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-   -   Engine out terrain clearance (https://www.pprune.org/tech-log/524172-engine-out-terrain-clearance.html)

john_tullamarine 28th Sep 2013 11:44

Then we agree to disagree.

Unless the sector is terrain benign, if I am wearing an ops eng hat I'll run the entire sector through the number crunching.

My previous comments were philosophically generic. What folks might do specifically with Calgary is not for me to say ...

My comments remain the same .. without the specific aircraft data and the geometry, there is no rational specific answer available.

BOAC 28th Sep 2013 12:09

There you go, Jammed Stab, if you are still 'on frequency' - there is no real answer - best

a) Be aware of terrain yourself
b) Ask your ops dep how they do iot
c) Hope JT is your ops eng guy

flyboyike 28th Sep 2013 13:13

He knows there's no real answer, that's why he asked the question in the first place.

JammedStab 28th Sep 2013 13:14


Originally Posted by BOAC (Post 8071256)
There you go, Jammed Stab, if you are still 'on frequency' - there is no real answer - best

a) Be aware of terrain yourself
b) Ask your ops dep how they do iot
c) Hope JT is your ops eng guy

Correct, there has been no answer given(and it is quite obvious that I could never get a correct one from Flyboyike). It would appear that perhaps there is no regulation.

Please don't get hung up on Calgary as I was only using the picture as an example of relatively flat followed by a wall of rock and stated that in that case the wall is quite far so forget the city name and use the picture as a reference.

No doubt, there is somewhere similar where the wall of rock is not nearly as far but isn't really close. If it is 72000 feet only or 10 miles or less for a turn to be required, there is an extremely high chance that someone will plow into it.

Think dark night/IMC at an unfamiliar airport with no radar and frequently, there is no radar in mountainous remote mountains.

flyboyike 28th Sep 2013 13:30


Originally Posted by JammedStab

Correct, there has been no answer given(and it is quite obvious that I could never get a correct one from Flyboyike).

That's obviuous indeed, correct answers come from smart people, I'm just a pilot.

What's not terribly obvious is what your actual point is. How far out do you want operators to look? The "not nearly as far, but not really close" bit is one of those statements that sounds akin to "a double cheesburger is not nearly as deadly as a triple one, but not really good for you as a single".

aterpster 28th Sep 2013 14:43

flyboyike:


What's not terribly obvious is what your actual point is. How far out do you want operators to look? The "not nearly as far, but not really close" bit is one of those statements that sounds akin to "a double cheesburger is not nearly as deadly as a triple one, but not really good for you as a single".
I want him to look out to the point where I am in level flight at the minimum en route altitude 5 miles each side of centerline as per FAR Part 121.189, et al.

aterpster 28th Sep 2013 16:08

j.t.


Unless the sector is terrain benign, if I am wearing an ops eng hat I'll run the entire sector through the number crunching.
And, I hope you will be applying FAA Advisory Circular 120-91 or its equivalent.


Advisory Circulars

What I find so frustrating about the for-hire performance and engineering companies is that they still do not offer a OEI rnav flight path option.

That, of course, begs the question of when or how the OEI rnav path gets loaded. I don't want the F/O heads down doing that at KMMH (Runway 27) for example, after an engine fails at rotation.

But, those smarter FMSes that have a second flight plan option, it can be pre-loaded where appropriate.

underfire 28th Sep 2013 16:22


What I find so frustrating about the for-hire performance and engineering companies is that they still do not offer a OEI rnav flight path option.
What do you mean? There are plenty of these procedures available, but given the expense, most airlines just go with RNP designs.

latetonite 28th Sep 2013 17:14

With some fiddling on the fix and legs page before departure, you can paint your EO routing on your PFD, if you fly a Boeing.

aterpster 28th Sep 2013 18:00

underfire:


What do you mean? There are plenty of these procedures available, but given the expense, most airlines just go with RNP designs.
Apparently you've never used the services of the two principal performance groups that non-carrier operators use (if they use any engineered data at all).

And, what RNP procedures are you referring to?

JammedStab 28th Sep 2013 22:04

I am just curious How Far Do they Look?

underfire 28th Sep 2013 23:54

Terpster,

Go back, are you are saying that there arent any RNAV OEI coded procedures available?

aterpster 29th Sep 2013 01:09

Underfire:


Go back, are you are saying that there arent any RNAV OEI coded procedures available?
No, I did not say that.

I asked you about RNP OEI coded procedures.

I know that Naverus designed one for China Airlines at the airport in Tibet. But, that is a giant exception to the norm.

And, outside of the big 121 operators, RNAV OE tracks are simply not done by the public purveyors of performance data.

john_tullamarine 29th Sep 2013 09:22

I hope you will be applying FAA Advisory Circular 120-91 or its equivalent.

.. and a bit of fat in addition should I consider it appropriate. I make no apologies for being a conservative engineer and have not the slightest concern when it upsets the bean counters. Being conservative has seen me comfortably out of potential legal hot water following a few fatals in aircraft with my mods embodied ... the mods might not be relevant but the good legal folk have a tendency to use a scatter gun approach to litigation.

With some fiddling on the fix and legs page before departure, you can paint your EO routing on your PFD, if you fly a Boeing.

One needs to be cognizant of accuracy available and accuracy required before one trusts one's life to JB technology ... while the line might be useful for orientation routinely the ops eng folk will have figured the escape with respect to achieveable flight path accuracy and that needs to be achieved .. no point following the line into the rocky bit believing it to be God's gift to pilots. My limited understanding of religion suggests that God doesn't necessarily see any pertinent need to protect folk intent on joining the Darwin Award group.

One problem which concerns me greatly in many areas is the observation gained over the past, say, 30 years wherein the up and coming folk are developing/have developed a blind faith in gizmo technology. As a long ago aerodynamics boss of mine observed some years ago after presenting a bunch of awards at a graduation event .. "pity none of them have a clue about ROM calculations and guarding against GIGO". Blindly following the magenta line without engaging the brain is a good recipe for surprises.

if they use any engineered data at all

.. and that's been a big worry for many decades now

Skyjob 29th Sep 2013 09:33


latetonite: on the fix and legs page before departure, you can paint your EO routing on your PFD, if you fly a Boeing.
Correct. Provided you factor in potential map shift, and many more possibilities.
Make you fixed named adequately so you can remember them in raw data, eg use a good naming convention.

FullWings 29th Sep 2013 09:49


I make no apologies for being a conservative engineer
I was amazed to find that there were companies operating similar aircraft to mine who didn't have ETs or did very limited analysis along the "dump at 1,500" line.

I suppose I'm lucky that we still appear to have a stock of conservative engineers. Flying NW out of Islamabad, we'd get initial and subsequent ETs but also restrictions on AEO achieved altitudes, maybe requiring en-route holding, plus a critical point and precise instructions on how to fly the driftdown or emergency descent. I was gobsmacked to find not everybody had this...

Regarding OEI FMS departures:


Correct. Provided you factor in potential map shift, and many more possibilities.
Those possibilities apply to all RNAV procedures, not just OEI ones - it's perfectly possible to hit a mountain on a normal RNAV SID/STAR/APP but one would hope an ANP alert would have gone off long before the GPWS.

We used to have coded ETs for some airports but they all appear to have gone to make room for the plethora of RNAV arrivals and departures required.

latetonite 29th Sep 2013 13:51

To Skyjob: My picture on the ND was not meant to be a stand-alone way of getting your engine out procedure correct, merely a reminder to get you in the right direction. The details of the exact routing have to be remembered.
Map shift? With modern aircraft with GPS updating, it would be a strange incident together with an engine failure. Anyway, it would be advertised in front of you. Would you not set it in the ND, cause you could have a map shift? Then also forget any normal departure, without engine failure. Or stay in bed. It is safer.

underfire 29th Sep 2013 18:21

terpster,

OEI missed approach is SOP for both Quovadis and Naverus.

There are very few coded DEP, let alone EO DEP.

Every RNP procedure I have seen from Quovadis and Naverus include EO missed approach. I have seen them as typical in Canada, Australia, and China.

This plate is one in China, but not an exception:

http://i40.tinypic.com/14mys7k.jpg

FullWings 29th Sep 2013 18:37

Wow! Can't see those ones being anything else but RNAV!

(At 1.2nm left track 243degs, after 0.7nm track 247degs, after 1.1nm track 230degs, speed < 180kts, after 0.6nm track...)

It would be quite "interesting" to watch this unroll on a CAVOK day, let alone with any weather. Some years ago I remember watching a D-reg Seneca take off from LSZS (SMV, Samedan in Switzerland, 5600'ASL) in light snow, OVC<100'. He'd strapped a GPS-90 (remember those?) to the control column and programmed in a series of user waypoints that took him down the Inn valley between the peaks. The official departure reads something like "maintain VMC to 14,000'"...

reynoldsno1 29th Sep 2013 22:12

NZ also has OEI missed approaches for RNP(AR) approaches. AFAIK only the US, Australia and NZ have developed criteria for OEI RNP(AR) departures (not yet developed by ICAO). The obstacle clearance assessment extends to the end of the emergency departure procedure, which may be a long way. The actual obstacle clearance is, err, meagre ...:oh:


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