McDonald generalized linear failure rate distribution

We introduce in this paper a new six-parameters generalized version of the generalized linear failure rate (glfr) distribution which is called mcdonald generalized linear failure rate (mcglfr) distribution. the new distribution is quite flexible and can be used effectively in modeling survival data and reliability problems. it can have a constant,decreasing,increasing,and upside down bathtub-and bathtub shaped failure rate function depending on its parameters. it includes some well-known lifetime distributions as special sub-models. some structural properties of the new distribution are studied. expressions for the density,moment generating function,conditional moments,mean deviation,bonferroni and lorentz curves also are obtained. moreover we discuss maximum likelihood estimation of the unknown parameters of the new model.