Regarding the Speeds to fly on a DME-arc...

This depends on the class of aircraft.

First of all, the poster that claimed 180kts. is a max on a dme-arc is talking absolute rubbish. Don't follow his/hers advice unless this is explicitly mentioned on your plates. This will cause disruption to the flow and irritated colegues and controllers.

Doc 8168 "Aircraft Operations" by ICAO has a table which is quite clear...
For example: Class C aircraft: min. 160kts. max. 240kts during the Initial Approach , which includes most DME-arcs. By the way, max speed for visual maneuvering is 180kts.

An FAA DME arc can competently be flown as high as 250 KIAS. But, as the arc nears the intermediate segment a speed reduction is prudent, but not essential if the intermediate segment is of sufficient length to decelerate within that segment. After all, speed reduction is what the intermediate segment is for.

Although there is no stated speed limit on this arc, some prudence may be in order:

http://i201.photobucket.com/albums/a...MEARCRwy01.jpg

location: in my seat.

I assume you haven't read the UK AIP GEN 1.7 then :rolleyes:

Checkboard:

The context appears to me to apply only to departure procedures.

The ICAO doc 8168 is my bible, If the Brits want to do it differently, that they mention it clearly on the plates. I do not have an AIP of every third world country... by the way, haven't seen many arcs in the UK
:rolleyes:
Also, doc 8168 has procedures described as procedural turns. These are outbound/inbound turns ( and racetrack procedures). Do not confuse both.

That's a real tight arc at Guatemala - 7NM is the PANS OPS minimum, I imagine it is the same for TERPS?

reynoldsno1:

Yes, 7 miles is also the TERPS minimum. But, TERPS provides more lateral protected airspace than does PANS-OPS for an arc.

One major U.S. airline that goes to MGGT considers it a special quals airport. Further, the IAP I posted is the only authorized ILS 1 IAP (there are also base-legs to the ILS.)

This particular air carrier limits speed to a maximum of 170 KIAS upon leaving 10,000 when IMC is anticipated, and final approach airspeed prior to rolling out onto the localizer. Makes sense to me having flown the procedure in Garmin's "simulator."

Pilot's who fly internationally are required to follow the laws of each country in which they are flying (just as a car driver must drive on the left, or right hand side). It is thus incumbent on international pilots (and you may one day grow up to be one ;) ) to read the "ICAO differences" section for each country in which they operate ...

... at the very least, it may save you the embarrassment of posting absolute comments such as "the poster that claimed 180kts. is a max on a dme-arc is talking absolute rubbish." when you later admit you don't know what you are talking about.

Sure enough, in GEN 1.7, that's what it says. But wouldn't you expect such a limitation to be mentioned in ENR 1.5 — HOLDING, APPROACH AND DEPARTURE PROCEDURES? I think GEN 1.7 is intended to be informational, not the primary source of procedural design limitations.

bookworm:

The context is departure procedures.

GEN 1.7 actually mentions the limit twice, once in the context of departure procedures, the other in the context of Missed Approach Segment. But the question stands. Would you not expect the limitations to be detailed in ENR 1.5?

bookworm:

Both departures and missed approaches are closely related procedures. I don't know anything about ENR 1.5.

If you stick to standard rate turns, you're not bothered about the angle of bank.

The radius turns out to be V(kts)/187, in nm - which is pretty close to 0.5% of your speed. Make appropriate adjustments for wind.

I loved the DME arc from the north into Kingston. In our dinasaur B727 we started our turn 2.5 early to join the 15 DME arc at 250 knots and used the simple 1% lead to join and stay easily within .3 miles of arc. A gentle bank made it like a U control model airplane flying the arc. I used the rmi to simulate the control lines. It was so easy but fun.

We have some dandies in FAAdom. Helena has a fair amount of traffic and no ATC radar below en route altitudes:

http://i201.photobucket.com/albums/a.../HLNILS27Z.jpg

Approach speed briefing text for EGGW:

http://i201.photobucket.com/albums/a...eedsatEGGW.jpg

Well. as we fly all DME Arc in LNAV I would expect to see the appropriate RNP for the phase of flight, normally 0.3 for approach. While raw data monitoring is normal, no one in their right mind flys a commercial jet on a DME arc in HDG SEL..why would you? As for speed, VNAV will give a sensible speed base on the next limiting waypoint, as one contributor observed you would normally not fly a long arc at 180kts, in reality we could be 50 DME from touchdown.

My trusty 727 did great arcs at 250 knots using heading select. I didn't know I just had to find the LNAV and VNAV buttons. Actually most of the time I rolled into about an 8 degree bank so the bank never changed.

You can try sticking to standard rate turns at 250 knots. :ooh:

Avenger:

A DME arc is an initial approach segment, so I would expect to see "terminal" or RNP 1.0.