In pre-glass cockpit days, the number of engine status indicators in the cockpit used to be directly proportional to the number of engines in the aircraft. For example, a twin engine aircraft would generally have almost twice the number of dials as say a single engine aircraft.
Consequently, pilots in a multi-engine aircraft had a lot more dials to contend with. In fact, there were more dials then they could possibly manage to keep their eye on. To an extent, this dangerous situation was mitigated by the presence of the co-pilot and the flight engineer. Thus there was more than one pair of eyes keeping track on the engine and flight status.
Modern digital technology changed all that. Modern digital technology made possible the ability to capture and convey all of the information the pilots may want in a non-cluttered, easily understood and highly accurate manner.
Over the years, the size and complexity of the airplanes has grown. Even the humble twin engine aircraft has more than doubled in physical size. Pilots need to know the engine status at a glance and also aircraft’s precise location in relation to the flight path as well as the destination and also about any adverse weather that might affect aircraft performance.
Today, the cockpit instrument panel with its various individual instruments attached has evolved into a sophisticated computer-controlled digital interface with LCD display screens and prioritized messaging. In fact, even the LCD screens have given way to sophisticated touch screens dramatically reducing the number of physical buttons and switches.
Let us understand the specific differences between single engine management systems and twin engine management systems. As you are probably aware, there are three basic kinds of instruments in the cockpit; engine instruments, flight instruments and navigation instruments. For aircraft that carry passengers, there are some additional instruments that provide such data as cabin pressure, temperature and so on.
Whether single engine or Precision Engine Monitoring, the aircraft will have one set of instruments providing basic information such altitude, airspeed, magnetic direction, artificial horizon, turn coordinator, and vertical speed indicator. All these are often combined into a single digital display unit.
There is another set that provides engine related information. The only difference between engine instruments of single engine and twin engine Fuel gages is the physical size of the instrument panel and the quantum of data displayed.
Everything from pressure to temperature, fuel, oil quantity and tachometers for each engine is displayed in a single unit through use of multiple pointers on the same dial face.
The third set of instruments (and common to single and twin engine aircraft management systems) are the navigation Instruments. Modern navigation instruments are enormously sophisticated and generally incorporate Global position systems (GPS).
The leading manufacturer of all three types of modern day basic instruments for single and twin engine management is of course the California based J.P. Instruments. More information on them here: https://www.jpinstruments.com/