How do you fly an Arc? I saw something on an approach chart, that before going on final approach course, .....

Question

.... you have to fly some miles on a 24 DME Arc of a VOR. But theoretically, this would mean that the aircraft must fly a small, but constant bank angle, to be all the time on this 24 DME, right? And: How do you really know the situation of the Arc. Do you just put at the FIX page your VOR, and then enter a degree in combination with the 24 DME, so like 360/24?

Or do you just look at your VOR that the DME is not greater than 24 DME?

Answer 1

Flying a DME arc depends on how your plane is equipped. The most basic equipment required is VOR  and a DME receiver. If you're using that equipment, you fly to or from the VOR who's ARC you are going to fly along a specific radial.

(Usually DME ARC's are used on conjunction with some sort of approach.)  

As you proceed along the radial, watch the DME output and start your turn about .5nm before you get to the ARC distance, so at 23.5nm if you are flying outbound and 24.5nm if you are inbound.  (the distance depends on how fast your plane is, .5nm is for "normal" general aviation planes)  Turn to a heading that is 100 degrees from your current heading and in the direction that you want to fly along the ARC.  Once you are established on the ARC, turn your VOR receiver to a radial that is 10 degrees in front of you on the arc, continue to fly your heading of the outbound radial +/- (depends on which direction you are going on the ARC)  100 degrees until the VOR centers on the next radial. When it does, turn to a new heading of 100 degrees +/- the radial heading. Keep doing this until you reach your inbound radial, where you turn on to the approach path, either a GPS, VOR and ILS/LOC.  Basically your flying a series of straight lines that are tangential to the

DME ARC which is a circle.

Now, if you have more modern equipment, you can program your FMS/GPS navigator, turn on the autopilot and it will fly the plane along the ARC, turn inbound on the approach selected, fly the approach, and IF you have a really nice plane, land the plane for you.

Answer 2

You don't have to fly the arc exactly.  Approximate the arc by turning to a new heading each 10º, 20º, or 30º degrees--depending on your speed--and advancing your course or omnibearing selector.  (Approximate the arc with relatively straight segments).

Answer 3

It's easy with an RMI needle to, just like you would use an NDB, but the RMI at the 90 degree position (9 o'clock or 3 o'clock, depending on the direction of the arc) and keep it there (no wind).

There are corrections for wind, but it's been so long since I've seen an arc'ed approach...

Answer 4

haha no dont fly a small angle of bank

well don't let me stop you but the other ways are easier ways

just fly at right angles to the station first then make corrections to your heading of ten deg or so every tim the DME says you are point 1 out nothing particularly hard