Question regarding asymmetric loadouts and Trim

[Spudknocker]

So I know there is a separate thread that is similar to this one but I have a very specific question regarding asymmetric load outs in the Hornet.

 

As we get more and more PGM's I think I will feature asymmetric load outs more and more in my multiplayer missions.

 

My question is, is there a button or a function in the FCS that automatically trims out the jet to level flight? Seems to me like there would have to be if you're gonna do a cat-shot with a fuel tank on centerline and one on a wing station. That big of an asymmetrical loadout can't be good coming off the deck of the carrier.

 

If there isn't a function for this what do pilots do on the carrier? Kinda eyeball the trim and then after launch perfect that trim?

[noisy_lightning]

I expect their mission planning software pre flight would do a lot of the calculations for them and is then loaded into the aircraft at startup.

 

Sent from my ONEPLUS A3003 using Tapatalk

[Nealius]

The manual has a chart for these trim settings, I believe. I've only looked at them once, so my memory is pretty fuzzy, but I believe the settings were in some strange unit like "difference in pounds per square ____" or something like that, instead of a straight "if your right wing is x lbs heavier than your left, trim y amount."

 

Whatever that unit was, I just ignored the chart because in the end we have no way of knowing the units we would need from the DCS GUI.

[Eddie]

Stores asymmetry is measured in ft/lbs of torque. I can't be measured in weight because a given weight produces a different torque loading depending on how far it is from the centre of rotation (i.e. outboard vs inboard stations).

 

Information on how to calculate the stores asymmetry is in the pocket checklist (NFM-500).

Edited December 17, 2018 by Eddie

[Frederf]

Let's assume there's no automated system for advising or setting the roll trim when loaded asymmetrically because it probably doesn't exist and it would be valuable to have the required understanding and skill anyway. It certainly doesn't exist when in flight.

 

There is a paragraph 8.2.5 and chart, figure 8-1 in the NFM 000 describing asymmetrical stores takeoff trim. Given an asymmetric moment number (explained shortly) there is an amount of unloaded wing down trim 2-6° to apply.

 

Moment is a term describing a force. In this case it is the force of the store and its tendency to roll the airplane. It is a function of its weight and the lateral distance from the center, simply the multiplication of the two values. For example a 1000 lb. bomb 40 inches away and a 500 lb. bomb 80 inches away will have the same moment. They will both have 40,000 pound-inches moment as 1,000x40 and 500x80 both equal 40,000.

 

What is needed for the calculation is the station location for the particular stations you're interested in (figure 4-4 NFM 000) and the weight of each store. Call for example all stations on the left negative distance and right positive distance. Multiply the distances times the weights for each station and then add all the numbers. If the sum is >0 then the right side has extra loading if <0 then left side is heavier.

 

Then go to the chart and find that location (e.g. 15,000 in-lb) and trace upward to the line (e.g. 4.3°). Then apply that much stab dissimilar deflection.

Edited December 18, 2018 by Frederf

[Bones1775]

https://youtu.be/hlDdknkSNPU?t=9m32s

 

interview with a navy hornet driver and talks about trimming double ugly

Edited December 17, 2018 by Bones1775