ios app crash after download due to low memory in ipad 1

ios app crash after download due to low memory in ipad 1

my ios application download some .zip files and then start unzip. if .zip
file is higher than 50MB, program crash after downloading. i can see it is
fully downloaded in progress event but complete event cannot dispatch.
also app crash when zip file is higher than 150MB in ipad 3. adobe air:3.7
ios: 6.1.3