Two strange incidents involving Qantas Airlines jets have us wondering about the safety of their planes.

First up, a giant hole is torn into the belly of one of their 747s last Friday, forcing an emergency landing in Manila.

Qantas boss Geoff Dixon says jet explosion 'out of our control':

The airline today said it had done all it could to prevent the explosion which forced one of its Boeing 747-400s to make an emergency landing in Manila last Friday. After Melbourne-bound QF30 landed, a hole up to two metres across was discovered in its fuselage. Authorities are investigating whether an oxygen cylinder may have exploded mid-flight.

Qantas flight drama

Once we had landed and started to disembark it was obvious something major had happened. The hole was wedged up by the luggage. It dawned on a lot of people that this was a major incident. There were 350 people up there who were very lucky.

Oxygen gets you high // Calm as hindu cows!

Exploded canister parts found

A PIECE of metal from a ruptured oxygen bottle sliced into the cabin of Qantas Flight 30 on Friday, missing passengers but almost causing a mid-air disaster. A source said investigators found the jagged object while searching the jumbo late on Sunday.

The Australian Transport Safety Bureau yesterday confirmed that an oxygen tank was missing and that a number of components, including part of a valve, were found near the hole. A source said the piece of metal and myriad fragments appear to have travelled bullet-like through the baggage compartment, piercing bags and the roof. The shrapnel was found in the cabin section near where food is prepared for business-class passengers. In the same area the cabin floor was buckled, leading to a belief that it was caused by the exploding cylinder. "The force of a cylinder exploding at 29,000ft (9000m) would have been extreme," a source said.

Another emergency happened yesterday when an undercarriage door failed to properly close:

Another emergency for Qantas

QANTAS'S reputation as the world's safest airline took another blow last night with a passenger jet forced to make an emergency landing after an undercarriage door failed to close. The Boeing 767-338 flying from Melbourne to Adelaide was forced to turn around 20 minutes after it took off at 5.40pm and make an emergency landing at 6.15pm. Civil Aviation Safety Authority spokesman Peter Gibson said the aircraft's wheels came up after take-off but the undercarriage door would not retract.

Disgruntled passengers on QF692 last night said they would refuse to fly with Qantas again following the airline's second mid-air scare since Friday. Most of the passengers were transferred onto later Qantas flights but some refused, choosing to fly with Virgin Blue, or take other means of transport. South African tourist and QF692 passenger Gunter Kubler said he would not fly to Melbourne because of fears of flying with Qantas.