Flying a DME arc
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Flying a DME arc
Hi Guys. Im new to all this so please be gentle. 
Im in the middle of my Command Multi Instrument Ratings and was after some advice on flying a DME arc. When flying a DME arc with a HSI is it correct procedure to place the head of the needle on the VOR radial for guidance? (ie as you fly around the arc dialing up a radial 20 degrees ahead for guidance, and turning in 20 degrees to maintain distance) Is it incorrect to place the head of the needle the other way around? (ie pointing towards the reciprocal of the radial which will be towards the VOR) I find it easier to visualise with the needle pointing towards the VOR but was wondering if I will get a slap on the wrists later on in my flying career for doing this. Thanks heaps in advance! 
Im in the middle of my Command Multi Instrument Ratings and was after some advice on flying a DME arc. When flying a DME arc with a HSI is it correct procedure to place the head of the needle on the VOR radial for guidance? (ie as you fly around the arc dialing up a radial 20 degrees ahead for guidance, and turning in 20 degrees to maintain distance) Is it incorrect to place the head of the needle the other way around? (ie pointing towards the reciprocal of the radial which will be towards the VOR) I find it easier to visualise with the needle pointing towards the VOR but was wondering if I will get a slap on the wrists later on in my flying career for doing this. Thanks heaps in advance!
Grandpa Aerotart
Generally aircraft with a HSI also have an RMI. Leave the HSI set to your final inbound radial and use the RMI needle, set to VOR, to cue your turns. At 1% of ground speed turn to put the RMI needle about 5-10 degrees ahead of wing, hold heading until RMI needle about 5-10 degrees behind wing or if you like between 275 relative and 265 relative)..watching the DME of course and modify as appropriate to maintain within tolerance. A DME arc of course being many short straight lines. Clearly if the first turn brings you exactly onto the right DME distance you be better served to have small adjustments 5 ahead/behind....but using 1% of groundspeed works a treat and should get you within 1/2nm.
RMI needle also shows your lead bearing indicating where to begin turn to intercept final inbound track. Hint with using HSI needle...turn to put lubber line over head of HSI CDI and then keep it there as the CDI moves back towards 'on track'.
Constantly adjusting the HSI as you fly the arc is way too much work and will end in confusion...the secret with smooth IFR flying is preparation...have it all set up well in advance and then just fly the aircraft.
If aircraft not fitted with RMI then you're a bit stuffed unless NDB colocated...probably not often. If you absolutely must adjust the HSI CDI as you fly the arc always have it orientated correctly. Start with the inbound track to the IAF and the as you fly the arc adjust it 10 degrees at a time as you alter course 10-15 degrees at a time while monitoring DME. At least then one of your 10-20 degree adjustments will put it on your final inbound track orientated correctly for the final intercept. Later when flying RMI equiped aircraft revert to having the HSI set for the final inbound track (at TOPD) and track to the IAF via the RMI needles...being sure you set them to VOR.
Another hint with DME arcs is to be aware of the nm flown in the arc....easily calculated mentally with 1/60 rule. 15nm arc distance travelled in nm = 1/4 of the bearing change between IAF and final track...20nm arc=1/3rd etc. Obviously in slower aircraft this can effect your arrival estimate...10nm travelled basically perpendicular to track at 120kts = 5 minutes later arrival in circling area. Also essential knowledge if descending on the arc and checking to see if you're high or low with respect to the required alt at FAF....also factoring in distance travelled on the arc to enroute descent point...know how many nm/1000' the aircraft travells at typical descent speeds....example 180kts = 3nm/minute...descending at 500'/min (unpressurised aircraft) = 6nm/1000'...have little gates. example if the require start alt is 2000' and you're cruising at 8000' start descent at 51DME (for a 15nm arc)...or when you're more up to speed/ahead of the game descend on the arc. example 12nm on the arc (15nm arc with 48 degree bearing change) FAF alt = 3000'...cruising at 8000'...5000' to lose = 30 track miles between enroute desent point and FAF + a little buffer to slow down and configure...5nm maybe. Anyway you can calculate back from the FAF and have target altitudes (gates) at various points...say half way round the arc and at the IAF...if a little high or low adjust ROD and check at next 'gate'.
As you are a beginner I suggest you fly the arcs level as you will NOT have the excess brain capacity for constant mental arithmatic and flying at the same time...it will come with experience however.
If you want any hints on departure briefs and proper IFR arrival briefs post your aircraft type and a approach you're familiar with and I'll give you a brief for departure and arrival that logically covers all you SHOULD be thinking about...that'll blow the socks off your instructor....not to mention your examiner
RMI needle also shows your lead bearing indicating where to begin turn to intercept final inbound track. Hint with using HSI needle...turn to put lubber line over head of HSI CDI and then keep it there as the CDI moves back towards 'on track'.
Constantly adjusting the HSI as you fly the arc is way too much work and will end in confusion...the secret with smooth IFR flying is preparation...have it all set up well in advance and then just fly the aircraft.
If aircraft not fitted with RMI then you're a bit stuffed unless NDB colocated...probably not often. If you absolutely must adjust the HSI CDI as you fly the arc always have it orientated correctly. Start with the inbound track to the IAF and the as you fly the arc adjust it 10 degrees at a time as you alter course 10-15 degrees at a time while monitoring DME. At least then one of your 10-20 degree adjustments will put it on your final inbound track orientated correctly for the final intercept. Later when flying RMI equiped aircraft revert to having the HSI set for the final inbound track (at TOPD) and track to the IAF via the RMI needles...being sure you set them to VOR.
Another hint with DME arcs is to be aware of the nm flown in the arc....easily calculated mentally with 1/60 rule. 15nm arc distance travelled in nm = 1/4 of the bearing change between IAF and final track...20nm arc=1/3rd etc. Obviously in slower aircraft this can effect your arrival estimate...10nm travelled basically perpendicular to track at 120kts = 5 minutes later arrival in circling area. Also essential knowledge if descending on the arc and checking to see if you're high or low with respect to the required alt at FAF....also factoring in distance travelled on the arc to enroute descent point...know how many nm/1000' the aircraft travells at typical descent speeds....example 180kts = 3nm/minute...descending at 500'/min (unpressurised aircraft) = 6nm/1000'...have little gates. example if the require start alt is 2000' and you're cruising at 8000' start descent at 51DME (for a 15nm arc)...or when you're more up to speed/ahead of the game descend on the arc. example 12nm on the arc (15nm arc with 48 degree bearing change) FAF alt = 3000'...cruising at 8000'...5000' to lose = 30 track miles between enroute desent point and FAF + a little buffer to slow down and configure...5nm maybe. Anyway you can calculate back from the FAF and have target altitudes (gates) at various points...say half way round the arc and at the IAF...if a little high or low adjust ROD and check at next 'gate'.
As you are a beginner I suggest you fly the arcs level as you will NOT have the excess brain capacity for constant mental arithmatic and flying at the same time...it will come with experience however.
If you want any hints on departure briefs and proper IFR arrival briefs post your aircraft type and a approach you're familiar with and I'll give you a brief for departure and arrival that logically covers all you SHOULD be thinking about...that'll blow the socks off your instructor....not to mention your examiner
Last edited by Chimbu chuckles; 25th Oct 2004 at 13:34.
It's also better to stay on the inside of the arc, and not the outside.
Inside the arc then the arc will always eventually cross your track (if you're S&L) so it's somewhat self correcting. If you're positioned outside the arc then the arc track will be continuously moving away from the a/c so a lapse of attention can lead to exceeding the tolerance.
You can use rate of closure to see when the arc will start to close with you again. After you commence each straight section the rate of closure will eventually reduce to zero then increase again. A zero closure rate means you're at the closest approach to the station and therefore at the furthest distance from the arc that your current straight section will achieve. After this the closure rate will increase.
With practice it's relatively easy to keep the a/c within a few decimal points of a nm on the inside of the arc eg 10nm arc, closest approach to the DME 9.6nm, furthest distance 10nm. If you want more S&L/fewer heading adjustments remember that the tolerance allowed is +/-2nm so you can use quite coarse heading changes if you wish. Be aware of wind effect ie whether or not a x-wind is helping or hurting wrt your position & the arc tolerance.
Inside the arc then the arc will always eventually cross your track (if you're S&L) so it's somewhat self correcting. If you're positioned outside the arc then the arc track will be continuously moving away from the a/c so a lapse of attention can lead to exceeding the tolerance.
You can use rate of closure to see when the arc will start to close with you again. After you commence each straight section the rate of closure will eventually reduce to zero then increase again. A zero closure rate means you're at the closest approach to the station and therefore at the furthest distance from the arc that your current straight section will achieve. After this the closure rate will increase.
With practice it's relatively easy to keep the a/c within a few decimal points of a nm on the inside of the arc eg 10nm arc, closest approach to the DME 9.6nm, furthest distance 10nm. If you want more S&L/fewer heading adjustments remember that the tolerance allowed is +/-2nm so you can use quite coarse heading changes if you wish. Be aware of wind effect ie whether or not a x-wind is helping or hurting wrt your position & the arc tolerance.
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Thanks heaps guys for the information. They have been very helpful!Chimbu chuckles that would be great if you could give me some hints on IFR departure and arrival briefs. Im currently doing the IR in a Piper Seminole and flying out of Moorabbin. Thanks heaps!
Grandpa Aerotart
Ok first thing about briefs is they should flow logically...from brakes release to the MSA/LSA or TOPD to parked.
Plan how you'll taxi out to the required runway. Tune & Ident all required departure aids while the engines are warming up. by the time you begin taxiing all you should need to do is the runups in the runup bay, the brief and then, when cleared, enter the active runway and depart with a clear plan of how you will depart both normally and after an emergency. I recomend a nmeumonic to keep it in logical order.
RANN...Runway Assymetric Normal Navaids
You are in the run-up bay for 17L at YMMB, all preflight checks complete/navaids set/transponder code etc. Lets assume weather is OVC at 600'/vis 3.4km/wind calm. You turn to the instructor/examiner and your brief will be.
"Are you ready for a departure brief?"
"Umm...ahh..yeah?"
We are departing rwy 17L at morrabin, engine failure/fire before wheels up/blue line/ and still visual I will close both throttles and land straight ahead. Engine failure/fire after/in IMC I will continue (at this point call out and touch drill your EFATO drill) I will then track 164 climbing to the MSA of 2200', note MORA beyond 25nm is 3100'. I'll call MAYDAY on MEL Center on 120.0 (have it preset in comm 2 and point to it as you say it) and request radar vectors to MMBSA on climb 2600 and enter the hold (have that plate handy so you're not going to have to grope for it while flying assy in IMC/under the hood, you could even brief the actual hold at this point to save brain space later...just- Inbound track is 054, it's a left hand pattern, minimum alt 2600'), when I've sorted everything out we'll return via the GPS RWY 35R approach which I'll brief in the hold.
Assuming a normal departure we'll .....(I've no idea what standard IFR departure procedures are in place in MB) MSA is 2200 to the south, 3300 to the northwest and 4700 to the northeast. LSA on track is xxxx. hint: if you expect extended radar vectors be aware of and brief the appropriate grid MORAs outside 25nm MSAs.
Navaids, I have NAV 1 (and 2?) tuned/identified on xyz (usually first on track aid if no aid defines your departure track), ADF tuned/identified on MB (or whatever is more appropriate) and the GPS is loaded and checked (You have checked all the waypoints right after you loaded the route from your FP right?) RMI selectors ADF/VOR (which ever is more appropriate...for instance if departing on a VOR radial have them on VOR if via an NDB track have them on ADF.)
Any questions?
Gotta go out for dinner now so I'll give you a brief for an approach using the YMML ILS/DME RWY 16 tomorow, or later tonight if I'm sober enough
Plan how you'll taxi out to the required runway. Tune & Ident all required departure aids while the engines are warming up. by the time you begin taxiing all you should need to do is the runups in the runup bay, the brief and then, when cleared, enter the active runway and depart with a clear plan of how you will depart both normally and after an emergency. I recomend a nmeumonic to keep it in logical order.
RANN...Runway Assymetric Normal Navaids
You are in the run-up bay for 17L at YMMB, all preflight checks complete/navaids set/transponder code etc. Lets assume weather is OVC at 600'/vis 3.4km/wind calm. You turn to the instructor/examiner and your brief will be.
"Are you ready for a departure brief?"
"Umm...ahh..yeah?"
We are departing rwy 17L at morrabin, engine failure/fire before wheels up/blue line/ and still visual I will close both throttles and land straight ahead. Engine failure/fire after/in IMC I will continue (at this point call out and touch drill your EFATO drill) I will then track 164 climbing to the MSA of 2200', note MORA beyond 25nm is 3100'. I'll call MAYDAY on MEL Center on 120.0 (have it preset in comm 2 and point to it as you say it) and request radar vectors to MMBSA on climb 2600 and enter the hold (have that plate handy so you're not going to have to grope for it while flying assy in IMC/under the hood, you could even brief the actual hold at this point to save brain space later...just- Inbound track is 054, it's a left hand pattern, minimum alt 2600'), when I've sorted everything out we'll return via the GPS RWY 35R approach which I'll brief in the hold.
Assuming a normal departure we'll .....(I've no idea what standard IFR departure procedures are in place in MB) MSA is 2200 to the south, 3300 to the northwest and 4700 to the northeast. LSA on track is xxxx. hint: if you expect extended radar vectors be aware of and brief the appropriate grid MORAs outside 25nm MSAs.
Navaids, I have NAV 1 (and 2?) tuned/identified on xyz (usually first on track aid if no aid defines your departure track), ADF tuned/identified on MB (or whatever is more appropriate) and the GPS is loaded and checked (You have checked all the waypoints right after you loaded the route from your FP right?) RMI selectors ADF/VOR (which ever is more appropriate...for instance if departing on a VOR radial have them on VOR if via an NDB track have them on ADF.)
Any questions?
Gotta go out for dinner now so I'll give you a brief for an approach using the YMML ILS/DME RWY 16 tomorow, or later tonight if I'm sober enough
Last edited by Chimbu chuckles; 24th Oct 2004 at 11:47.
If the arc is not in the GPS database(RNAV) and has to be flown 'raw data'/ auto-pilot engaged. Deselect the lateral mode and TCS a few degrees AoB( depends on IAS/ arc dist.). Suck it and see, adjust as required.
If tracking DCT to navaid turn at 1% GS for intercept of arc. 120GS=1.2NM therefore 11.2DME for 10 DME arc.
VOR and DME identified, no flags.
Course bar set on final approach course.
RMI pointers set to VOR or NDB depending on approach.
Don't forget to let us know what your instructor says .
If tracking DCT to navaid turn at 1% GS for intercept of arc. 120GS=1.2NM therefore 11.2DME for 10 DME arc.
VOR and DME identified, no flags.
Course bar set on final approach course.
RMI pointers set to VOR or NDB depending on approach.
Don't forget to let us know what your instructor says
.
Last edited by hoss; 26th Oct 2004 at 08:32.
Grandpa Aerotart
The problem with that is if you try and fly the whole arc at a few degrees AOB the typical GA AI can 're-erect' itself, for want of a better term, and you'll end up with a dogs breakfast while you try and accurately fly an aircraft with a confused AI. Certainly fly the arc on A/P, if the seminole has a decent one, but do it in heading mode and make small corrections to stay within tolerance.
It's 0130 and multitudinous beers later so more tomorrow.
It's 0130 and multitudinous beers later so more tomorrow.
Oi Chuckles.............wantok I think you longlong liklik.....................
the formula is to turn at 1% of groundspeed, not 10% (i.e. 180 k, turn at 1.8 DME before the arc, not 18 DME before the arc).
No wonder your arc approaches see you missing out often!
the formula is to turn at 1% of groundspeed, not 10% (i.e. 180 k, turn at 1.8 DME before the arc, not 18 DME before the arc).
No wonder your arc approaches see you missing out often!
Grandpa Aerotart
Edited for brain failure...wasn't the dme arc tolerance +/- 20nm
?Anyway thrustmaster to coontinue
Just to reiterate a little for the departure. If you're departing somewhere with a SID the tracking in a normal departure is set out for you. In an emergency it's may be, but maybe not. If the SID is a noise abate SID perhaps you can follow it anyway but if it has obstacle considerations you probably won't be able to...particularly in a semenhole
In this situation it's much like departing somewhere that doesn't have a SID...like YMMB, and you need to think about it. The first place I look in this situation is the missed approach for the runway approach pertaining to the runway in use...which is where I got the "track 164 on climb 2200' " from. It's also good to look at a WAC or VTC and look for obstacles along any escape route you may consider..aerials, towers and terrain.
Never underestimate how far out you may end up climbing on one engine...particularly climbing assy in a light piston twin...200' odd/min at whatever groundsped is appropriate for a semenhole...80kts? 11 odd minutes at 1.5nm/min...always worth thinking about.
Anyway to the arrival and brief.
Two things to get your head around.
1/. Profiles. This is just a way of simply calculating a descent point and then keeping track of it to pick up trends early. At the speeds you'll be descending at in the seminhole perhaps 4x would be good. 4 x alt = dme distance (or track miles to fly)...which = 4nm/1000'...which, @ 150kts, means that you'll be losing 1000' every 1.6 minutes or 625'/min. You'll need to make sense of the answer by putting a decimal place in a sensible spot. Work out a profile for your aircraft that gives a target ROD around 550'-600'/min max...this is important so that if you end up high you'll have some buffer to increase your ROD without exceeding 1000'/min in an unpressurised aircraft....doesn't matter a toss in a pressurised one...in the 767 we descend on a 3x at 400+kts TAS...see if you can work out the still air ROD
2/. The actual approach plate brief...best way to get in the habit of briefing them logically and without missing out important stuff is to take a pencil and write on your plates numbers 1-10 next to each important point on the plate and then when you brief the plate just follow the numbers. In time it will become second nature and you can stop defacing your charts. The following is what I do...and it's important to note that this whole rave is just one way to do things...my way....you may come up with a variation that works better for you...or someone else could post straight after me with an idea that never occurred to me which I think is a better way of doing something and I'll encorporate that into what I do. Like my two wantoks above....man I always wondered why I was 20nm out joining arcs
Note: I use Jepp Charts.
1/. Chart name. i.e. ILS Rwy 26 for Essendon
2/. Chart number and date. Chart 11-1 date 6 June 03.
3/. MSA
4/. Holding pattern. Always brief it..you never know when you'll get a last minute hold instruction.
5/. Lead bearing (if app) and final inbnd track.
6/. frequency
7/. Glideslope check hieghts/ markers set
8/. Minima/threshold elevation/Vis required and runway position if for a non precision approach (i.e. "Minima is xxx' threshold elevation is xx' and I expect the runway to be left/right of the nose") It's very important to remember to set the altimeter bug (if you have one, at this point and to remember to add whatever corrections are appropriate for PEC/forecast QNH etc. Also good idea to brief the localiser only minima for an ILS in case the G/S fails..why throw away a perfectly good approach?..if you brief the higher minima just reset the bug and continue.
9/. Missed approach. Including expected sector entry if tracking back to the hold for a second go.
10/. Notes.
So lets put it together. You're inbound to YMEN on W382 for an ILS Rwy 26, cruising at 9000'.
You of course have planned the descent and approach in plenty of time to brief it all to the ATO in the RHS by 20nm before TOPD. Start off with the 10-1 chart (TAC), also have handy and in this order 10-4C (last page of noise abate) 11-1 (ILS plate for 26) and also over the page on 11-1 the aerodrome diagram.
Note my chart dates may not be current as I'm based o/s and have been very slack amending my Oz Jepps
Also I picked essenden for a reason..no DME! Quite probably you are allowed to use GPS in your training so can easily put D-> PLENTY and therefore have a constant, accurate distance to go while being vectored...thereby making the whole thing too bloody easy...but maybe your instructor or the ATO is a Caring Understanding Nineties Type and has decided to fail said GPS! I would have I like Jepps because they give me this really cool ruler that allows me to measure track and distance in a few seconds so I would have pulled it out and worked out a DME distance and bearing from AV to LLOYD, which is 4 odd miles before TOPD. G/S and a 4X profile give me a target ROD to be at PLE at 3000'...so poke the nose down and descend at that rate and you'll be bloody close...if you're high doesn't matter as the procedure turn at PLE gives you some buffer and if you were REALLY high just join the hold and lose alt/configure as desired. Obviously passing over EN will give you a guide too...if you were leaving 5300' overhead EN things would be looking pretty reasonable...4x2300'=9.2 dmeSOOOO!!
"Are you ready for an arrival Brief?"
"Ahh...yeah
""Descent point while be 14nm EN. On the 10-1(TAC) All significant terrain is west of LLOYD and well north of YMML so not a consideration, MORA is 4700' but expect to be under RADAR vectors. MSA is 3700 south of EN and 4500' north. Track LSA is 2900' inbound on W382 to EN. (now stow 10-1 folded for easy reference). Noise abate not a consideration however on 10-4C we have some training flight considerations (just briefly touch on those that affect the flight you are on) (note: don't read the numbers out loud) We'll be carrying out the 1/. Rwy 26 ILS @ YMEN. 2/. Chart number 11-1 dated 6 june 03. 3/. MSAs as discussed. 4/. Holding is at PLE, it's a 1 minute left hand pattern, track inbound 257, minimum altitude 3000' We'll be doing a parrallel entry. 5/. From PLE we track 257 on the LOC to G/S capture at 3000', 6/. Frequency 109.9, 7/. G/S check hieght is 1550' at the OM, 8/. Minima is 490' (bug it) threshold elevation 239' and minimum vis required is 1.5km. If we lose the G/S the LOC only minima is 670' actual QNH and 1.8km/2.7km HIALS out. 9/. If we are not visual the missed approach is turn left track 130 degrees climb to 3000', then left turn tracking to PLE Lctr where we'll do a parallel entry to the hold. Once on the ground we'll vacate via first right onto taxiway P. 10/. Notes are a caution for incorrect course indications within 10nm east of PLE, we shouldn't be affected, and aircraft may be vectored to PLE Lctr.
Weather for our arrival is (brief the ATIS with particular reference to the reported cloud base/ vis.)
Notams we have none affecting our arrival.
Navaids. I have NAV 1 tuned 109.9 IEN,course bar set 257, ident to come, marker beacon set high, ADF 1 tuned identified to EN and ADF 2 tuned identified PLE. RMI selectors ADF.
Fuel. We are arriving with xxx litres so we can hold for xx minutes before diverting to YMML/YMMB.
You could even make up a nmeumonic..I just did and came up with DMLPWNF
You could even remember it by saying something like Dopey Men Love Pathetic Women who Never F*ck
D-Descent point
M- MORA/MSA
L-LSA
P- Plate Brief
W-Weather
N-Notams /Navaids
F-Fuel/Holding & divert.
You could write the nmeumonic down in a verticle list on the back of your flight plan and use that as a guide to ensure you cover everything.
PS: If you want to be REALLY clever and earn some MAJOR browny points (but more likely confuse the ATO 'cause he'll have no idea what you're talking about you could even think about the temperature on the ground at EN and work out the ISA DeVN and how that will effect the INDICATED altitude at the OM....wanna know how???
Ok guys...pick holes in it!!!!
Last edited by Chimbu chuckles; 26th Oct 2004 at 07:55.
Ah Chuck you have redeemed yourself admirably.
One of my crusades is to get the other pilot to call the FAF crossing and check height. Sure, this is not such a drama at YMEN where there is radar monitoring, but if we all got in the habit of doing this everywhere we went (especially sh!tty approaches into black holes outside radar coverage), aviation would occupy the front page far less frequently. Do a search for the report on the Air NZ 767 doing an ILS into Apia at night a few years ago when they got a false glideslope and you will understand my zeal.
Also not a bad idea to brief on what you can expect to see at the MDA.......sure, on an ILS the runway is usually straight ahead, but not always the case on an NPA, or if you are battling a king-size crosswind. Likewise circling options should that become necessary. Also what sort of lights you might encounter, plus VASI, PAPI or whatever else you might rely on for slope guidance below the MDA.
Otherwise Chuck has described how the masters of the skies do it.
One of my crusades is to get the other pilot to call the FAF crossing and check height. Sure, this is not such a drama at YMEN where there is radar monitoring, but if we all got in the habit of doing this everywhere we went (especially sh!tty approaches into black holes outside radar coverage), aviation would occupy the front page far less frequently. Do a search for the report on the Air NZ 767 doing an ILS into Apia at night a few years ago when they got a false glideslope and you will understand my zeal.
Also not a bad idea to brief on what you can expect to see at the MDA.......sure, on an ILS the runway is usually straight ahead, but not always the case on an NPA, or if you are battling a king-size crosswind. Likewise circling options should that become necessary. Also what sort of lights you might encounter, plus VASI, PAPI or whatever else you might rely on for slope guidance below the MDA.
Otherwise Chuck has described how the masters of the skies do it.
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Chimbu chuckles thanks mate for all the effort you have put in to this post. Your feedback has been excellent! Hopefully il really impress my instructor on the next flight!
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Yeah! All good stuff this and Thrusty would be well set up if he takes note of all that Chimbu has told him. Mind you, his examiner/instructor is going to wonder who the hell he's been talking to!
Anyway, the only thing I can add is a variation on the intro to the brief. In my experience it's usually gone along these lines...
F/O: Uh!..Skip, we're approaching descent point, you wanna do a brief for the Guam ILS?
CAPT: Uh!...thanks Shags! Been dozing off there and thinking about how much my super is worth.
( Capt does brief )
CAPT: Any questions?
F/O: Mind if I smoke?
CAPT: Don't be a smart arse, Shags!
Anyway, the only thing I can add is a variation on the intro to the brief. In my experience it's usually gone along these lines...
F/O: Uh!..Skip, we're approaching descent point, you wanna do a brief for the Guam ILS?
CAPT: Uh!...thanks Shags! Been dozing off there and thinking about how much my super is worth.
( Capt does brief )
CAPT: Any questions?
F/O: Mind if I smoke?
CAPT: Don't be a smart arse, Shags!
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1. When tracking direct to the station use GS divided by 200 to give you your lead distance for the turn on to the arc. (rate 1 turn will put you spot on every time)
2. Use the speed range from the initial approach fix appropriate to your aircraft category around the arc.
3. Lead radials are generally displaced 2 nm (there are some exceptions - usually a greater distance) from your final approach track. If you commence a rate one turn as soon as you hit the published lead radial, you will be out of tolerance for the final approach track unless you are in something fast and/or have a howling tailwind. I find that a half rate turn has you within or very close to tolerance of the final approach track unless you have a strong headwind. You could also use a lead radial that was displaced one mile from the final approach track for an aircraft with a GS of 200 kts or less. At 10 nm this would be 6 degrees, at 12 nm 5, at 15nm 4, etc..
If you can find it, read AIC C1/90, DME Arc Operations.
2. Use the speed range from the initial approach fix appropriate to your aircraft category around the arc.
3. Lead radials are generally displaced 2 nm (there are some exceptions - usually a greater distance) from your final approach track. If you commence a rate one turn as soon as you hit the published lead radial, you will be out of tolerance for the final approach track unless you are in something fast and/or have a howling tailwind. I find that a half rate turn has you within or very close to tolerance of the final approach track unless you have a strong headwind. You could also use a lead radial that was displaced one mile from the final approach track for an aircraft with a GS of 200 kts or less. At 10 nm this would be 6 degrees, at 12 nm 5, at 15nm 4, etc..
If you can find it, read AIC C1/90, DME Arc Operations.
, those two briefs were the most well written, informative posts I have read on this site. Kudos to you 
There realy are professionals here.
Excellent stuff Chimbu, particularly the pneumonic!
Noticed however you set marker beacons to HIGH - what is the general concensus on this?
During training I was always taught to set them to LOW, and the argument was that with the lower sensitivity the marker beacons would sound for a shorter time and make it easier to do an accurate OM check.
It's only since i've finished training and flown with a few different people that I've seen other ideas. I guess it's always good to see how other people do things (i.e Chimbu's brief) so you can basically develop your own way of doing things (company SOPs permitting of course!).
Thoughts/comments?
TL
Noticed however you set marker beacons to HIGH - what is the general concensus on this?
During training I was always taught to set them to LOW, and the argument was that with the lower sensitivity the marker beacons would sound for a shorter time and make it easier to do an accurate OM check.
It's only since i've finished training and flown with a few different people that I've seen other ideas. I guess it's always good to see how other people do things (i.e Chimbu's brief) so you can basically develop your own way of doing things (company SOPs permitting of course!).
Thoughts/comments?
TL
LOW sensitivity for beacons used during an approach. HIGH sense. is for airways that use (erm....used) beacons to mark progress along the airway.
The greater sensitivity was to counter the greater attenuation of the signal at cruising altitudes.
The greater sensitivity was to counter the greater attenuation of the signal at cruising altitudes.