Boeing 737-9 N37516

Summary

On 28 June 2023 at about 14:19 local time, a Boeing 737-9 registered N37516, operated by United Airlines, was involved in an incident near Newark, New Jersey, United States. 184 people were on board and nobody was injured. The aircraft was slightly damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

28 June 2023 at 14:19

Classification

Incident

Location

Newark, New Jersey, United States

Nearest airport

Newark Liberty Intl (EWR)

Coordinates

40.6887, -74.1737

Aircraft

Boeing 737-9

Registration

N37516

Category

Airplane

Year built

2020

Engines

2

Operator

United Airlines

Operating rule

Part 121: Air Carrier

Phase of flight

Not recorded

Route

Fort Lauderdale → Unknown

Aircraft damage

Minor

Weather

Unk

Light

Day

NTSB number

ENG23LA031

Nobody was injured.

A No. 1 (left) engine fire due a fuel leak that originated from the fuel nozzle 17 b-nut connection that was not properly torqued in accordance with the aircraft maintenance manual procedure.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The No. 1 (left) engine fire was caused by a fuel leak that originated from an improperly torqued fuel nozzle 17 pilot secondary inlet b-nut. The leaked fuel ignited when it contacted hot engine case surfaces and resulted in an undercowl fire. Fuel nozzle b-nut torque measurements recorded during the engine teardown revealed that the pilot secondary inlet b-nuts of fuel nozzles 17 and 18 both had zero torque and backed off with no resistance. Four fuel nozzles (positions 4, 16, 17 and 18) were examined at the GE Aerospace Failure Analysis Laboratory in Evendale, Ohio and no anomalies were identified that would have precluded normal function if the b-nuts had been torqued in accordance with the aircraft maintenance manual. Although, not directly causal to the incident engine fuel leak, CFM LEAP series engine fuel nozzle coking has driven early and repetitive fuel nozzle replacements throughout the fleet. According to United Airlines (UAL), they have completed 443 fuel nozzle set replacements on their CFM LEAP fleet as of October 2024.

Quoted verbatim from the NTSB record.