Photofragment translational spectroscopy, which utilizes pulsed electric field time-of-flight mass spectrometer, has been used to study the photodissociation dynamics of $t-C_4H_9I$ at 277 and 304 nm. The time-of-flight measurements yield the energy disposal for channels leading to I ($^2P_\frac(1)(2)$) and $I^*$ ($^2P_\frac(3)(2)$) for both wavelengths. The average energy disposed into internal excitation of $t-C_4H_9$ radical is 65% ($I^*$) and 72% (I) at 277 nm and 60% ($I^*$) and 74% (I) at 304 nm. The quantum yield for $I^*$ production is 0.038 and 0.15 at 277 and 304 nm, respectively. The results are compared to an impulsive description of the dissociation dynamics of the alkyl iodides.