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

EOSID -v- EFP any comments on differences?

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

EOSID -v- EFP any comments on differences?

Thread Tools
 
Search this Thread
 
Old 27th Oct 2010, 04:29
  #21 (permalink)  
 
Join Date: Jun 2004
Location: Australia
Posts: 1,843
Likes: 0
Received 0 Likes on 0 Posts
A fast reply mcdhu, on the way to Metric QFE land

I do not recall making an earlier post along those lines, but here's my fast (not completely thought out) reply.

I don't see the Increased Speeds / Improved climb as being any more dangerous in comparison to V2min.

In comparing V2min Vs Increased Speeds / Improved climb, FOR A GIVEN WEIGHT / MASS, V2min will offer improved vertical clearance of 'colse in' 1st Segment obstacles, but degraded vertical clearance of further out 2nd Segment obstacles. Increased Speeds / Improved climb will be the reverse.

That's for a constant Weight, depending upon the location of the most critical obstacle (close in / further out) and if optimising the Speed schedule, the RTOW max may be at V2min, Increased speeds, or somewhere in between.

In pre-EFB times on the B777 and using paper Airport Analysis, many Takeoffs offered improved RTOW at the Improved Climb schedule, whereas there was no data at all for Improved Climb if 2nd Segment limited. The OPT in the EFB calculates the Optimum speed schedule for the actual obstacle array

That's the fast answer, probably a few points not well covered, later notes may be needed to fill in the picture. Mutt also number crunches the B777, and will hopefully come in with a better explanation than mine.

Both methods are safe, depending on the obstacle array, one may be safer than the other on a given day, but both will meet the obstacle clearance criteria satisfactorily.

Regards,

Old Smokey
Old Smokey is offline  
Old 27th Oct 2010, 06:56
  #22 (permalink)  
Moderator
 
Join Date: Apr 2001
Location: various places .....
Posts: 7,186
Received 94 Likes on 63 Posts
Why flying fast on Improved/Increased V2 after an EF is dangerous - particularly when limited by a close in obstacle - and even more particularly when using wet figures.

While concurring with OS, perhaps the question relates to flying faster than the overspeed schedule calls for ? In this case

(a) screen will be achieved further along the runway which may compromise a variety of limits in the calculations.

(b) alternatively, if the speed is allowed to increase during the initial climb, the short term climb gradient will be compromised significantly.

(c) the potential for conflict with the early obstacle is obvious if either (a) or (b) applies. The basic overspeed calculation, however, will have addressed the obstacle and provides no inherent hazard greater than for a routine takeoff.

For a wet calculation, (b) is similar. However, due to wave and impingement drag on the runway, (a) might be VERY much more compromising and, in a limiting case, might see the aircraft not achieve the higher speed presumably chosen by the pilot on the day in violation of the prescribed procedure.

In general, unless one knows what is going on and has a very good knowledge that the procedure is going pear shaped, it is far better, on the odds, to follow the declared procedure.
john_tullamarine is offline  
Old 31st Oct 2010, 15:38
  #23 (permalink)  
 
Join Date: Mar 2005
Location: Uh... Where was I?
Posts: 1,338
Likes: 0
Received 0 Likes on 0 Posts
Dear masters of the Universe
The level here is going too high!


The point of view of a humble 320 FO

If the EFP or EOSID is standard, then I relax, all I have to know is to what side is the turn, and where are the most prominent obstacles.

By "standard" I mean what the provider for my airline does for most of the runways: straight ahead, at 1,500 turn either right or left to a fix and hold. Accel alt is not given, but min and max accel alt instead. 99% of the times 1,500 (A320 default altitude) is within that range. So most of the times the procedure is basically the same.

If obstacles are a factor and this is not possible, then a "non-std" procedure has to be carried out.

When the EFP is non-std and specially in IMC, I review carefully and brief before departure.

This "standard and non-standard" way of looking at it helps me a lot.

Then again, in simulators, when the FI acting as ATC tells me to turn right heading 150º before reaching accel alt because he wants to save sim time I always doubt what to do. If I depart from the procedure, I could hit an antenna or somthing. And I have no means, in that moment, to know if I am safe or not, so I think the only sensible thing to do is "unable, call you back when ready for turn".

If I find a very strange EFP by EAG in LEVC I will post it here to see if you, masters of the univers find any sense in it.

thanks
Microburst2002 is offline  
Old 5th Nov 2010, 10:33
  #24 (permalink)  
Thread Starter
 
Join Date: Feb 2009
Location: UK
Age: 57
Posts: 88
Likes: 0
Received 0 Likes on 0 Posts
LEVC 'Non std' EFP

LEVC R30
At D5 VLC turn RIGHT to 090°. At 2000 turn LEFT to SGO HP. Maintain V2 TKOF flaps during first turn. 356 SGO HP: Inbound 229°, RIGHT turn
Reviewing a typical EFP for VLC, which would be non std due to an early turn, found the above floating around. Have not got my topographic maps out but a quick look at the plates and use of my compass seems reasonable to me?
Ops_Room_Junkie is offline  
Old 7th Nov 2010, 21:57
  #25 (permalink)  
 
Join Date: Oct 2010
Location: Below Radar
Age: 54
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
Ops_Room_Junkie

What is the acceleration altitude and is it a twin aircraft?
TruthHurts is offline  
Old 8th Nov 2010, 14:02
  #26 (permalink)  
Thread Starter
 
Join Date: Feb 2009
Location: UK
Age: 57
Posts: 88
Likes: 0
Received 0 Likes on 0 Posts
Truth.

for a twin and Min Acc Alt 1420 ft QNH


rgds
ORJ
Ops_Room_Junkie is offline  
Old 8th Nov 2010, 14:40
  #27 (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
Our supplier suggests: At 10 DME VLC right turn to VLC VOR. EO ACC ALT is at "standard" 1500 AFE, however MNM EO ACC ALT is only 60 ft lower which certainly is not the common case.

Yours,
FD (the un-real)
FlightDetent is offline  
Old 8th Nov 2010, 19:14
  #28 (permalink)  
Moderator
 
Join Date: Apr 2001
Location: various places .....
Posts: 7,186
Received 94 Likes on 63 Posts
The recent discussion highlights several important points -

(a) very few runways have only one potential (ie useable) escape path - most have multiple options

(b) different operators may choose different escapes paths - this will be driven largely by Type (different aircraft have different performance signatures - speeds and climb capability) and, perhaps, standardisation considerations across multiple fleets

(c) one must NEVER pinch someone else's procedure for one's own aircraft without doing all the sums for the latter to make sure that the procedure fits the particular aircraft and terrain profile
john_tullamarine is offline  
Old 8th Nov 2010, 19:56
  #29 (permalink)  
Thread Starter
 
Join Date: Feb 2009
Location: UK
Age: 57
Posts: 88
Likes: 0
Received 0 Likes on 0 Posts
JT.

Spot on.
Ops_Room_Junkie is offline  
Old 9th Nov 2010, 09:53
  #30 (permalink)  
 
Join Date: Oct 2010
Location: Below Radar
Age: 54
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
I see no issue at all with your EFP

But I would rather turn them back before acceleration, to keep them in an area I am very positive of the obstacles.

I just looked at the area using the VOR RWY 12, so I do not have much info on the obstacles.

Good Luck
TruthHurts is offline  
Old 9th Nov 2010, 13:41
  #31 (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
j_t, you're helping turn the alphabet into workable training curriculum! q) r) s) are done, only 7 to go; of course we may want to re-sort the topics later on.

There's one other thing for which I have answer am not happy with.

On my type, EO ACC ALT is defaulted at 1500 AFE and if obstacle data require, will be raised in the computation result to comply with MNM EO ACC value.

Here's the problem:
For certain types of RWY contaminant, manufacturer specifies that WET (equivalent) figures shall be used. The certified wet envelope ends at -5 deg C which is logical. Hence if the OAT is lower, the software (and paper RTOW tables as well) will require the pilot to enter the calculation with -5. As far as TORA, TODA, ASDA, and gradient are concerned the result will be more conservative than actual achieved performance. So far so good.

Normally MNM EO ACC ALT derived form the calculation is corrected for altimeter density error, so the chosen EO ACC ALT makes sure to lift you over obstacles by (35?) feet even at ISA -20 i.e. OAT-5. However, when true OAT is -25 and we use wet equivalent figures for frosty runway take-off, the displayed value is not corrected by 20 deg K, which invalidates MNM EO ACC ALT by quite a large margin. Solution would be to manually correct EO ACC ALT by delta (-5) minus OAT. That is a major training problem/cost. Exactly opposed to what computerised tkof performance aim to achieve.

Any thougts?

Sincerely,
FD (the un-real)
FlightDetent is offline  
Old 9th Nov 2010, 15:13
  #32 (permalink)  
 
Join Date: Mar 2005
Location: Uh... Where was I?
Posts: 1,338
Likes: 0
Received 0 Likes on 0 Posts
About VLC rwy 30 EAG's EFP for 320:

We have to maintain V2 and take off flaps till after the first turn towards the sea, according to the procedure.
This turn is to be carried out at 5 DME from the VOR. In the sim, I reach acceleration altitude (1,500) before the 5 miles.

What do I do, then?

An what if I reached 2,000 before 5 DME? Direct to SGO?

That day it was a "free" sim (We had the chance to use it for free for a couple of hours) so we got inside without any briefing with a training captain who is a friend of us. So I was in LEVC rwy 30, engines already running, we set things up "Come on, Are you ready?" Yes, yes. During rotation, one engine flames out. I control the airplane (easy in a 320), keep V2 plus some knots, center the beta target, gear up, TOGA, follow SRS, plenty of rudder trim till my leg is relaxed, ask for runway heading (I don't ask for AP, for practice purposes), then I am climbing nicely, "I have controls & comms", I call "pan pan... runway heading climbing to x thousand", "ECAM actions", I feel good so far, I watch the DME, and see that I will clearly reach accel alt 1,500 ft before 5 DME. I reach 1,500: Fu*k, What do I do now? Levelling off without accelerating is quite moronic, so I keep climbing on runway heading, but then... Should I Keep TOGA or what?
DME is 5 and I start turning right from HDG 300º but I reach 2,000 well before HDG is 090º. Shall I turn now to SGO or wait till 090º? and When the hell do I level off to accelerate?

This procedure sucks. Having an specific accel alt is most confusing when performance is so good (climbing like a rocket) and there is a fix over which you have to start the turn maintaining V2.

Any thoughts?
Microburst2002 is offline  
Old 10th Nov 2010, 01:02
  #33 (permalink)  
Moderator
 
Join Date: Apr 2001
Location: various places .....
Posts: 7,186
Received 94 Likes on 63 Posts
I would rather turn them back before acceleration, to keep them in an area I am very positive of the obstacles.

if one is not very positive about the obstacle profile, one has NO business scheduling the escape path over that area. The problem with accelerating first is that the distance covered (take the DC9 as a nasty example) can be VERY significant ... turning back in the second segment, where feasible, saves a lot of ops eng hard work.

As far as TORA, TODA, ASDA, and gradient are concerned the result will be more conservative than actual achieved performance.

Perhaps. However, unless that protocol is prescribed explicitly in the AFM .. I would be getting OEM concurrence with the presumption of conservatism for contaminated fluids where mean fluid density becomes a driving factor. Likewise I have a concern with tapeline heights as you have identified in your subsequent comments.

In the sim, I reach acceleration altitude (1,500) before the 5 miles. What do I do, then?

I have no familiarity with the aerodrome so I am speaking generically.

(a) if you are AEO, keep climbing until you complete the turn - the only concern should be engine thrust time limits and they ought not to be a problem

(b) if you are OEI, and the failure was near V1, go back to your ops eng and suggest that they redo the sums

(c) if you are OEI, and the failure was well post V1, keep climbing and commence the third segment after the turn. If that puts you past the engine limit in the sim, you might run the concern past your ops eng folk for resolution and review of the procedure.

From the sound of your description, the company procedure is not well thought out or described - my suggestion is that the ops eng folk should revisit it to sort out the problems.
john_tullamarine is offline  
Old 10th Nov 2010, 13:16
  #34 (permalink)  
 
Join Date: Mar 2000
Location: Sunrise Senior Living
Posts: 1,338
Likes: 0
Received 0 Likes on 0 Posts
I suppose the only other rater obvious thought about the 5nm turn is that you might conceivably reach SA while waiting for 5DME to turn up, in which case you now have some discretion over what you do - possibly not at VLC though!
mcdhu is offline  
Old 10th Nov 2010, 21:50
  #35 (permalink)  
DFC
 
Join Date: Mar 2002
Location: Euroland
Posts: 2,814
Likes: 0
Received 0 Likes on 0 Posts
is infinitely preferrable to flight with those MORONIC BLOODY IDIOTS who would follow the normal SID following engine failure.
While it will not happen "reguluarly", provided that the OEI in all segments keeps the aircraft above the SID profile then this meets the requirement that if you can you follow the departure clearance - it is also already in the FMS!!

The "idiots" are the ones who either;

a) simply compare second segment climb to sid gradient and forget (ignore) the level 3rd segment which will put them below the SID

b) will schedule segment 3 at 6000ft (London) when you can't get there within 5 mninutes never mind accelerate to clean.

c) limit take-off weight to enable the sid to be followed when the only reason for increased climb gradient is airspace but they can't be bothered to check the obstacle requirement.

d) claim that it is unsafe to follow the side due to close-in obstacles. If it is safe to follow the SID minimum gradient with all engines then flying far enough above it OEI to make room for an acceleration segment is just as safe (some would say safer!!)

e) Never bother to check what the actual altitude will be when the net altitude is 1500ft. Or expect the aircraft to accelerate at a net altitude of 1500ft but tell the pilots to accelerate at 1500ft + airfield elevation as indicated on the altimeter.

The most important thing about an OEI lateral procedure is that it must be either in the fms or very very very simple.
DFC is offline  
Old 17th Nov 2010, 21:44
  #36 (permalink)  
 
Join Date: Oct 2010
Location: Below Radar
Age: 54
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
PM

Ops_Room_Junkie I have sent you a PM
TruthHurts is offline  
Old 17th Nov 2010, 23:20
  #37 (permalink)  
fdr
 
Join Date: Jun 2001
Location: 3rd Rock, #29B
Posts: 2,956
Received 861 Likes on 257 Posts
what to do?

Engine out SIDs (EOSIDs)

Standard Instrument Departures (SIDs) or departure procedures (DPs) are designed in accordance with U.S. Standards for Terminal Instrument Procedures (TERPS) or ICAO Pans-Ops. These are based on normal all-engine operations and assume that the aircraft are capable of maintaining a climb profile.
These departure procedures are normally published as specific routes to be followed or as omni-directional departures, together with procedure design gradients and details of significant obstacles. They are normally established for each runway where instrument departures are expected to be used and they define a departure procedure for the various categories of aircraft used.
In the event of an engine failure, continued adherence to departure procedures may not be possible as SIDs or DPs do not necessarily assure that engine-out obstacle clearance requirements are met.
An engine failure during takeoff is a non-normal condition, and therefore, takes precedence over noise abatement, air traffic, SID’s, DPs, and other normal operating considerations.
The fundamental difference between SIDs and EOSIDs is that SIDs provides the minimum performance considerations to meet the departure requirements assuming an all engine operation whereas EOSIDs are based upon engine out performance in relation to obstacle clearance. EOSIDs can be in the form of a straight departure and or a series of turns.
Note: Development of Engine Out Takeoff Procedures is the responsibility of the operator.

Civil Aviation Regulations 1988, Reg 235, Takeoff and Landing of Aircraft etc.
Civil Aviation Order Part 20, Section 20.7.1B, Issue 5, Aeroplane Weight and Performance Limitations — Specified Aeroplanes Above 5700 kg — All Operations (Turbine and Piston and Engined)
Civil Aviation Order Part 40, Section 40.2.1, Issue 4 Instrument Ratings. Getting to Grips with aircraft Performance, Airbus Publication Boeing Performance Training - Operations Course notes Boeing Jet Transport Methods, Document D61420, Seventh Edition dated May 1989 Boeing FMS RNAV Workshop February 9,2000
Code of Federal Regulations Title 14, Aeronautics and Space Part 25—Airworthiness Standards – Transport Category Airplanes.
Code of Federal Regulations Title 14, Aeronautics and Space Part 77—Objects Affecting Navigable Airspace.
Code of Federal Regulations Title 14, Aeronautics and Space Part 121—Operating Requirements, Domestic, Flag, and supplemental Operations.
Boeing Document D6-39067-3 RNP Capability of FMC equipped 737, Generation 3 Joint Aviation Requirements for Large Aeroplanes JAR-25
ICAO Procedures for Air Navigation Services, DOC 8 168 Volume II, 4th Edition, Construction of Visual and instrument Flight Procedures.
FAA Order 8260.3, United States Standard for Terminal Instrument Procedures (TERPS), current edition.
FAA Order 8260. 48 Area Navigation (RNAV) Approach Construction Criteria
FAA Order 8260.44A Civil Utilisation of Area Navigation (RNAV) Departure Procedures
FAA Order 8260.40B Flight Management System (FMS) Instrument Procedures Development
FAA Advisory Circular 120- OBS-11, Airport Obstacle Analysis, Draft Copy Issue
RTCA DO-236A, Minimum Aviation System Performance Standards: Required Navigation Performance for Area Navigation, dated September 13,2000
RTCA DO-201A Standards for Aeronautical Information, dated April 19, 2000 ARINC Specification 424-17 Navigation System Data Base, published August 31, 2004 Collins FMS Newsletter Business and Regional Systems July 1998 Volume 1, Issue 2 FAA Notice N8400.80 Special Instrument approach and Engine Out Missed approach Procedures.
CAAP 235-4(0) Guidelines for the Consideration and Design of: Engine Out SID (EOSID) and Engine Out Missed Approach Procedures, Nov 2006


The rules and operators obligations under FAA, JAR etc are fairly obvious.

CAAP 235 is about as concise a answer as you can get...
fdr is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



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.