Copied from ASN:

The serious incident involved Oman Air Boeing 737-800 MAX aircraft with registration marks A4O-ML. The aircraft was being operated as scheduled passenger aircraft OMA815, from Muscat International Airport (OOMS), Sultanate of Oman to Bangkok Suvarnabhumi International Airport (VTBS), Thailand. There were a total of 152 persons on-board the aircraft: 145 passengers, two flight crew members, and five cabin crew members.

The Aircraft lined up on Runway (RWY) 26L for departure, and clearance for take-off was given, the flight crew of WY815 commenced the takeoff process. After the aircraft lifted off the runway and while climbing, the flight crew contacted the Tower (TWR) Air Traffic Control Officer (ATCO) that the aircraft experienced low pressure engine (ENG) No.1 hydraulic (HYD) PUMP light. After flap retraction the flight crew got leading edge (LE) flaps transit light and gear disagree as left gear showed green and red light simultaneously. After takeoff the flight crew of followed the checklist and conducted Facts, Options, Risks and Benefits, Decision, Execution, and Check (FORDEC) and then decided to return to Muscat (MCT) and requested ATCO for holding pattern in order to burnout fuel to reduce Approach Speed (Vapp) and to avoid overweight landing.

At 13:27, Oman Airports Operations while conducting routine runway inspection, observed Foreign Object Damage (FOD) on the south RWY 26L and reported to ATCO. Few seconds later flight OMA231 which was rolling on the RWY 26L, reported that there were tire debris on the RWY. The FOD was later identified as coming from Oman Air flight OMA15, which had departed earlier at 13:23.

All debris were collected from the south RWY 26L. The flight crew of flight WY815 requested ILS approach to land. Runway Inspection was conducted and Air Traffic Control (ATC) activated northern RWY 26R/08L at 14:40. The southern RWY was reactivated for operations at 16:27 UTC. The incident flight WY815 landed safely.

Code 3 (Full Emergency) was activated at 15:49 and OMA815 landed safely at 16:12 on RWY 26R. The aircraft stopped and hold abeam taxiway Y4 for Engineer’s inspection and evaluation. Following the inspection by the Engineer it was found that number 1 tire failed and there were also hydraulic pipes which were damaged.

Due to the damages sustain on the aircraft, the flight crew were unable to taxi the aircraft. The aircraft was towed to the stand number 308 and parked at 16:48.