A BBC investigation has revealed serious security lapses at Manchester Airport, programme makers claim.
Michelle Cox got on to a plane which should have been sealed at night
A reporter working as an aviation security officer was encouraged to flout Department for Transport rules on bag searches, the BBC says.
It said she also found planes left open and unattended overnight and that staff knowingly used faulty metal detectors.
The airport said travellers' safety was its "highest priority" and any breaches in procedure were fixed "immediately".
A spokesman said: "Manchester Airport's procedures, systems and equipment are part of a robust effective defence system comprising several different levels, which changes and evolves as necessary.
"Together with regular reviews and inspections this provides an intricate
system of checks and cross-checks which taken together provide a robust security
"We take any allegations of shortcomings extremely seriously and any breaches
in procedure are rectified immediately."
Journalist Michelle Cox spent ten weeks working at the airport.
Programme makers said on one occasion around 1,000 passengers passed through the airport from Pakistan but only three random bag searches took place.
"Michelle was told by colleagues to exaggerate the figures, with one workmate openly declaring, `We cheat'," a statement said.
"Michelle also discovered planes left open and unattended on the tarmac
overnight with easy access provided by the steps, which had been left attached,
contrary to security rules."
The reporter was also able to gain access to one of the planes and film undisturbed, the programme said.
The BBC also claims the film will show a metal detector failing to sound when
a knife and gun were passed through it as part of a test.
It said: "The detector failed to go off on a number of occasions and was shut down.
"The second detector in the area was tested with a large pair of scissors and
also failed to go off on a number of occasions.
"This one was not shut down and staff continued to allow approaching
passengers through security using the unreliable machine."
Security team leaders are also alleged to have tipped off colleagues about
covert DfT inspectors, phoning their physical descriptions through to colleagues.
The BBC show was broadcast on Tuesday at 2100 BST on BBC One as part of the Whistleblower series.