= Release Notes for Version 1.8.1 include::release-head.adoc[] :doctype: article Version 1.8.1 includes an important bug fix for Apogee Lockout operation in all flight computers. Anyone using this option must update firmware. This release also contains a change in how flight computers with accelerometers deal with speeds around and above Mach 1. In previous versions, the flight computer would completely disregard the barometric sensor above 330m/s (around Mach 1). Now, the data from the barometric sensor is reduced in effect without ever going away entirely. This prevents early drogue deployment for flights which spend considerable time above Mach 1. 1.8.1 also contains a couple of minor fixes for AltosUI when analyzing saved data files. == AltOS AltOS Bug Fixes * Handle time value wrapping in Apogee Lockout correctly. Without this, apogee lockout would sometimes prevent any drogue charge from firing. * Change Kalman filter on flight computers with accelerometer to continue using the barometric sensor even at high speeds to avoid unintentional drogue deployment during deceleration. == AltosUI and TeleGPS Applications AltosUI New Features * Add new 'Huge' font size to make text even bigger on high resolution monitors. AltosUI Bug Fixes * Prevent some crashes when reading older saved flight data for graphing or KML export. * Load frequency preference at startup. The loading code was broken, so you'd see only the default frequencies.