Budget carrier SpiceJet had another rough day on Tuesday as the airline's Delhi-Dubai flight was diverted to Karachi due to a malfunctioning fuel indicator and its Kandla-Mumbai flight did priority landing in Maharashtra's capital city after cracks developed on its windshield mid-air.

The two incidents of Tuesday have taken the total number of technical malfunction incidents on SpiceJet aircraft - which have taken place in the last 17 days - to seven.

• Stranded SpiceJet passengers leave Karachi, reports hindustntimes.com

According to officials of the Directorate General of Civil Aviation (DGCA), the aviation regulator is investigating all the seven incidents.

The Boeing 737 Max aircraft -- which was heading from Delhi to Dubai Tuesday morning -- started showing unusual fuel quantity reduction from its left tank when it was mid-air, following which it was diverted to Karachi, they said.

When an inspection was done at the Karachi airport, no visual leak was observed from the left tank, they added.

An official of Pakistan Civil Aviation Authority (PCCA) said the pilot of SpiceJet's Delhi-Dubai flight contacted the control tower while flying over Pakistan airspace, stating that the aircraft has developed some technical fault.

After the plane was allowed to land on humanitarian grounds, engineers of the Pakistan International Airlines worked with SpiceJet crew to locate and rectify the technical fault, the PCCA official added.

Apparently, there was a problem with the aircraft's light indicator machinery, but it could not be repaired immediately so another aircraft was arranged to take the passengers to Dubai, he said.

Another source at the Karachi airport said around 150 passengers were on board the aircraft and were provided food and refreshments.

Later during the day, a Q400 plane of SpiceJet conducted a priority landing at Mumbai airport after its windshield cracked at 23,000 feet altitude, DGCA officials said.

The Q400 plane -- which was coming from Kandla in Gujarat -- did not face any cabin pressurisation issues, they noted.

About the Kandla-Mumbai flight incident, SpiceJet said, "On 5th July, 2022, SpiceJet Q400 aircraft was operating SG 3324 (Kandla-Mumbai). During cruise at FL230 (23,000 feet altitude), P2 side windshield outer pane cracked. Pressurization was observed to be normal. The aircraft landed safely in Mumbai."

Commenting on the Delhi-Dubai flight incident, the airline said, On July 5, 2022, SpiceJet B737 aircraft operating flight SG-11 (Delhi-Dubai) was diverted to Karachi due to an indicator light malfunctioning. The aircraft landed safely at Karachi and passengers were safely disembarked."

"No emergency was declared and the aircraft made a normal landing. There was no earlier report of any malfunction with the aircraft," it mentioned.

Passengers have been served refreshments, it said earlier, adding that a replacement aircraft is being sent to Karachi that will take the passengers to Dubai.

Since June 19, there have been seven incidents on SpiceJet planes.

On June 19, an engine on SpiceJet's Delhi-bound aircraft carrying 185 passengers caught fire soon after taking off from Patna airport and the plane made an emergency landing minutes later. The engine malfunctioned because of a bird hit.

In another incident on June 19, a flight for Jabalpur had to return to Delhi due to cabin pressurisation issues.

Fuselage door warnings lit up on two separate planes while taking off on June 24 and June 25, forcing them to abandon their journeys and return.

On July 2, a SpiceJet flight heading to Jabalpur returned to Delhi after the crew members observed smoke in the cabin at around 5,000-feet altitude.

Notably, SpiceJet has been making losses for the last three years.

The carrier incurred a net loss of Rs 316 crore, Rs 934 crore and Rs 998 crore in 2018-19, 2019-20 and 2020-21, respectively.

With COVID-19 pandemic petering out, aviation consultancy firm CAPA had on June 29 stated that Indian carriers' losses are expected to moderate from around USD 3 billion in 2021-22 to USD 1.4-1.7 billion in 2022-23.

In March 2021, IndiGo's Sharjah-Lucknow flight did an emergency landing at the Karachi airport after a passenger complained of chest pain and fell ill. The doctors who came on board could not save the passenger who passed away due to a cardiac arrest, and the aircraft later left for its destination.