A string of near misses between RAF fighter jets since the beginning of the year could have been avoided and are "extremely worrying", says the SNP.
In the latest incident on 6 Mar 2015 an RAF Tornado and Hawk fighter jet sped at 518mph within 367 feet of each other above Alnwick in Northumberland.
On 5 February a Tornado fighter travelling 345mph and a Tucano propeller plane came within 400 feet of each other while performing a training mission.
Both of the near misses could have been avoided if the Tornados were fitted out with an airborne collision avoidance system, according to freshly published investigations prepared by the UK Airprox Board, Britain's air safety authority.
The military has reported 12 incidents involving its aircraft to the organisation since the beginning of 2015. Another incident in February involving the Tornado jets was, in part, due to the collision avoidance system being confused by the contours of the landscape.
"This is yet another extremely worrying incident of there being a near-miss involving RAF aircraft," said SNP defence spokesperson Brendan O'Hara. "These incidents are coming along way too frequently.
"How many near misses must there be before all these aircraft are fitted with such basic safety equipment?" he asked of the anti-collision technology. "It appears the Ministry of Defence [MoD] are continuing their cavalier attitude on this system."
The SNP has been calling for a speedier roll out of the technology across the RAF fleet since two Tornado fighter jets collided over Moray Firth in 2012, killing three airmen. The early warning collision system was recommended for use in 2008 but not installed in each jet.
A military investigation was carried out and recommended the installation of collision-warning systems as a necessity.
"The system has been fitted to eight aircraft to date and these will shortly be joined by a ninth aircraft," according to an MoD spokesman. "While the introduction of Traffic Alert and Collision Avoidance system on Tornado will add an additional layer of safety, there are already a multitude of measures in place to minimise the risk of mid-air collision." In all the RAF has 87 active Tornado jets.
They added that the system is "being progressively rolled out" across the fleet as the fighter jets receive scheduled maintenance.
This is not enough, said O'Hara.
He called for "an immediate review of procedures and a firm timetable for the roll out of a collision warning system to all fast jets and future joint strike fighter".