Wingloading and turbulence

[Biggles]

Thanks for all the resonses, I think i am getting somehwere with this.

The Va for my wing is 64mph then which is above what I will ever acheive with my current set up(I cruize at 45mph). With a VNe of 90mph I am well within the envelope. I think people were getting the wrong idea of how I am flying.

So why pull the wing in at all in turbulance? By the logic above decreasing speed should lead to a smoother flight?

I did a quick search but have to log off now but how would trimming a wing effect wing loading?

[KFA]

I think you are getting it. If you fly slower, the workload will be less because sudden changes will be less agressive. I just want to add to my post on Va. You only use this formula when there is no published figure for your specific setup, ALWAYS follow the manufactures specs. Just to confuse you more, Va is a changing number. It is not constant and changes with weight. IAW if your weight changes, your stall speed changes and your Va will then change. It's interesting to note that Va does increase with an increase in weight, this is due to the fact that your control responses become more sluggish and you have to fly faster in order for the controls to respond in the same manner as they would when the plane is light. BUT there is a limit to all of this and when we reach that limit we come back to what Kloot explained in his post. This is actually a very technical question and if you are unsure then just stick to the FAA guideline of 1,7 times your stall for a safe Va.

[Asterix]

Thanks to all for all the ifo provided above - this will surely help a lot.

A question though - what is the appropriate maneuver when turbulence changes yout pitch drastically? This has happened to me a few times - either nose goes up steeply, or tail picks up and you are facing the ground looking forward?

What I have done is in the first instance - pulll bar al the way into my stomach untill nose comes down, and in the second - push forward on bar untill nose picks up?

Is this right?

[kloot piloot]

Biggles, you mentioned that you fly a Spirit 15 wing. You cruise at 45mph, Vne at 90mph and Va at 64mph.

At what speed does the wing stall, or what speed is placated as stall speed ? And is it possible to post a picture of the wing in flight ? It would be interesting to know how much margin you have between cruise and stall.

[kloot piloot]

Asterisk,

pulll bar al the way into my stomach untill nose comes down, and in the second - push forward on bar untill nose picks up?

The problem with this (reactive) type of flying is that you end up being hell-of-a-busy trying to fly as level as possible. The bigger problem with reactive flying is that you are constantly changing your margin between cruise (or Va) and your stall speed.

Allow the ups and downs, the wing will do the rest. These delta wings are designed to keep you away from stalls as long as you don't overfight them.

[Biggles]

Biggles, you mentioned that you fly a Spirit 15 wing. You cruise at 45mph, Vne at 90mph and Va at 64mph.

At what speed does the wing stall, or what speed is placated as stall speed ? And is it possible to post a picture of the wing in flight ? It would be interesting to know how much margin you have between cruise and stall.

Yes, spirit 15, it's on the slow setting and a very slight rear pressure on the bar gets me 50mph.
wings specs are:
Stall:26mph
Cruise: 50-70mph
VNE: 90mph

I have a theory that my airspeed indicator is slightly under reading. I need too record airspeed vs. gps ground speed for a while and work it out. But generally speaking I notice up to 5mph difference in calculated wind speed when I change heading.

I don't have a picture of the wing in flight...

[Biggles]

Does wingloading increase when you trim a wing ie. if you increase airspeed.

I have looking and can only find references to 3 axis where it does increase the wing loading.

[KFA]

I can not see how more speed increases your wing loading per se. Wing loading is the size of the wing devided by the weight of the craft. Yes you do increase lift with more speed, if you look at the lift formulas CL=1/2 Rho Vsq S . But hey I am no engineer. But it's still interesting to discuss. It could be because you are increasing lift but not using it to climb, but instead you are flying faster by pulling the bar in so there is now more pressure/m2 of wing area and that is why you are increasing the wing loading.

[kloot piloot]

Does wingloading increase when you trim a wing ie. if you increase airspeed.

I have looking and can only find references to 3 axis where it does increase the wing loading.

Wing loading always remains the same at any speed, as long as you fly a 1G positive load. The only time when wing loading increases is when you apply additional load on the wing i.e. putting more fuel in, loading a pax, or during a 1G flight exert a higher G force than 1 G on the wing, whether 3 axis or trikes.

So by increasing your speed you do not increase wing loading.