Sign in to follow this  
Guest william273

C172 take-off, flight dynamics...

Recommended Posts

I have a question on the default C172 take-off behaviour which I find quite odd.To clarify things, I'm not a real pilot, and I've only ever done one trial flight (which was in a C152, and the instructor made me take-off and land the plane, which was a nice adrenalin rush).I'm 'wasting' my time mostly making scenary and other mods, but rarely take the time to actually spend some quality time flying. For a change, this week I put some time aside to practice my flying skills. Now, I've read stacks of books, so I know a good deal of theory.Here's what happens:As I run down the runway, I need to apply right rudder (with wind coming from ahead), which is fair enough (slipstream, torque, etc). As a side note, if I have about 10 kts wind from the right, I actually need to apply left rudder to keep straight, I assume the wind pushes the tail around? Is 10 kts really enough for such an effect to happen?Another sidenote, I need to apply forward pressure to prevent the C172 taking off too early, this surely is wrong as with a C172 one would usually apply back pressure to avoid wheelbarrowing, but if I do that, I lift off at about 40kts and bounce a bit like a kangaroo.Anyway, when I reach 55 - 60 kts and roll off the runway, I madly have to stomp onto the right rudder, otherwise the C172 will roll (and subsequently yaw) to the left and I will die shortly afterwards as the left wing impacts the ground (it's like a death spin to the left). The only way to get out of this is to really push the right rudder down hard and use the ailerons to turn right also, which of course is a mad manouvre that close to stall speed, in fact, usually I do stall subsequently with no positive outcome. I'd really like to know if this is realistic. I'm getting better at the sudden, firm right rudder input on take-off, and my take-offs start to look a bit better, but it does not exactly feel safe. I thought the lift-off would be a quite smooth buisiness, this feels more like flying a helicopter, and being close to stall speed surely doesn't help. Usually, I'm back in control at about 100-200ft AGL, but anything below surely is a delicate balancing act. One way to counter, is to wait for ground speed to be over 60kts, which gives a bit more play over stall speed and also stabilises the plane a bit, but that's taking off quite late.If this behaviour indeed is real, what causes it? Propeller torque as the wheels aren't in contact with the ground anymore to counter? And how many pilots usually die miserably in the early stages of learning how to fly?Cheers, Christian

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Christian,I am actually surprised that this is the way you experience the default C172. I quickly jumped in one and could not see anything unusual regarding the roll or yaw (rudder) soon after takeoff besides what real C172 requires - definitely nothing that would be even close to loosing control of the aircraft - it is a real pussycat. No, I don't like default C172 having flown a real one for over hundred hours and I can definitely tell you Flight1's C172 is much more realistic but let me tell you this - in my personal opinion neither C172 correctly replicates amount of right rudder you have to apply during first phases of the climb - in real life you have to use even more right rudder.Michael J.WinXP-Home SP2,AMD64 3500+,Abit AV8,Radeon X800Pro,36GB Raptor,1GB PC3200,Audigy 2, Omega 2.7.90 (4xAA 16xAF)

Share this post


Link to post
Share on other sites

i've been going through something along those lines too. someone mentioned using more trim and that help get me off the ground closer to 55 knots than before. i had it set even with the index but now i set it at one line below and it works alot better, it depends on how the a/c is configured. as for the wind i had the same question but i changed runways instead of using the same one i usually do and i didn't get the same BIG pull to the left also the wind was about 4 or 5 knots which is less than usual. i use real weather also. i do have to retrim after takeoff though. i have seen aircraft wobble a bit after takeoff but fortunitly not as much as you have experienced. you might change the sensitivities on the rudder maybe. anyway, i'll be watching this thread myself to pick up what ever i can. good luck. william

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this