Post by CoolP on Apr 22nd, 2011 at 1:11pm
Impressive work there, catching all the stuff in the screens, kiniu.
So lets see if I can help you then.
First of all, try to make use of the ADEU flight plan reader to avoid entering the waypoints manually. This manual approach may be cool on shorter routes, but as longer ones come in, you will be very tired from the typing alone and you are running the risk of entering stuff wrongly while the ADEU reader would just read your given flight plan and programs the INS for you.
You would only check the data entries then, like a good pilot would do. So much workload saved and safety gained then.
See the link to some neat flight plan converted on p.1 of this thread.
Second tip, always set up your current position in the INS. Even if it already shows the right coordinates, type them in again after bringing the units alive. See this as some sort of forced reset for the things.
Concerning your problem. When you look at the screens where the units are in the DSRTK mode, you will see that the INS actually commands the headings you are flying. So it seems like the INS to AP links works, but the commands from the INS doesn't seem to match your expectations.
For instance, this picture shows that the INS is on the leg from waypoint 0 to waypoint 1. 0 would describe your current position and 1 is the first waypoint of the plan. Now, since the unit is in the DSRTK mode, it will show you the desired track in the left side of the display. In this case, it's a heading of 96 degrees. So the unit tells you that it's now trying to track those 96 degrees which will result of a aircraft heading of around 96 since the INS does some corrections for the winds.
Your CDI shows you to be on 96 degrees, so the command chain INS to AP works. Conclusion, the technical side of your setup is ok.
Now, what could be the problem in your setup?
As said, the technical side is ok, the logical one seems to struggle.
You can always force the INS to reset the desired track by using the direct-to operation. If you want to go from your current position (which then will be 0) to the first waypoint of your plan, you have to press WYPT CHG, 0 (=current pos) and the number of the waypoint you'd like to go to, in this case 1. Last step, press INSERT.
The desired track then gets recalculated, showing the exact value which is necessary to turn the aircraft directly to the waypoint which was desired.
Try to perform this direct-to action when entering the runway or just before switching the AP over to the INS navigation, to ensure that the desired track calculated takes your current position into account. You have to force this recalculation to update the leg between 0 and 1.
If you, after taking off, are commanded directly to waypoint 3 of your flight plan, you therefore will press WYP CHG, 0, 3 and INSERT. Check the desired track in the INS display and then connect the INS to the AP if not already connected.
The other possible error source are wrong coordinates. If you for example mix up some numbers for the first waypoint, the INS will think of "I have to go South" while you are expecting it to go North.
So check those numbers to make sure that everything is fine. I sometimes mixed up numbers or even West and East (or North and South) coordinates, leading to a useless INS then since it takes you around the globe then. ;D
So the pre-activation check of the INS (=before you connect it to the AP) will always mean that you look at that desired track when in the DSRTK mode. Does it match your roughly assumed flight plan route? If so, enable the AP link. If not, stay on manual headings and check the data in the units.
So lets see if I can help you then.
First of all, try to make use of the ADEU flight plan reader to avoid entering the waypoints manually. This manual approach may be cool on shorter routes, but as longer ones come in, you will be very tired from the typing alone and you are running the risk of entering stuff wrongly while the ADEU reader would just read your given flight plan and programs the INS for you.
You would only check the data entries then, like a good pilot would do. So much workload saved and safety gained then.
See the link to some neat flight plan converted on p.1 of this thread.
Second tip, always set up your current position in the INS. Even if it already shows the right coordinates, type them in again after bringing the units alive. See this as some sort of forced reset for the things.
Concerning your problem. When you look at the screens where the units are in the DSRTK mode, you will see that the INS actually commands the headings you are flying. So it seems like the INS to AP links works, but the commands from the INS doesn't seem to match your expectations.
For instance, this picture shows that the INS is on the leg from waypoint 0 to waypoint 1. 0 would describe your current position and 1 is the first waypoint of the plan. Now, since the unit is in the DSRTK mode, it will show you the desired track in the left side of the display. In this case, it's a heading of 96 degrees. So the unit tells you that it's now trying to track those 96 degrees which will result of a aircraft heading of around 96 since the INS does some corrections for the winds.
Your CDI shows you to be on 96 degrees, so the command chain INS to AP works. Conclusion, the technical side of your setup is ok.
Now, what could be the problem in your setup?
As said, the technical side is ok, the logical one seems to struggle.
You can always force the INS to reset the desired track by using the direct-to operation. If you want to go from your current position (which then will be 0) to the first waypoint of your plan, you have to press WYPT CHG, 0 (=current pos) and the number of the waypoint you'd like to go to, in this case 1. Last step, press INSERT.
The desired track then gets recalculated, showing the exact value which is necessary to turn the aircraft directly to the waypoint which was desired.
Try to perform this direct-to action when entering the runway or just before switching the AP over to the INS navigation, to ensure that the desired track calculated takes your current position into account. You have to force this recalculation to update the leg between 0 and 1.
If you, after taking off, are commanded directly to waypoint 3 of your flight plan, you therefore will press WYP CHG, 0, 3 and INSERT. Check the desired track in the INS display and then connect the INS to the AP if not already connected.
The other possible error source are wrong coordinates. If you for example mix up some numbers for the first waypoint, the INS will think of "I have to go South" while you are expecting it to go North.
So check those numbers to make sure that everything is fine. I sometimes mixed up numbers or even West and East (or North and South) coordinates, leading to a useless INS then since it takes you around the globe then. ;D
So the pre-activation check of the INS (=before you connect it to the AP) will always mean that you look at that desired track when in the DSRTK mode. Does it match your roughly assumed flight plan route? If so, enable the AP link. If not, stay on manual headings and check the data in the units.