Aircraft Engine Start Gas turbine aircraft engines such as turbojets, turboshafts and turbofans often use air/pneumatic starting, with the use of bleed air from built-in auxiliary power units (APUs) or external air compressors now seen as a common starting method. Often only one engine needs be started using the APU (or remote compressor). After the first engine is started using APU bleed air, cross-bleed airfrom the running engine can be used to start the remaining engine(s). #aerospace #aviati

Formation of First World War biplane and triplane vintage aircrafts in flight