EXTERIOR HANDLE NOT CLOCKED PROPERLY. ENGAGING 90 DEGREES OFF. REMOVED AND REPLACED HANDLE SHAFT ASSEMBLY - [SDR AALA202503089000](https://openairdocs.org/sdr/AALA202503089000.md): Controller · faulted · Mar 5, 2025 · N300UB · Boeing 7378 · Cabin Pressure Controller > AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED AN THE AIRCRAFT DIVERTED TO ATL DUE TO AUTO PRESSURIZATION FAILURE. THE AIRCRAFT LANDED SAFELY AT ATL. AIRCRAFT WAS ON AN MEL FOR CABIN PRESSURE CONTROLLER #2 INOPERATIVE. MAINTENANCE REPLACED THE OUTFLOW VALVE - [SDR AALA202503086361](https://openairdocs.org/sdr/AALA202503086361.md): Outflow Valve · faulted · Mar 5, 2025 · N300UB · Boeing 7378 · Pressure Regulator/Outflow Valve > AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED AN THE AIRCRAFT DIVERTED TO ATL DUE TO AUTO PRESSURIZATION FAILURE. THE AIRCRAFT LANDED SAFELY AT ATL. AIRCRAFT WAS ON AN MEL FOR CABIN PRESSURE CONTROLLER #2 INOPERATIVE. MAINTENANCE REPLACED THE OUTFLOW VALVE ## The whole list in SQL Runs in DuckDB 1.2 or later on the release's Parquet files over HTTPS: ```sql SELECT sdr_id, difficulty_date, n_number, aircraft_make, aircraft_model, part_name, part_condition, jasc_code, discrepancy FROM 'https://openairdocs.org/data/latest/faa_service_difficulty_report.parquet' WHERE n_number = 'N300UB' AND registry_match = 'registration' ORDER BY difficulty_date DESC ``` This list as a web page: https://openairdocs.org/aircraft/N300UB/reports --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.