The Flight Director as a Backup
I’ve noticed that a lot of general aviation pilots tend to ignore the flight director on the attitude indicator. A lot of pilots don’t even know what it’s there for or how to use it. Talk to any airline pilot, though, and he or she will tell you how important the flight director actually is.
In most high performance airplanes, the flight director comes on when the autopilot comes on. Essentially, the autopilot is following the flight director, which tells the autopilot where to go. The flight director can also be used with the autopilot off, when hand flying an approach, for example. By turning the flight director on, it will show you where you need to fly to stay on course and on glide slope.
The flight director is most often controlled by the autopilot controller. The same buttons you use to put the autopilot in heading mode also tells the flight director to follow the heading bug when the autopilot is off. When you move the heading bug (or change course on the GPS, depending on which mode you have selected), the flight director will show you when you need to turn and when you need to stop turning. It directs your flight attitude, hence the name.
I recently discovered it’s a great backup when you have some instruments on the fritz. I went on a long flight in a steam gauge Piper Malibu and the attitude indicator started reading erratically. While flying straight and level, it would randomly indicate that I was in a 10 degree bank to the right, swing back and show wings level, then show a 3 degree turn left. This went on for a while. We were in VMC conditions, so legality wasn’t a problem, but it was kind of disorienting.
After a little while of this, the autopilot started acting up. It would start oscillating the pitch up and down, making it seem like we were going through a moguls course in the air. I ended up turning the autopilot off and hand flying the airplane.
This led to a conundrum, since my attitude indicator was unreliable. I could definitely look outside, since it was VMC, seeing when I was level and when I wasn’t. That would create a higher workload for me, which on a long flight like I was on, would lead to an increase in fatigue. The solution? The flight director!
I turned the autopilot off, but I left the flight director up. It wasn’t referencing the bank angle that the attitude indicator was showing since the KFC 150 goes off of the turn coordinator. So, if I just followed the attitude indicator, I could just keep scanning the instruments and relieve a little bit of my workload.
It actually worked really well. By just following the flight director, I was able to stay on course and on altitude with only minor attitude adjustments whenever we hit turbulence.
So, if you’re attitude indicator and autopilot decide to stop working on you, then bring up the flight director, push the same buttons you would if you were using the autopilot, and it works as a great backup.
