Max speed on a DME arc?
- Thread starter DE727UPS
- Start date
I still maintain 300 if I'm descending on the arc following a HI jet penetration, and slow to 250-275 just prior to the inbound turn, in preparation for final intercept and configuration. Depending on how low the DME number is on the arc (how tight the arc is) will dictate whether I configure on the arc or following the inbound turn. Reference, tech order guidance for the aircraft.
For all others, I'd say likely 250, or IAW 14 CFR 91.117 a-d.
For all others, I'd say likely 250, or IAW 14 CFR 91.117 a-d.
DE727UPS
Well-Known Member
Wow. That's fast. I was thinking TERP's would call for a lower speed but I don't have a copy handy. Got into a situation in the sim last week where we really needed to be on the ground fast and the Capt slowed way down cause it was non-radar on a 7 DME arc to an ILS. He was worried about overshooting the inbound turn and slowed to about 160. I was thinking 200 would be okay. We actually had to repeat the scenario cause he was so slow. Made it in the second time, okay, but I was still wishing he'd have picked it up. Just wanted to give my fellow gouge seekers something to think about and a hard number to reference when the sim instructor says "you were too fast on the arc".
FlyChicaga
Vintage Restoration
I for one would slow to at least 200, but not lower than maybe 170-180. I don't have a max speed reference for the arc, but after watching someone blow through the arc in mountainous terrain, I don't see ANY need to hurry. This wasn't even at 250 kts.
I'm curious, what was the situation which hurried the approach? Fire?
I'm curious, what was the situation which hurried the approach? Fire?
DE727UPS
Well-Known Member
Fuel contamination with engine surge and compressor stall in both engines. The other scenario was volcanic ash. I can't be certain, but I think both of them have a limit on the amount of time before you lose the airplane (we went over the limit the first time...hehe). The idea is for you to do whatever it takes to get the thing on the ground ASAP.
We saw a good video about volcanic ash. Wouldn't have a problem now shutting down all engines with an ash encounter and going for a restart when you get out of it. Never would have said that had I not seen the video. I guess that's what training is all about.....
We saw a good video about volcanic ash. Wouldn't have a problem now shutting down all engines with an ash encounter and going for a restart when you get out of it. Never would have said that had I not seen the video. I guess that's what training is all about.....
[ QUOTE ]
Fuel contamination with engine surge and compressor stall in both engines. The other scenario was volcanic ash. I can't be certain, but I think both of them have a limit on the amount of time before you lose the airplane (we went over the limit the first time...hehe). The idea is for you to do whatever it takes to get the thing on the ground ASAP.
We saw a good video about volcanic ash. Wouldn't have a problem now shutting down all engines with an ash encounter and going for a restart when you get out of it. Never would have said that had I not seen the video. I guess that's what training is all about.....
[/ QUOTE ]
Wow. Interesting.
For a 7 DME arc, I'd definately slow to 190-200 and configure with gear on the arc, in order to be dirty by the final turn yet still have some maneuvering speed. Depending on the fuel weight, that's be my final approach speed if heavy, or I'd knock it down to 8 units AOA if I'm lighter
Fuel contamination with engine surge and compressor stall in both engines. The other scenario was volcanic ash. I can't be certain, but I think both of them have a limit on the amount of time before you lose the airplane (we went over the limit the first time...hehe). The idea is for you to do whatever it takes to get the thing on the ground ASAP.
We saw a good video about volcanic ash. Wouldn't have a problem now shutting down all engines with an ash encounter and going for a restart when you get out of it. Never would have said that had I not seen the video. I guess that's what training is all about.....
[/ QUOTE ]
Wow. Interesting.
For a 7 DME arc, I'd definately slow to 190-200 and configure with gear on the arc, in order to be dirty by the final turn yet still have some maneuvering speed. Depending on the fuel weight, that's be my final approach speed if heavy, or I'd knock it down to 8 units AOA if I'm lighter
MidlifeFlyer
Well-Known Member
I don't think there is any other than the speed limits that apoly to the airspace in whick the arc is located.
Aeronautik
New Member
I was going to start a new thread on this but seeing as this is related:
During my IFR training, whenever we did DME arcs (rare-mostly in the sim), we used an RMI. They're actually pretty fun, I think. But I was told that you can fly 'em without an RMI. I never learned how, but is this entirely accurate? I've tried to think about all the different ways you could do it but in the end, I can't think of a more accurate way than an RMI.
During my IFR training, whenever we did DME arcs (rare-mostly in the sim), we used an RMI. They're actually pretty fun, I think. But I was told that you can fly 'em without an RMI. I never learned how, but is this entirely accurate? I've tried to think about all the different ways you could do it but in the end, I can't think of a more accurate way than an RMI.
[ QUOTE ]
I was going to start a new thread on this but seeing as this is related:
During my IFR training, whenever we did DME arcs (rare-mostly in the sim), we used an RMI. They're actually pretty fun, I think. But I was told that you can fly 'em without an RMI. I never learned how, but is this entirely accurate? I've tried to think about all the different ways you could do it but in the end, I can't think of a more accurate way than an RMI.
[/ QUOTE ]
Using an HSI or an OBS/DG. You just need to do a little more crosschecking of your heading, which radial you're going to intercept inbound/outbound at the termination of the arc, an appropriate lead radial, and of course your DME to determine if you check into the arc more, or hold heading and drift to the outside of the arc more (depending on where you happen to be DME-wise). Our HSIs incorporate an RMI function on the outer ring, so you're always getting info on what radial you're crossing in relation to which one you wish to intercept. It's a tad more work, but completely doable.
I was going to start a new thread on this but seeing as this is related:
During my IFR training, whenever we did DME arcs (rare-mostly in the sim), we used an RMI. They're actually pretty fun, I think. But I was told that you can fly 'em without an RMI. I never learned how, but is this entirely accurate? I've tried to think about all the different ways you could do it but in the end, I can't think of a more accurate way than an RMI.
[/ QUOTE ]
Using an HSI or an OBS/DG. You just need to do a little more crosschecking of your heading, which radial you're going to intercept inbound/outbound at the termination of the arc, an appropriate lead radial, and of course your DME to determine if you check into the arc more, or hold heading and drift to the outside of the arc more (depending on where you happen to be DME-wise). Our HSIs incorporate an RMI function on the outer ring, so you're always getting info on what radial you're crossing in relation to which one you wish to intercept. It's a tad more work, but completely doable.
Chris_Ford
Well-Known Member
[ QUOTE ]
I've tried to think about all the different ways you could do it but in the end, I can't think of a more accurate way than an RMI.
[/ QUOTE ]
Ahh, geez, the kids are spoiled nowadays
Never having flown a DME Arc with an RMI, I'd still venture to say it probably is the most accurate way.
However, the other way to do it is using your HSI or just a standard Nav. Let's say for example you're arcing from 090-360 radial on the VOR. You would track inbound on the 090 radial until you reached your desired DME, and lead your turn by about .5 NM (at least in the slow things I fly
. You then turn your OBS to 080 and fly a heading of 350 (assuming a no wind condition). Once the 080 radial centers (it should come from top to bottom, you tune the OBS 10 degrees left and turn the aircraft 10 degrees left. You continue this until you reach the 360 radial. It's not quite an arc, it's more of a partial triacontakaihexagon.
I've tried to think about all the different ways you could do it but in the end, I can't think of a more accurate way than an RMI.
[/ QUOTE ]
Ahh, geez, the kids are spoiled nowadays
Never having flown a DME Arc with an RMI, I'd still venture to say it probably is the most accurate way.
However, the other way to do it is using your HSI or just a standard Nav. Let's say for example you're arcing from 090-360 radial on the VOR. You would track inbound on the 090 radial until you reached your desired DME, and lead your turn by about .5 NM (at least in the slow things I fly
Maximilian_Jenius
Super User
For those of us not in the know and not IFR rated (yet) what is a DME arc.
BTW I'm aware that DME stands for Distant measuring equipment. But thats all I know!
-Matthew
BTW I'm aware that DME stands for Distant measuring equipment. But thats all I know!
-Matthew
Chris_Ford
Well-Known Member
A DME arc is a way to get from your enroute fix (usually an airway) to your initial or final approach fix, so you can land where you want to.
Here's a link to an approach with a DME arc:
http://204.108.4.16/d-tpp/0504/05117VDG3.PDF
That curved part is the DME arc, and your job as the pilot is to fly it around to set yourself up on the final approach course. You fly a circle around the VOR, and then when at the right position, you turn towards the airport. Usually seen more out west to get around mountains and things, but there are quite a few in other places
Here's a link to an approach with a DME arc:
http://204.108.4.16/d-tpp/0504/05117VDG3.PDF
That curved part is the DME arc, and your job as the pilot is to fly it around to set yourself up on the final approach course. You fly a circle around the VOR, and then when at the right position, you turn towards the airport. Usually seen more out west to get around mountains and things, but there are quite a few in other places
mtsu_av8er
Well-Known Member
[ QUOTE ]
Never having flown a DME Arc with an RMI, I'd still venture to say it probably is the most accurate way.
[/ QUOTE ]
I'm not sure it's any more accurate than using a standard VOR display/HSI. It's certainly easier to maintrain situational awareness!!
[ QUOTE ]
For those of us not in the know and not IFR rated (yet) what is a DME arc?
[/ QUOTE ]
A DME arc is simply a method of manuevering an aircraft in a curved path, maintaining a constant distance from a VOR/DME or VORTAC. With either a standard VOR indicator or an RMI, it requires the pilot to continuously remain aware of his/her position with relation to the station.
The challenges are many, the biggest one being that there are few pilots (read NONE) that are able to fly the plane in a true curved flight path and remain at an exact distance from the VOR. Therefore, the DME arc is flown as a serious of 10 degree turns. The turns are then adjusted more or less, depending on the wind, and the frequency of the turns are adjusted based upon both the wind and the distance desired from the VOR.
Typically, a DME arc is used to transition the aircraft from the enroute structure onto a final approach course. It can also be used as a final approach course or along a missed approach leg.
Make sense?
Never having flown a DME Arc with an RMI, I'd still venture to say it probably is the most accurate way.
[/ QUOTE ]
I'm not sure it's any more accurate than using a standard VOR display/HSI. It's certainly easier to maintrain situational awareness!!
[ QUOTE ]
For those of us not in the know and not IFR rated (yet) what is a DME arc?
[/ QUOTE ]
A DME arc is simply a method of manuevering an aircraft in a curved path, maintaining a constant distance from a VOR/DME or VORTAC. With either a standard VOR indicator or an RMI, it requires the pilot to continuously remain aware of his/her position with relation to the station.
The challenges are many, the biggest one being that there are few pilots (read NONE) that are able to fly the plane in a true curved flight path and remain at an exact distance from the VOR. Therefore, the DME arc is flown as a serious of 10 degree turns. The turns are then adjusted more or less, depending on the wind, and the frequency of the turns are adjusted based upon both the wind and the distance desired from the VOR.
Typically, a DME arc is used to transition the aircraft from the enroute structure onto a final approach course. It can also be used as a final approach course or along a missed approach leg.
Make sense?
aloft
New Member
[EDIT: bah! simultaneous post! Nice touch with the Approach From Hell!
]
[ QUOTE ]
For those of us not in the know and not IFR rated (yet) what is a DME arc.
BTW I'm aware that DME stands for Distant measuring equipment. But thats all I know!
[/ QUOTE ]
It's simply flying a constant-radius arc around the DME station (usually a VORTAC). It's pretty simple with an RMI, you just keep the bearing pointer off the inside wingtip. It's tougher with an HSI or OBS as you keep making 10 degree adjustments in heading and radial
[ QUOTE ]
Our HSIs incorporate an RMI function on the outer ring
[/ QUOTE ]
Yeah, that type of HSI is the shiz-nit!
[ QUOTE ]
For those of us not in the know and not IFR rated (yet) what is a DME arc.
BTW I'm aware that DME stands for Distant measuring equipment. But thats all I know!
[/ QUOTE ]
It's simply flying a constant-radius arc around the DME station (usually a VORTAC). It's pretty simple with an RMI, you just keep the bearing pointer off the inside wingtip. It's tougher with an HSI or OBS as you keep making 10 degree adjustments in heading and radial
[ QUOTE ]
Our HSIs incorporate an RMI function on the outer ring
[/ QUOTE ]
Yeah, that type of HSI is the shiz-nit!
mtsu_av8er
Well-Known Member
Dangit, Chris - beat me to it!!
I was just up at KLAF this morning!! Didn't have time to arrange a meet with anybody from JC....pop-up trip to drop somebody off. Nice airport you guys have up there!!
I was just up at KLAF this morning!! Didn't have time to arrange a meet with anybody from JC....pop-up trip to drop somebody off. Nice airport you guys have up there!!
aloft
New Member
[ QUOTE ]
The challenges are many, the biggest one being that there are few pilots (read NONE) that are able to fly the plane in a true curved flight path and remain at an exact distance from the VOR.
[/ QUOTE ]
Well, without a little "help", anyway!
SkyWChris told me once that the FMS in the CRJ will fly the proper bank angle to maintain the arc in a continuous turn, rather than the series of straight-and-level segments us mere mortals have to fly! So presumingly, the flight director will indicate the same thing, allowing a pilot to hand-fly that continuous turn and maintain the arc!
The challenges are many, the biggest one being that there are few pilots (read NONE) that are able to fly the plane in a true curved flight path and remain at an exact distance from the VOR.
[/ QUOTE ]
Well, without a little "help", anyway!
SkyWChris told me once that the FMS in the CRJ will fly the proper bank angle to maintain the arc in a continuous turn, rather than the series of straight-and-level segments us mere mortals have to fly! So presumingly, the flight director will indicate the same thing, allowing a pilot to hand-fly that continuous turn and maintain the arc!
kellwolf
Piece of Trash
Ya mean once you get to the airlines, there's no more "turn 10, twist 10?" Where's the fun in that?
Personally. I've never flown with an RMI. I fear technology. Give me two Navs and a DG anyday. Then again, I try to keep my training costs down. DME arcs can be tough at first (especially with the equipment I listed) due to the mental acuity to keep up and remember everything, but it's not that hard once you get the hang of it. That is, unless the wind is blowing. THEN it gets interesting.
Personally. I've never flown with an RMI. I fear technology. Give me two Navs and a DG anyday. Then again, I try to keep my training costs down. DME arcs can be tough at first (especially with the equipment I listed) due to the mental acuity to keep up and remember everything, but it's not that hard once you get the hang of it. That is, unless the wind is blowing. THEN it gets interesting.