A complainant had claimed that a phrase in the charity's literature about the aircraft on display being "the only complete examples in the world" was misleading on two counts.
The complainant said the wording was misleading because many of the aircraft in the museum were also on display in other museums in the UK and Europe. They also said the aircraft were not original models, but had been rebuilt using materials from other aircraft.
But the ASA ruled that readers would "interpret the claim in context", understanding that the museum's Mosquito Nightfighter and Halifax Bomber were the only complete examples in the world and that the claim did not to refer to all 40 aircraft on display.
The watchdog also "noted that the leaflet did not claim to offer original models of any of the aircraft on display" and said readers were likely to understand that some aircraft might have required rebuilding or restoration.
A museum spokesman welcomed the verdict.
"The text endeavours to do justice to the significance of some of our rare aircraft and to give an indication as to the wide variety of these on display, within a restricted number of words," he said. "However, we will take this rare complaint as constructive criticism for the future."