More terror for United passengers after plane is forced to make emergency landing over 'complete hydraulic failure,' with airline's planes also suffering gear failure, lost wheel and engine malfunction this week

A United Airlines flight had to make an emergency landing on Friday after a fault with the aircraft's hydraulic system, making it the fourth incident for the airline this week. 

The airline said the flight heading to Mexico City from San Francisco had to make an emergency landing in Los Angeles due to the fault. 

All 105 passengers and five crew members on board landed safely and deplaned at the gate, with a new flight having to be scheduled. 

The incident rounds off a week of problems for the airline, with a plane going off the runway on Friday, a wheel coming off a flight on Thursday and a plane engine shooting flames on Monday. 

The United Airlines flight that lost its wheel had also departed from San Francisco and was on its way to Osaka in Japan when the wheel of the Boeing 777-200's wheel came off. 

The airline said the flight, seen here, was heading to Mexico City from San Francisco had to make an emergency landing in Los Angeles due to the fault

A Boeing 737 Max operated by United Airlines veered off the tarmac into the grass when exiting the runway at George Bush Airport in Houston early Friday

Several vehicles in the employee car parking lot were badly damaged by the falling wheel that also mangled a fence.

The plane landed safely at LAX about 1:20 pm with no further incident and no injuries reported on the ground.

'The 777-200 has six tires on each of its two main landing gear struts. The aircraft is designed to land safely with missing or damaged tires,' United said. 

A new plane had to be scrambled to take the passengers to Japan from Los Angeles falling the incident.

On Friday, another flight veered off the runway after landing in Houston, having suffered some form of gear collapse as it exited the runway at George Bush Airport. 

Shocking footage showed the plane on its wings on grass by the side of the runway, with passengers being hurried from an emergency gate ladder. 

Despite the rocky end to the flight, a passenger claimed that the landing was smooth, but they felt some bumps as the plane began to taxi. 

'Felt like when you have a flat tire in a car,' the passenger told Click2Houston. 

The United Airlines flight 35 left San Francisco Airport on its way to Osaka in Japan and was barely off the runway with the Boeing 777-200's wheel came off

Cars written off by the falling wheel are now nothing more than twisted metal

In a statement, Houston Airports said: 'Around 8am [Friday], a United Airlines flight landed at George Bush Intercontinental Airport (IAH). 

'As it was exiting the runway, the aircraft left the pavement and entered the grass along Runway 9-27.

'Fortunately, no one on board was injured. The Houston Fire Department and Houston Airports Operations immediately responded and safely evacuated all passengers.' 

On Monday, another United flight was hit with problems when its engine caught fire after departing from Houston while bound for Fort Myers, Florida. 

United said on Thursday that they believe bubble wrap to have been sucked into the engine, causing the problems. 

Footage taken from a passenger window shows white-hot flashes streaming out of the jet's engine. 

'Hey ladies and gentlemen, we realized something happened outside,' a crewmember can be heard warning passengers before the clip cuts out. 

One of the engines on another United Airlines 737 in Texas burst into flames mid-flight in a terrifying fireball earlier this week

Moments later, they were forced to make an emergency landing and return to George H. Bush Intercontinental Houston Airport moments after takeoff. No injuries were reported in the incident. 

Passenger Dorian D. Cerda told Storyful the plane was 'approximately 15 minutes' into the two-hour trip when the incident occurred, with the jet landing just before 7pm.

'The flight landed safely and the passengers deplaned normally,' United Airlines said, adding that they 'arranged for a new aircraft to take our customers to their destination.' 

The model of plane in the Houston incident was a Boeing 737-900, a similar jet to the Max fleet which was grounded in January after an exit door blew out during an Alaska Airlines flight over Oregon.

Bolts appear to be missing from the door plug that blew out of a Boeing 737 MAX during an Alaska Airlines flight on January 5

The door plug was recovered from the back yard of a home after it blew out on January 5

On Monday, the Federal Aviation Administration said its six-week audit of Boeing and Spirit AeroSystems found 'multiple instances where the companies allegedly failed to comply with manufacturing quality control requirements'.

'The FAA identified non-compliance issues in Boeing’s manufacturing process control, parts handling and storage, and product control. The FAA is providing these details to the public as an update to the agency’s ongoing investigation,' the statement said.

The administration announced it would continue to ground Boeing's 171 jets and had halted production expansion of the Boeing 737 MAX.

The news was a blow to the aircraft manufacturer, which saw its market value plummet by $30 billion in the wake of the disaster.

Boeing's share price also plunged by 20 percent in the month following the blowout.