I think that a pressure altimeter that stores maximum will misread copiously (upwards, in altitude)) about when the motor burns out (hint: bernoulli suction on the pressure port at the maximum speed will fake an altitude much greater than really attained. Worse, the peak in the record will NOT indicate maximum altitude and there should be no way to read it off the record - perhaps it would make a saddle curve and the bottom of the saddle would be the apogee - if the horizontal speed would be negligible - but it will not be ;-). The maximum altitude can be recorded with an apogee switch, by pressure or otherwise. Now, who knows about a reliable apogee switch (not the magneto resistive one please). Perhaps you could use a horizon sensor with 4 photocells and sense tilt from near-vertical. Peter -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body