![]() |
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#9
|
|||
|
|||
![]()
Ron Natalie wrote:
Matt Whiting wrote: Not true. The vertical fin can only provide a weather-vane affect when a slip or skid has been induced. You have no clue what you are talking about. The skid and slip are the result of the airplane NOT weather vaning into the wind. There are a number of reasons for this. The primary one in turns is the "adverse yaw" due to the differing drag caused by the displaced ailerons. Many designs do a lot of things to mitigate this. Still it takes a lot of aileron displacement to overcome the natural desire for the airplane to track into the wind (due to the vertical stab). In coordinated flight there is no slip or skid and hence the fin provides no lateral force. This is the definition of coordinated flight, not cause and affect. The rudder isn't there to help the vertical stab do its job, it is there to do a job that the vertical stab can't do. Sorry. The incorrect. You need the vertical stab to even fly coordinated when you are not turning. If it is two small the airplane will tend to yaw on it's own (the more bulbous your fuselage, the more this is a probelm...there was a design Piper tried that used an almost helicopter like bubble on the front... without the slab sides to help the vertical stab, the plane just would as well fly slipping as nromal). The vertical stab is nearly always set up to get the aircraft to fly coordinated in normal cruise level flight. It is frequently slightly offset to correct for other aerodynamic unbalances. The rudder is just at trim to handle other flight regimes. It's mostly there for the high AOA regimes of Take-off and landing. I don't know where you got your engineering degree, but you better demand a refund. A vertical stabilizer does not provide any lateral force unless there is some degree of slip or skid. In coordinated flight, it is just along for the ride. Many airplanes will oscillate slight in the yaw axis for this reason. It takes a very large vertical stab to keep the excursions small enough to not be detectable, especially in a longer fuselage airplane. The rudder can provide a side force in anticipation of a slip or skid and thus maintain coordinated flight and never allow the slip or skid to develop in the first place. Matt |
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Question: Standard rate turns, constant rate turns, and airspeed | Robert Barker | Piloting | 5 | April 15th 07 04:47 PM |
Coordinated turns and the little ball | Mxsmanic | Piloting | 51 | October 11th 06 10:17 PM |
Is rudder required for coordinated turns? | Mxsmanic | Piloting | 41 | September 24th 06 06:40 PM |
DGs and Autopilots | Andrew Gideon | Products | 11 | April 14th 05 06:04 PM |
Coordinated turning stall and spins | Chris OCallaghan | Soaring | 20 | November 18th 03 08:46 PM |