Minimum Enroute IFR Altitude (height)

RNAV, GNSS, GPSS. Your place to discuss all aspects pertaining to Instrument Flying.

Moderator: Moderators

Plettflyer
Fuelling up
Posts: 34
Joined: Fri Nov 11, 2016 3:45 pm
Closest Airfield: FAPG
Has liked: 2 times
Been liked: 0

Minimum Enroute IFR Altitude (height)

Unread post by Plettflyer » Sun Feb 18, 2018 8:30 pm

This follows on from an interesting question on MSA posed by Jim in the Academy Section concerning MSA.

This concernes Minimum Enroute Altitude: What is the minimum night VFR or day/night IFR altitude in terms of terrain clearance - other than for take off or landing.

The reason I ask is that there seem to be two answers.
1. CAR 91.06.32 and AIP ENR 1 1.1.1 say 1000' above the highest obstacle within 5 nm provided the terrain or obstacle do not exceed 5000' OR, 2000' if the terrain or obstacle does exceed 5000';
2. The AIP then states in a number of references that the Enroute Safe Altitude is 1500' above the highest obstacle within 5nm of the aircraft.

Why the two conflicting requirements?

(And regarding MSA, the AIP states that the clearance is 1500' above the highest obstacle within a 25nm radius etc. etc. - whereas Jeppesen generally use 1000' - or such higher values supplied by the State. So does a Jepp MSA in the Republic provide clearance of 1500'?)
User avatar
tansg
Engine full power confirmed
Posts: 185
Joined: Thu Mar 19, 2009 8:29 pm
Closest Airfield: OMAA
Has liked: 8 times
Been liked: 15 times

Re: Minimum Enroute IFR Altitude (height)

Unread post by tansg » Mon Feb 19, 2018 1:15 pm

Plettflyer wrote:2. The AIP then states in a number of references that the Enroute Safe Altitude is 1500' above the highest obstacle within 5nm of the aircraft.

(And regarding MSA, the AIP states that the clearance is 1500' above the highest obstacle within a 25nm radius etc. etc. - whereas Jeppesen generally use 1000' - or such higher values supplied by the State. So does a Jepp MSA in the Republic provide clearance of 1500'?)
I have been trying to find these references lacklustardly. Could you possibly PM me these ones so we don't have thread drift?
Plettflyer
Fuelling up
Posts: 34
Joined: Fri Nov 11, 2016 3:45 pm
Closest Airfield: FAPG
Has liked: 2 times
Been liked: 0

Re: Minimum Enroute IFR Altitude (height)

Unread post by Plettflyer » Mon Feb 19, 2018 4:13 pm

Stand by for the AIP references. Should have access to the AIP on Wednesday.
User avatar
tansg
Engine full power confirmed
Posts: 185
Joined: Thu Mar 19, 2009 8:29 pm
Closest Airfield: OMAA
Has liked: 8 times
Been liked: 15 times

Re: Minimum Enroute IFR Altitude (height)

Unread post by tansg » Tue Feb 20, 2018 6:41 am

Plettflyer wrote:Stand by for the AIP references. Should have access to the AIP on Wednesday.
Thanks :)
Plettflyer
Fuelling up
Posts: 34
Joined: Fri Nov 11, 2016 3:45 pm
Closest Airfield: FAPG
Has liked: 2 times
Been liked: 0

Re: Minimum Enroute IFR Altitude (height)

Unread post by Plettflyer » Wed Feb 21, 2018 1:40 pm

Sorry, training session cancelled due weather. I might have access to the AIP tomorrow. If anyone else has a copy, the reference to minimum enroute altitude is in the Enroute section.
User avatar
michael_v
Power off stall
Posts: 334
Joined: Tue Jun 30, 2009 7:11 am
Closest Airfield: HMS FAKR
Location: Where the propeller takes me!
Has liked: 0
Been liked: 0

Re: Minimum Enroute IFR Altitude (height)

Unread post by michael_v » Sun Mar 04, 2018 7:18 pm

AIP ENR 1.1 CARs 91.06.32 and cats 91.07.2
N1 TO/GA
Fuelling up
Posts: 32
Joined: Sun Jun 26, 2016 1:51 pm
Closest Airfield: FAJS
Has liked: 0
Been liked: 0

Re: Minimum Enroute IFR Altitude (height)

Unread post by N1 TO/GA » Mon Mar 05, 2018 10:01 pm

Interesting thread :idea: ... I wonder if there is more information to clarify on the difference between what is published in the SA AIP and what is published in the Jeppesen Airway Manual. I don’t have access to an electronic/digital AIP - this is the 21st Century #-o - but, surely the statements extracted from a very current Jeppesen Airway Manual would be accurate?
STATE PAGES RULES AND PROCEDURES

These pages contain flight information applicable to the specific state. They are compiled by Jep-pesen using the state's Aeronautical Information Publication (AIP) as primary source material
And this;
South African Rep.

GENERAL

In general, the air traffic rules and procedures in force and the organization of the air traffic serv-ices are in conformity with ICAO Standards, Recommended Practices and Procedures
I don’t see the Minimum Sector Altitude section under th FLIGHT PROCEDURES, PROCEDURE LIMITATIONS AND OPTIONS. The previous Jeppesen Airway Manuals used to have the Minimum Sector Altutde as 1 500ft AGL within 25nm.

Anyone with some industry insight able to help?
You do not have the required permissions to view the files attached to this post.
Plettflyer
Fuelling up
Posts: 34
Joined: Fri Nov 11, 2016 3:45 pm
Closest Airfield: FAPG
Has liked: 2 times
Been liked: 0

Re: Minimum Enroute IFR Altitude (height)

Unread post by Plettflyer » Tue Mar 06, 2018 9:43 pm

You will find reference to Enroute Safe Altitudes at the following places in the latest version of the AIP:

Enroute 1.1 General Rules
1.1.1 Minimum Heights (mentions the 1000'/5000' and 2000'/5001' within 5 nm which is common to FAA and EASA rules)

Enroute 1.7 Altimeter Setting Procedures
6.2 Terrain clearance (mentions 1500' clearance)

Enroute 1.8 Regional Supplementary Procedures
1.2 Glossary of Terms
1.2.10 Enroute Safe Altitude (mentions 1500')
1.2.19 MSA (mentions 1500')

So certain parts of the AIP (and CARS/CATS) require you to clear any terrain/obstacles below 5000' by 1000' and terrain/obstacles 5001' and higher by a minimum of 2000'. In other parts, they still refer to 1500'.
User avatar
V5 - LEO
Fife Thousand feet
Fife Thousand feet
Posts: 5632
Joined: Mon Dec 05, 2011 4:18 pm
Closest Airfield: FYWH
Location: Namibia
Has liked: 26 times
Been liked: 8 times

Re: Minimum Enroute IFR Altitude (height)

Unread post by V5 - LEO » Wed Mar 07, 2018 9:22 am

Plettflyer wrote:You will find reference to Enroute Safe Altitudes at the following places in the latest version of the AIP:

Enroute 1.1 General Rules
1.1.1 Minimum Heights (mentions the 1000'/5000' and 2000'/5001' within 5 nm which is common to FAA and EASA rules)

Enroute 1.7 Altimeter Setting Procedures
6.2 Terrain clearance (mentions 1500' clearance)

Enroute 1.8 Regional Supplementary Procedures
1.2 Glossary of Terms
1.2.10 Enroute Safe Altitude (mentions 1500')
1.2.19 MSA (mentions 1500')

So certain parts of the AIP (and CARS/CATS) require you to clear any terrain/obstacles below 5000' by 1000' and terrain/obstacles 5001' and higher by a minimum of 2000'. In other parts, they still refer to 1500'.

...so in an exam with a one selection answer, which one would be right? My guess is the minimum of 1000' as per SACAA's own CARS/CATS ?
In God I trust. The masses are never right, the minority are sometimes right, but the truth is always right.
“One good teacher in a lifetime may sometimes change a delinquent into a solid citizen.” — Philip Wylie
Plettflyer
Fuelling up
Posts: 34
Joined: Fri Nov 11, 2016 3:45 pm
Closest Airfield: FAPG
Has liked: 2 times
Been liked: 0

Re: Minimum Enroute IFR Altitude (height)

Unread post by Plettflyer » Fri Mar 09, 2018 6:52 pm

Good question V5. This seems like a fundamental oversight where perhaps the AIP has not been updated in synch with the CARs'. Perhaps someone more familiar with the workings of the CAA could shed some light on this.
User avatar
tansg
Engine full power confirmed
Posts: 185
Joined: Thu Mar 19, 2009 8:29 pm
Closest Airfield: OMAA
Has liked: 8 times
Been liked: 15 times

Re: Minimum Enroute IFR Altitude (height)

Unread post by tansg » Sun Mar 11, 2018 7:39 am

Plettflyer wrote:Good question V5. This seems like a fundamental oversight where perhaps the AIP has not been updated in synch with the CARs'. Perhaps someone more familiar with the workings of the CAA could shed some light on this.
The fundmental problem here is that the SA AIP is still created using manual methods. The background behind this is that it was agreed in around 2010 that ATNS would take over the production (a service provider role) of the AIP and CAA would revert back to their primary role as the oversight entity as required by ICAO. ATNS was at that stage producing the AIP for Namibia in an electronic format and so had all the software to perform the role. However despite this agreement, ATNS has been reluctant to take over this function for political reasons and the fact that they do not see it as a significant enough revenue stream to cover their costs. There were other reasons also offered but I forget them now. The fact that ATNS had agreed to take over this function, as is their role as designated service provider for South Africa, meant that SACAA could not justify the cost of the purchase of software to perform this role in line with the requirements of the SWIM processes and ultimately produce an electronic AIP. The result was that I came up with a number of stop gap initiatives such as the CDs that were produced for a while and the AICs, AIP Supps and charts on the website to try and alleviate the pressure for this service. The software used to create these documents is however not conducive to electronic publishing I.e. it is very labour and skill intensive which the AIS Dept did not have to sustain a "manually" produced electronic AIP. So what this means is that all changes to the content have to manually managed. This relies on peoples memories as to where what information located in the document and to remember to go and update them if they were even notified that such changes had occurred. I am sure they would appreciate if you notified them of the inconsistencies so they could investigate and rectify them. If I remember right their contact is ais@caa.co.za or aim@caa.co.za

Please remember my info may be a bit outdated as I have been out of the "system" in SA for 4 years but I am sure it is largely still correct.
User avatar
V5 - LEO
Fife Thousand feet
Fife Thousand feet
Posts: 5632
Joined: Mon Dec 05, 2011 4:18 pm
Closest Airfield: FYWH
Location: Namibia
Has liked: 26 times
Been liked: 8 times

Re: Minimum Enroute IFR Altitude (height)

Unread post by V5 - LEO » Sun Mar 11, 2018 7:45 am

.....txs Plettflyer and Tansq, pity though that this safety function at times cannot function to its full potential as the powers responsible therefor sees it as a "job" only. Another reason for airmen to be pro active and very sharp when in the cockpit.
In God I trust. The masses are never right, the minority are sometimes right, but the truth is always right.
“One good teacher in a lifetime may sometimes change a delinquent into a solid citizen.” — Philip Wylie
User avatar
tansg
Engine full power confirmed
Posts: 185
Joined: Thu Mar 19, 2009 8:29 pm
Closest Airfield: OMAA
Has liked: 8 times
Been liked: 15 times

Re: Minimum Enroute IFR Altitude (height)

Unread post by tansg » Sun Mar 11, 2018 7:50 am

V5 - LEO wrote:.....txs Plettflyer and Tansq, pity though that this safety function at times cannot function to its full potential as the powers responsible therefor sees it as a "job" only. Another reason for airmen to be pro active and very sharp when in the cockpit.
I disagree with this comment as the people who are performing this function are doing it to the best of their ability with the tools they have and largely are doing a more than good job with one hand tied behind their back. The problem is the politics between the senior management of CAA and ATNS in not having this issue resolved 10 years ago. I am not going to put my personal opinion of this on Avcom but you welcome to PM me if you want to know more.
User avatar
V5 - LEO
Fife Thousand feet
Fife Thousand feet
Posts: 5632
Joined: Mon Dec 05, 2011 4:18 pm
Closest Airfield: FYWH
Location: Namibia
Has liked: 26 times
Been liked: 8 times

Re: Minimum Enroute IFR Altitude (height)

Unread post by V5 - LEO » Sun Mar 11, 2018 8:01 am

...txs for putting me straight, so in short the manpower behind this is able and willing, the puppetmaster is once again politics, the mind boggles as to how vain a person can become and not see the common goal for benefit of safe air travel?
Txs
In God I trust. The masses are never right, the minority are sometimes right, but the truth is always right.
“One good teacher in a lifetime may sometimes change a delinquent into a solid citizen.” — Philip Wylie
Plettflyer
Fuelling up
Posts: 34
Joined: Fri Nov 11, 2016 3:45 pm
Closest Airfield: FAPG
Has liked: 2 times
Been liked: 0

Re: Minimum Enroute IFR Altitude (height)

Unread post by Plettflyer » Sun Mar 11, 2018 1:01 pm

Hi Tansg, I will certainly try to get in touch and make these discrepancies known. I think it is important for all licence holders to take responsibility and make these issues known to the regulator. Otherwise, we just become part of the problem.

Return to “Instrument Flying”