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EASA All-weather operations NCO - finally we may have GPS substitution for ADF/DME

this is a proposal sent out for comments

Yes I am aware of that; I get them on email also.

It was the convoluted language I could not work out. When is this applicable? It is like this which almost nobody seems to know about but which means that the EASA approach ban does not exist if there is no RVR measurement hardware.

should be able to see a minimum of 2 runway markers when lined up at the threshold.

One airline pilot told me it is 3

I don’t think they really care if Jacko takes off from his own airfield on 0/0 conditions, crashes his aircraft and kills himself

Well, obviously nobody is going to be looking, but if it could be proved (which is impossible beyond reasonable doubt, but for insurance – a civil action – it needs to be BRD only) the insurance may not pay out.

Of perhaps more interest is whether the above approach ban concession is applicable to allowing a 150m departure for light GA.

Administrator
Shoreham EGKA, United Kingdom

150m was the minimum visibility to allow a B747 to taxi along an airport. Or so they told me 20 years ago…

EBST, Belgium

RobertL18C wrote:

Famously Pitts forward visibility on take off and landing is around zero.

Seems so, if you are faster than 20kts on the runway all you need is a glimpse on objects sitting 10m to one side (or both sides) to press on the rudder without any forward visibility my comment on ground loop is when slow (ground roll or taxi), one tend to use far away objects: fixed clouds in the sky (or fixed stars for the braves), the far buildings or trees at 2pm…these provide better references on position/orientation better than objects nearby: they either don’t move or move too much

Pitts pilots know how to live in obstructed flat geometry but probably not very good in hyperbolic geometry , you can add some taxi in unlit grass on cloudy nights before sending them solo for taxi/takeoff in 150m visibility?

airways wrote:

150m was the minimum visibility to allow a B747 to taxi along an airport. Or so they told me 20 years ago…

How much of that relates to turn radius on ground? or engine/break inertia on taxi speeds?
It is 70m wing span, so 150m works for checking that the strobes are flashing

Last Edited by Ibra at 10 Feb 10:28
ESSEX, United Kingdom

How much of that relates to turn radius on ground? or engine/break inertia on taxi speeds?
It is 70m wing span, so 150m works for checking that the strobes are flashing

None. You’ll just be able to see the taxi guide line.

EBST, Belgium

Peter wrote:

So a KLN94 cannot be used (not approved for RNAV1) but a GNS430 can (?).

This is really quite amazing that some 30 years on, this block is finally beginning to move.

If this were a US regulation, I read the “or RNP APPR” as an alternative. The KLN94 complies with RNP APPR.

KUZA, United States

PepperJo wrote:

If I read this correctly it would not allow to fly a VOR or NDB approach with the GPS (like in the US?). At least not if VOR/NDB are used in the final approach segment:

That is not allowed in the US either. The US does not permit substitution on the final approach segment for the VOR or NDB if it is being used for lateral navigation. It can be used to determine ATD to a fix. The only exception is if the approach is an overlay approach and includes “VOR or GPS” or “NDB or GPS” in the title.of the procedure and these are no longer in the US approach procedure inventory.

KUZA, United States

johnh wrote:

Seems not to be true any more:

https://aviation.stackexchange.com/questions/35904/can-a-pilot-use-their-gps-fms-to-fly-a-vor-or-ndb-approach

It’s somewhat moot anyway since I doubt if there are any approaches which haven’t long since had a GPS overlay.

US still requires that the VOR or NDB be operational and that the final approach course indication be monitored in the cockpit, so the equipment must be installed and working. This has always been true, but the FAA made a clarification that effectively allowed a VOR or NDB approach to have the autopilot guided by the GPS as long as the raw data is displayed and monitored for course alignment. If the VOR or ADF indication is not within normal tolerances during the approach, then you have to miss the approach or use the VOR or ADF indication for guidance,

KUZA, United States

That suggests that the ability of US pilots to remove the ADF or the DME is based on

  • not many NDBs around anymore
  • not many IAPs being “DME mandatory”
  • lots of overlay approaches, or GPS approaches

Europe fails on all three.

Administrator
Shoreham EGKA, United Kingdom

Airborne_Again wrote:

In principle the difference could be due to different software versions, but I think it is more likely that the installation approvals are what the manufacturer asked for (i.e. needed to provide evidence for) and/or what the particular competent authority agreed to approve.

In the case of Cessna it is the FAA that approved the POH so it is the FAA that would have to be convinced. In the case of Diamond it is EASA or the Austrian competent authority. Recall what I wrote in an earlier post that European authorities used to be reluctant to give RNAV/RNP-1 installation approvals.

An upgrade for the DA40 would most likely be a paper-only exercise but it could cost a lot in money and effort.

AC 90-100A describes the requirements for U.S. Terminal and En Route Area Navigation (RNAV) Operations. Usually the AFMS will include the approvals, but many AFMS pre-date the advent of PBN and various RNAV/RNP type specifications. The FAA dealt with this by publishing a spreadsheet and later replaced by a pdf document of a FAA AC 90-100A Compliance Matrix local copy. This only applies to FAA land, but the G1000 and GNS430/530 legacy equipment is approved for RNAV 1 as well as DME/ADF/VOR substitution. The compliance list is by vendor.

KUZA, United States

Peter wrote:

That suggests that the ability of US pilots to remove the ADF or the DME is based on

not many NDBs around anymore
not many IAPs being “DME mandatory”
lots of overlay approaches, or GPS approaches
Europe fails on all three.

US is eliminating most NDB and reducing VOR by about a third.
Many IAP require DME, but GPS substitution is allowed for all but about two weird DME arc approaches (not able to be coded in database) where the DME is used for lateral guidance on the final approach segment.
Virtually no overlay approaches exist, not sure I could find one.
Only 37 GPS stand alone approaches exist in the US.
At airports where VOR (1741) or NDB (391) approaches still exist, there are RNAV (GPS) procedures (16,456) .

KUZA, United States
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