In a shocking revelation, civil aviation officials have found that Alliance Air had, in gross violation of safety recommendations by the Directorate General of Civil Aviation (DGCA), used a six-times retreaded tyre in a Boeing 737 chartered by the Army to ferry its personnel from Leh last Friday. The negligence led to tyre damage during take-off, forcing the plane carrying 93 passengers to make an emergency landing at Indira Gandhi International Airport (IGIA) on Friday. The tyre’s top layers had worn off. This increased pressure on the outer tyre, making landing a riskier affair.While DGCA norms do permit use of retreaded tyres in routine operations, there are specific recommendations for flights operating from high altitude airports like Leh. Aviation experts said the tyres are exposed to extreme pressure while taking off from Leh. For instance, a plane has to touch about 120-130 knots depending on its load before taking off from IGIA. At Leh, an aircraft needs to attain a minimum speed of 140 knots to take off.‘‘This along with high-altitude conditions at Leh increase the pressure tremendously on tyres which is why retreaded tyres are not recommended. In fact, the DGCA made these recommendations precisely after receiving few reports on tyre damage at Leh,’’ said a senior Ministry of Civil Aviation official on condition of anonymity.The IAF also does not use retreaded tyres in its aircraft operating from high-altitude locations. Decapping or wearing off, sources said, is a known phenomenon at Leh and Alliance Air ought to have maintained caution on this aspect.Alliance Air officials argue that DGCA norms do permit the use of a tyre which has been retreaded up to six times. However, private airlines like Jet don’t retread beyond three times. Downplaying the close shave on Friday, these officials emphasised the retreaded tyre was fitted on the inside. ‘‘Decapping is nothing uncommon. In fact, there was no need for a full emergency to be declared at IGIA because the in-flight engineer had confirmed the plane could land despite the tyre suffering damage during take off,’’ said a senior Alliance Air official. Alliance Air head Menet Paes refused to comment.But according to Airports Authority of India, the airlines should know better that the major risk in such cases is the increased chance of fire due to friction while landing with damaged tyres. Both these aspects are now under specific investigation by the DGCA inquiry team which is expected to submit its report soon.
