TOT indicator question

Hello,

I was looking for some info on what indicators there are when you set a TOT in the F-18C.

For instance in the Viggen it tells you when you should take off with a timer. Then on the HUD it lets you know if your slow or fast.

I must be missing something right in front of me.

I would think there is some help from the computer to get you to your target on time.

I set TGT way point, TOT Time, Ground Speed. It shows the proper info on my Data page of the HSI.

I just don't see any ques on the HUD. and the hsi info didn't really make any sense.

Thanks for any help on this.

The airspeed indicator on the hud will have a line and a carrot below the box try and line them up to arrive at your set TOT for that waypoint in the sequence

Also make sure the ground speed you set makes sense or don’t set it at all because the MC will use TOT for cuing not the ground speed setting

Thanks for the help.

I also was setting Std time NOT ZULU time so my indicator never worked as the TOT is in Zulu i was 4hrs off before.

Hit my target today +/- 5 sec within TOT time set.

It would be nice if we could use ZULU in the mission editor.

Tot questions

Hi guys,

so i experimented with tot programming a little bit and found out that the entered ground speed doesnt effect the early/late Caret unless you haven't set your target Waypoint as a Navigation Waypoint. If you set your target Waypoint as a Navigation Waypoint then the early/late Caret just indicates if you are slower or faster than your entered ground speed (but it doesnt take into account the tot anymore). Is that intended?

So using tot in a waypoint sequence just helps me to be on time at the target waypoint in a way that it gives me the right speed which should be then the same during the complete waypoint sequence. But then it doesnt take into account the Ground Speed after the initial point.

So here is how it should worked (if i got it right):

early/late Caret gives you the correct speed so that you arrive at the initial point at the correct time which corresponds to the correct tot taking into account the entered ground speed.

E.G.: If you enter a higher ground speed then you should be at the initial point at a later point in time, therefore the early/late Caret should move to the right (which doesnt happen). If you enter a lower ground speed you need to be at the initial point earlier (because you need more time to the target) which means the early/late Caret should move to the left (you need to fly faster), which it doesnt.

Am i getting something wrong here or is the tot programming buggy?

Any advice is greatly appreciated.

Am i getting something wrong here or is the tot programming buggy?Any advice is greatly appreciated.

Yes I have the same results. It's very basic & un-innovative. I would think that the RL F-18C would have a more sophisticated TOT features then that? After all TOT or TOS is essential in all war-operations.

It gives no indication when to take-off, no speed & time-keeping reference etc. I think it's still buggy, but I dunno?

Would be great if we could get an RL F-18C driver explaining the TOT function.

Am i getting something wrong here or is the tot programming buggy?

AFAIK TOT is still buggy.

• If you don't enter a Ground Speed, TOT works correctly.

• Entering a GS for the IP --> TGT ingress, the speed carrot changes (at the IP) to show the desired GS but TOT is off because the TOT calculation doesn't allow for the speed change.

Bug Report / Detail : https://forums.eagle.ru/showthread.php?p=3797785#post3797785

Ok, thx for the replies. Since this was already reported in February i guess there is no answer to when this will be fixed right?

Btw, i didnt study the warthog yet but there is a TOT feature as well right? Does it work for the warthog correctly?

Does it work for the warthog correctly?

Yes, though IIRC it's a simpler system that gives a required speed to reach a waypoint on time and doesn't take the flight plan or any other waypoints into account.

So as a note for the developers i wrote down the correct formula to calculate the correct speed to get the TOT-feature working correctly (hope i didn't miss something). The stuff is not too complicated and could be implemented easily (at least i hope so). If anything is wrong just let me know.

https://www.dropbox.com/s/t2wjyr5xihys5um/vtot%20calculations.png?dl=0

Btw i couldnt add a pic properly so i posted the dropbox link. Sorry for inconvenience. Any advice on how to add pictures is greatly appreciated (maybe via pm).

Formula for TOT-Calculations

So the calculation should be as followed:

v_TOT=s_waypoints/(t_IP-t_now ) with t_IP=t_TOT-s_(IP to targetwaypoint)/v_GSPD , current time t_now, s_(IP to targetwaypoint) being the distance between the IP and the target waypoint, t_IP being the time you should be at the IP and t_TOT being the time on target.

s_waypoints is the sum of the distances between two consecutive waypoints in the waypoint sequence (starting with the currently selected waypoint and ending with the IP) plus the distance to the currently selected waypoint.

The early/late Caret should be placed appropriately after comparing the current groundspeed with v_TOT.

The Dropbox-link above gives a better overview because of a better representation of the fractions and variables. If anything is wrong just let me know.

I have a question about TOT aswell.

How can you disable the TOT symbology in the HUD after passing the selected waypoint? After passing it, the HUD stil shows the carret under the airspeed and in the HSI it shows me a negative speed to get there.

My setup for the waypoint was only the time i want to be there, I didn´t type in the groundspeed.

I have a question about TOT aswell.

 

 

How can you disable the TOT symbology in the HUD after passing the selected waypoint? After passing it, the HUD stil shows the carret under the airspeed and in the HSI it shows me a negative speed to get there.

 

 

My setup for the waypoint was only the time i want to be there, I didn´t type in the groundspeed.

After passing the target waypoint I UN-selected the SEQU1 button at the bottom right of the HSI, that got rid of the TOT symbol and all the data relating to the TOT. I maybe pressed the WAYPT (top right of HSI) button on and off also. It was one of those buttons that did the trick.

AFAIK TOT is still buggy.

 

• If you don't enter a Ground Speed, TOT works correctly.

 

• Entering a GS for the IP --> TGT ingress, the speed carrot changes (at the IP) to show the desired GS but TOT is off because the TOT calculation doesn't allow for the speed change.

 

Bug Report / Detail : https://forums.eagle.ru/showthread.php?p=3797785#post3797785

So far it worked fine for me. If the mission is pre-planned in ME and I know my TOT, I set my GS for IP>TGT considering the weapons, threats, terrain, etc. (for me it's usually very fast) and adjust GS for each leg playing with the throttles occasionally if I have to snake around the terrain or any other factors get in the way.

If I'm orbiting on station and get set of coordinates, convert them to WPT then set that WPT as TGT in DATA. Your "station" WPT becomes IP. I then set TOT and realistic GS to get there. If I'm way to early I continue orbiting until the caret starts creeping in. Then just keep the caret in the center. Now, if I'm at high altitude and using guided weapons and time to impact comes into play then it forces me to think a little...:noexpression:

A workaround would probably be as follows:

If the Mission is preplanned in the ME then you check the time you have to be at IP. Set your TOT to this time and your target should be the IP. When you reach this on time adjust your speed to the corresponding ground speed between IP and "real" target. This way you get there on time AND with the correct speed.

Would be happy if the bug could be smashed anyway.

@The developers: Consider my formula to calculate the appropriate speed for correct TOT :-)

A workaround would probably be as follows:

If the Mission is preplanned in the ME then you check the time you have to be at IP. Set your TOT to this time and your target should be the IP. When you reach this on time adjust your speed to the corresponding ground speed between IP and "real" target. This way you get there on time AND with the correct speed.

Would be happy if the bug could be smashed anyway.

 

@The developers: Consider my formula to calculate the appropriate speed for correct TOT :-)

Yep, you're right. The speed setting seems to be ignored. I've always been using this feature with high winds aloft and the primary concern for me was getting there on time not as much being at certain ground speed in the final stage I've never really paid attention to a/s discrepancies on HSI especially being that close to an attack. I've seen the differences between the ground and true versus calibrated on HUD... oh well, that's about right:smilewink: Today I set a no wind condition at low level, hit the IP on the mark and... required GS was 80 knots slower then it shoud have been. It's good somebody out there pays attention!:)