Approach Climb Gradient vs EOSID

[MD83FO]

at our company we are required to fly the EOSID in case SE missed approach at certain airports and OAT.

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 ?

thank you!

[captom]

Yes you can. Just check you are not over MTOW for that runway for given conditions.

[Microburst2002]

I don't think so.

Approach climb gradients are mandatory, I think. The airplane should be able to carry out the missed approach procedure and clear all obstacles with one engine out, if it is initiated at or above DA or MDA.

[Starbear]

I think that answer is rather too simplistic. Take an example where you have just departed an airport at maximum TOM and suffer and engine failure/fire, say one that won't extinguish. You decide that you want to return immediately to the same runway at the current weight/mass.

A quick check (or even better a slow one before departure) shows that yes, you can stop on that runway but in the event of a missed approach you cannot meet the E/O gradient. Its now up to you. You may be able to come up with an alternative missed approach procedure which MAY or may not be the same as the EOSID you had just used 10 minutes ago. The primary goal being to conduct a MAP safely avoiding all terrain and of course you must get ATC approval before commencing the approach (maybe too late if you call for it during the miss).

A word of caution though: MD83FO I really hope your company has checked that such EOSIDs are appropriate for the airfileds at which they wish you to use this procedure. An EOSID has nothing to do with a missed approach whatsoever as they are both flown from geographically different locations e.g. 2 nm or more difference. However it may be the case at certain airfileds it will be perfectly possible to safely follow the EOSID during a miss, whilst at others it may well not.

[ggofpac]

Actually, i have the same question.

An approach with 2 different DA depending on your approch climb gradient. So you punch in the figures in the computer and it tells you cannot make the climb gradient for the lower DA.

By using the higher DA, what happens if the engine fail after you passed that (higher) DA?:confused:

I can't remeber which airfield it is now...i know i've seen the charts before....:O

[john_tullamarine]

what happens if the engine fail after you passed that (higher) DA?

It's called risk assessment and management and, to the maximum extent practicable, should be done by the operator's flight standards and ops eng people in the comfort of their offices and well ahead of the event ...

(a) identify and assess the risk. This may be able to be done quantitatively or, in many cases, only qualitatively

(b) determine what options may be available to mitigate the risk

(c) what mitigation is practical, put in place

(d) if the risk cannot be mitigated to the level desired, either don't do the operation or escalate the decision to accept/reject the risk to an appropriate level

Depending on the operation, there may/may not be regulatory requirements in respect of acceptable risk.

Main thing is not to blunder blindly into the situation of risk and then wonder what might be a good way of surviving ... that's just a good way of killing yourself.

[Capn Bloggs]

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 ?
I would say No. You must comply with the certification weight requirements ie be at or below Approach Climb or Landing climb limited weights, regardless of terrain. I don't believe there is any relief from the landing certification requirements based on takeoff performance ie EOSIDs. On top of that comes the potentially more-limiting Missed Approach gradient requirements that ggofpac mentions.

Take an example where you have just departed an airport at maximum TOM and suffer and engine failure/fire, say one that won't extinguish. You decide that you want to return immediately to the same runway at the current weight/mass.
A fire that will not go out would be considered an emergency, and there is no requirement to comply with any certification rules in that case.

If I was on fire there is absolutely no way I'd be not conducting an immediate return to land simply because I was over the normal Landing Climb or Approach Climb limit weight. The other option, going somewhere else/burning off fuel, is obviously not going to work. To keep the G/A option up your sleeve, you could keep the speed up (until committed to land) to aid climbing, as well as land at a lower flap setting.

[C182]

An approach with 2 different DA depending on your approch climb gradient. So you punch in the figures in the computer and it tells you cannot make the climb gradient for the lower DA.

By using the higher DA, what happens if the engine fail after you passed that (higher) DA?

Very simple answer to that one: as you are visual after passing the higher DA/MDA you complete the landing!!!
Best RGDS

[Dream Land]

IMHO I don't feel that your company needs follow their current procedure unless you are flying a Cessna 402. An MD80 will easily comply with the gradient from DH on SE.

Cheers, D.L.

[Capn Bloggs]

An MD80 will easily comply with the gradient from DH on SE.

I wouldn't be so sure about that. The 717 (not the most underpowered thing in the sky) is a real dog hot n high on one engine and the 2.5% MA gradient is quite limiting sometimes.

[FlightPathOBN]

The airplane should be able to carry out the missed approach procedure and clear all obstacles with one engine out, if it is initiated at or above DA or MDA.

No, this is not correct. Missed Approach is based on all-engine. MDA and DA are based on all-engine missed.

2.5% is all engine...make no mistake about that. One has to remember that the Missed and EO consider the hottest day of the year for that aerodrome. Many EO procedures in AUS use 60'/nm as climb gradients.

http://fsims.faa.gov/wdocs/Orders/8260_52_files/image254.jpg

If you call up the different procedures in the box, you will likely see completely different routes for EO procedures.(RNP)

EOSID can help you decide if you want to land at that aerodrome if you are on EO approach, or go to an alternate. Engine out procedures are not in any design criteria. You must submit them to show what would be your route, but you will never get anything but a thank you.

One reason you may see different DA's can be because of extreme cold temps. There will be a DA for temps down to -20C, then another DA for temp below -20C on baro...

[Microburst2002]

Some operators do this:

go around above DA: follow missed approach procedure
go around below in IMC: follow EOSID

but I never saw anyone briefing for the latter possibility

[FlightPathOBN]

For a go around below the MDA/DA there are 'balked' landing procedure designs as well.

[Capn Bloggs]

2.5% is all engine...make no mistake about that.
No it's not. The 2.5% is merely what your aircraft needs to achieve to miss the obstacles on the Missed Approach path. Nothing more, nothing less. If your aeroplane will not do that (eg with an engine out) then you have to either increase your minimum, lighten the weight so that you can make the 2.5% or, in some other way (eg company EOSID/MA procedure), get to the MSA without running into terra firma.

Let's face it, if all the engines are running, this discussion is purely hypothetical. Any modern aircraft will kill any of the requirements (even a 402).

[FlightPathOBN]

Sorry, but you are incorrect. This is a common misconception...but still wrong.

The climb gradient is based on normal operations, not EO operations. Just because you may be able to achieve that gradient EO is irrelevant to the regulatory environment.

The NET climb profile EO is much different that the NET climb profile all engine.

You are a declared emergency on EO. There is NO criteria that addresses EO parameters, therefor NEVER expect that the DA/MDA includes this emergency operation.

There are 'specials' that address EO operations, but unless you have one of those specific designs, you are NOT covered for EO.

Let's face it, if all the engines are running, this discussion is purely hypothetical. Any modern aircraft will kill any of the requirements (even a 402).

The criteria assumes all engines, and a worst case scenario with aircraft class, performance loading, and temperatures.

This criteria is used to evaluate obstacles to set the DA/MDA...obstacle determine the DA/MDA.

[de facto]

JAA:aircraft performance(weight/thrust)must comply with approach climb gradient(one engine at TOGA thrust and flaps 15).
For example missed approach is 3%,aircraft engine fails on final,continue on landing flaps to minima,no visual,go around to a flaps 15.
Dispatch must ensure 'scheduled' weight allos the gradient for conditions at destination eta.
If conditions change(weather,runway in use),crew must assure themselves of such perforlance by calculating actual single engine flaps 15 gradient using boeing onboard FCOM 'dispatch performance' tables.

ICAO/FAA: no such requirement.pilot decision.i guess its all about statistics/risk assessment in their case.

Flight pathobn:
[QUOTE][One reason you may see different DA's can be because of extreme cold temps. There will be a DA for temps down to -20C, then another DA for temp below -20C on baro.../QUOTE]
are you on drugs?:E

[MD83FO]

there doesn't seem to be a consensus.

we use the customized 10-7 (EOSID) plates which include a temperature chart indicating weather the airplane will comply with the published missed approach OEI,
but my query is regarding regulated approach weight if you may.

since we are supposed to fly the eosid, the missed approach gradient shouldn't be limiting if i use common sense.

i'll take it up to the company thanks for the input.

[de facto]

JAA:YES REGULATED landing weight to comply with missed app climb gradient!
For 737,it is based on one engine at TOGA,flaps 15.
FACT!
Check the regulations!CS25 i think under destination airport.

[FlightPathOBN]

defacto: ???

Note on the plates the low temp limit. The criteria temperature is based on the criteria 3 GPA, effective GPA going down to 2.71.
Some regulatory agencies allow the effective GPA down to 2.5, based on the same 3 GPA. Hence there can be a DA for 2.71, to meet criteria, and another for 2.5, based on temperature.

[Capn Bloggs]

we use the customized 10-7 (EOSID) plates which include a temperature chart indicating weather the airplane will comply with the published missed approach OEI, but my query is regarding regulated approach weight if you may.

since we are supposed to fly the eosid, the missed approach gradient shouldn't be limiting if i use common sense.
That's different. In your first post you only mentioned "EOSID" which implied you were using the takeoff EOSID and RTOW for the Missed Approach.

If your EOSID charts specifically mention limit weights for the missed approach (on the EOSID track), I'd say that you wouldn't have to worry about the certification missed approach gradient requirements/weights. But, you'd better ask your performance engineers if that really is the case.

The other issue, as Starbear said earlier, is tracking. To use an EOSID for a Missed approach, you'd have to make sure the tracks matched.

FlightPathOBN, I still reckon you've got the wrong end of the stick. That diagram you posted is totally irrelevant with all engines running (even on a 4-holer). The gradients achieved would be far in excess of what you show there. And doesn't matter how many engines are going, if I can make 2.5% I will clear the obstacles. It's up to me to organise my weight to achieve that. Obviously, the OEI is the only case I need to consider.

One has to remember that the Missed and EO consider the hottest day of the year for that aerodrome. Many EO procedures in AUS use 60'/nm as climb gradients.
Are you talking about Australia? Can you give an example?

[FlightPathOBN]

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."

[FlightPathOBN]

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.

[Capn Bloggs]

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?

[FlightPathOBN]

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.

www.faa.gov/other_visit/aviation.../AC120_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:

[Capn Bloggs]

As far as I can tell, this thread has nothing to do with RNP procedures.

[FlightPathOBN]

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 (http://www.scribd.com/doc/51842892/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?

[Capn Bloggs]

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?

[Zeffy]

CAAP 235-4(0) (http://www.casa.gov.au/wcmswr/_assets/main/download/caaps/ops/235_4.pdf)


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 (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/list/AC%20120-91/$FILE/AC120-91.pdf).

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.

[FlightPathOBN]

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.

[Capn Bloggs]

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.

[FlightPathOBN]

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.

[john_tullamarine]

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.

[FlightPathOBN]

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.

[Escape Path]

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? :confused:

[john_tullamarine]

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.

[FlightPathOBN]

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!

[john_tullamarine]

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.

[FlightPathOBN]

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)

[john_tullamarine]

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 (http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=802ed12bf879d241cdd14d143fc56cd3&rgn=div8&view=text&node=14:1.0.1.3.11.2.155.17&idno=14)

(b) FAR 25.121 (http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=802ed12bf879d241cdd14d143fc56cd3&rgn=div8&view=text&node=14:1.0.1.3.11.2.155.18&idno=14)

(c) FAR 25.123 (http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=802ed12bf879d241cdd14d143fc56cd3&rgn=div8&view=text&node=14:1.0.1.3.11.2.155.19&idno=14)

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).

[FlightPathOBN]

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...

[FlightPathOBN]

One has to remember that the FAR and CFR, is for aircraft manufacturers for airworthiness certification.

Nothing in the CFR states, "a pilot shall" , a 'pilot' can/should/or would.

In the cert process, there are always exemptions and compliance mitigations.

It is far better to refer to PansOps or TERPS on the approach and missed parameters that are the foundation for what you use as a result, the charts.

[aterpster]

FlightPathOBN:

One has to remember that the FAR and CFR, is for aircraft manufacturers for airworthiness certification.

Nothing in the CFR states, "a pilot shall" , a 'pilot' can/should/or would.

What about FAR 121.189?

[FlightPathOBN]

Thanks for the laugh! I guess I deserved that, but still, nothing in the 121.189 states, "a pilot shall" , a 'pilot' can/should/or would.

These are great rules! :ok:

The 'person' can take-off as long as the aircraft can miss all the obstacles by at least 35 feet.

AND the landing and takeoff distances cannot be longer than the runway.

What else does one need?

[Pugilistic Animus]

Electronic Code of Federal Regulations: (http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=df03a6daeecb83f403982dcaa41194de&rgn=div6&view=text&node=14:3.0.1.1.5.9&idno=14)
it says "no person shall" innumerable times-in the relevant FARS on
WAT limits...:=
:ugh:
:\
edit: really pay attention to what J_T is writing about!!!!!!!!!

[Zeffy]

it says "no person shall" innumerable times-in the relevant FARS on
WAT limits...

Of course it does -- in the operating regulations.

However FAR 25 is not an operating regulation -- rather it defines certification standards to Boeing, Embraer, Airbus, etc. Describes minimum flight paths for flight test engineers who are compiling data for AFM.

The operating rules such as 121.189 tell "persons" how the AFM data must be applied to determine maximum takeoff weight for that aircraft for the specified runway and obstacle environment. AC 120-91 (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/list/AC%20120-91/$FILE/AC120-91.pdf) provides guidance for compliance with 121.189 et al.

Isn't that what j_t and FpOBN were saying -- that there's a difference between Design standards and Operating Rules?

[FlightPathOBN]

Good Form Zeffy!

If they had meant pilots, it would have stated 'pilots', instead, it specifically states 'persons'.

The title is 'airworthiness'...

[john_tullamarine]

Nothing in the CFR states, "a pilot shall" , a 'pilot' can/should/or would

I am having trouble believing what I have been reading if the protagonists are presumed to be competent.

Consider -

(a) compliance/certification with the Design Standards ends up in the Type Certificate and the Flight Manual. These are the documents at the top of the aeroplane food chain ..

(b) the Flight Manual gives you limitations and operating requirements which include things such as WAT limits

(c) can I ask you to explain the significance of FAR 121.173(d) which says something like

The performance data in the Airplane Flight Manual applies in determining compliance with §§121.175 through 121.197 ...

To my simple mind it follows that, if you are required to follow the operations documentation .. then you are required to follow the Flight Manual requirements ?

there's a difference between Design standards and Operating Rules?

I suggest that the philosophy is along the lines that the Design Standards start the ball rolling with a nice new shiny aeroplane. The Operational Standards then address both the implementation of the Design Standards within the operational environment and all those other things which pertain to operations but which have naught to do with Design Standards.

[FatFlyer]

Hi,
I have always assumed that the approach climb gradient found from tables in the 737 manual or from LPC for A320 were single engine, as when going around at DA, we have to assume that one engine may fail and still be able to make the required gradient?
The common figures of around 3-5% would surely refer to single engine as with both engines and at normal landing weights, the climb gradient would be at least double this?
If I have completely misunderstood this and the figures refer to all engines, perhaps someone would be kind enough to explain the low figures?

[FlightPathOBN]

fatflyer..

Within the criteria, the missed is defined using the hottest day on record for the aerodrome, at max landing weight, and lowest engine performance. That is why the low numbers. If you apply that same standard to EO, performance is significantly less.

Does the chart you are using show an EO missed track?

The criteria uses all engine for the missed approach.

from an earlier post in this thread...

"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:"

AC120_91overview (http://www.scribd.com/doc/51842892/AC120-91overview)

[FlightPathOBN]

The performance data in the Airplane Flight Manual applies in determining compliance with §§121.175 through 121.197 ...

To my simple mind it follows that, if you are required to follow the operations documentation .. then you are required to follow the Flight Manual requirements ?

This means that the performance data was used to determine compliance. Its doesnt say how it was used, or other mitigations on the compliance, it just states that this particular dataset was 'applied in the determination'

The specific FM will be the compilation of all of the negotiations, mitigations, and determinations for compliance of that specific variant.

[john_tullamarine]

it just states that this particular dataset was 'applied in the determination'

I wish you well if you ever try to present that sort of nonsense to a judicial enquiry.

The specific FM will be the compilation of all of the negotiations, mitigations, and determinations for compliance of that specific variant

Indeed ... and the resulting document then constitutes the minimum Standards for the operation of that aircraft. Are you really suggesting that it is acceptable to plan and conduct operations in a manner unconservative with respect to the Approved Flight Manual ?

I take it that you have no legal competence ?

[Capn Bloggs]

I have always assumed that the approach climb gradient found from tables in the 737 manual or from LPC for A320 were single engine, as when going around at DA, we have to assume that one engine may fail and still be able to make the required gradient?
The common figures of around 3-5% would surely refer to single engine as with both engines and at normal landing weights, the climb gradient would be at least double this?

Correct. Approach Climb is single-engine.

I wish you well if you ever try to present that sort of nonsense to a judicial enquiry.
I must admit I have had trouble following this...

[FlightPathOBN]

Indeed ... and the resulting document then constitutes the minimum Standards for the operation of that aircraft. Are you really suggesting that it is acceptable to plan and conduct operations in a manner unconservative with respect to the Approved Flight Manual ?

No...I was saying that the AFM is your guidance and nothing else.

Other:

Correct. Approach Climb is single-engine.

WRONG. Did you look at the powerpoint from the FAA?

I take it that you have no legal competence ?

Again, wrong.

[Capn Bloggs]

OBN, if I'm "wrong", how do you explain this:

From CAO 20.7.1b:

APPROACH CLIMB PERFORMANCE
9.1 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%; or
(b) for a 3 engined aeroplane — 2.3% or
(c) for a 4 engined aeroplane — 2.4%.

10 LANDING CLIMB PERFORMANCE
10.1 For the purposes of subparagraph 5.1 (c), the landing climb requirements are met if, in the landing configuration an aeroplane has a gross gradient of climb of not less than 3.2% at a climbing speed not in excess of 1.3 VS with all engines operating.
:confused:

[john_tullamarine]

No...I was saying that the AFM is your guidance and nothing else

I have a reasonable background in certification and AOC stuff and I would describe that statement as "innovative". I guess that we shall just have to agree to disagree at this stage.

Takeoff ..

Heavy aircraft takeoff escape planning is based on OEI

Approach climb ..

Any time we are talking about Design Standards, approach climb means OEI, landing climb means AEO. The operations engineering folk will consider this when looking at developing landing escape procedures for nasty runways.

In the operations world, however, OEI is the operator's (pilot's) problem and one should presume that the routine runway paperwork is predicated on AEO.

[aterpster]

FlightPathOBN:

Thanks for the laugh! I guess I deserved that, but still, nothing in the 121.189 states, "a pilot shall" , a 'pilot' can/should/or would.

121.189 a, b, c, and d all state:

No person operating a turbine engine powered airplane... (may takeoff without doing something then specified)

What are pilots, turnips?

[FlightPathOBN]

Take the time and review the AC120 overview provided by the FAA to help clear up these types of issues.

Note page 12 EOP Criteria
Part 25 Min NET: 1.6%
AND
CFRPart 121.189.D(2):NET must clear all obstacle by 35 feet.

Note page 18, 19, 20
specifically what EOP's are NOT.

Note page 32.
KCOS Special procedures for Engine failure during takeoff or missed approach.
Note page 38
KRNO special missed approach engine out..note that on charts the EO path will be dashed. note that the EO missed track is NOT the same as the standard missed approach shown on page 37.

Note page 46
A one engine missed approach can FREQUENTLY be flown following the PUBLISHED missed approach procedure.
Doesnt this state that there is a difference? If the standard missed approach was EO, why state this?

[john_tullamarine]

Take the time and review the AC120

Keeping in mind that ACs hold no particular status other than that compliance with the recommendations should be acceptable to the FAA as constituting compliance with the related regulation.

However, one still needs to read things with an eye to linguistic logic ...

[HazelNuts39]

From FAR Part 91:
§ 91.9 Civil aircraft flight manual, marking, and placard requirements.

(a) Except as provided in paragraph (d) of this section, no person may operate a civil aircraft without complying with the operating limitations specified in the approved Airplane or Rotorcraft Flight Manual, markings, and placards, or as otherwise prescribed by the certificating authority of the country of registry.The approved Airplane Flight Manual, Chapter Limitations, contains the airworthiness limitations, which are the legal limits of validity of the Certificate of Airworthiness. Violation is against the law, except as provided in Part 91.

As stated in Part 91, the airworthiness limitations apply irrespective of the type of operation conducted. In addition to Part 91, there are operating regulations which apply for particular types of operations, e.g. Part 121 and Part 135.

For Large Transport Airplanes, the airworthiness limitations for performance include the takeoff and landing WAT limits, and the minimum distances required for takeoff: TOD, TOR and ASD. In addition to those, the AFM contains the performance data required for complying with the operating rules specified in Part 121 and Part 135, e.g. landing distances and engine-out flight path data for takeoff, en-route, and landing.

Regards,
HN39

[Zeffy]

Yes -- and for Large/Transport airplanes, Part 91 goes on to state:
§ 91.605 Transport category civil airplane weight limitations.
[...]
(b) No person may operate a turbine-engine-powered transport category airplane certificated after September 30, 1958, contrary to the Airplane Flight Manual, or take off that airplane unless—

(1) The takeoff weight does not exceed the takeoff weight specified in the Airplane Flight Manual for the elevation of the airport and for the ambient temperature existing at the time of takeoff;

(2) Normal consumption of fuel and oil in flight to the airport of intended landing and to the alternate airports will leave a weight on arrival not in excess of the landing weight specified in the Airplane Flight Manual for the elevation of each of the airports involved and for the ambient temperatures expected at the time of landing;


However, compliance with the above is no guarantee that an airplane will be able to extract from an IFR approach simply by flying the (all engines) published missed approach procedure after losing an engine. That calculation is left to the operator and its provider of performance engineering/analysis.

[FlightPathOBN]

However, compliance with the above is no guarantee that an airplane will be able to extract from an IFR approach simply by flying the (all engines) published missed approach procedure after losing an engine. That calculation is left to the operator and its provider of performance engineering/analysis.

Exactly. Try using the numbers in the AFM at Bangda, Lhasa, or Cuzco.

The AC was published specifically to detail that the missed approach shown on the charts is NOT EO. While you MAY be able to meet the 2.5% requirement, the obstacle clearance surface and ROC is designed for all engine missed.

I am currently designing RNP approaches into Bandga, are you saying I should stick with the AFM climb gradients of 2.5%?.... how 'innovative'

Look at it this way, you are on final airport elevation near 5000, temp 25C, flaps 30 or 40...down to Vref around 140kts, so almost all of your energy is gone, and lose an engine. You now have to get the engine spooled up, all the bleed/icing etc off, balanced and to flaps 1 (the AFM basis for climb)...and not drop below the MDA...and is your climb near 2.5%

[Pugilistic Animus]

However FAR 25 is not an operating regulation -- rather it defines certification standards to Boeing, Embraer, Airbus, etc. Describes minimum flight paths for flight test engineers who are compiling data for AFM.Yes, but part 121, which is what I've linked, are operating regulations...:ooh:

Edit you use the lowest of the weights to meet the most restrictive limits as certified and approved by the POI :confused:

the minimum missed approach is designed for OEI---if you can't meet that limit you are overweight for the operation and are therefore operating illegally---at least with TERPS the assumption of OEI-missed approach must be built in to the procedure design:eek:

[aterpster]

FlightPathOBN:

I am currently designing RNP approaches into Bandga, are you saying I should stick with the AFM climb gradients of 2.5%?.... how 'innovative'

I would say you should stick with FAA Order 8260.52.

Order of priority:

1. First line of minima single-string. Additional lower line of minima up to four total if the criteria increments can be satisfied.

2. Attempt to fit non-RNP missed approach with a climb gradient of 200 feet per mile. If that doesn't work, then next is a non-RNP missed approach with a climb gradient up to 425 feet per mile, if necessary to support lowest possible minimums. If that won't work then an RNP missed approach, and perhaps still with a climb gradient of as much as 425 feet per mile.

Presumably, you are third-party developer. If you are working for a specific operator, presumably they would also want you to develop a OEI procedure. But, if you have had to resort to an RNP missed approach with a climb gradient of 425 feet per mile, or thereabouts, the OEI procedure at such a location could be a tough nut to crack.

Then again, some of the business aircraft that are RNP AR capable can exceed a sustained 425 feet per mile with one engine inoperative at max landing weight, or less. Even though they have to level off to clean up as per the OEI profile, their performance is sufficiently robust that they don't fly into the 425' per mile constant slope. So, it's an easy nut to crack for aircraft like those.

I don't know where Bangda is, but I suspect you may have your hands full satisfying the requisite survey requirements.

[aterpster]

Pugilistic Animus:

at least with TERPS the assumption of OEI-missed approach must be built in to the procedure design.

You might want to recheck your sources on that one.

[Pugilistic Animus]

• Land within the distance required by the regulations.
• Climb from the missed approach point (MAP)
and maintain a specified climb gradient with one
engine inoperative.
• Perform a go-around from the final stage of
landing and maintain a specified climb gradient
with all engines operating and the airplane
in the landing configuration.

Aterpster I would defer to you on those matters however---but if you could please explain what I'm missing here? that isn't the approach climb [missed approach flight path] predicated on a minimum gradient unless special procedures apply

[aterpster]

Pugilistic Animus:

I don't know what document you are quoting, but here is what TERPs says:

201. TERPS. Concept of Primary Required Obstacle Clearance (ROC). The title of this order, United States Standard for Terminal Instrument Procedures (TERPS), contains a key word in defining the order's content. The word is "STANDARD;" something set up and established by authority as a rule for the measure of quantity, weight, extent, value, or quality.

a. The TERPS document specifies the minimum measure of obstacle clearance that is considered by the FAA (the Federal authority) to supply a satisfactory level of vertical protection. The validity of the protection is dependent, in part, on assumed aircraft performance. In the case of TERPS, it is assumed that aircraft will perform within certification requirements.

b. The following is an excerpt from the foreword of this order: "These criteria are predicated on normal aircraft operations for considering obstacle clearance requirements." Normal aircraft operation means all aircraft systems are functioning normally, all required navigational aids (NAVAID's) are performing within flight inspection parameters, and the pilot is conducting instrument operations utilizing instrument procedures based on the TERPS standard to provide ROC. While the application of TERPS criteria indirectly addresses issues of flyability and efficient use of NAVAID's, the major safety contribution is the provision of obstacle clearance standards. This facet of TERPS allows aeronautical navigation in instrument meteorological conditions (IMC) without fear of collision with unseen obstacles. ROC is provided through application of level and sloping OCS.

Also, Paragraph 7 in AC 120-91.

[Pugilistic Animus]

Aterpster
Paragraph 7 seems to be dealing with DP and SIDs...I'm not suggesting that TO OEI flight path is based on following a SID or DP only the approach climb I though a minimum climb gradient over the OCS is specified in the initial design-for OEI approach climb and AEO landing climb-as district from OEI special procedures for TO, perhaps I'm loose with my phrasing...I'm not suggesting following the SID or any other Flight path for obstacle avoidance for EFATO...I'm only referring to the approach climb


sorry, that except is from the 'instrument procedures handbook'...:)

edit Pprune automatically writes out engine failure on TO for EFATO not me:O

see EFATO, EFATO, EFATO

[Zeffy]

Pugilistic Animus
From the Instrument Procedures Handbook:
Typically, the AFM for a large turbine powered airplane should contain information that allows flight crews to determine that the airplane will be capable of performing the following actions, considering the airplane’s landing weight and other pertinent environmental factors:
• Land within the distance required by the regulations.
• Climb from the missed approach point (MAP) and maintain a specified climb gradient with one engine inoperative.
• Perform a go-around from the final stage of landing and maintain a specified climb gradient with all engines operating and the airplane in the landing configuration.

One must be mindful that the procedure-specified "gradient" in a missed approach is linear -- compare to a sheet of plywood.

But we know that Transport Airplanes don't climb along a linear path in the real world.

The AFM data for approach climb specify the operative engine(s) at takeoff thrust. There are time limits for takeoff thrust. And we also know that available thrust will be decreasing with altitude as the jet climbs in the clean configuration (enroute and final) with thrust set at max continuous. So the actual climb path will be anything but linear.

An IFR procedure's missed approach may include instructions to "fly runway track to _______MSL, then turn to (heading), intercept _____ radial until leaving______ MSL, then proceed direct_______"

In WAT-limiting conditions, the aircraft may be many, many miles downstream prior to reaching the first turn's altitude, may find itself up against time limitations for the approach climb thrust and may require a transition to enroute and final climb configuration (yet another set charts).

So it's a little simplistic for the Instrument Procedures Handbook to state that "crews can determine that the airplane will be able to maintain a specified climb gradient with one engine inoperative." (paraphrasing)

The key sentence in AC 120-91 paragraph seven may be:
For the purposes of analyzing performance on procedures developed under TERPS or PANS-OPS, it is understood that any gradient requirement, specified or unspecified, will be treated as a plane which must not be penetrated from above until reaching the stated height, rather than as a gradient which must be exceeded at all points in the path.

The OEI performance analysis for locations with lengthy and complex missed approach procedures can tax or exceed the skill sets and competence of average cockpit crew. (Such an analysis is certainly beyond my own abilities.)

[HazelNuts39]

I haven't come across an "Instrument Procedures Handbook". I wonder if anyone could enlighten me as to its origin and status. To whom it is addressed? Thanks in advance.

Regards,
HN39

[Pugilistic Animus]

HN39---the IPH is an FAA publication for pilots earning an instrument rating or moving up to more advanced airline procedures:)

[Zeffy]

Link. FAA Instrument Procedures Handbook (http://www.faa.gov/library/manuals/aviation/instrument_procedures_handbook/)
PREFACE
This handbook supercedes FAA-H-8261-1, Instrument Procedures Handbook, dated 2004. It is designed as a technical reference for professional pilots who operate under instrument flight rules (IFR) in the National Airspace System (NAS). It expands on information contained in the FAA-H-8083-15, Instrument Flying Handbook, and introduces advanced information for IFR operations. Instrument flight instructors, instrument pilots, and instrument students will also find this handbook a valuable resource since it is used as a reference for the Airline Transport Pilot and Instrument Knowledge Tests and for the Practical Test Standards. It also provides detailed coverage of instrument charts and procedures including IFR takeoff, departure, en route, arrival, approach, and landing. Safety information covering relevant subjects such as runway incursion, land and hold short operations, controlled flight into terrain, and human factors issues also are included.

[Pugilistic Animus]

Zeffy would not the actual performance be a gross gradient over the obstacle clearance surface? perhaps it's true that a five or 10 minute limits may make a difference, but usually the limit is most severe on a WAT-limited OEI TO procedure---Engineers like Mutt have even discussed the possibity of of Negative climb performnce for the OEI TO climb to 1500 above the airport elevation---

all the pilot can do is assure that the WAT limits for approach climb are legally met

[HazelNuts39]

Thanks Pugilistic Animus;

I understand the IPH is educational rather than regulatory, and find this statement somewhat simplistic:
Typically, the AFM for a large turbine powered airplane should contain information that allows flight crews to determine that the airplane will be capable of performing: (...)
• Climb from the missed approach point (MAP) and maintain a specified climb gradient with one engine inoperative.FAR 25.1587(b)(3) requires the AFM to provide no more than:
(3) The following performance information (determined by extrapolation and computed for the range of weights between the maximum landing weight and the maximum takeoff weight):

(i) Climb in the landing configuration.

(ii) Climb in the approach configuration.

(iii) Landing distance.Regards,
HN39

[aterpster]

HazelNuts39:

Thanks Pugilistic Animus;

I understand the IPH is educational rather than regulatory, and find this statement somewhat simplistic:...

The FAA, when left to its own devices, tends to internalize. That doesn't happen with certification regulations because they are very thoroughly vetted with industry (powerhouses like Boeing and AB).

Advisory Circulars are sometimes vetted very well but other times not.

Publications like the IPH are not vetted at all; rather they are the product of staff of varying competency and experience within the organization.

I give them an "E" for effort, but that is about it.

[Capn Bloggs]

I am currently designing RNP approaches into Bandga, are you saying I should stick with the AFM climb gradients of 2.5%?.... how 'innovative'

Look at it this way, you are on final airport elevation near 5000, temp 25C, flaps 30 or 40...down to Vref around 140kts, so almost all of your energy is gone, and lose an engine. You now have to get the engine spooled up, all the bleed/icing etc off, balanced and to flaps 1 (the AFM basis for climb)...and not drop below the MDA...and is your climb near 2.5%

For a start, the AFM requires the aircraft to be able to climb at 2.1% in the Approach-climb config at the airfield elevation, so that is the immediate go-around taken care-of.

What terrain clearance parameters are you going to use for the rest of the Missed Approach?

[Zeffy]

Zeffy ...
all the pilot can do is assure that the WAT limits for approach climb are legally met

PA
And that assurance guarantees little with respect to obstacles that may be lurking in the published missed approach track.

This thread (http://www.pprune.org/tech-log/365283-v1-cut-obstacle-clearance.html#post4778554) is now two years old, but is always worth another visit.

[Pugilistic Animus]

FAR 25 approach climb gradients for TERPS IAPs may be simply implied within the chart...similar to second segment limitation [a certification standard]---it might not say explicty, but implicit within other charts with an annotation such as "cross hatched area -does not meet approach climb limits" however for certain special cases it is up to the airline operation to meet FAR-121 and gain at least an equivalent level of safety as an engineering goal...altogether the TO case MUCH more difficult to meet than any other from what I've learned here from the performance engineers...:)

With regards to the IPH it's a very good publication aloowing pilots to better understand TERPS criteria and the NAS

Zeffy I'm in that thread...:8:p:}

[john_tullamarine]

And that assurance guarantees little with respect to obstacles that may be lurking in the published missed approach track.

.. again, certification Design Standards have NO interest in the rocky bits .. that problem belongs to the operator.

All the WAT limits do is give some level of confidence that the aircraft might just go up gradually ... rather than down.

[Zeffy]

Exactly. Thank you.

I should have said "guarantees nothing".

:)

[FlightPathOBN]

Terpster,

I am currently designing RNP approaches into Bandga, are you saying I should stick with the AFM climb gradients of 2.5%?.... how 'innovative'

I would say you should stick with FAA Order 8260.52.

I was being factious. All I do is design procedures, all over the world...

What I am having trouble with is is explaining to this forum, the plain and simple fact that TERPS and PANOPS public procedure designs are ALL engine missed.

The DA/MDA and missed approach, shown on the charts, unless specifically noted, is based on all engine.

For a start, the AFM requires the aircraft to be able to climb at 2.1% in the Approach-climb config at the airfield elevation, so that is the immediate go-around taken care-of.

The DA/MDA on the plates is based on a very simple concept. You decide to go missed, and 8 seconds later, the aircraft climbs at 2.5%. This is the basis for the 'level' section. The 8 seconds takes into account the decision and aircraft reaction time. Again, you are at flaps 30 or 40, idle descent, around 140kts...and in 8 seconds, you are telling me that the engines are spooled up, flaps are at Flaps 1, and you are climbing at 2.5%? This is what the obstacle clearance surfaces are based on.

[john_tullamarine]

What I am having trouble with is is explaining to this forum, the plain and simple fact that TERPS and PANOPS public procedure designs are ALL engine missed

I don't think any of us have a problem with understanding that simple matter .. and that OEI remains the operator's (pilot's) problem.

you are telling me that the engines are spooled up, flaps are at Flaps 1, and you are climbing at ..

I presume you are talking 737. If a pilot couldn't do the miss and be reconfigured for the initial missed approach with GA thrust and climbing within 8 seconds ... one would be looking a bit seriously at him/her, I think.

A while since I last flew the 737 and my recollection might have faded a tad .. but why flap 1 ? My recollection is that the missed approach configuration is 15° and that 1° comes along a bit later during the climb.

[4dogs]

Folks,

It seems to me that there have been a lot of posts mixing up a number of concepts.

The Certification rules determine minimum installed power in an obstacle free environment - it is done by requiring minimum gradients in various configurations.

The Operating rules determine maximum allowable mass in a real world environment - it is done by requiring obstacle clearance in various configurations.

Instrument Procedure designs determine obstacle clear planes regardless of various configurations.

How does it all come together for me as a pilot: fairly simply really, because I have to obey the operating rules and that satisfies the others. The mass at which I operate must take into account the limiting obstacle clearance requirements, regardless of the particular procedure and considering contingencies, the most common of which is OEI.

If there is no procedural requirement related to obstacles, then my operating rules limit is WAT. If there are procedural limits, then I operate to a mass that allows me to follow my operating techniques and remain above the obstacle clearance plane. That mass needs to calculated by performance folks who take into account where the operating techniques place the aircraft in relation to the obstacles.

Much good work is done every day on operational take-off procedure design. :D Operational missed approach procedural design is much more difficult and not as commonly done due to the difficulty of establishing the actual commencement point of the climb and the related issue of keeping the operational missed approach flightpath above the Instrument Procedure obstacle clearance plane. :eek: :eek:

Stay Alive,

[DFC]

This issue is more simple that it first seems.

Generally, the procedure designer will select a missed approach that requires the minimum climb gradient.

Even where there are no obstacles in the missed approach area, the standard minimum climb gradient is 2.5%.

So with no other factors one expects that the procedure designer has already selected a missed approach routing that requires the minimum climb gradient even if this is greather than 2.5%.

However, in some cases, ATC, airspace and other issues can prevent the route of least obstacles and the actual missed approach area is designed over an area of higher obstacles.

In this case it would be possible to design a missed approach procedure for emergency purposes that avoided the higher obstacles.

This procedure could not simply be the OEI take-off route since the dimensions of that are different to a missed approach area, the obstacle clearance requirments are different and while on lift-off the aircraft will never be more than 1/2 runway from the centerline at the missed approach point it can be much further depending on navaid accuracy etc etc.

[Capn Bloggs]

Operational missed approach procedural design is much more difficult and not as commonly done due to the difficulty of establishing the actual commencement point of the climb and the related issue of keeping the operational missed approach flightpath above the Instrument Procedure obstacle clearance plane.
So it's left up to Capt and FO Bloggs to work it out themselves. How are we going to do that, given only some basic graphs in the AFM? I know that if I am below the APPR Climb weight we'll do the G/A OK, and that if I maintain at least 2.5% and follow the Missed Approach procedure I'll miss the hills by at least 100ft, the question is, just how do I work out a suitable weight to achieve that? For example, with say an MSA of 5000 ft, that's a temperature drop of 10° before I even start thinking of turns.

That's why I asked FlightPathOBN what he uses as terrain clearance parameters for his Missed Approach procedures.

Alternatively, here was I thinking that RNP approaches and their Missed Approaches would provide adequate terrain clearance OEI. Perhaps that is not the case. :hmm:

[HazelNuts39]

If a pilot couldn't do the miss and be reconfigured for the initial missed approach with GA thrust and climbing within 8 seconds ... It's not quite so simple. In rules that have been discussed in rule making circles, the critical engine is assumed to fail at the initiation of go-around. The relation between Vref and the stall speed in the approach configuration permits immediate retraction of flaps by one notch. According to the rule makers, retraction of the undercarriage must wait until the airplane has achieved a steady rate of climb of 100 ft/min, at Vref, approach flap, gear down, one engine inoperative. A tough nut to crack in 8 seconds. The U/C then needs another 5-7 seconds to retract.

Regards,
HN39

[aterpster]

DFC:

In this case it would be possible to design a missed approach procedure for emergency purposes that avoided the higher obstacles.

That certainly could be done at some locations. But, where the published missed approach is 40:1-clear (2.5% clear) what would be the point?

And, unlike OEI contingency procedures, any alternate missed approach would have to have full TERPs or PANS-OPs lateral containment areas. And, unlike any OEI contingency procedure, the alternate missed approach would have to be accepted by the approving authority.

[Neupielot]

.......5 pages.....86th replies...
seems like alot of different opinion....who has the correct answer....my poor brain can't handle this much info:{

[DFC]

That certainly could be done at some locations. But, where the published missed approach is 40:1-clear (2.5% clear) what would be the point?

And, unlike OEI contingency procedures, any alternate missed approach would have to have full TERPs or PANS-OPs lateral containment areas. And, unlike any OEI contingency procedure, the alternate missed approach would have to be accepted by the approving authority.


If the lowest minima are based on a 2.5% missed approach gradient then there is no need to do any more work. If however, there are minima provided for the 2.5% missed approach and lower minima provided for aircraft that can acheive a higher missed approach gradient, there may be something to be gained by revisiting the missed approach design with a few to making the route over more favourable terrain or even tailoring the procedure for example to the specific aircraft type that will be used (it might be at the lower end of the C/D speed range for example.

Yes indeed the alternative missed approach would have to meet all the PANS-OPS or TERPS criteria and not only that but when the publsihed missed approach involves a significant turn, one has to consider the posibility of an engine failure during or just after the turn perhaps when the aircraft has now turned towards the significant obstacles.

As far as obtaining authority approval, there would be no difference between this alternative OEI missed approach and the OEI departure. They are acheiving the exact same thing at different stages of the flight - allowing higher operating weights or in some cases operation in cases which would be impossible otherwise. Provided that the design is correct and the numbers work then safety is ensured.

[FlightPathOBN]

Too many questions!

That's why I asked FlightPathOBN what he uses as terrain clearance parameters for his Missed Approach procedures.

Alternatively, here was I thinking that RNP approaches and their Missed Approaches would provide adequate terrain clearance OEI. Perhaps that is not the case.

For standard missed approach, the TERPS/ PansOps criteria.

For RNP, 8260.52, the standard missed approach is all engine. The criteria are based on the following assumptions: (page 4-1 8260.52)
• Aircraft climb at a rate of at least 200 ft/NM (3.29%) in the missed
approach segment.
• A 50-ft height loss is inherent in MA initiation.
The standard MA construction is a continuation of the final approach course. The OEA expands at a 15° splay from the FAS RNP value to a value of 1.0, using a 40:1 OCS slope ratio. Missed approach RF turns that are speed limited must limit bank angles to 15° maximum.

For RNP EO missed, this is a custom design that looks at all segments, with emphasis on turns/bank angles.
OCH determination. 4.7.2.1 First, determine the height of the highest approach obstacle penetrating the final approach OAS or the horizontal plane from Dveb to the origin of the Z surface.
4.7.2.2 Next, reduce the heights of all missed approach obstacles to the height of equivalent approach obstacles by the formula given below:
ha = [(hma*cot Z) - (XZ-X)]/(cot VPA+cot Z)
where:
ha = height of the equivalent approach obstacle
hma = height of the missed approach obstacle
cot Z = cotangent of the Z surface angle
cot VPA = cotangent of the VPA
XZ = origin of the missed approach surface (Z) relative to LTP (Fictitious LTP if appropriate). It is
positive before the LTP/FTP and negative after.
X = Obstacle distance from threshold
and
Missed Approach MOC is:
50 m (164 ft) (Cat H, 40 m (132 ft)) for turns more than 15 degrees and
30 m (98 ft) for turns 15 degrees or less
and a few other borish calcs...

RNP EO procedures are sim and flight checked. THE EO tracks in RNP will be on the specific operators approach charts. Here is a generic example (page 8 (http://www.aci-na.org/static/entransit/dalton.pdf))

According to the rule makers, retraction of the undercarriage must wait until the airplane has achieved a steady rate of climb of 100 ft/min, at Vref, approach flap, gear down, one engine inoperative. A tough nut to crack in 8 seconds. The U/C then needs another 5-7 seconds to retract.

Hence the AC120 (http://www.scribd.com/doc/51842892/AC120-91overview)...

"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”

[FlightPathOBN]

A tough nut to crack in 8 seconds. The U/C then needs another 5-7 seconds to retract.

You think 8 seconds is tough, look what the criteria thinks you do...

http://fsims.faa.gov/wdocs/Orders/8260_52_files/image254.jpg

Turn this into an MDA....

[Pugilistic Animus]

The DA/MDA on the plates is based on a very simple concept. You decide to go missed, and 8 seconds later, the aircraft climbs at 2.5%. This is the basis for the 'level' section. The 8 seconds takes into account the decision and aircraft reaction time. Again, you are at flaps 30 or 40, idle descent, around 140kts...and in 8 seconds, you are telling me that the engines are spooled up, flaps are at Flaps 1, and you are climbing at 2.5%? This is what the obstacle clearance surfaces are based on.
Although certification standards require this it's usually SOP to be spooled up to approach thrust settings

"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”

but again from AC -120 those contraventions are speaking about SIDS and DPs...what about approaches?...that diagram [from what I understand] shows that from the MAP a gradient 200' nm -3.3% must maintained above the obstacle clearance plane [dotted line segement? - if that is the technically correct term-but at lower gradient it's seems you'd still have clearance-to get around the obstacles...for the various engine numbers---while you don't get the full protection of an assumed 3.3% gradient. it seems the FAR 25 provisions still allow obstacle clearance-as long as WAT allows for certificated gradients?

[FlightPathOBN]

PA,

When you say at approach thrust settings, Vref is thrust 0, which is the SOP setting that you are talking about? There is the FOQUA...

For obstacle protection, its best to look at the different standards. There is the Part 77 surfaces and the ICAO stds, and if the aerodrome is certified.
This means that the agency is active in surveying and maintaining the obstacle surfaces.
http://www.ngs.noaa.gov/AERO/yplanfar77.gif
The various P77 surfaces range from 2%, 2.9% and 5% in various distances and configs from the runway endpoints. There is also the blanket requirement for all structures over 200' tall to be submitted to the FAA for eval, but this is little enforced.
What is interesting is the P77 looks at the approach surface, but little for the missed.
http://www.ngs.noaa.gov/AERO/OIS/Dmissapp.gif

NOAA source (http://www.ngs.noaa.gov/AERO/OIS/ois.html)

To be clear, that diagram from the other post is from 8260.52, RNP....illustrating one method to avoid an obstacle by raising CG. Getting this approved is virtually impossible.

A better diagram is the figure 4.2, which the basic MA OCS.

[Pugilistic Animus]

The following civil airport imaginary surfaces are established with relation to the airport and to each runway. The size of each such imaginary surface is based on the category of each runway according to the type of approach available or planned for that runway. The slope and dimensions of the approach surface applied to each end of a runway are determined by the most precise approach procedure existing or planned for that runway end.
(a) Horizontal surface. A horizontal plane 150 feet above the established airport elevation, the perimeter of which is constructed by SW.inging arcs of a specified radii from the center of each end of the primary surface of each runway of each airport and connecting the adjacent arcs by lines tangent to those arcs. The radius of each arc is:
(1) 5,000 feet for all runways designated as utility or visual;
(2) 10,000 feet for all other runways. The radius of the arc specified for each end of a runway will have the same arithmetical value. That value will be the highest determined for either end of the runway. When a 5,000-foot arc is encompassed by tangents connecting two adjacent 10,000-foot arcs, the 5,000-foot arc shall be disregarded on the construction of the perimeter of the horizontal surface.
(b) Conical surface. A surface extending outward and upward from the periphery of the horizontal surface at a slope of 20 to 1 for a horizontal distance of 4,000 feet.
(c) Primary surface. A surface longitudinally centered on a runway. When the runway has a specially prepared hard surface, the primary surface extends 200 feet beyond each end of that runway; but when the runway has no specially prepared hard surface, the primary surface ends at each end of that runway. The elevation of any point on the primary surface is the same as the elevation of the nearest point on the runway centerline. The width of the primary surface is:
(1) 250 feet for utility runways having only visual approaches.
(2) 500 feet for utility runways having non-precision instrument approaches.
(3) For other than utility runways, the width is:
(i) 500 feet for visual runways having only visual approaches.
(ii) 500 feet for non-precision instrument runways having visibility minimums greater than three-fourths statue mile.
(iii) 1,000 feet for a non-precision instrument runway having a non-precision instrument approach with visibility minimums as low as three-fourths of a statute mile, and for precision instrument runways.
(iv) The width of the primary surface of a runway will be that width prescribed in this section for the most precise approach existing or planned for either end of that runway.
(d) Approach surface. A surface longitudinally centered on the extended runway centerline and extending outward and upward from each end of the primary surface. An approach surface is applied to each end of each runway based upon the type of approach available or planned for that runway end.
(1) The inner edge of the approach surface is the same width as the primary surface and it expands uniformly to a width of:
(i) 1,250 feet for that end of a utility runway with only visual approaches;
(ii) 1,500 feet for that end of a runway other than a utility runway with only visual approaches;
(iii) 2,000 feet for that end of a utility runway with a non-precision instrument approach;
(iv) 3,500 feet for that end of a non-precision instrument runway other than utility, having visibility minimums greater that three-fourths of a statute mile;
(v) 4,000 feet for that end of a non-precision instrument runway, other than utility, having a non-precision instrument approach with visibility minimums as low as three-fourths statute mile; and
(vi) 16,000 feet for precision instrument runways.
(2) The approach surface extends for a horizontal distance of:
(i) 5,000 feet at a slope of 20 to 1 for all utility and visual runways;
(ii) 10,000 feet at a slope of 34 to 1 for all non-precision instrument runways other than utility; and
(iii) 10,000 feet at a slope of 50 to 1 with an additional 40,000 feet at a slope of 40 to 1 for all precision instrument runways.
(3) The outer width of an approach surface to an end of a runway will be that width prescribed in this subsection for the most precise approach existing or planned for that runway end.
(e) Transitional surface. These surfaces extend outward and upward at right angles to the runway centerline and the runway centerline extended at a slope of 7 to 1 from the sides of the primary surface and from the sides of the approach surfaces. Transitional surfaces for those portions of the precision approach surface which project through and beyond the limits of the conical surface, extend a distance of 5,000 feet measured horizontally from the edge of the approach surface and at right angles to the runway centerline.


PA,

When you say at approach thrust settings, Vref is thrust 0, which is the SOP setting that you are talking about? There is the FOQUA...

Approach thrust settings allow for rapid engine acceleration to GA thrust ---SOP ususally have a minimum altitude for having the engines spooled...in readiness-it's not a good idea in general to be at idle setting so low down---could mean windshear as one possibility...if speed chasing requires an idle setting or for that matter a very high setting---:\

the designer's assumption is evaluated for the worst case it seems-as would be good enginering practice anyway...but

even with plane at a lower gradient must not the aircraft flying the MA in question maintain -A FAR 25 specified gradient above that OCP? and that in this case [like second climb segment info] the ability to maintain far 25 gradient is implicit in 121/135 operations
hence would not meeting FAR 25 standards automatically qualify for 121 operating procedures...obviously far 25 allows a lower gradient than AEO over the OCP but the MAP OCP allows for 121 operators to perform at the minimum specifies gradients using the nornal IAP MA

I can't see how TERPS and FAR 25 /121 can be so diverged?

[FlightPathOBN]

Approach thrust settings allow for rapid engine acceleration to GA thrust ---SOP ususally have a minimum altitude for having the engines spooled...in readiness-it's not a good idea in general to be at idle setting so low down

Concur. This is why I have issues with the criteria speeds for each class of aircraft for the final approach segment.

the designer's assumption is evaluated for the worst case it seems-as would be good enginering practice anyway
Exactly. in design, if you take the worst case for the missed, the airport alt, highest temp for that airport, max weight, all the bleeds, etc...you use this CG for the EO missed. In my experience, for a twin, this is less than 2.5%. For RNP, this means doing obstacle surveys for the MA corridor.

As you can see, there is little the P77 survey does for the missed..the OCS is 2.5%, so if your climb is at 2.5%, you have no ROC.

I can't see how TERPS and FAR 25 /121 can be so diverged?

Good comment! When you look through and try to design procedures to meet all of the applicable rules, you find many conflicts. The FAA exempts themselves on the rules when designing procedures, but unless you are able to dig into the 8260 forms, you dont know what they have exempted.

[aterpster]

FlightPathOBN:

From your Post #92:

To be clear, that diagram from the other post is from 8260.52, RNP....illustrating one method to avoid an obstacle by raising CG. Getting this approved is virtually impossible.
The FAA the RNP AR procedures designers routinely use climb gradient missed approach procedure, and more than a few to the max of 425 feet per mile. No approval is required because it is permitted by Chapter 4 of 8260.52.

And, from your Post #94:

Good comment! When you look through and try to design procedures to meet all of the applicable rules, you find many conflicts. The FAA exempts themselves on the rules when designing procedures, but unless you are able to dig into the 8260 forms, you dont know what they have exempted.
I peruse IAPs of interest to my organization when they are in coordination. There are occasionally Flight Procedures Standards Waivers, but they are relatively few, and must document an equivalent level of safety (provided for in 8260.3B). I know of no "exemptions," though.

[Pugilistic Animus]

wouldn't then you then be following the OCP gradient exactly that's not a zero ROC:confused:


---the operator has to worry about such things as bleeds as that would be detailed performance data...not applicable to the procedure design...only if the expectaion is similar to flying above the NTOFP...a protection that can't be had generically in the IAP criteria-the operator is responsible for assuring that the airplane meets FAR 25 WAT limits ...and that a minimum gradient can be maintained.
one can not have the same luxuries as the gross vs NTOFP--in determining the minims w/o writing expensive special procedures just for an extremely rare WAT limiting case

[aterpster]

Pugilistic Animus:

You cite FAR 77 surfaces, which are only for the purpose of providing guidance to proponents when they must file under FAR 77. If they fail to do so, the FAA has zero enforcement options. If, however, it is a transmitter tower that requires an FCC license, if the FAA notifies the FCC, then the FCC will not issue a transmitter license.

If it is a building, often the insurance company has the real clout when a proponent either fails to file when required by Part 77, or when the proponent does file but ignores a Determination of Hazard by the FAA.
A proponent with deep pockets can choose to flight a hazard determination under the Part 77 appeals process. That can become quite interesting. It is far more productive for the proponent to enter into negotiations with the regional FAA office to turn a hazard determination into a no hazard determination.

I can't see how TERPS and FAR 25 /121 can be so diverged?
TERPs does not, and cannot, account for OEI surfaces. That would require accounting for the lowest common denominator, which would make TERPs procedures useless for the 99.9% of the time when operations are normal.

[Pugilistic Animus]

I think it's the converse that applies according to the post in this thread part 121 and 25...account for TERPS limitations...:)


we are such nerds...:8:8:8:p

[FlightPathOBN]

The FAA the RNP AR procedures designers routinely use climb gradient missed approach procedure, and more than a few to the max of 425 feet per mile. No approval is required because it is permitted by Chapter 4 of 8260.52.

Yes you can, with 'specials', but I have not seen this with public RNP, at least with 3rd party developers, I have noted specific CG on a few plates, but very few. Without waivers, a design based solely on the published criteria would useless...18 degree max bank angle with winds being my favorite.

by 'exemptions' I did mean wavers...sorry 'bout that.

TERPs does not, and cannot, account for OEI surfaces.

Exactly my point throughout this entire thread.

Operator Training Concerning One Engine Inoperative Contingency Planning For IFR Departure Procedures. (http://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afs/afs400/afs420/acfipg/open/media/Hist_09-02-287.pdf)

FAA has zero enforcement options

Actually, the FAA does have some teeth in these regards..at Palm Springs, several wind turbines were relocated, but yes, you are correct, there is little pro-active enforcement, and with RNP, you are typically outside of the P77 surfaces, so you are on your own.

[Pugilistic Animus]

but the operator had better meet them gradients OEI...:}

[FlightPathOBN]

Terpster,

I see in the FAA guidance, AC 90-101A (http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2090-101A.pdf) the CG that you refer to.

The 'sample' plate they give, shows quite a few waivers, first off, the different RNP levels, RNP 0.15 at the IAF?!?!?, the angle before final segment (they dont want to admit the FMS would do some sortof turn here), missed approach less than RNP 1, DA of 276, but you must make 4000' by WODVU ??...I know this is an example...but I believe this is the plate for KPDX

Some of the public RNP plates are even better...look at the helo RNP for NY,NY..the entire procedure is over the Hudson, including the MAP, but you go 12.9 miles visual to the helipad...

[aterpster]

FlightPathOBN:

The 'sample' plate they give, shows quite a few waivers, first off, the different RNP levels, RNP 0.15 at the IAF?!?!?, the angle before final segment (they dont want to admit the FMS would do some sortof turn here), missed approach less than RNP 1, DA of 276, but you must make 4000' by WODVU ??...I know this is an example...but I believe this is the plate for KPDX.

None of the options shown all those example charts require waivers. They are all provided for in criteria.

What is supposed to require a waiver, but this comes and goes, is when a single-string line of minimums cannot be provided as one of the lines of minimums. This often requires two procedures to a given runway.

Climb gradients are very common in RNP AR IAPs in the western U.S. Some are at the maximum of 425 feet per mile, others are close to that.
I can't speak to a 'Copter RNP AR. Those have been designed by one third-party developer who has the expertise.

[aterpster]

Pugilistic Animus:

but the operator had better meet them gradients OEI...
This is only required of the commercial operators of Part 25 aircraft. If it wasn't required of them, then they wouldn't be providing the highest level of safety expected of them.

[FlightPathOBN]

None of the options shown all those example charts require waivers. They are all provided for in criteria.

Sorry cant agree with that, .52 is very 0.30 specific on approach and RNP 1. there is an option to go to a smaller RNP, but that requires approval from 420...if you are a 3rd party developer.

"The standard MA construction is a continuation of the final approach course. The OEA expands at a 15° splay from the FAS RNP value to a value of 1.0, using a 40:1 OCS slope ratio"

"Dsplay = 7.464(1−RNPFAS )" the standard calculations have some of these values built in such as the RNP approach to RNP 1 missed splay distance.

The 8260.52_V7.4 spreadsheets that the FAA requires us to use has this hard coded as well...for the MA splay, Formula 4-1, the only input is the RNP value for the approach...and the VEB OCS Form 3-17 is hard locked at RNP .3...

[aterpster]

FlightPathOBN:

Sorry cant agree with that, .52 is very 0.30 specific on approach and RNP 1. there is an option to go to a smaller RNP, but that requires approval from 420...if you are a 3rd party developer.

Could be, I don't know. My comments are about RNP AR IAPs developed by the FAA.

Third-party developers design specials I never see. The very few public RNP AR the third-party developers have developed are all quite simple at easy (not obstacle or terrain rich) airports. BDL and SAV come to mind.

[galaxy flyer]

Two questions, Aterpster on KBDL and KSAV

KBDL RNAV (RNP) 15, why is there a wingspan limitation. I'm based there and it escapes me.

KSAV RNAV (RNP) 27, why is there a "RF required" notations, as all the transitions to final seem to be RF legs?

GF

[FlightPathOBN]

The very few public RNP AR the third-party developers have developed are all quite simple at easy (not obstacle or terrain rich) airports. BDL and SAV come to mind.

exactly..I am very familiar with BDL....thats about all the FAA will let a 3rd party do...AND they gave themselves a waiver for the trees on the ridge on approach, but not for 3rd party...

KBDL RNAV (RNP) 15, why is there a wingspan limitation. I'm based there and it escapes me.

The wingspan limit is to keep the design within the parameters of a 737 NG.

KSAV--

http://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afs/afs400/parc/parc_reco/media/2010/101007_RNPBenefitsRecsCoverLetter.pdf

BTW...a 4.3r to a 5.2r is a busted curve....this must not fly very well...

You would have to ask Jepp what the hell they meant, it looks like radio fix, not RF turns...

[aterpster]

g.f.:

KSAV RNAV (RNP) 27, why is there a "RF required" notations, as all the transitions to final seem to be RF legs?

I believe you mean Runway 28. Also, I believe you meant to ask why is there not an RF required notation. The entry from FEXEM does not require RF so instead of the procedure stating "GPS and RF Required" each IAF except for FEXEM should be annotated "RF Required." But, it is a third-party procedure and the FAA folks who develop FAA RNP AR procedures refuse to do any QC on third-party procedures. I forced Ball Note 5 "radar required" for FEXEM and UCETA, because I commented for my organization during coordination. But, I missed the RF notation screw-up. In any case, I'm not Jeppesen's or GE's QC guy. :) I believe this is a Jeppesen developed procedure (wearing their third-party developer hat, not their chart maker hat).

[aterpster]

FlightPathOBN:

BTW...a 4.3r to a 5.2r is a busted curve....this must not fly very well...

Those are distances along the RF legs, not radii. Radii are not shown on the chart. They are on source and usually shown in the FMS legs page.

Source shows the radius for each of those legs to be 3.70 miles:

http://avn.faa.gov/acifp/ndbr/00380RRZ28O-SAV-NDBR/GA_SAV_RNAV(RNP)_Y_RWY28_ORIG_NDBR.pdf

[Zeffy]

KBDL RNAV (RNP) 15, why is there a wingspan limitation. I'm based there and it escapes me.

http://i202.photobucket.com/albums/aa92/zeffy_bucket/BDLRNP15.png

Unlike an ILS, an airplane flying an RNP approach may encounter an RF leg in the final.

The RF leg may require significant bank angle. (Not the case for this approach, but the issue remains applicable.)

The "down wing" on large airplanes can extend below the normal gear height. So appropriate allowances must be made.

Per Appendix 1 in the 8260.52, the assumptions are:

Semi-span for narrow body fixed at 68
Semi-span for wide body fixed at 131

Because the BDL procedure is restricted to Cat C aircraft, the designer also had to note that the approach was designed using narrow-body geometries. (2 X 68' = 136'). :8

Hope you can win at least a few beer-bets with that bit of arcana, gf

"Amaze your friends !"
:ok:

[galaxy flyer]

Thanks, Zeffy, Aterpster, FlightOBN

Aterpster, please check your PM.

GF

[FlightPathOBN]

terpster, you crack me up...

The wingspan limit is to keep the design within the parameters of a 737 NG.
Because the BDL procedure is restricted to Cat C aircraft, the designer also had to note that the approach was designed using narrow-body geometries. (2 X 68' = 136').

History of KBDL:

The FAA used the airport as a certification of the 3rd party developer Naverus. The FAA and Naverus designed procedures simultaneously for the FAA to determine if Naverus would have the same solution. The design parameters were set with a 737NG as the basis for the design, hence the wingspan limit on ClassC...

The FAA design came in with a lower DA because they waivered the canopy height on the hillside to the approach.

BTW..BDL was the foundation for the need to require the precipitous terrain algorithm...

Now that may get you a few beers...

[aterpster]

Zeffy:

Unlike an ILS, an airplane flying an RNP approach may encounter an RF leg in the final.

The RF leg may require significant bank angle. (Not the case for this approach, but the issue remains applicable.)

The "down wing" on large airplanes can extend below the normal gear height. So appropriate allowances must be made.

The wingspan aspect of 8260.52 has been questioned by not a few folks, at least for larger RNP values.

I guess if the procedure is only RNP 0.10 and the FROP is at minimum distance then the large bird's wing could drop below the VEB and in extreme circumstances dig into the dirt in a maxed out obstacle environment. We wouldn't want a 747 doing that and not even (I guess) a 380.:ok:

[FlightPathOBN]

The wingspan aspect of 8260.52 has been questioned by not a few folks

The wingspan has been used, creatively, to create procedures for the 737 capabilities, without the limitations of other aircraft designated as Class C. The 136 leaves out the 757 as an example.

That class designation, with final approach speed of 140kts, no longer has any basis in reality.

Also, with some of the Class C aircraft such as the 757, having bank angle limits of 25 degrees, thus the 18 degree FAA limit, this severely restricts the 737 which can bank limit to 30.

[aterpster]

The wingspan limit is to keep the design within the parameters of a 737 NG.
terpster, you crack me up...

Because the BDL procedure is restricted to Cat C aircraft, the designer also had to note that the approach was designed using narrow-body geometries. (2 X 68' = 136').



History of KBDL:

The FAA used the airport as a certification of the 3rd party developer Naverus. The FAA and Naverus designed procedures simultaneously for the FAA to determine if Naverus would have the same solution. The design parameters were set with a 737NG as the basis for the design, hence the wingspan limit on ClassC...

The FAA design came in with a lower DA because they waivered the canopy height on the hillside to the approach.

BTW..BDL was the foundation for the need to require the precipitous terrain algorithm...

Now that may get you a few beers...

Why did I crack you up? Those aren't my comments. :=

[FlightPathOBN]

Sorry to terpster and Zeffy...

the 'quotes' portion of this thread diso'd on me...

the text and quotes are not related..

you still crack me up....

[aterpster]

As I stated previously, FAA Aero Nav Services, the FAA entity that develops most FAA RNP AR IAPs, will have nothing to do with third-party developed RNP AR IAPs. No review and no QC. Here is the disclaimer on Aero Nav Services National Database Review for the SAV Runway 28 RNP AR IAP. Database review isan important component of the requirement for operators or their authorized designee to validate RNP AR database source.

http://i201.photobucket.com/albums/aa214/aterpster/SAVNDBReview.jpg

[aterpster]

I misspoke previously when I stated that the Jepp chart for SAV RNP Y 28 didn't have the RF leg annotation at the required points. I missed the ball note.

Below I include that chart and the FAA version for comparison. The FAA chart is arguably easier to decipher in this regard.


http://i201.photobucket.com/albums/aa214/aterpster/JeppSAVRNPY28.jpg



http://i201.photobucket.com/albums/aa214/aterpster/SAV28RNPY.jpg

[FlightPathOBN]

As I stated previously, FAA Aero Nav Services, the FAA entity that develops most FAA RNP AR IAPs, will have nothing to do with third-party developed RNP AR IAPs. No review and no QC.

3rd party design get full review from many different parts of the FAA. I designed and submitted PSP, SCC, and parts of BDL from beginning to end with the FAA.
The 8260 forms are required and reviewed, waivers are reviewed, the procedures are required to be sim checked, obstacle validated, and flight validated.

It AFS 420/460 and AVN that deal with procedure design.

"The Flight Procedures Standards Branch is the principal element of the Flight Technologies and Procedures Division for 14 CFR Part 97, non Part 97 terminal instrument procedures, 14 CFR, Part 95 en route instrument procedures, the administration of the flight procedures and airspace program, and the direction, control, management, and program analysis of all instrument flight procedure standards and criteria development programs."

Flight Procedure Implementation and Oversight Branch-Policies & Guidance (http://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afs/afs400/afs460/policies_guidance/)

[aterpster]

FlightPathOBN:

3rd party design get full review from many different parts of the FAA. I designed and submitted PSP, SCC, and parts of BDL from beginning to end with the FAA.

The 8260 forms are required and reviewed, waivers are reviewed, the procedures are required to be sim checked, obstacle validated, and flight validated.

It AFS 420/460 and AVN that deal with procedure design.

I understand that. Nonetheless, my statement is correct. The real QC expertise lies within Aero Nav Services, because they design and QC FAA-developed RNP AR IAPs all the time.

As to ASF, I have no involvement with the third-party process, but I understand AFS-460 has that program.

AFS-420 may provide some ad hoc input, but as your mission statement sets forth, they develop the TERPs standards and maintain the 8260.19 handbook.

I deal with both Aero Nav Services and AFS-420 all the time.:)

The Aero Nav folks have my picture on the wall for dart practice.;)

[FlightPathOBN]

Sorry, but AVN rules for us....

We design and develop instrument flight procedures (IFPs), publish aeronautical charts and digital products for air carrier and general aviation pilots for use throughout the United States and around the world, provide aircraft maintenance and engineering services, operate a fleet of flight inspection aircraft for airborne evaluation of electronic navigational signals and flight validation of ground-based and GPS performanced based IFPs.

Aviation System Standards - AJW-3 (http://www.faa.gov/air_traffic/flight_info/avn/)


I am curious about the SAV plate, was this the eval procedure for Jepp with the FAA? as BDL was with Naverus?

I am with the other guy, why state RF? This is AR, so the users should understand the plate.

Do you know of anyone who has an OpSpec for less than .3RNP. Perhaps Fedex and Alaska, but I dont know of too many carriers that even have an RNP OpSpec, let alone a .15....

[aterpster]

FtlopsOBN:

I am curious about the SAV plate, was this the eval procedure for Jepp with the FAA? as BDL was with Naverus?

I believe so, but I do not know that with certainty.

I am with the other guy, why state RF? This is AR, so the users should understand the plate.

Because a fairly large PARC working group was formed to establish RNP AR charting specifications for the United States. That was one of many specs that came out of several meetings.

Do you know of anyone who has an OpSpec for less than .3RNP. Perhaps Fedex and Alaska, but I dont know of too many carriers that even have an RNP OpSpec, let alone a .15....

With the present fleet of Boeing transports that can do RNP AR, the smallest value that can be approved is 0.11. I am sure at least CAL, Alaska, DAL, and AAL have approval to 0.11. Horizon (Alaska's commuter carrier) can do 0.30, and may be working for lower in aircraft equipped with a single IRU.

Some models of the Gulfstream are approved for RNP 0.10 provided the airframe has the latest mods and the crew has the training, and has completed the required number of practice approaches or approaches to 0.30 minimums. One of the members of our committee works for a G550 operator with 0.10 approval. The Falcon 900EX is either approved for 0.10 or soon will be.

The U.S. operators who fly into Quito are now using two hybrid RNP AR IAPs that require 0.15.

[FlightPathOBN]

Thanks for the info...I havent been keeping up with US operations too much lately.

I am curious about the SAV plate, was this the eval procedure for Jepp with the FAA? as BDL was with Naverus?
This may be why it is denoted in the navdata as it is...

In regards to the charts, I actually like to see the radius on the turn, I feel this may help the crew if there are winds to deal with.

(at least they gave the some decent waypoint names, not like FUGOV MORON)

an kinder FAA...how nice!

There is the EO tracks for Burbank, that was a real interesting approval process...(the controlling obstacle is the monument to aviation)...how is the FAA handling the EO procedures...just making each carrier submit their own for review?

[aterpster]

FlightPathOBN:

In regards to the charts, I actually like to see the radius on the turn, I feel this may help the crew if there are winds to deal with.

I don't see how knowing the radius of an RF leg would help the crew at all with winds. As you know, the wind assumptions required by the 8260.52 are very conservative; so much so SWA has used historical winds at some locations in order to obtain slight smaller radii. With a bit of practice an RF leg is easy to fly, even with a significant wind component. Further, if the RNP value for the final segment is less than 0.30, many operators gain approval based on roll-steering auto-flight or, at least, roll-steering flight director.

Finally, the radius of turn is on the FMS legs page. Most RNP AR crews refer to the legs page more than the chart once the IAP is underway.

(at least they gave the some decent waypoint names, not like FUGOV MORON)

I don't know anything about FUGOV but the fix called MORON was called Morongo for many years, after the Native Americans of the area.


...how is the FAA handling the EO procedures...just making each carrier submit their own for review? I don't know. That is beyond the scope of work I do. When I flew for a major airline and did some ALPA safety work there, I had the impression that no one at the FAA looked at the company's OEI procedures, such as they were. But, that was a long time ago.

[FlightPathOBN]

I don't see how knowing the radius of an RF leg would help the crew at all with winds.

Some of the procedures I design are 400nm long...winds aloft are important. The FAA model considers all winds as a tailwind additive..(ref table 1.3 8260.52) it does not use a wind spiral. Cross winds are an important consideration that is not accounted for in the criteria, and is important at some sites.

FUGOV and MORON are waypoints at PSP.

[Pugilistic Animus]

Great Stuff Aterpster FlightPathOBN :ok::ok::ok:

There is the EO tracks for Burbank, that was a real interesting approval process...(the controlling obstacle is the monument to aviation)...how is the FAA handling the EO procedures...just making each carrier submit their own for review?

ooh can we see:8

Also I've been meaning to post this; but does anyone have a copy the FAA orders regarding " Holding Pattern Criteria"---I've found it once but it since disappeared sorry for being off topic---


Aterpster I too prefer the NACO charts to the Jepps...less visual clutter:)

[FlightPathOBN]

From the source...

7130.3A - Holding Pattern Criteria - Document Information (http://www.faa.gov/regulations_policies/orders_notices/index.cfm/go/document.information/documentID/10408)

Portal of Folded Wings Shrine to Aviation : Reference (The Full Wiki) (http://www.thefullwiki.org/Portal_of_Folded_Wings_Shrine_to_Aviation)

[aterpster]

P.A.:

Also I've been meaning to post this; but does anyone have a copy the FAA orders regarding " Holding Pattern Criteria"---I've found it once but it since disappeared sorry for being off topic---

Download it here:

7130.3A - Holding Pattern Criteria - Document Information (http://www.faa.gov/regulations_policies/orders_notices/index.cfm/go/document.information/documentID/10408)

There is also this policy memo for RNAV holding patterns that modifies pattern selection for RNAV HILPTs:

http://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afs/afs400/afs420/policies_guidance/memo_TILS/media/Interium%20Guidance%20for%20Evaluating%20RNAV%20Holding%20Pa tterns.pdf

Aterpster I too prefer the NACO charts to the Jepps...less visual clutter:)

I meant only in this isolated situation. Jeppesen charts have been a way of life for me. They can be tailored and they cover the world.:)

[A-3TWENTY]

Dear Folks,

When a SID is designed , if no info concerning climb gradient, 3,3% is to be considered. If more climb gradient is required it will published in the plate. The regulators basically , are telling you "to avoid obstacles , you have to comply with it" .EO considerations are left to you.

Suposing that your SID has a climb gradient you can not comply with , your operator must have an EOSID available for the EO case.

Now , about the approach climb performance:

All app plates consider as standard 2,1% for ILS CAT1 and 2.5% for ILS CAT2 and 3.
If , to avoid obstacles , they need you figures above the standard ones , they will state that.

Your operator , has to provide you with one table with the necessary adjustements in case you can not comply with that climb gradient SE.
The same table we have in the FCOM 3.05.35 (airbus) , but including higher climb gradients (in the FCOM`s we only have to 2.1% and 2.5%).I flew in one company which had this table available for some airports with a more demanding approach climb performance.

Some fellows referred the low temperatures. When corrections to the DA have to be made due to low temps, actually we are adjusting your DA to keep the same height at Mapt. So in case of go-around you´ll be complying with very same "vertical profile".

My 2 cents.

A-3TWENTY

[Zeffy]

Suposing that your SID has a climb gradient you can not comply with , your operator must have an EOSID available for the EO case.

The implication that a SID can provide protection for performance losses with one engine inop is not always correct.

SID's do not take into account low, close-in obstacles in the Initial Climb Area. Those obstacles may be a threat to a WAT-limited airplane with one engine inop.

http://i202.photobucket.com/albums/aa92/zeffy_bucket/KHOUObstacles.png


The case of low, close-in obstacles is one of the reasons that paragraph 7 of AC 120-91 (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/list/AC%20120-91/$FILE/AC120-91.pdf) states:

...Further, compliance with TERPS all-engines-operating climb gradient requirements does not necessarily assure that one-engine-inoperative obstacle clearance requirements are met.


Procedure designers also have options to publish ceiling and visibility minimums for the purpose of avoiding obstacles within 3 miles of the departure end of the runway.

http://i202.photobucket.com/albums/aa92/zeffy_bucket/KPOU_TAKEOFF.png


However, the operating rules (14 CFR 121.189 and equivalent) make no exceptions for weather conditions.

Thus, reliance on a SID or published (all engines) Obstacle Departure Procedure may not adequately protect for the loss of an engine during takeoff.

`

[Capn Bloggs]

The irony of it all. Micrometer management of the takeoff situation, with no "requirement" at all to ensure terrain clearance in a Missed Approach apart from the WAT limit. :confused:

[aterpster]

Capn Bloggs:

The irony of it all. Micrometer management of the takeoff situation, with no "requirement" at all to ensure terrain clearance in a Missed Approach apart from the WAT limit. :confused:

1. The certification process dwells extensively on the balanced runway and the takeoff flight path.

2. Every flight has a takeoff. And, often above max landing weight; perhaps well above.

3. Missed approaches occur on a small percentage of flights. If an engine becomes inoperative during the flight, often the IAP with a missed approach performance problem can be avoided.

4. There is no "takeoff" flight path defined in certification for the missed approach flight path.

Related to both the takeoff flight path and the missed approach flight path is the lack of clear, concise guidance on how to get from the end of the takeoff flight path safely into the en route structure, especially in mountainous areas.

[Capn Bloggs]

Procedure designers also have options to publish ceiling and visibility minimums for the purpose of avoiding obstacles within 3 miles of the departure end of the runway.
Do the designers honestly believe that increasing the vis requirement to 1nm (less than the length of a runway) is going to enable a satisfactory visual terrain avoidance manoeuvre after takeoff? In less than 30 seconds, you have to visually identify the obstacle, work out whether or not you are going to hit it, and then manoeuvre laterally to avoid it, all with an engine out?

Aterpster, thanks to this thread, I have a better understanding of what the rules are; I was just pointing out what I consider to be the irony of the Takeoff verses the Missed Approach.

[aterpster]

Capn Bloggs:

Do the designers honestly believe that increasing the vis requirement to 1nm (less than the length of a runway) is going to enable a satisfactory visual terrain avoidance manoeuvre after takeoff? In less than 30 seconds, you have to visually identify the obstacle, work out whether or not you are going to hit it, and then manoeuvre laterally to avoid it, all with an engine out?

First and foremost: the designers are not charged with designing a departure procedure to provide for an engine failure. That is solely the operator's responsibility.

Now, do designers provide a visibility requirement for close-in obstacles that they honest believe will aid in the avoidance of the obstacle? No, they are usually not pilots, and even the few that are have no heavy, or significant line experience. The flight inspection pilots are suppose to be the "check valve" but they are often checking off the numbers on a nice clear day.

Plus, takeoff minimums have a larger political component (and less science) than do landing minimums.

[john_tullamarine]

a satisfactory visual terrain avoidance manoeuvre after takeoff?

My thoughts might be heresy for some of the more skilful folk.

However, my contention is that visual tracking for terrain clearance OEI in a heavy is arrant nonsense. Even in a light twin it's more than a bit tenuous, especially SP.

With the typical deck angles, it just isn't feasible to wing it on the fly.

Furthermore, the climb angles are so shallow (typically) that the human brain has great difficulty figuring whether or not the aircraft is really going up, flying level, or going down .. other than by rigorous attention to the IF scan.

Hence my boring and repetitive comments that the takeoff and miss, OEI, have to be preplanned with detailed attention to intended tracking and obstacle clearance.

[FlightPathOBN]

Thus, reliance on a SID or published (all engines) Obstacle Departure Procedure may not adequately protect for the loss of an engine during takeoff.
Concur, SID are all engine, and will virtually never protect you EO.

Hence my boring and repetitive comments that the takeoff and miss, OEI, have to be preplanned with detailed attention to intended tracking and obstacle clearance.

Exactly. This is why I am really harping on the engine out procedures, and especially, that the criteria missed approach is all engine. A coded engine out assures the crew that the procedure will have the obstacle clearances, turns, and destination already figured out, leaving the crew to aviate, not navigate.

Plus, takeoff minimums have a larger political component (and less science) than do landing minimums.
oh yes!

The flight inspection pilots are suppose to be the "check valve" but they are often checking off the numbers on a nice clear day.

Flight checks are required to be in daylight in non-IFR conditions.

Furthermore, the climb angles are so shallow (typically) that the human brain has great difficulty figuring whether or not the aircraft is really going up, flying level, or going down .. other than by rigorous attention to the IF scan.

Exactly, as I was pointing out, many of the EO missed procedures in AUS have climb rates near 70'/nm for twins, you dont feel like you are pushing away from the dirt. The climb rates dont require a terrain challenged airport to be a problem, and cell towers popping up everywhere...

Thread Comments:

This has been a great discussion from an ops and design perspective. Many times, when training pilots on procedures, there are very few questions.
Discussions like this really help in the training outlines, to explain the nuances of procedures, procedure design, differences, and with the coded procedures, especially EO, why it is important to use them.
I am going to add an entire section on performance engineering, especially EO, so that the operators can see the BCOP, etc data input/ouput, and the parameters that a procedure engineer uses when generating the profiles.

[aterpster]

j.t.:

My thoughts might be heresy for some of the more skilful folk.

However, my contention is that visual tracking for terrain clearance OEI in a heavy is arrant nonsense. Even in a light twin it's more than a bit tenuous, especially SP.

With the typical deck angles, it just isn't feasible to wing it on the fly.

Furthermore, the climb angles are so shallow (typically) that the human brain has great difficulty figuring whether or not the aircraft is really going up, flying level, or going down .. other than by rigorous attention to the IF scan.

Hence my boring and repetitive comments that the takeoff and miss, OEI, have to be preplanned with detailed attention to intended tracking and obstacle clearance.

Spot on. If a pilot is "winging it" in day VFR conditions, he might just pick the spot where impact will happen a bit later rather than sooner.

[FlightPathOBN]

he might just pick the spot where impact will happen a bit later rather than sooner.

Have you seen the Ron White skit in these regards...

Flying with engine problems

[Capn Bloggs]

This is why I am really harping on the engine out procedures. A coded engine out assures the crew that the procedure will have the obstacle clearances, turns, and destination already figured out, leaving the crew to aviate, not navigate.
Repeating my earlier question, what terrain clearance do you provide in the missed approach procedures you design, or do you put the "required" gradient on the chart?

[Pugilistic Animus]

FlightPathOBN---very, very hilarious for this thread!!!:}:}:}

[FlightPathOBN]

what terrain clearance do you provide in the missed approach procedures you design, or do you put the "required" gradient on the chart?

The charts that I provide are certainly custom. They are RNP transition to a GBAS final, or just RNP. With the custom, all is coded, the missed approach and EO missed are coded, and therefore the alignment is reflected on the chart, if allowed by the regulator. SID and EO departures are shown on different plates.

Typically, the charts have a set DA/MDA, required gradients are not shown on the chart, as the entire procedure is coded in, and the procedures are custom designed for the aircraft.
The approach, same as the public criteria, is based on the coldest day of that airport (ie lowest effective GPA) with the required ROC.
The missed is based on the hottest day, max landing weight based on the elev/performance, etc to get the min net per the criteria.

Now, I do have charts with performance DA's. This is a specialty of my firm, operations based navigation, hence the name.

These procedures are based on the missed AND the required gradient is provided. The approach is still the same basis as above, but the missed is based on a real time performance for the aircraft/airport. So if the operator, based on weight/temp/etc determines the climb grade, at 6.5%, this is the DA/vis required. These CG range from the criteria 2.5% up to 12%. This design does not include any EO missed, that is separate.

For the obstacle clearance, where to begin...
Depends on several factors, rad alt, baro, head loss, and momentary descent for the particular aircraft, latency, exposure time, prox and regulators.

For all engine, the respective criteria clearances are used. This somewhat assures that the state is maintaining the obstacle database, and from a liability perspective, I consider this the BARE minimum.

For EO, I try to use the criteria obstacle surfaces, but can fall back to the 35 foot min with turn additives, etc. Turn additives and winds are significant factors in obstacle clearances. There are also mountainous and precipitous terrain additives

Another big factor is the respective aircraft and the prox warnings...some regulators allow for a prox warning on EO, others do not. a Smiths/Honeywell/thales/etc all have different settings for the warning, so that is really a wildcard in the design.

So...long story short, there is a combination of many factors when looking at a 'clearance' in the design. Clearances can be real of assumed additives.

The coded procedure has met the approval of all of the applicable minimums and worst case scenario given.

[Capn Bloggs]

Interesting! Thanks.

But, if
required gradients are not shown on the chart, as the entire procedure is coded in, and the procedures are custom designed for the aircraft.
How does the crew know what weight they can do the approach at and still successfully complete an EO Missed Approach up to the MSA/LSALT?

[FlightPathOBN]

in some respects 2 separate issues.

In PBN procedures...or in airport procedures EO are NOT accounted for. EO is completely up to the operator. If you want to use the public plates, you have to limit you weights, based on CG to get the 2.5%. As temps rise, you limits weights...

In a coded procedure, If you select the EO, you know that all of the mins have been accounted for.

If one looks at the performance with temps, this really limits MTOW. You an still get 2.5%, but as temps rise MTOW gets you to the paint on the aircraft.

To open up departures, a custom EO is designed, with temps and obstacles, to show the regulators, one can navigate an EO with extended weights.

Given climate change, either you will be sitting on the ground more often, be severely weight limited, or you will have a custom EO design.

[Pugilistic Animus]

Given climate change, either you will be sitting on the ground more often, be severely weight limited, or you will have a custom EO design.


I was just recently speaking to my expert contact on climate change, Ms Tooey...currently Mrs Hollaway,....becuase it's all a bunch of Horse hooey...:}
YouTube - The Honeymooners-Hero Part 2

skip to 8:30...:}:}:}

seriously interesting topic...but I've put to rest climate change on JB...as scientific nonsense...and if you'd take note of my location...;)

[FlightPathOBN]

hahaha...

Climate change is real...its just not man-made....

you have to figure how oil is formed, millions of years of warm, tropical temperatures, vegetation is compressed to form the oil....

where are some of the biggest reserves? the North Slope in Alaska.....

[Pugilistic Animus]

FPOBN

Only major changes in earth's orbital mechanics can account for major climate change...i.e wobble and tilt...incidentally CO2 levels rise during warm periods because of higher rates of cellular respiration and greater biological productivity...:8

come join us...

http://www.pprune.org/jet-blast/283315-climate-change-debate-192.html

:E

:)

[Capn Bloggs]

EO is completely up to the operator. If you want to use the public plates, you have to limit you weights, based on CG to get the 2.5%. As temps rise, you limits weights...

This goes to the heart of what I have been asking.

So if I use one of the "public" plates, then I just need to achieve 2.5%? I assume that will give me 35ft obstacle clearance up to the MSA. I can cope with that.

In a coded procedure, If you select the EO, you know that all of the mins have been accounted for.
How do you present the gradient info to the operator so that they can work out the maximum weights for a procedure, or do you crunch the performance numbers for an EO and provide that data to the operator?

[FlightPathOBN]

Cap,

I wish it was that simple...

So if I use one of the "public" plates, then I just need to achieve 2.5%? I assume that will give me 35ft obstacle clearance up to the MSA.

The 35 feet is not based on a 2.5% CG, the 35 feet is based on SID, the min obstacle clearance plane is based starting at the end of the runway, sloping up, with a min CG gradient of 3.3% The aircraft is assumed, for criteria calculations, to be at least 35 feet above the end of the runway. This 'surface' is what one needs to clear.

http://www.tc.gc.ca/media/images/ca-opssvs/700-016-flightpath.gif

If, and IF, you have a 2.5% CG with EO Missed Approach, it may work, but you have to look at all of the factors. (just dont turn for a while)

How do you present the gradient info to the operator so that they can work out the maximum weights for a procedure, or do you crunch the performance numbers for an EO and provide that data to the operator?

With a coded procedure, it is a combination of worst case factors...highest temps for the airport, bleeds, etc on performance...this generates a max weight. We have to remember that the procedure for the public criteria is based on an ISA delta. So we try to design a path, that extends the weight limits aside from the public procedure.

Designs are good for a certain temperature. You may have an airport where the ISA D is always high, and you will always be weight limited for that airport. This is something that the people back in the office are always calculating the load diagrams for that aircraft. (you think ATC has it tough, look at what these people do)
Your aircraft should not have been loaded higher, using the the real-time temp at the destination, than all of these factors.
I am not sure of the SOP on EO, but many airlines contract EO procedures, just so they can extend weight limitations past the required 2.5% CG.

[Pugilistic Animus]

legal requirements for the TO case mandate that a NTOFP...that clears all obstacles vertically by at least 35' and 200' horizontally within the airport boundaries...and 300' horizontally after passing the boundaries....The NTOFP is the actual flight path reduced by 0.8, 0.9,an 1.0...for twins, trijets and quads, respectively until a height of 1500' above the airport elevation,...after that it is a performance engineer's* art...:)

this thread needs a little Krupa

YouTube - Gene Krupa with Stan Freeman at piano 1950's TV













* J_T, O_S and Mutt

[FlightPathOBN]

ummmm...are you explaining the profile:)

an engine out missed profile looks nothing like this...

there are also missed approaches that turn before the end of the runway...

[Pugilistic Animus]

Since the beginning of this thread, I've not yet figured out whether this thread is about departures or approaches...:}:ouch:

[FlightPathOBN]

its 2 (click) 2 (click) 2 threads in one....

at our company we are required to fly the EOSID in case SE missed approach at certain airports and OAT.

The thread has tried to illustrate the differences between EOSID and EO missed.

How are we doing?:ugh: :ok: :mad: :{

[aterpster]

All engine operating SIDs, ODP, and missed approaches assume a constant gradient; i.e, no level segment for acceleration.

Perhaps that is understood here, but I am not so sure.

In the United States, if the constant slope for the SID, ODP, or missed approach is greater than 200 feet per mile, then a 24% additive is factored in to compensate for more likely performance errors.

Having said that, the FAA is seriously considering doing away with the 24% additive for two reasons: 1. The smart, conservative guy who sold the concept has been retired for some time now. 2. The airline lobby doesn't like the additive because it can affect payload (read: revenue).

[4dogs]

Capn Bloggs,

Forgot to mention (busy with the Senate) that a handy page for you to contemplate is page 4.7 of the Performance Engineers Manual (Andy has it!) which gives you the Gross GA Climb Gradient (OEI, A/C Off, Gear Up, F18 and with icing corrections) as a function of airport Pressure Altitude and Ambient Temp, weight and airspeed. :cool: :cool: Unfortunately, it is in pounds...:eek:

Stay Alive,

[Capn Bloggs]

Thanks Dogs. I'll check it out.