Avionics technology company Rockwell Collins has sent retirement offers to some employees as part of its plans to cut about 500 jobs from its workforce of about 20,000.The Des Moines Register reports that the retirement offers are not focused on specific locations.Company spokeswoman Pam Tvrdy-Cleary says the offers are one-time incentive opportunities for eligible Rockwell employees in the U.S. to leave the Cedar Rapids-based company by Dec. 18.She says the offers are a way for Rockwell Collins to trim its payroll without layoffs.The company announced Friday that it expects fiscal 2016 revenue of between $5.3 billion and $5.4 billion, citing weak demand for business and regional jets. The figures were lower than analysts' forecasts.