Instruments Procedures
Hi everybody,
I have a few questions on the way procedures are designed. 1. I've read with interest the lot of discussions about MSA but can't find a final answer, that is to say: is it legal to fly at the MSA once we're inside the 25 NM radius according to PANS-OPS? It seems to me that yes 2. What are the criteria that make that a base turn is sometimes preferred to a procedure turn in reversal procedure and vice versa? I can't find the rationale for that in PANS-OPS. 3. Similarly, what are the criteria that make that a racetrack procedure is sometimes preferred to a reversal procedure and vice-versa? 4. Are any reversal and racetrack procedures protected for any entry, or only for direct entries? If the answer is that it is protected for any entry, it means that it is possible to enter a racetrack or reversal procedurefrom an omnidirectionnal arrival, even an offset or parallel entry? It is a lot of questions I know, but i hate not understanding the reasons why things are done.... :ugh: Thanks a lot for your answers / highlights ! FP |
Ok, I think I answered by myself to question 4... :)
I understood from a more detailed reading of PANS-OPS that racetrack are protected for all types of entries as holding patterns are, but that it is possible to combine a racetrack with a higher holding pattern forcing the aircraft to arrive direct into the racetrack. As for reversal procedure, I understood that there are only protected for a +30/-30 entry from the outbound leg, that can be extended to the virtual continuation of the inbound leg. The entry can also be restricted to a the outbound heading using a symmetrical holding pattern. Someone can confirm? |
flying at MSA...MSA is for emergency use only...otherwise, in absence of proper radar vectors, you should either be:
on a published portion of the approach, or a published feeder route with alitude listed. IF you have an RNAV chart, you might have the Minimum Off Route Altitude for a lat long Grid and you might use that altitude, provided you know which grid you are in . all in all, follow published procedures to the letter. now, one might do a 90/270 course reversal on the same side as a published procedure turn. and you must do a racetrack/holding pattern in lieu of procedure turn when it is published, IE 1 min from OM. |
Thanks for your answers.
Maybe I wasn't clear enough regarding my question on whether using racetrack or reversal procedure, and using base turn or procedure turn with a reversal procedure: I was looking at charts from a designer point of view and asking me: well, basically, racetrack and reversal, whether using base or procedure turn, have the same goal which is bringing the aircraft at the desired track and altitude. So I was wondering why a procedure designer would rather choose a racetrack than a reversal, and if he/she chooses a reversal, what will make him/her decide to use a base or a procedure turn... Difficult to explain... Hope someone followed me... |
flying at MSA...MSA is for emergency use only... So formally it is legal, as long as you comply with ATC instructions/clearances of course. |
3.2 TYPES OF MANOEUVRES
3.2.1 Where no suitable IAF or IF is available to construct the instrument procedure in the form shown in Figure I-4-3-1, a reversal procedure, racetrack or holding pattern is required. NOTE: Racetrack procedures are used where sufficient distance is not available in a straight segment to accommodate the required loss of altitude and when entry into a reversal procedure is not practical. They may also be specified as alternatives to reversal procedures to increase operational flexibility (in this case, they are not necessarily published separately). :ok: |
MSA may not give you radio nav...just terrain clearance
regarding RACETRACK...be advised you can do a regular procedure turn if a procedure turn is published...but you must use a racetrack if it is published inorder to stay within safe distance of fix. if a procedure turn is published, you could conceivable use a racetrack to turn around...provided you are on the same side as the procedure turn |
Seven,
Are you basing your answer on FAA/TERPS or PAN-OPS? Gladly, this is a very international forum. |
minimumunstick:
Not true. Earlier it was in the definition of MSA that it should only be used for emergency purposes, but this is taken out of the definition, and some companies will allow you to navigate freely within MSA to position yourself for the approach. Look at the MSA on this one: http://aeronav.faa.gov/d-tpp/1102/06941R18.PDF |
MINIMUM SAFE ALTITUDE (MSA)
Altitude depicted on an instrument approach chart and identified as the minimum safe altitude which provides 1000 feet of obstacle clearance within a 25 NM radius from the navigational facility upon which the MSA is predicated. If the radius limit is other than 25 NM, it is stated. This altitude is for EMERGENCY USE ONLY and does not necessarily guarantee navaid reception. When the MSA is divided into sectors, with each sector a different altitude, the altitudes in these sectors are referred to as “minimum sector altitudes”. MINIMUM SECTOR ALTITUDE (MSA) (ICAO) The lowest altitude that may be used under emergency conditions that provides a minimum clearance of 300 meters (1000 feet) above all obstacles within a sector of a circle of 46 kilometers (25 NM) centered on a navigational aid. ICAO and FAA are the same.:ok: |
9.G:
What version of MSFS do you fly? |
aterpster, it's the same like for the most of us called Jeppesen, if that's what you're referring to. :ok: BTW in your example MSA is predicated on the RNAV way point RW 18 therefore it's not sectored and logically it can't be it's not a nav aid after all. Yet MSA is quite useful if you simply climb to MSA regardless of your position as long as you're within 25 NM and above MSA you're good.:ok:
|
9.G - what is your reference for the ICAO def of Minimum Sector Altitude?
|
Jeppesen, Manual Text, main volume, section-chart glossary.
Same definition under ATC chapter ICAO definitions.:ok: |
Thanks for answers.
9.G, it seems to me that your Jeppesen extract is not equivalent to ICAO? In Doc 81/68 PANS-OPS Volume II, the definition is just the same without "under emergency conditions". (ok I got the Fifth Edition 2006, maybe some things have changed since...) BTW, your quote of PANS-OPS about racetrack is interesting, but I was precisely disturbed because of this; - what is your understanding of "entry into a reversal is not practical"? - what is your understanding of "increase operational flexibility"? And any idea about using procedure turn rather than base turn or vice versa? |
funkypilot, I use online Jeppesen and it's certainly most up to date revision.
4 SEP 09 © Jeppesen, 1999, 2009. All Rights Reserved. AWM AIR TRAFFIC CONTROL International Civil Aviation Organization -- Definitions Definitions in this listing are extracted from the following ICAO documents: ICAO RULES OF THE AIR, ANNEX 2 PROCEDURES FOR AIR NAVIGATION SERVICES — AIR TRAFFIC MANAGEMENT, PANS-ATM (Doc 4444) PROCEDURES FOR AIR NAVIGATION SERVICES — AIRCRAFT OPERATIONS, PANS-OPS (Doc 8168) |
- what is your understanding of "entry into a reversal is not practical"? - what is your understanding of "increase operational flexibility"? when is the entry into reversal not practical- it's when you come outside the cone of 30 degrees of the centerline, in this case you initially need to enter the holding before you commence the reversal procedure. I think, in this case racetrack is more useful and does increase operational flexibility. I stand to be corrected though. :ok: |
Well, we differ! The latest on-line Jepp ATC section that I can find has NO mention of "under emergency conditions" (page 4/ 1.2.5 Minimum Sector Altitude) and as funky says, nor does 8168. Do you have a newer copy?
|
Minimum safe altitude is FAA definition containing for EMERGENCY USE ONLY
Minimum sector altitude is ICAO definition without referring to emergency use. I beg a pardon I was looking into the chart glossary as it contains both.:ok: |
9.G
aterpster, it's the same like for the most of us called Jeppesen, if that's what you're referring to. BTW in your example MSA is predicated on the RNAV way point RW 18 therefore it's not sectored and logically it can't be it's not a nav aid after all. Yet MSA is quite useful if you simply climb to MSA regardless of your position as long as you're within 25 NM and above MSA you're good. Let's say I suffer a loss of GPS at F70 at MDA and at the MAP. First, I have some significant terrain to the SE although the MSA controlling obstacle is well to the NE. And, to get to 12,100 from MDA within 25 miles I must make good a climb gradient of approximately 410 feet per mile, or 6.73%. In the process I hope I don't hit lesser, but nonetheless, potentially fatal terrain. Not a pleasant prospect unless I am flying a really high-performance jet; one that well exceeds the minimum climb performance requirements. Or I could tune in a local VOR and figure out a much lower safe altitude than 12,100. |
aterpster, discontinuing the RNAV GPS approach isn't an emergency IMHO but a maneuver based on accuracy's degradation prediction called RAIM, that doesn't mean you've lost the accuracy yet it's a prediction. We're sliding off into a complete separate topic here cover by the FAA as well. In order to be eligible to fly this kinda approaches you must be an approved operator using approved equipment and certified staff etc. Long story short you must check the availability of GPS and file a none GPS alternate. Prior to start the approach somewhere 2 NM prior to IAF the RAIM function of your on board equipment once again checks the integrity of the whole mission and if you're given no warnings you're good to go. The chances for you to lose GPS Primary are nearly NIL and even if you do like you described you still have sufficient accuracy to conduct missed approach. Of course it'd be easier to simply tune a VOR but why bother in the age of GPS. BTW a modern jet easily makes up to 11% climb gradient in normal conditions. No afterburner needed. Aircraft Performance Database V2.0 - Details :ok:
|
this is the extract from FAA AIM whether right or wrong well it's not up to me to decide.
MINIMUM SECTOR ALTITUDE [ICAO] — The lowest altitude which may be used under emergency conditions which will provide a minimum clearance of 300m (1,000 feet) above all obstacles located in an area contained within a sector of a circle of 46 km (25 NM) radius centered on a radio aid to navigation. Go figure:ok: |
9.G
aterpster, discontinuing the RNAV GPS approach isn't an emergency IMHO but a maneuver based on accuracy's degradation prediction called RAIM, that doesn't mean you've lost the accuracy yet it's a prediction. We're sliding off into a complete separate topic here cover by the FAA as well. In order to be eligible to fly this kinda approaches you must be an approved operator using approved equipment and certified staff etc. Long story short you must check the availability of GPS and file a none GPS alternate. Prior to start the approach somewhere 2 NM prior to IAF the RAIM function of your on board equipment once again checks the integrity of the whole mission and if you're given no warnings you're good to go. The chances for you to lose GPS Primary are nearly NIL and even if you do like you described you still have sufficient accuracy to conduct missed approach. Of course it'd be easier to simply tune a VOR but why bother in the age of GPS. BTW a modern jet easily makes up to 11% climb gradient in normal conditions. No afterburner needed. Aircraft Performance Database V2.0 - Details What are the airman's certificates and ratings you hold? Total flight time? Any other qualifications you care to share. |
aterpster, take the info for granted or check it. I'm willing to discuss matters not my credentials. :ok: Take it easy buddy.
|
All I'll add is that if a go-around or missed approach is begun in IMC below the MSA, I hope you do it via the " black lines" on the chart. No diverse, omni-directional climb to the MSA. :=
GF |
9.G:
aterpster, take the info for granted or check it. I'm willing to discuss matters not my credentials. Unlike you, I have my credentials in my public profile. |
I thought this was a question about MSA? It seems that nobody got it right, mind you I did check my son's version of MSFS and saw several references here that were evidently taken from that game.
Soooooo, ICAO Rules of the Air, Annex 2 Procedures for Air Navigation Services, PANS-ATM (Doc 4444)… Minimum Sector Altitude - The lowest altitude with may be used which will provide a minimum clearance of 300m (1000 feet) above all obstacles located in an area contained within a sector of a circle of 46 kilometres (25 NM) radious centred on a radio aid to navigation. and, PANS-OPS (Doc 8168)… Minimum Sector Altitudes or Terminal Arrival Altitudes are established for each aerodrome and provide at least 300 m (1000 feet) obstacle clearance with 46km (25nm) of the navigation aid, initial approach fix or intermediate fix associated with the approach procedure for that aerodrome. Both can be found in the Jeppesen Airway manual (Revision date 21 Jan 2011), ATC section, pages 107 and 223. |
I think I got it right...MSA...see early posts.
you guys need to understand the GRID MORA (not all of you...some of you know)...that might be helpful |
PappyJ:
Minimum Sector Altitude - The lowest altitude with may be used which will provide a minimum clearance of 300m (1000 feet) above all obstacles located in an area contained within a sector of a circle of 46 kilometres (25 NM) radious centred on a radio aid to navigation. Further, as you cite, they provide 1,000 feet of obstacle clearance. In the Designated Mountainous Areas (DMAs) of the U.S. the pilot is required to maintain 2,000 feet off published routes, and MSAs are not published routes or sectors under FARs Part 95 or 97. The rules vary all over the map (literally), but what I state is for FAA-dom. |
sevenstrokeroll:
you guys need to understand the GRID MORA (not all of you...some of you know)...that might be helpful Having said that, MORAs could save a pilot who has the skills and is a world of hurt, especially lost comm, etc. |
aterpster. The question was about MSA, not designated mountainous areas, GRID MORA, etc. Focus son, focus.
But I do need to ask; How would MORA save a guy suffering from a lost com? Do you yanks have new rules about Comm Failures that require us to descend to the MORA 7 minutes after recognition that the radios ain't working? :rolleyes: sevenstrokeroll. I think you may be confusing MSA and MEA. MSA is always within the reception range of a radio aid to navigation. MEA (Minimum Enroute Altitude) is another story, and often includes MRA (Minimum Reception Altitude) which is often higher than the MEA. It is agreed that the FAA has several oddities within their rules and procedures, but since over 65% of Pprune readers are European, it would seem that the majority will be interested in ICAO, EU-OPS, JAA, etc. What you yanks need to learn, is that outside of the USA, there is a thriving, safe and prosperous aviation community. |
papy j
I don't think I am confusing anything. Besides being an atp and a captain for a major airline, I spent years as an instrument instructor. MSA Grid MORA MEA MOCA MRA and even MAA Let's see, us YANKS invented the airplane, did the first ''blind'' landings, and were the first to fly non stop from New York to Paris. First across the atlantic in airplanes, first around the world in airplanes. Oh yeah, we didnt use too many spitfires in WW2...but quite a few commonwealth nations used planes like the P40 and F4F. And we have lots of mountains to worry about. And no where in our rules is there a seven minute rule about lost com help me out here aterpster! European...you bet you are! |
sevenstrokeroll:
help me out here aterpster! |
PappyJ:
aterpster. The question was about MSA, not designated mountainous areas, GRID MORA, etc. Focus son, focus. Some of us yanks check in here because we are interested in aviation events and accidents around the world. Weird, isn't it. |
aterpster
as you know there are all sorts of altitudes...even MANDATORY altitudes...not too high, not too low...just right or traffic and so many other things don't work right. its getting to the point where I don't care about these ignorant chaps who can't buy an AIM or TERPS good luck to you aterpster...hope the wx is nice down by san clemen te |
Since the US ATP was the easiest certificate I have obtained of my five ATPL's (Japan, JAA, and several others). I can't say that I'm impressed by a "ATP holding Airline Captain."
Also, although the US may have built the first airplane, please remember that they were first conceived by an Italian. Finally, there are two "P's" in Pappy! |
PappyJ, there's two different definitions Minimum SAFE altitude and minimum Sector altitude. The latter one is ICAO the first one is FAA. We can all benefit a great deal from other's knowledge and experience. The fact that aviation business is predominately run in English gives the Yanks, Canucks and Aussies an advantage. It's clearly visible in the new approach to the AOM in the EU OPS mainly done to harmonize it with FAA. Admittedly it's clearer and better concept. However it always boils down to the famous RTFQ so understanding isn't about language it's about effort. Provokative slanders from both sides are contra-productive.:ok:
|
pappy j.
US atp easy? sure....its what you do with your certificate, not how easy it is to get. I still get a kick out of all the stuff you have to go through to get the atp in different countries. But after you write down your exams, pages and pages of written material...none of that makes you a pilot. flying a plane makes you a pilot. I think flying was conceived by the greeks...a certain fellow who flew too near the sun etc. |
PappyJ:
Since the US ATP was the easiest certificate I have obtained of my five ATPL's (Japan, JAA, and several others). I can't say that I'm impressed by a "ATP holding Airline Captain." I would think you would have a great grasp of that concept. |
All times are GMT. The time now is 22:08. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.