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hdjuey
05-23-2007, 03:22 PM
what is ment by 2 min turn and when flying should the bubble be center even banking and turning

hdjuey
05-23-2007, 03:22 PM
what is ment by 2 min turn and when flying should the bubble be center even banking and turning

Taylortony
05-23-2007, 03:47 PM
Easy one this, The rate of turn is the actual rate at which the airplane is rotating. Tick marks show a 'standard rate turn'. The standard rate for most airplanes is 3 degrees per second, or 2 minutes per 360 degrees. One minute is often used in low speed aircraft like gliders, and 4 minutes is standard in high speed aircraft like the Concorde. The indicator is a white vertical needle. There are white markings at top center (for zero rate of turn), and one on each side, representing standard rate of turn to the left and right, respectively.

you will note on some these days that they are marked as no pitch attitude as well, this goes back to an accident in the USA where the pilot was using it wrongly and believeing it worked the same as an artificial horizon and he crashed, after that we had to either mark on it no pitch attitude or replace with one that says that too....hope that helps...


yes a clean turn will have the bubble in the centre if its off say to the left in a right turn it means the aircraft is dropping into the turn, and vice versa it is sliding outward in the turn..the optimum is to keep it in the middle

Lurch1962
05-23-2007, 04:14 PM
I thought it referred to the time it took to execute a full 360 turn in azimuth. In coordinated flight, a specific bank angle would accomplish this, hence the reference marks for that specific bank angle. And yes, when the bubble is centered you're in coordinated flight, meaning the lift vector--hence G-force--is oriented perpendicular to the plane defined by the wings. In other words, the pilot *feels* as though the plane is flying perfectly level, and not slipping to one side.

--Lurch--

FritzGryphon
05-23-2007, 04:18 PM
2 min is short for 'too minimal'. You fly like a grandma and will surely be shot down.

Taylortony
05-23-2007, 04:21 PM
When the aircraft yaws, or rotates about its vertical axis, it produces a force in the horizontal plane that, due to precession, causes the gyro and its gimbal to rotate about the gimbal axis. It is restrained in this rotation plane by a calibration spring; it rolls over just enough to cause the pointer to deflect until it aligns with one of the doghouse shaped marks on the dial, when the aircraft is making a standard-rate turn.

The dial of these instruments is marked "2 MIN TURN." Some turn-and-slip indicators used in faster aircraft like the Concorde are marked "4 MIN TURN." In gliders, the calibration spring is usually set for a one minute standard rate turn. A standard-rate turn is being made whenever the needle aligns with a doghouse.

Taylortony
05-23-2007, 04:27 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Lurch1962:
I thought it referred to the time it took to execute a full 360 turn in azimuth. In coordinated flight, a specific bank angle would accomplish this, hence the reference marks for that specific bank angle. And yes, when the bubble is centered you're in coordinated flight, meaning the lift vector--hence G-force--is oriented perpendicular to the plane defined by the wings. In other words, the pilot *feels* as though the plane is flying perfectly level, and not slipping to one side.

--Lurch-- </div></BLOCKQUOTE>

yes it is, in my attempt to over simply it i made a right hash of it LOL corrected it http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

TX-EcoDragon
05-23-2007, 04:29 PM
I guess Tony and Fritz are being funny. . .
Lurch said it though. . .it's simply the time that will elapse when the turn indicator (needle or miniature airplane) is lined up with the white marks. For most aircraft a "standard rate turn is one that happens with a heading change of three degrees per second. . .as such it takes 120 seconds to turn 360 degrees, and the face of the instrument is labeled "Two minute Turn".

Very fast aircraft will often be calibrated with half standard rate marks on the instrument such that a 360 takes four minutes, and the turn rate is 1.5 degrees per second because the faster an aircraft goes the steeper the bank must be to maintain a constant rate of turn.

The value of this info is that if the directional gyro fails and you only have a magnetic compass (which is susceptible to many errors when maneuvering) you can use standard rate turns along with some math to make "timed turns". Standard rate turns are also useful in instrument flying in general for standardizing maneuvers.

[edit]Whoa. . .a little editing goes a long way eh Tony?? heheh