The Directorate General of Civil Aviation said on Monday that an insufficient number of engineers has been certifying aircraft of various carriers before take-off, PTI reported.

The aviation regulator made the observation after conducting spot checks. The airlines have been asked to tend to all the flaws and shortcomings by July 28.

The maintenance engineers deployed by airlines are incorrectly identifying the “cause of a reported defect”, the aviation regulator said. “They [the spot checks] also found that there has been an increasing trend of MEL [minimum equipment list] releases of aircraft,” it added.

The list provides for the operation of aircraft, subject to specified conditions, with some inoperative equipment until the repairs are carried out.

“It is also seen that airlines are resorting to frequent one-off authorisation to Category A certifying staff at transit stations which is not in line with existing regulatory provisions,” the aviation watchdog added.

Category A comprises limited scope engineers who are allowed to approve a plane’s departure only when there is no complex defect. Mechanical snags are handled by B1 category engineers and defects in equipment are corrected by B2-level employees.

“It has been decided that all aircraft at base and transit stations shall be released by certifying staff holding AME Category B1 or B2 license with appropriate authorisation by their organisation,” the Directorate General of Civil Aviation said.

The aviation regulator’s order comes after several aircraft reported technical snags in the last month.

On Sunday, an IndiGo flight made an emergency landing in Pakistan’s Karachi airport after the pilot observed a technical glitch.

The incident took place a day after an Air India Express flight from Kozhikode to Dubai had to be diverted to Oman’s capital city Muscat after the passengers smelled a burning odour in the cabin.

At least nine incidents of technical malfunction have been reported on SpiceJet planes in the last 30 days.

On Sunday, Aviation Minister Jyotiraditya Scindia met the regulator officials and members of the ministry, The Indian Express reported. He “re-emphasised to strictly adhere to the prescribed safety norms and avoid any kind of laxity towards passenger safety”.