Aviation regulator DGCA issued a show-cause notice Wednesday to SpiceJet after its planes reported eight technical malfunctions over the past 18 days, as airline chief Ajay Singh said a lot of these incidents are "minor" in nature but assured the carrier will be "doubly careful" and strengthen aircraft inspection.

In its notice to SpiceJet, the Directorate General of Civil Aviation (DGCA) said the airline has failed to "establish safe, efficient and reliable air services" under the terms of Rule 134 and Schedule XI of the Aircraft Rules, 1937.

"The review (of the incidents) transpires that poor internal safety oversight and inadequate maintenance actions (as most of the incidents were related to either component failure or system-related failure) have resulted in degradation of the safety margins," it added.

The DGCA has given the airline three weeks to respond to the notice.

"Financial assessment carried out by DGCA in September 2021 has also revealed that the airline is operating on 'cash-and-carry' (model) and suppliers/approved vendors are not being paid on a regular basis, leading to shortage of spares and frequent invoking of MELs (minimum equipment lists)," the notice read.

However, Singh told PTI that none of the incidents that have happened in the last few weeks have anything to do with shortage of spare parts.

"This is an audit that they are referring to from last year (September 2021) that they had done. The aviation sector has been under a great deal of (financial) stress. That does not mean that there can be any compromise on safety," he explained.

"All vendors that are relevant to anything related to safety or spare parts are always paid or settlements are reached with them. There is no failure here," he added.

Singh said a lot of these incidents that are being reported are relatively minor in nature and happen to every airline. "This is nothing unique".

"When you have thousands of flights, sometimes the air conditioning will fail, sometimes a bird will hit the plane, and sometimes a fuel indicator will light up," he said.

"These things are going to happen and, of course, we have to minimise that to the greatest extent possible. That is our job and it is the regulator's job to push us to make things better, which we will do," he said.

When asked what changes SpiceJet will now undertake to deal with the safety concerns, he said, "We have to be doubly careful. We will rigorously inspect aircraft when they leave for a flight, which we already do, but we will strengthen the inspection."

Reacting to the DGCA notice, Civil Aviation Minister Jyotiraditya Scindia asserted that passenger safety is paramount.

"Even the smallest error hindering safety will be thoroughly investigated and course-corrected," the minister said in a tweet.

In a statement on Wednesday, the airline said it will respond to the DGCA notice within the specified time period.

"We are committed to ensuring a safe operation for our passengers and crew. We are an IATA-IOSA (IATA Operational Safety Audit) certified airline. SpiceJet successfully completed the meticulous audit program for recertification in October 2021," it stated.

The airline said it has been regularly audited by the DGCA.

"All our aircraft were audited a month ago by the regulator and found to be safe. All flights of SpiceJet are conducted in compliance with the applicable regulations of the DGCA Civil Aviation Regulations on the subject," it noted.

At least eight incidents of technical malfunction have taken place on SpiceJet planes in the last 18 days.

On Tuesday, a SpiceJet freighter aircraft, which was heading to Chongqing in China, returned to Kolkata as the pilots realised after the take-off that its weather radar was not working.

On the same day, 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.

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

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

On June 19, an engine on the carrier's Delhi-bound aircraft carrying 185 passengers caught fire soon after it took off from the 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 SpiceJet flight for Jabalpur had to return to Delhi due to cabin pressurisation issues.

The airline has been making losses for the last three years. It incurred a net loss of Rs 316 crore, Rs 934 crore and Rs 998 crore in 2018-19, 2019-20 and 2020-21 respectively.

Like SpiceJet, IndiGo and Vistara also suffered to technical malfunction incidents Tuesday.

An engine of a Vistara aircraft on way from Bangkok failed after it landed at the Delhi airport but all passengers disembarked safely, officials of the aviation regulator DGCA said on Wednesday.

When approached for comments, the airline said the integrated drive generator (IDG) on the engine developed a "minor" electrical malfunction after it landed at the Indira Gandhi International Airport on Tuesday.