Hi, someone here must know the formular for turn radius base on airspeed and bank angle? I think it'll be really helpful for approaches.

Presume you are in an aircraft conducting a circling approach at 100 kias at an airport with a field elevation of 2,500 feet MSL, and maintaining a constant standard-rate turn, you will be flying a circle which is 1.05nm in diameter. Example on the numbers:KTAS=IAS*(1+(.02*ALTITUDE IN FEET/1000))KTAS=105D=KTAS/100[OR 105/100]D=1.05 NMBA=Bank angleBA=TAS*.15orBA=((TAS*.10) + (TAS*.10)/2)Presume you are flying at 140 kts21=140*.15or14=(TAS*.10)7=14/221=7+14This information comes from an article in AVWEB from Joseph E. (Jeb) BurnsideHope this helps. Have funRegards,Cliff ScottAAL415MiamiPrivate PilotCherokee 180

whow, that's pretty cool! Gotta write this down for my next flight! :DBut, is there anyway to relate bank angle and radius? Or am I missing something? (I haven't had all the time to digess yet :()

Bank Angle and Radius is treated correctly with the use of both formulas. Radius being your distance.

captbulldog,If you are looking for useful formulae to use for turn radii in approaches here are a couple that I was taught in my military training. They are based on the 1 in 60 rule (which has many many applications in instrument flying). They are easy to remember and I have found them quite useful and in fact use them all the time when flying:1. To intercept a radial from an arc (for example you are on an arc to intercept the final approach course, ie to calculate the lead radial):For a rate 1/2 turn (I believe the other poster gave you the formula but calculating the bank for a half rate of turn but here it is again: TAS/20+7)So, begin your rate 1/2 turn at 60/DME arc x 1 percent of your groundspeed. For example, if on the 12 mile arc to intercept the 180 deg radial (or loc) inbound and have a groundspeed of 200 knots, begin your rate 1/2 turn at 60/12 x 2 = 10 radials (look at the tail of the needle on the DRMI) before the desired course.2. To intercept an arc from a radial, using rate 1/2, simply start the turn onto the arc at 1 percent of your groundspeed. For example, if grounding at 240 knots and approaching the 12 mile arc, begin your rate 1/2 turn at 2.4 nm before the arc, or 14.4nm.Try these and you will see they work beautifully every time. However, if you want to keep it really simple, at the typical 767 intermediate approach speeds, use 2nm as your turning radius and you will not be far off.Kevin in CYOW