in flight turbulence

[FlyBoyJae]

when i was on my student solo x country last week to meet the >150nm >3point requirement for PPL, i encountered moderate turbulence(at least to me, it was moderate, i definitely had to watch the pitch, speed, altitude and heading)...when i was flying through it i first thought that it was inevitable since i was flying about 2500AGL over the mountain area and tried to slow the plane down a bit to fly somewhere near Va for the C152. i did remember to be very smooth with the control inputs.
however, i noticed that the airspeed would fluctuate and soon enough i was "chasing the needle"...the speed would go from 85 to 100 then stay there for like 30 sec and come back down to 85 and so on and i noticed the RPM would also fluctuate a little...

i was a bit surprised to see such a big change since i never encountered anything like it on dual x countries.
what should i have done to avoid "chasing the needle"? i wanted to keep my throttle at one specific setting and not worry about it but i didn't eve have the full fuel tank(ie the plane was not as heavy as it woudl have been with full tank) at the time and did not feel like i should let the speed to go up to a 100 knots...but this meant i had to constantly play around with the throttle.
any suggestions for a newbie?

 

[viper548]

First I would select a power setting that would keep my airspeed below Va. In a 152 or 172 that would be about 2200 RPM. You're a student, so you must have been VFR, so use the horizon to maintain a level pitch attitude. Allow the airspeed and altitude to fluctuate, just maintain a level flight attitude.

 

[E_Dawg]

Just set the power for Va or close to it and leave it alone... the 152's va is what, 99 kts? That's nearly full throttle, you can probably use around 2400 RPM.

Then it's just a matter of keeping the wings and pitch attitude level... forget the instruments and just look outside. If it's severe turbulence you can't see the instruments anyway

 

[jjm]

I second the comments made by viper/skyguy.

I ran into the exact same situation on my own solo XC just about a month ago... The airspeed changes you're seeing are most likely a result of the turbulent airflow and thermals...but I could be wrong.

So here's my idea-- If you've got the power setting for cruise, (90-95) go ahead and trim the airplane for level flight (it might be a little tough with the turbulence). The plane's dynamic stability will ultimately allow it to work it's way back to straight and level flight after turbulence or thermal upsets.
But the instructors here are right-- keep looking outside the airplane.

On the early solos-- it's really easy to start thinking that the RPM's are jumping around a little too much, etc. I know, b/c on my solo, I started chasing needles around even though I'd been taught not to do that...

If you're trying to correct a loss in altitude or heading, do it in two parts: stop the change, and then make the correction, smoothly, just like you did.


By the way, if I'm completely off-base-- someone jump in and correct. (I'm just a student as well!)

Have fun!

j

 

[Icelandair]

What if you were on a stage check and it was bumpy from thermals? You would still have to hold +/- 100 feet, +/- 10 knots of airspeed wouldnt you?

 

[stuckingfk]

[ QUOTE ]
What if you were on a stage check and it was bumpy from thermals? You would still have to hold +/- 100 feet, +/- 10 knots of airspeed wouldnt you?

[/ QUOTE ]

If a stage check pilot failed a student on a turbulent day, the stage check pilot would get an ass kicking. As long as the student tries to maintain altitude somewhat, and doesn't get frustrated and give up, he/she should never fail.