Jet Airways has initiated an internal inquiry into the matter (File picture of a Jet Airways plane taking off)

While the plane they were flying plunged 5,000 feet, a Jet Airways pilot was asleep and the co-pilot was busy on an iPad checking out flight information. Both have been suspended by aviation regulator DGCA which is now investigating the incident.280 passengers were on the flight from Mumbai to Newark via Brussels when it fell from 34,000 feet to 29,000 feet, according to the Press Trust of India.A spokesperson for Jet, however, told NDTV that the descent was of about 2,000 feet. While the plane was in Turkish airspace, Air Traffic Controllers noted the descent and sent an emergency message to the aircraft ordering it to climb back up. The co-pilot then woke up the commander.Both pilots were summoned by the DGCA yesterday for questioning. While the commander said he was on "controlled rest", a short nap inside the cockpit which is allowed by flight operation procedures, the co-pilot testified that she was working on her iPad which had aircraft documents loaded on to it, said unnamed sources to the Press Trust of India.Confirming the incident, an airline spokesperson said Jet Airways has initiated an internal inquiry into the matter."The airline is also extending all co-operation in the matter to the DGCA by providing all necessary assistance for the inquiry," the spokesperson said.The DGCA is now dissecting Jet Airways' training procedures for pilots.The regulator also wants to know why the airline or the pilots failed to report the incident to it - an anonymous message to the DGCA disclosed the mid-air scare.

While both the pilots kept flying until they were grounded two days ago, they did not file a flight safety report, which is a mandatory exercise to document any unusual incident during the course of a flight