I thought this might be of interest to anyone considering the TruTrak ADI. I asked several times on this list about what this device actually indicates and got lots of conflicting answers. Even Trutrak reps seemed to have trouble explaining it. Well I just powered one up in the palm of my hand and I have the definitive answer.
Regarding Pitch:
It does not detect pitch, it detects pitching. Once the pitching stops, the device returns to an indication of level flight, even if you're pointing uphill/downhill. However, the device also measures vertical speed via a static air connection and uses this to maintain an up or down pitch indication. For example, you nose up to climb. The gyro detects the pitching and indicates nose up. Once you settle into a stable nose up attitude the device is held in a nose up indication by the vertical speed detector.
Regarding Bank:
This thing doesn't measure bank at all, nor does it measure yaw; it measures yawing and indicates it via bank. That is to say it will only detect when you are turning around the vetical axis. Once the turning stops, it returns to indicate level flight. For example, you could put the plane in a slip and, since you're not actually turning, it would indicate wings level even though they're not. Incidently, this is exactly what a turn indicator does.
Having said all this, I still think this thing is a bacon-saver and think it's the perfect piece of backup equipment for my Day VFR/Aerobatic mission.
Steve Zicree
RV4 Wiring and playing with gadgets
Regarding Pitch:
It does not detect pitch, it detects pitching. Once the pitching stops, the device returns to an indication of level flight, even if you're pointing uphill/downhill. However, the device also measures vertical speed via a static air connection and uses this to maintain an up or down pitch indication. For example, you nose up to climb. The gyro detects the pitching and indicates nose up. Once you settle into a stable nose up attitude the device is held in a nose up indication by the vertical speed detector.
Regarding Bank:
This thing doesn't measure bank at all, nor does it measure yaw; it measures yawing and indicates it via bank. That is to say it will only detect when you are turning around the vetical axis. Once the turning stops, it returns to indicate level flight. For example, you could put the plane in a slip and, since you're not actually turning, it would indicate wings level even though they're not. Incidently, this is exactly what a turn indicator does.
Having said all this, I still think this thing is a bacon-saver and think it's the perfect piece of backup equipment for my Day VFR/Aerobatic mission.
Steve Zicree
RV4 Wiring and playing with gadgets