Q: What is the estimated operating life of the MARTEK 4596 28V 250 Watt bulb?
According to the manufacturer, the approximate operating life of this bulb is 25 hours.
Q: This bulb has a clear lens which I associate with a narrow beam landing light, but my part book list 4596 as a taxi light. Your ad describes this as a landing light. Can you tell me what the beam width is?
It could be used for either taxi or landing. It is likely that your aircraft has one mount that is pointed slightly down for the taxi light and one level that would be for landing and they use different bulb part numbers for those locations.