Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

EO Go-Around at Max TOW

Wikiposts
Search
Tech Log The very best in practical technical discussion on the web

EO Go-Around at Max TOW

Thread Tools
 
Search this Thread
 
Old 18th Sep 2018, 12:41
  #1 (permalink)  
Thread Starter
 
Join Date: Oct 2010
Location: EASA land
Posts: 27
Likes: 0
Received 0 Likes on 0 Posts
EO Go-Around at Max TOW

A question for sim trainers / examiners ( and applicable in real life too ):

Suppose we are taking of at maximum design take off weight.
On take off there is an engine failure with damage and smoke in cabin so we have first to follow the engine the EOSID and land over-weight almost immediately after that - at least there is no time to reduce weight.

On the short final the proverbial aircraft on the runway appears and the ATC issues the Go Around commmand.

So now aircraft is close to MAX To and single engine in a Go Around.

What we have to follow the Missed Approach procedure or the EOSID and what are the performance considerations then?
TOGA Tap is offline  
Old 18th Sep 2018, 13:44
  #2 (permalink)  
 
Join Date: Jun 2012
Location: india
Age: 39
Posts: 96
Likes: 0
Received 0 Likes on 0 Posts
Anytime our company came out with a EOSID, we were also told whether to follow that EOSID for a MAP as well for that runway. In HKG circular for us says follow EO routing if MAP with singLe engine.

i think your operator as well should tel you to resolve this ambiguity. What criteria they determine to do or NOT to do is upto them.
agg_karan is offline  
Old 18th Sep 2018, 14:43
  #3 (permalink)  
 
Join Date: Aug 2013
Location: PA
Age: 59
Posts: 30
Likes: 0
Received 0 Likes on 0 Posts
You have an EOSID, but not an EO Missed? Aside from that, When you GA don't you follow the missed approach?
underfire is offline  
Old 18th Sep 2018, 18:35
  #4 (permalink)  
 
Join Date: May 2005
Location: France
Age: 69
Posts: 1,142
Received 3 Likes on 2 Posts
The two profiles start under different circumstances.

1. EFTO: approaching the end of the runway, ground level, gear down, fixed flap setting until accel ht, probably reduced thrust.

2. EO GA: 2/3nm from threshold (potentially nearly 3nm before the EFTO point), 200ft agl, gear about to retract, flaps retracting to the GA setting and full thrust available.

So, while following the EOSID might be wise, it depends on the circumstances and may not be necessary.
eckhard is offline  
Old 18th Sep 2018, 18:54
  #5 (permalink)  
 
Join Date: Jan 2014
Location: N5109.2W10.5
Posts: 720
Likes: 0
Received 0 Likes on 0 Posts
All Jeppesen missed approach profiles quote a minimum climb gradient up to MSA, first stop Alt or Acceleration Altitude. If you can’t make the published gradient then you’ll need another plan.
Goldenrivett is offline  
Old 18th Sep 2018, 21:32
  #6 (permalink)  
 
Join Date: Aug 2013
Location: PA
Age: 59
Posts: 30
Likes: 0
Received 0 Likes on 0 Posts
So, while following the EOSID might be wise, it depends on the circumstances and may not be necessary.
So if there is an EO SID, you ignore the Missed Approach procedure?
underfire is offline  
Old 18th Sep 2018, 23:41
  #7 (permalink)  
J74
 
Join Date: Jan 2015
Location: I'd rather live close to home
Posts: 214
Likes: 0
Received 0 Likes on 0 Posts
As somebody tried to point out the scenario, basically if you take off and you have and EO, taking for example HKG, and you are at MTOW you have to follow the contingency procedure, as the normal SID gradient maybe too high in respect what you need (you have to calculate this according your actual aircraft mass and see if you still able to produce the requred climb gradient)
But if you go around, depends, at which distance and/or Height you go around, probably able to follow the go around profile...if not able due the gradient be too high for your actual condition, again, you need to follow your contingency procedure!
need to ask your Company!!
J74 is offline  
Old 19th Sep 2018, 09:22
  #8 (permalink)  
 
Join Date: Jan 2000
Location: FL410
Posts: 860
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by eckhard
The two profiles start under different circumstances.
1. EFTO: approaching the end of the runway, ground level, gear down, fixed flap setting until accel ht, probably reduced thrust.
2. EO GA: 2/3nm from threshold (potentially nearly 3nm before the EFTO point), 200ft agl, gear about to retract, flaps retracting to the GA setting and full thrust available.
eckhard is spot on, the missed approach starts at a different location, from a different height, therefore requires different performance for obstacle clearance, as obstacles are lower and further (comparable to OEI Takeoff). Using the departure OEI profile is SAFE, but is not REQUIRED to meet regulations. Your aircraft type and the associated minima for approach define published missed approach capability, hence on some charts minima are a factor of aircraft classification and climb gradient, which is based on your actual weight, ambient conditions etc, use the OPT (or equivalent) to find out what the capability of your type is.
Only ONE situation arises which is dubious, which is a missed approach below published minima in which case you cannot guarantee obstacle clearance as charted exists, then following the OEI profile would be safest option.
Skyjob is offline  
Old 19th Sep 2018, 09:39
  #9 (permalink)  
 
Join Date: Oct 2007
Location: Location, Location
Posts: 741
Likes: 0
Received 0 Likes on 0 Posts
All go-around procedures are based on attaining 2.5% gradient (in europe), or higher due obstacles/terrain etc(in which case it should be on your chart).

If you calculate your single-engine climb gradient (approach climb) at your current weight you can see if you will be able to achieve the required go-around gradient for that approach. If you can't achieve it then most airlines give you the option of flying the engine-out takeoff procedure for that runway (for reasons as described above).

Above all, if you're returning to land immediately due to some major time-critical event like an uncontained fire then going around isn't likely to be one of your available options - you can't plan for every eventuality and multiple scenarios.
Mr Good Cat is offline  
Old 19th Sep 2018, 09:48
  #10 (permalink)  
 
Join Date: Aug 2007
Location: sincity
Posts: 1,195
Received 33 Likes on 17 Posts
Check the m.app gradient on the chart, check your gradient, if no good use the t.o. eo chart or similar.
your performance will be much better than at V1
maggot is offline  
Old 19th Sep 2018, 12:15
  #11 (permalink)  
 
Join Date: Nov 2017
Location: australia
Posts: 172
Received 11 Likes on 7 Posts
In past companies the story was, below the minimum follow the EOSID, above follow the IAP MA procedure and if that was not sufficient at max weight, the company would have procedures in place to cover that.
exfocx is offline  
Old 19th Sep 2018, 12:31
  #12 (permalink)  
Moderator
 
Join Date: Apr 2001
Location: various places .....
Posts: 7,185
Received 94 Likes on 63 Posts
Suppose we are taking of at maximum design take off weight.

That is to say, the operation likely is WAT-limited

- at least there is no time to reduce weight.

Or else one follows the B727 double failure scenario .. initiate dumping with NO delay (presuming you have a dump provision). By the time the aircraft is back on final, a lot of fuel (and weight) has gone under bridge, as it were.

On the short final the proverbial aircraft on the runway appears and the ATC issues the Go Around command.

The mayday call on takeoff should have made this a miniscule probability

What we have to follow the Missed Approach procedure or the EOSID and what are the performance considerations then?

The main problems relate to the obstacle environment and tracking accuracy. For the missed approach the aircraft's varying (with reconfiguration) gradient capability may make the obstacle clearance considerations rather difficult unless the sums have been run ahead of time .. certainly not something to do on the fly. For the takeoff OEI escape, the problem is tracking to capture the escape path and ensuring that the aircraft configuration/speed/height is not less than the takeoff case when the aircraft gets to the runway head position.

we were also told whether to follow that EOSID for a MAP as well for that runway

That is the sums need to be run ahead of the game

You have an EOSID, but not an EO Missed? Aside from that, When you GA don't you follow the missed approach?

The unfortunate reality is that not all operators address the OEI miss case. Not much point following the published approach miss if it results in a highly likely CFIT due to degraded gradient capability ?

All Jeppesen missed approach profiles quote a minimum climb gradient up to MSA, first stop Alt or Acceleration Altitude. If you can’t make the published gradient then you’ll need another plan.

Fine AEO. However, the OEI miss is a dynamic procedure with changing gradients throughout associated with reconfiguration and acceleration. How do you match the two sets of data ?

So if there is an EO SID, you ignore the Missed Approach procedure?

If the published miss isn't going to work for you due to CFIT considerations, is there much in the way of alternatives ?

But if you go around, depends, at which distance and/or Height you go around, probably able to follow the go around profile

"Probably" doesn't cut the mustard, I fear.

Using the departure OEI profile is SAFE

But only IF you can find your way to the starting point - keep in mind that the splays aren't all that wide and there may be real tiger country to the sides ..

but is not REQUIRED to meet regulations

.. which may be paraphrased "don't crash". Now, the problem is just how you can go about making sure that that is the outcome.

Your aircraft type and the associated minima for approach define published missed approach capability

Tell me again, now .. was that AEO or OEI ?

Only ONE situation arises which is dubious, which is a missed approach below published minima in which case you cannot guarantee obstacle clearance

This is one rather MORE dubious situation ... all OEI escapes are problematic in the presence of terrain unless a bunch of sums has been run ahead of time with the calculated flight path overlaid on the terrain profile. Basically, you lose one and you are in a potential world of hurt UNLESS all the relevant and necessary sums have been done by competent personnel ahead of time.

All go-around procedures are based on attaining 2.5% gradient (in europe), or higher due obstacles/terrain etc(in which case it should be on your chart).

Hence things might be a tad sweaty in the case of OEI WAT limited situations if the pilot decides to wing things on the fly ?

If you calculate your single-engine climb gradient (approach climb) at your current weight

Now, were you going to account for the time/distance/gradients associated with reconfiguration and acceleration from landing to approach configurations ?

you can't plan for every eventuality and multiple scenarios.

That's in keeping with design and operating philosophies. We want to be very confident we can handle one major failure and reasonably confident that we have a workable plan for the second. Beyond that, sometimes it just doesn't pay to get out of bed in the morning ... Not that we don't always endeavour to have multiple fall back plans up our sleeves .. it's just a case that they might not always work out well.

your performance will be much better than at V1

Maybe yes .. maybe no. How about the case where the scheduled runway takeoff is for a low flap setting and you are starting the miss from landing flap ? Might be a bit messy ? You could have a significant speed delta to make up and a significant time/distance/gradient problem for reconfiguration. Throw away answers just don't cut the mustard, I'm afraid, for difficult airports and runways.

the company would have procedures in place to cover that.

Unfortunately, some operators fall down in this regard.
john_tullamarine is offline  
Old 19th Sep 2018, 18:50
  #13 (permalink)  
 
Join Date: Apr 2012
Location: In Space
Posts: 683
Likes: 0
Received 0 Likes on 0 Posts
The app gradient is based on OEI and usually the most limiting. The missed approach is based on a minimum of 2.5% if you cannot make this, then you cannot perform the approach, most cases at max landing weight this is not a problem.

To get extra performance being overweight, consider a bleeds/Packs off landing (of course if your performed any smoke removal checklist this may not be possible).
B737900er is offline  
Old 19th Sep 2018, 21:54
  #14 (permalink)  
Moderator
 
Join Date: Apr 2001
Location: various places .....
Posts: 7,185
Received 94 Likes on 63 Posts
The app gradient is based on OEI and usually the most limiting.

Approach climb OEI gear up, landing climb AEO gear down, and different speeds. As to what limit may be critical, that will depend on the aircraft. The big problem is going to be reconfiguration and acceleration to get to the appropriate speeds

The missed approach is based on a minimum of 2.5%

As a procedures design consideration but doesn't consider what the aircraft constraints may be

if you cannot make this, then you cannot perform the approach

or you need to adjust the approach by, for example, adopting a higher minimum

most cases at max landing weight this is not a problem.

The OP's concern was for a maximum takeoff weight situation with an immediate return .. things might be a lot tighter now, don't you think ?

To get extra performance being overweight, consider a bleeds/Packs off landing

For a significantly overweight landing, that is a bit like rearranging the deck chairs on the Titanic, methinks.
john_tullamarine is offline  
Old 19th Sep 2018, 23:22
  #15 (permalink)  
 
Join Date: Mar 2002
Location: Seat 1A
Posts: 8,556
Received 74 Likes on 43 Posts
To get extra performance being overweight, consider a bleeds/Packs off landing

For a significantly overweight landing, that is a bit like rearranging the deck chairs on the Titanic, methinks.
Both packs off gives me another 0.9% compared to leaving one pack on.
Capn Bloggs is offline  
Old 20th Sep 2018, 09:29
  #16 (permalink)  
Moderator
 
Join Date: Apr 2001
Location: various places .....
Posts: 7,185
Received 94 Likes on 63 Posts
Except that, for a lot of aircraft at MTOW OEI in the landing configuration at Vref or so ... 0.9 isn't a lot of immediate assistance ?
john_tullamarine is offline  
Old 20th Sep 2018, 10:20
  #17 (permalink)  
 
Join Date: Apr 2012
Location: In Space
Posts: 683
Likes: 0
Received 0 Likes on 0 Posts
What do you suggest John? Without being rude, you have picked apart everyones suggestions so far.
B737900er is offline  
Old 20th Sep 2018, 10:53
  #18 (permalink)  

Only half a speed-brake
 
Join Date: Apr 2003
Location: Commuting not home
Age: 46
Posts: 4,319
Received 3 Likes on 3 Posts
I think JT points out that the suggestions are shoes which do not fit perfectly. He's not saying there's a better pair...

The fact alone, that there's no regulation requiring an all-round valid solution for the given scenario, provides a bit of insight.

If you have concurrently:
- MTOW tkof
- ENG fail
- A/C where MTOW >> MLW so that 2,5% is definitely not achievable even with Bleeds OFF and reduced approach flap
- the absolute necessity of a G/A in spite of a previous MAYDAY
- there are real obstacles below the MISAP path
- valley so complex where EO SID is not possible to intercept properly (bit of scaremongering here, right?)
- IMC
- and you did not run the figures beforehand at the dispatch phase

... the options are spelled out nicely above, and JT did a peer review of the risks with each of them. The task may as well be finished at this stage.

2pc.
FlightDetent is offline  
Old 20th Sep 2018, 12:37
  #19 (permalink)  
Moderator
 
Join Date: Apr 2001
Location: various places .....
Posts: 7,185
Received 94 Likes on 63 Posts
Apologies if I appear to be on a black hat check witch hunt here. My concern is that a great many folk try to oversimplify that which is not amenable to such.

Two points of note -

(a) this stuff is not suitable for line crews to wing on the fly with simplistic notions .. better than nothing, certainly, but not satisfactory at all. If it is to have much show of working, it must be done in the back room ahead of time and preferably by the ops engineering folk with good OEM data and a sound engineering understanding of flight dynamics. Unfortunately, it's a rubbery area which many of us have had concerns about for decades .. can't see anything changing too soon, though.

(b) as FlightDetent infers .. the certification and operational rules cover us so far ... only ... if you get too far out of left field, it might just not be your day. There are no guarantees .. only probabilities. We do our best to load the dice our way but .. if we get too far out of line .. it just might not work out to our advantage.

What really concerns me is that folk don't appear to be hammering on the Flight Operations Manager's door to get good, sound, ops engineering work done on all non-trivial runways ... sure, it costs ... but try the cost of a CFIT with a full load of passengers.
john_tullamarine is offline  
Old 20th Sep 2018, 18:56
  #20 (permalink)  
 
Join Date: Aug 2013
Location: PA
Age: 59
Posts: 30
Likes: 0
Received 0 Likes on 0 Posts
John, Getting the information from Flight Ops is the best. Simply following the EOSID when going missed, especially as a blind statement, is fought with disaster. Look at MEL, follow the EOD SID when going missed RW 16, and you risk an encounter with the crossing traffic from Essendon. There are several missed approach procedures at airports where you have to do a right turn at the midpoint of the runway.
Go missed at the MAP, level, then follow the EOSID? It is unclear how you would blend the 2 procedures together in many places, not to mention other aircraft that departed after you.
underfire is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.