The sunrise ozone depletion problem has been recently raised with regards to the stratospheric model validity question. The results of two morning flights at 42 km altitude which showed a 5% depletion of the ozone concentration during half hour following the break of the dawn are examined here. These measurements are discussed by comparison with those of several authors. Our measurements are consistent with all these results already published. This leads to the conclusion that the ozone concentration decreases at sunrise in the 40 km altitude range and up.