Pilots of a Jet Airways flight to Jaipur from Mumbai forgot to turn on the cabin pressure switch yesterday causing at least 30 passengers to bleed from their noses and ears as the plane climbed.

The Boeing 737 with 166 passengers turned back to Mumbai, but not before panic swept through the cabin.

The incident reminded many in the aviation industry of the Helios Airways flight 522 which crashed near Athens in 2005 following almost an identical cockpit failure.

People on board the Jet Airways flight posted photos and videos of the calamity online, with one purported passenger, Darshak Hathi, uploading footage on Twitter showing travellers using oxygen masks, reports AFP.

"Panic situation due to technical fault in @jetairways 9W 0697 going from Mumbai to Jaipur," he tweeted, adding that all passengers were safe.

Another traveller said the pilot did not make any announcement other than that the flight would turn back to Mumbai.

"I was in the business class and the oxygen mask came down suddenly. One passenger came running from the back asking everyone to put on the masks," he told the NDTV news network.

"All the passengers were panicking, those sitting at the back and who were unable to wear the masks started bleeding from their mouths and noses."

Five travellers who suffered bleeding and were rushed to a Mumbai hospital were suffering from mild deafness that would take some 10 days to recover, a doctor told reporters.

An official with India's national aviation regulator told the Press Trust of India the crew "forgot to select (the) bleed switch" to maintain the aircraft's cabin pressure.

The flight crew "has been taken off scheduled duties pending investigation", Jet Airways said in a statement.

The incident could be seen by some as "not major" but the failure to ensure correct cabin pressure configuration of the plane had led to a major aviation disaster.

In 2005, a Boeing 737 of Helios Airways with 121 souls crashed in Greece killing all on board.

Before Helios flight 522 took off on August 14, 2005, Larnaca, Cyprus, to Athens, Greece, it had gone through cabin pressurisation leak check for which a ground engineer had to go into the cockpit and turn the cabin pressure switch to "manual" position from "auto".

The engineer did not reset the switch to "auto" after his check was complete and the cockpit crew failed to do the same while completing three pre-flight checklists.

The plane took off and the cabin pressure decreased as it gained altitude and alarms in the cockpit were misinterpreted and ignored.

Eventually, the cockpit crew was overcome by hypoxia and passed out. The passengers lost consciousness after the oxygen supplied from the overhead masks ran out.

As the pilots of the plane went incommunicado, jet fighters were scrambled. The fighters intercepted a ghost plane. They saw the Boeing's pilots were unconscious, passengers' oxygen masks were dangling and only one flight attendant, who used a portable oxygen cylinder, was conscious.

The flight attendant entered the cockpit and waved at the F-16 fighter jets but almost immediately one of the 737's two engines stopped due to fuel starvation. The other engine flamed out a few minutes later and the jet crashed 40km north of Athens.