Narrative:

After a thunderstorm with hail passed over the airport; and during the following 90 minute or so ramp delay due to lightning within 5 miles; the first officer and I each performed separate walk-arounds to see if there had been any hail damage to our plane. We also sought higher vantage points (top of the jet bridge stairs) and from no location were we able to find any evidence of hail damage. As we were then awaiting our turn to speak with maintenance; we overheard several different crews asking questions regarding any additional inspections required. In all cases those crews were instructed that per maintenance control; if the pilot performing the walk around could not detect any damage; the aircraft was ok to continue. During the delay; I also heard this information come straight from an on-duty mechanic speaking to another crew on a different gate. The following day; I received a call after we blocked in at the end of our trip from a chief pilot informing us that around 18 planes; including ours; had been taken out of service due to hail damage that 'was not visible from a normal walk around/from the ground.' as far as the 'cause' section of this form is concerned... The first officer and I were confident we had done everything necessary for the safe operation of flight.although this is the first time in my 17-year aviation career that I've ever experienced hail damage to an aircraft; I think a procedure for maintenance to inspect aircraft from above to detect any possible 'undetectable' damage would be beneficial to us all.

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Original NASA ASRS Text

Title: After a strong thunderstorm with large hail. A A319 Captain performs a walk around; detecting no damage. Maintenance advises several crews that if there was no visible damage on a walk around/preflight inspection; the flight was good to go without a maintenance inspection. Damage is discovered the next day.

Narrative: After a thunderstorm with hail passed over the airport; and during the following 90 minute or so ramp delay due to lightning within 5 miles; the First Officer and I each performed separate walk-arounds to see if there had been any hail damage to our plane. We also sought higher vantage points (top of the jet bridge stairs) and from no location were we able to find any evidence of hail damage. As we were then awaiting our turn to speak with Maintenance; we overheard several different crews asking questions regarding any additional inspections required. In all cases those crews were instructed that per Maintenance Control; if the pilot performing the walk around could not detect any damage; the aircraft was ok to continue. During the delay; I also heard this information come straight from an on-duty mechanic speaking to another crew on a different gate. The following day; I received a call after we blocked in at the end of our trip from a Chief Pilot informing us that around 18 planes; including ours; had been taken out of service due to hail damage that 'was not visible from a normal walk around/from the ground.' As far as the 'cause' section of this form is concerned... the First Officer and I were confident we had done everything necessary for the safe operation of flight.Although this is the first time in my 17-year aviation career that I've ever experienced hail damage to an aircraft; I think a procedure for maintenance to inspect aircraft from above to detect any possible 'undetectable' damage would be beneficial to us all.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.