By Rajesh Kumar Singh and Abhijith Ganapavaram (Reuters) -Boeing Co on Wednesday warned its recovery from a crippling safety and economic crisis would take longer than expected after taking a $2.8-billion hit on loss-making defense contracts, sending its shares down sharply. The heavy writedown came a day after Reuters reported a shake-up in operational management at the company’s defense unit and unexpectedly drove the aerospace giant into a deeper loss in the third-quarter. “Our path to recovery is taking a bit longer than expected, driven by the challenging macro environment,” Chief Financi…