Ever wonder how a pilot navigates a plane at night? The secret's in the six-pack
When driving a car, you turn the steering wheel in the direction you want to go, you press the break when you want to stop, and your turn your fog lights on when it's hard to see. Even when the weather is nasty, you can generally find your way around town with landmarks, street lights and familiarity of the neighbourhood. But unlike the open road, the open air can sometimes leave pilots feeling a little disoriented – especially at night or in other unfavourable conditions. It's in these instances where a six-pack comes in handy.
Arguably the most important and basic of all flight instruments, a "six-pack" is a set of gauges that help pilots navigate to and from their destinations safely. They provide pertinent information about the planes motion and orientation in relation to what's around them (even in bad weather when visibility can sometimes be reduced to zero), making them the most critical installs an aviation technician will work on.
While a number of these tools have become digital, Centennial College's Avionics Maintenance program will ensure you're well-versed in both electric and analogue devices, as you're bound to see both in your career. Here's a little more about the six-pack instruments and why they're so vital:
- Airspeed Indicator – Just like your car has a speedometer, an aircraft has a similar instrument called an airspeed indicator, which measures air pressure inside and outside the cabin. The speed of the plane is incredibly important to maintain, as too slow of speed will cause the plane to stall and too fast can lead to structural breakdown of the craft.
- Attitude Indicator – Of all the instruments, this one plays one of the biggest roles in helping combat spatial disorientation (a dangerous condition in which a pilot believes they are in one position when they're actually in another). The attitude indicator tells a pilot the plane's position in relation to the ground. Much like a floating-ball compass, an artificial horizon moves in relation to the angle of the craft, indicating whether the nose is angled up or down (climbing or descending), and whether the wings are tilted left, right, or flying level.
- Altimeter – An altimeter measures the height of an aircraft above sea level by measuring barometric pressure. As the plane ascends or descends, pressure in the cabin will change accordingly. Decreased pressure indicates a higher altitude, while increased pressure indicates lower altitude.
- Vertical Speed Indicator – This piece of equipment measures how fast an airplane is climbing or descending in feet per minute (FPM). It does so by calculating how quickly the barometric pressure changes with increased or decreased altitude.
- Heading Indicator – A heading indicator is a compass made specifically for flight. Because an aircraft's movements and speed can change quickly, a regular compass would result in erroneous readings. In order to give accurate information, a heading indicator is stabilized using a gyroscope, so no matter what angle the aircraft is flying on, the pilot can tell which direction they're headed in.
- Turn Coordinator – Like the attitude indicator, the turn coordinator shows the angle of an aircraft's wings – whether they're tilted left or right, or flying level. What it also does is helps guide the pilot through a turn smoothly by indicating if the plane is slipping toward the inside or skidding toward the outside of the turn.
The role of an avionics maintenance technician is incredibly important. While it'd be next to impossible to get a plane off the ground without proper communications, electrical and guidance systems, it's the safety of pilots, passengers and those on the ground that makes this job even more critical. And it's the functioning six-pack that can ensure this safety.
By Ashley Breedon