Narrative:

At FL360; and approaching 08n150w we entered a cumulous top that we were not aware of primarily due to our map scales being too large to see the radar return. We encountered moderate turbulence and strong up and down drafts. We scaled down our map displays and immediately requested a climb to FL370 and a course deviation; but only the altitude was approved. We were denied the course deviation due to traffic. We saw an immediate need to deviate to the right by only about 5 miles off course; which we did; and returned to our slop of R2 after passing the threat. Also; due to the up and down drafts being as strong as they were; our altitude deviated by about 200 feet and we got 4 overspeed warnings; which we observed to be about 5 knots. The weather cell was small; but intense and rising rapidly. The whole event lasted around 3 minutes after which we checked on the cabin crew and found everyone to be okay. Afterwards the airplane displayed status messages of 'cruise flap fault' and 'flaps secondary fault.' on arrival and on descent; we got several EICAS messages regarding GPWS and single source ILS. The radar did not display weather until we were in it; when it finally displayed a large green area of what turned out to be moderate rain and turbulence. We were at 12;000 feet. The subsequent vectoring; ILS approach; and landing were uneventful and routine. The airplane suffered a lighting strike on departure on the previous leg and was inspected before we accepted it. We took a 3 hour delay for the inspection; which we were made aware of the night before. On takeoff and descent; my position was international relief officer on this leg in the right rear jumpseat. It has a very limited view; and it is very hard to hear communications between the crewmembers because of the location and the noise from the ventilation.

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Original NASA ASRS Text

Title: B787 flight crew reported entering a small thunderstorm at night that they did not notice on Radar due to the large scale selected.

Narrative: At FL360; and approaching 08N150W we entered a cumulous top that we were not aware of primarily due to our map scales being too large to see the radar return. We encountered moderate turbulence and strong up and down drafts. We scaled down our map displays and immediately requested a climb to FL370 and a course deviation; but only the altitude was approved. We were denied the course deviation due to traffic. We saw an immediate need to deviate to the right by only about 5 miles off course; which we did; and returned to our SLOP of R2 after passing the threat. Also; due to the up and down drafts being as strong as they were; our altitude deviated by about 200 feet and we got 4 overspeed warnings; which we observed to be about 5 knots. The weather cell was small; but intense and rising rapidly. The whole event lasted around 3 minutes after which we checked on the cabin crew and found everyone to be okay. Afterwards the airplane displayed status messages of 'Cruise Flap Fault' and 'Flaps Secondary Fault.' On arrival and on descent; we got several EICAS messages regarding GPWS and Single Source ILS. The radar did not display weather until we were in it; when it finally displayed a large green area of what turned out to be moderate rain and turbulence. We were at 12;000 feet. The subsequent vectoring; ILS approach; and landing were uneventful and routine. The airplane suffered a lighting strike on departure on the previous leg and was inspected before we accepted it. We took a 3 hour delay for the inspection; which we were made aware of the night before. On takeoff and descent; my position was IRO on this leg in the right rear jumpseat. It has a very limited view; and it is very hard to hear communications between the crewmembers because of the location and the noise from the ventilation.

Data retrieved from NASA's ASRS site 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.