what is the accuracy reqd in DME arc
Join Date: Oct 2002
Location: In my seat
Posts: 822
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.
Guest
Join Date: Apr 2009
Location: On the Beach
Posts: 3,336
Likes: 0
Received 0 Likes
on
0 Posts
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:
Although there is no stated speed limit on this arc, some prudence may be in order:
Originally Posted by despegue
First of all, the poster that claimed 180kts. is a max on a dme-arc is talking absolute rubbish.
I assume you haven't read the UK AIP GEN 1.7 then
Procedure speed restrictions.
Unless otherwise stated, procedures are speed restricted to a maximum IAS of 185 kt.
Unless otherwise stated, procedures are speed restricted to a maximum IAS of 185 kt.
Guest
Join Date: Apr 2009
Location: On the Beach
Posts: 3,336
Likes: 0
Received 0 Likes
on
0 Posts
Checkboard:
The context appears to me to apply only to departure procedures.
"Unless otherwise stated, procedures are speed restricted to a maximum IAS of 185 kt."
Join Date: Oct 2002
Location: In my seat
Posts: 822
Likes: 0
Received 0 Likes
on
0 Posts
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
Also, doc 8168 has procedures described as procedural turns. These are outbound/inbound turns ( and racetrack procedures). Do not confuse both.
Also, doc 8168 has procedures described as procedural turns. These are outbound/inbound turns ( and racetrack procedures). Do not confuse both.
Guest
Join Date: Apr 2009
Location: On the Beach
Posts: 3,336
Likes: 0
Received 0 Likes
on
0 Posts
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."
That's a real tight arc at Guatemala - 7NM is the PANS OPS minimum, I imagine it is the same for TERPS?
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."
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...
) 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.
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 ...
Guest
Join Date: Apr 2009
Location: On the Beach
Posts: 3,336
Likes: 0
Received 0 Likes
on
0 Posts
bookworm:
The context is departure procedures.
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.
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?
Guest
Join Date: Apr 2009
Location: On the Beach
Posts: 3,336
Likes: 0
Received 0 Likes
on
0 Posts
bookworm:
Both departures and missed approaches are closely related procedures. I don't know anything about ENR 1.5.
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?
Join Date: Mar 2011
Location: Canada
Age: 53
Posts: 47
Likes: 0
Received 0 Likes
on
0 Posts
The Radius of Turn = Vsquared / [g.tanθ]...
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.
Join Date: Aug 2005
Location: fl
Posts: 2,525
Likes: 0
Received 0 Likes
on
0 Posts
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.
Join Date: Nov 2000
Location: I wish I knew
Posts: 624
Likes: 0
Received 0 Likes
on
0 Posts
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.
Join Date: Aug 2005
Location: fl
Posts: 2,525
Likes: 0
Received 0 Likes
on
0 Posts
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.
Originally Posted by photofly
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.
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.
Guest
Join Date: Apr 2009
Location: On the Beach
Posts: 3,336
Likes: 0
Received 0 Likes
on
0 Posts
Avenger:
A DME arc is an initial approach segment, so I would expect to see "terminal" or RNP 1.0.
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.