The RCA 22 Series of vacuum artificial horizon are controlled by air driven precision gyros to present the pilot with pitch and roll information. The attractive color scheme of blue sky and brown ground presents a realistic spherical display of flight. Unless otherwise indicated all instruments have a "standard" display (dark blue/brown display with fixed pointer) and are unlighted.
All R.C. Allen vacuum gyros run off of 4.5" Hg, erect time is 3 min. The instrument fits in a standard 3 1/8 panel cutout. A ? -18 NPTF nylon tube slip fitting is recommended for vacuum hose installation. A 1/8 – 27 NPTF nylon tube slip fitting is recommended for vacuum gauge installation.