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Approach Climb Gradient vs EOSID

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Approach Climb Gradient vs EOSID

Old 29th Mar 2011, 15:23
  #21 (permalink)  
 
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For 737,it is based on one engine at TOGA,flaps 15.
FACT!
No, that is not correct.

Ref 8260.52 and PansOps 8168. Describes terminal procedure designs and the parameters. Currently, EO operations are not included in terminal design criteria. EO are referenced in airport operations as an operator requirement, but this design must be done by others, on a specific basis.

FAR Part 25 Airworthiness, describes how V 1.3 is determined.

"Aircraft approach category means a grouping of aircraft based on a speed of VREF, if specified, or if VREF is not specified, 1.3 Vsoat the maximum certificated landing weight. VREF, Vso, and the maximum certificated landing weight are those values as established for the aircraft by the certification authority of the country of registry."
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Old 29th Mar 2011, 15:41
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The diagram was from 8260.52 in an attempt to show how the missed surface is determined, and to lead one to the criteria. The criteria is based on all engine for approach procedures. The design criteria allows for turns at 400' for which there is no design criteria to determine the turn capabilities when EO.

There is nothing in the criteria to support EO design parameters, which is why EO are custom designs.

In AUS, I am very familiar with the YMML, YBBN, and YPAD. Some of the Airbus variants have 60' to 67'/nm climb gradients at EO at the high temperatures with the posted MLW.
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Old 29th Mar 2011, 16:05
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Some of the Airbus variants have 60' to 67'/nm climb gradients at EO at the high temperatures with the posted MLW.
That landing wouldn't be legal because those gradients are way below the Approach Climb certification requirement of 2.1% (127ft/nm). Are you talking about RNP approaches?
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Old 29th Mar 2011, 16:24
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Yes, these are RNP procedures.

Normal operations easily meet the criteria at 2.5%.

As I have stated, EO procedures, which are emergency based, do not have a criteria.

There are no public charts to my knowledge that show an EO track.

Here is a powerpoint from the FAA that describes the differences.

http://www.faa.gov/other_visit/aviat...91overview.ppt

Note page 20...

EOPs are NOT TERPS Or PANS-OPS Criteria
EOPs Do Not Provide Takeoff Data
EOPs Do Not Provide Standard ATC Departure
EOPs Are Not Developed or “Flight Checked”
EOPs Are Not Promulgated Under CFR Part 97
EOPs Are Not “Approved” By The FAA they Are “Accepted”
And… if the EOP is Associated With a “Special” IAP That Involves Unique Terrain or Pilot Flight Skills the Following Applies:

Last edited by FlightPathOBN; 29th Mar 2011 at 16:26. Reason: add link
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Old 29th Mar 2011, 22:50
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As far as I can tell, this thread has nothing to do with RNP procedures.
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Old 29th Mar 2011, 23:08
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Concur, and neither is the response...the procedures in AUS are RNP...
otherwise, the information is relevant...

Did you look at the FAA powerpoint?

AC120_91overview

This powerpoint distinctly describes the issues...

That landing wouldn't be legal because those gradients are way below the Approach Climb certification requirement of 2.1% (127ft/nm)
Again...

"EOPS do NOT need to meet TERPS requirements"

Look at it another way...on Final, for example a 737...
Approach: Vref is flaps 30, no thrust.
EO Missed climb: Stall is flaps 10...

How did one get from flaps 30 to flaps 10? What happened during those 35 seconds?

Last edited by FlightPathOBN; 29th Mar 2011 at 23:29.
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Old 29th Mar 2011, 23:37
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Nothing in that PP that is particularly relevant to this discussion that I can see. The thread is about following a takeoff EOSID procedure when conducting a Missed Approach.

Quote:
That landing wouldn't be legal because those gradients are way below the Approach Climb certification requirement of 2.1% (127ft/nm)
Again...

"EOPS do NOT need to meet TERPS requirements"
I can't see that Terps (or PANS OPS) has anything to do with the need to comply with the basic performance rules. Are you saying the performance requirement for Approach Climb (CAO 20.7.1b section 9) may be disregarded?
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Old 29th Mar 2011, 23:59
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CAAP 235-4(0)

1.1 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.
The guidance is quite similar to AC 120-91.

7. TERPS CRITERIA VERSUS ONE-ENGINE-INOPERATIVE REQUIREMENTS.
a. Standard Instrument Departures (SID) or Departure Procedures (DP) based on TERPS or ICAO Procedures for Air Navigation Services—Aircraft Operations (PANS-OPS) are based on normal (all engines operating) operations. Thus, one-engine-inoperative obstacle clearance requirements and the all-engines-operating TERPS requirements are independent, and one- engine-inoperative procedures do not need to meet TERPS requirements. Further, compliance with TERPS all-engines-operating climb gradient requirements does not necessarily assure that one-engine-inoperative obstacle clearance requirements are met.
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Old 30th Mar 2011, 00:17
  #29 (permalink)  
 
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CAO 20.7.1b section 9
For paragraph 5.1 (b), the approach climb requirements are met if, in the
approach configuration with the critical engine inoperative at a speed not more
than 1.5 VS, an aeroplane has a gross gradient of climb of at least:
(a) for a twin-engined aeroplane — 2.1%
What is the NET?

and also..
(b) a weight that will permit compliance with the take-off climb requirements
mentioned in subsection 7 taking into account either ambient temperature
and aerodrome elevation, or approved declared conditions;

and also...

(b) the height necessary to achieve obstacle clearance in accordance with
paragraphs 12.1 and 12.2.

and also...

For the purposes of subparagraph 4.1 (ba), the take-off obstacle clearance
requirements are met if the net flight path of the aeroplane, following failure of the critical engine so that it is recognised at V1 appropriate to a dry runway, would clear by at least 35 feet vertically all obstacles in the take-off area.
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Old 30th Mar 2011, 00:18
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I understand all that. The fact is that, at least in the vertical sense, the terrain clearance of 2.5% provided by a SID and most Missed Approach procedures is in excess of the OEI performance required for both takeoff and landing, so regardless of what is written on paper about what is designed for what, if one is able to achieve 2.5% (all-engine or OEI), one can follow the SID or published Missed Approach procedure and be "covered" (lateral tracking rules not-withstanding).

The thread issue, however, is about whether a operator can ignore the basic performance requirements for Approach Climb (2.1%) by following an EOSID (at or below the EOSID weight), during a Missed Approach.
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Old 30th Mar 2011, 00:27
  #31 (permalink)  
 
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No....

at our company we are required to fly the EOSID in case SE missed approach at certain airports and OAT
NOT the standard all engine missed. The poster was asking about an EO missed.

The thread is relevant.
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Old 30th Mar 2011, 01:22
  #32 (permalink)  
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whether a operator can ignore the basic performance requirements for Approach Climb (2.1%) by following an EOSID (at or below the EOSID weight), during a Missed Approach.

Just to refocus - the approach and landing climb requirements are WAT limits and, as such, are built into the basic AFM calculations - you CANNOT plan to exceed WAT limits. So while the thread discussion has been quite interesting, it is essential to keep in mind that the above question is not an option - the gross weight MAY NOT exceed any of the WAT limited weights - period.
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Old 30th Mar 2011, 02:12
  #33 (permalink)  
 
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Well, yes, and no....

There is a balance in the criteria base on worst case options.
The published procedure designs are based on the coldest day recorded for the aerodrome, while the missed and departure are based on the hottest day recorded.

That is why they plates show NA below and NA above.
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Old 30th Mar 2011, 03:07
  #34 (permalink)  
 
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in the regulatory sense, can we plan to fly an approach above max approach climb limiting weight if instead of the published GA we plan for EOSID ?
Umm, hang on. I seem to have forgotten the performance basics, but wouldn't that leave you in dire straits should the engine actually fail?

Wouldn't that make it something like taking off from an airport with a higher than standard (normal) SID climb gradient and planning to depart using the EOSID just to increase the payload?
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Old 30th Mar 2011, 05:50
  #35 (permalink)  
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can we plan to fly an approach above max approach climb limiting weight

No - the rules require you not to exceed WAT limits. The suggested option is not an option.
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Old 30th Mar 2011, 15:04
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thanks for grounding this..

That is not an option, because you may have to go missed on the approach.

This was a good discussion on several topics!
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Old 30th Mar 2011, 22:20
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because you may have to go missed on the approach.

From a regulatory point of view - irrelevant. The Design Standards mandate the WAT limits regardless of whether or not the aircraft experiences an engine failure on the day.

Equally, the WAT limits are not interested in terrain - the operator/pilot have to make sure that gross weights are constrained to an extent sufficient to provide adequate climb capability on the day.
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Old 30th Mar 2011, 22:35
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WATS
...the limiting conditions that will satisfy the minimum second-segment climb gradient requirement at a given flap setting....

Departure Climb Gradients;
1st segment - positive
2nd segment - 2.4% one engine inop or 5.2% all engines
3rd segment - 1.2% one engine inop
4th segment - 1.2% one engine inop or 4.0% all engines

Landing Climb Gradients;
1500ft above the aerodrome, a positive gradient
Balked Climb - 3.2% in the landing config with all engines operating
Approach Climb - one engine inop, gear up - 2.1%

ASSUMING there are no obstacles...(such as terrain)

Last edited by FlightPathOBN; 31st Mar 2011 at 00:13.
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Old 31st Mar 2011, 00:01
  #39 (permalink)  
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WAT limits are a bit more general than that and, in particular, second segment WAT is only one of a number of separate WAT limits.

For instance, the current FAR 25 words are along the following lines -

(a) FAR 25.119

(b) FAR 25.121

(c) FAR 25.123

As generally applies, the present rules don't apply retrospectively so, for any given Type, one needs to look up the relevant frozen Design Standards for the particular Certification. However, while the specific detail may vary historically the current rules give you a picture of something approximating what the story is for any recent Types.

Obstacles are quite irrelevant to Design Standards (eg FAR 25) and don't come into play until one looks at Operational Standards (eg FAR 121).
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Old 31st Mar 2011, 00:11
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Concur,

From a designers perspective, many of the regs conflict...which is why it is difficult to distinctly describe a situation...

Part 25 includes 25.111, and 25.125...
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