QUESTIONS have been raised as to how a state-of-the-art aircraft carrying relatives of 9/11 mastermind Osama bin Laden crashed landed in "near perfect" weather conditions, killing everyone on board.

The £7 million Saudi-registered Phenom 300 jet overshot the runway as it attempted to land at Blackbushe Airport near London on Friday afternoon, and colliding in a fireball explosion on top of dozens of cars lined up in a neighbouring car auction.

Rajaa Hashim, the al Qaeda founder's stepmother and a renowned philanthropist known for her charitable work with Saudi orphans, died along with her daughter and bin Laden's half-sister Sana bin Laden, Sana's husband Zuhair Hashim, and an unknown Jordanian pilot.

The plane, owned by Jeddah-based Salem Aviation, a company controlled by the wealthy bin Laden family, had flown from Milan, Italy to the private UK air field.

A joint investigation into the circumstances has been launched by Hampshire police and the UK's Air Accidents Investigation Branch, the same department probing the Clutha helicopter crash in Glasgow.

The Saudi General Authority of Civil Aviation has also sent its own investigators to the scene.

The private jet, which is equipped with fly-by-wire electronic system that is supposed to make it easy to control, was reportedly a regular visitor to Blackbushe Airport.

It was attempting a landing in near-perfect conditions on a runway that was fitted with Precision Approach Pathway Indicators (Papis), which warn the pilot if he is coming in too high or low.

Simon Moores, a flight instructor and pilot who has flown from Blackbushe many times, said: “It doesn’t make sense to me as an ordinary pilot why something that advanced and easy to fly would bury itself in the auction ground at the end of such a long runway.”

Osama bin Laden's family has been scarred by a series of aircraft tragedies. His billionaire father, Mohammed, was killed when his plane crash landed in Saudi Arabia 1967 as he was en route to wed his 23rd wife.

The terrorist's eldest brother also died in a plane crash in 1988 when he ploughed into powerlines in Texas.

Acting Chief Inspector Olga Venner, of Hampshire Police, appealed for witnesses to Friday's crash to come forward.

She said: "Sadly there were no survivors. No-one on the ground has been injured and we would urge anyone with any information, including pictures or videos, to contact 101."

Robert Belcher, a local aviation enthusiast, said he was driving home when he saw a plume of black smoke coming from the site.

He said: "I was passing the airport on my way home and there was a big column of smoke in the air.

"The fire service had closed the road behind me.

"I could see the plume of smoke waving from about five miles away and was hoping it was just a car fire rather than an aircraft accident."

Mr Belcher said he was "shocked" when he discovered that a jet had crashed.

He added: "Apparently the aircraft was landing and just didn't stop."

Meanwhile, an investigation has been launched after an aerobatics display plane crashed in front of thousands of spectators during a car show in Chesire.

The Folland Gnat was performing alongside a second jet at Carfest North in Oulton Park when witnesses said it appeared to spiral out of control shortly before 3pm on Saturday.

Spectator Neil Macew said: "Coming towards the end of it, they were doing some spirals - one seemed to lose control and crashed just beyond the north of the circuit."

The event, which raises money for Children in Need is the brainchild of broadcaster and motoring enthusiast, Chris Evans.

The presenter tweeted that he was "very sad" to hear of the accident.