View Full Version : trutrak ADI patent?

01-04-2007, 05:34 PM
The TruTrak website describes the patent for their ADI:
The patent for ADI was received in near record time.
It is so unique that it wasn't even challenged in the patent office

I can't find it in the USPTO database. Does anyone know the patent number?

01-04-2007, 07:40 PM
The patent number for the ADI is 6,961,643.
The patent was filed on 2Feb05 and issued on 1Nov05.
This is a very short processing time, my experience has been 24 to 30 months to get a patent through the system.

Other patents issued to James R. Younkin (Tru Trak) are:


D. Pansier

01-04-2007, 09:26 PM

A system and associated method where a vertical flight dynamic sensor is stabilized using pitch rate gyro information combined with azimuth rate gyro information corrected by scaling the azimuth rate gyro information in accordance with feedback derived from the difference between the vertical flight dynamic sensor signal and the corrected vertical flight dynamic output. In one embodiment, the vertical flighy dynamic sensor may be a vertical speed sensor. In another embodiment, the vertical flight dynamic sensor may be a pitch attitude sensor derived from the difference between an inertial based acceleration signal and a velocity based acceleration signal. The velocity based acceleration signal may be based on airspeed or GPS velocity.

See the entire patent at http://www.patentstorm.us/patents/6961643-fulltext.html

01-04-2007, 10:03 PM
I have wondered how the TT ADI worked in pitch, and skimming the patent, it looks to me that they are essentially presenting a cleverly filtered and stabilized instantaneous vertical velocity indication. My GRT PFD displays a velocity vector, as do many HUDs, and I find it a particularly precise method of tight altitude control. For instance, if you want to level off, just pin the Velocity Vector on the horizon - and you are in level flight (regardless of the attitude of the airplane. Rather than iterating on power and pitch, I just hold the vector there as the airplane accelerates after a level-off, and I never deviate from the altitude. Really slick.

I might be reading it wrong, but if that's what they are doing, I'd be pretty happy to fly that in instrument conditions if I had to...


01-04-2007, 10:55 PM
Thanks guys - I only could find 3 Trutrak patents using the USPTO search function.... As you might guess I'm thinking about which roll servo to put into my right wing and I thought this would help.

This is the best spot for quick technical answers.... if only the forum could help flute ribs quicker :D

01-05-2007, 07:15 AM
As I understand and fly my ADI Pilot 2, if you pin the dot on the horizon, you are in level flight. On mine, first tick up is 500 fpm, second tick, 1000 fpm.

It is different, but once you get it, it is really slick.

01-06-2007, 02:10 PM
>> I just hold the vector there as the airplane accelerates after a level-off, >> and I never deviate from the altitude. Really slick.

That is in fact how it behaves in practice. How it works nobody knows :)

As Pete mentioned you have ladder bars that are actually vertical speed. So, when I want to start a standard rate descent from altitude, I pin the dot on the first bar 500fpm and trim the plane up.

I've also noticed that it reacts much faster to deviations than my altimeter. So, I can often capture some sink and recover before it even shows on the altimeter. I also got the internal gps. So, my magnetic course is also displayed as well.

One negative (which is probably true of EFIS as well) is that there is quite a bit of info in one instrument. So, your traditional scan gets rusty.

Overall though, I like it very much especially in the tight panel of an RV4.