The Indian Air Force (IAF) today said most of the recent MiG-21 crashes have been caused due to inexperience of young pilots in handling the aircraft. â€œUnfortunately, except for one case, the other cases point towards inexperience of young pilots who were not able to handle the landing and approach (of the aircraft),â€ IAF Chief NAK Browne said here on Saturday. He was asked to comment on recent crashes of MiG-21 fighter aircraft this year including the one which crashed in Barmer district of Rajasthan on Friday. Speaking at the 79th Air Force Day parade at Hindon Air Base, located just outside Ghaziabad, Browne termed the security situation in Indiaâ€™s immediate neighbourhood as â€œextremely fragile and uncertainâ€, adding that it warrants close monitoring. â€œThe inimical intentions of our adversaries are further strengthened by radicalism and infusion of technology,â€ the IAF Chief added. Browne said the security of Delhi as well as other metros will be a priority. â€œWe will have a safety network that will comprise radars, early warning systems, missiles as well as air-borne fighters,â€ he told the audience. He said by 2014, a comprehensive and complete radar coverage network in the country would be in place. The most challenging are the mountainous areas and the process there may take about a year longer, Browne added. There are also plans to deploy fighter aircraft for quick response to any possible threat. At the parade today, the Air Forceâ€™s first all-woman team of six skydivers made its official debut. The team jumped out of an AN-32 transport aircraft and went through a series of mid-air formations before touching down at the tarmac. The newly inducted heavy-lift transport aircraft in the IAF C-130J was another major attraction. A total of 35 aircraft, including the Su-30 MKI, Jaguar, Mirage-2000 and the MiG-21 Bisons along with Mi-17 choppers, took part in the aerial display. Browne said the planned induction of the C-17 heavylift aircraft along with medium and heavylift choppers will increase IAFâ€™s operational flexibility. â€œUpgrades of Jaguar, Mirage-2000 and MiG-29 fighter aircraft along with An-32 transport aircraft are underway and will help in enhancing their operational relevance,â€ Browne said.