An Embraer ERJ-190LR was operating a domestic flight in Myanmar, between Yangon-Mingaladon Airport and Mandalay International Airport on this day in aviation history. Onboard a crew of 7 (3 flight crew and 4 cabin attendants) and 82 passengers.
The aircraft with its nose on the runway surface, just after landing (Source & © AAIB Myanmar)
The flight crew consisted of the Pilot in Command (PIC), a pilot under line training (Who has completed his type training but needs to gain line operating experience) and a safety pilot. The line training pilot was the pilot flying for the sector. At 07.15 local time (lt) the flight took off from Yangon-Mingaladon Airport. After an uneventful flight, the crew received clearance for an RNP approach to Runway 17 of Mandalay. The landing gear was selected down at approximately 7 nm (13 km) from the runway. Twenty seconds later a CAS (Crew Alerting System) message appeared, accompanied by a triple chime, "LG LEVER DISAG" indicating that not all the gears were down and locked. Further indications showed that the nose landing gear was not down and locked. The PIC took control and became Pilot Flying, while the safety pilot took the seat of the line training pilot. ATC was informed and the crew requested a heading of 270º and an altitude of 2000 feet to troubleshoot the situation. The relevant Quick Reference Handbook checklists were completed and a low pass over the field was flown.
Overview picture of the aircraft on the runway (Source & © AAIB Myanmar) ATC informed the crew after the low pass that a nose landing gear door was ajar and the gear was not extended. The crew were unable to extend the nose landing gear. At 08.38 a Mayday call was made followed by a briefing of the passengers. After another RNP approach to runway 17, the aircraft landed with only the main landing gear extended.
The aircraft came to a stop 4800 feet from the threshold of runway 17. All passengers and crew evacuated the aircraft safely, there were no injuries. No fire broke out.
The Nose Landing Gear jammed in the bay after the aircraft was lifted up. After nitrogen pressure was discharged from the nose gear strut the gear was free to extend. (Source & © AAIB Myanmar)
Damage to the aircraft was extensive, in the investigation report by the Aircraft Accident Investigation Bureau (AAIB) of Myanmar the following damages are listed;
Fuselage Lower Skin at Nose Landing Gear Section between FR3 and FR8 and STGR 26LH and 26RH
Lower Skin and Lip Skin of Left Engine Inlet Cowling
Nose Landing Gear Door
Forward Avionics Compartment Access Hatch
Control Wire and Circuit Breakers at Cockpit Console
Overview of the damaged nose section (Source & © AAIB Myanmar)
Over the period from the 8th of May till the incident flight, several defects were reported and actioned by the airline's maintenance staff, some in relation to the Weight on Wheels system (senses if the aircraft is on the ground or in the air) and the reported "shaking" of the nose landing gear during gear extension. The Flight Data Recorder was downloaded and this download revealed that over the last 23 flights there had been an issue with the Weight on Wheels sensing on the nose landing gear. The investigation report from the AAIB (available by clicking here) concluded that the Probable Cause of the incident was;
"Maintenance actions were not properly done as per the fault isolation manual in rectifying the intermittent Weight off Wheels System Fail fault and in 24 addition, poor workmanship in performing the Nose Landing Gear Strut N2 servicing.
Two safety recommendations were also made;
Maintenance action should be properly done as per the Fault Isolation Manual (FIM), and if necessary in close coordination with Embraer the aircraft manufacturer.
Flight crew should enter fault messages into the Technical logbook in a systematic and thorough manner, and let maintenance engineers know about it as soon as possible.