"THE DDTU HOUSES A 128MB FLASH MEMORY THAT CONTINUALLY STORES RECORDED INFORMATION; IT PROVIDES MAINTENANCE PERSONNEL WITH THE ABILITY TO VIEW ENGINE DATA WITHOUT ENTRY INTO THE AIRCRAFTOR APPLYING EXTERNAL POWER; IT OFFERS THE OPTION OF DOWNLOADING ALL RECORDED INFORMATION TO A STANDARD FORMATTED PERSONNEL COMPUTER MEMORY CARD INTERNATIONAL ASSOCIATION (PCMCIA) CARD; WHEN A PCMCIA CARD IS INSERTED INTO THE DDTU RECEPTACLE, THE INFORMATION ON THE 128MB FLASH MEMORY WILL BE TRANSFERRED TO THE PCMCIA CARD BY ONE KEYSTROKE ON THE DDTU;DDTU PROVIDES THE CAPABILITY TO DISPLAY SYSTEM STATUS INFORMATION WHEN 28 VDC AIRCRAFT BATTERY POWER IS APPLIED TO THE UNIT; IT PROVIDES A STATUS BUTTON, WHICH WILL DISPLAY A STATUS CODE, SPECIFYING MALFUNCTION RELATING TO THE ENGINE MONITORING FUNCTIONS OF THE FDR"