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All OEI and DEP are custom criteria, which is approved by exceptions by the host Country.
While these procedures are in use in many Countries, even some in S America, Africa, and Russia, there is no individual Country which has developed the public criteria in these regards. There is also no criteria for an RNP-AR missed approach, AE or OE. If you look at the coding for the procedures, there is the code for APP, which goes to the runway endpoint. Then the coding goes to MISS. In the FMS, on appraoch, the missed is armed. Because of the coding, only one missed is available. When you see the chart, there is a common segment, then the OEI continues. Therefore, when OEI is shown, the entire missed is designed for OEI. |
Pulling out my crystal ball....900 posts later...this thread will terminate with...'so who plans out their whole trip using single engine performance limitations, as you should?'
My assumption is that paid dispatchers at the airlines, give you this information based on weight, fuel, ect.... Right...? |
Originally Posted by JammedStab
FlyboyIke...I very much believe the main intent of the first sentence of your last post as a review of your posts shows that they add nothing useful to this thread. I am not here to tell how far I want operators to "to look". I am asking and have been asking from the beginning the question of How Far Do they Look? Quite a simple question for most to understand.
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It appears that I have discovered that there may be no regulation covering this subject.
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Originally Posted by JammedStab
there may be no regulation covering this subject
Sec. 25.111 Takeoff path. (a) The takeoff path extends from a standing start to a point in the takeoff at which the airplane is 1,500 feet above the takeoff surface, or at which the transition from the takeoff to the en route configuration is completed and VFTO is reached, whichever point is higher. In addition-- Sec. 121.189 Airplanes: Turbine engine powered: Takeoff limitations. (d) No person operating a turbine engine powered transport category airplane may take off that airplane at a weight greater than that listed in the Airplane Flight Manual-- (1) In the case of an airplane certificated after August 26, 1957, but before October 1, 1958 (SR422), that allows a takeoff path that clears all obstacles either by at least (35+0.01D) feet vertically (D is the distance along the intended flight path from the end of the runway in feet), or by at least 200 feet horizontally within the airport boundaries and by at least 300 feet horizontally after passing the boundaries; or (2) In the case of an airplane certificated after September 30, 1958 (SR 422A, 422B), that allows a net takeoff flight path that clears all obstacles either by a height of at least 35 feet vertically, or by at least 200 feet horizontally within the airport boundaries and by at least 300 feet horizontally after passing the boundaries. 1. PURPOSE. This advisory circular (AC) describes acceptable methods and guidelines for developing takeoff and initial climb-out airport obstacle analyses and in-flight procedures to comply with the intent of the regulatory requirements of Title 14 of the Code of Federal Regulations (...) relating to turbine engine powered airplanes operated under parts 121 and 135. The methods and guide lines presented in this AC are neither mandatory nor the only acceptable methods for ensuring compliance with the regulatory sections. Operators may use other methods if those methods are shown to provide the necessary level of safety and are acceptable to the Federal Aviation Administration (FAA). (...). 9. TERMINATION OF TAKEOFF SEGMENT. a. For the purpose of the takeoff obstacle clearance analysis, the end of the takeoff flightpath is considered to occur when: (1) The airplane has reached the minimum crossing altitude (MCA) at a fix or the minimum en route altitude (MEA) for a route to the intended destination; (2) The airplane is able to comply with en route obstacle clearance requirements (§§ 121.191, 121.193, 135.381, and 135.383); or (3) The airplane has reached the minimum vectoring altitude, or a fix and altitude from which an approach may be initiated, if the operator’s emergency procedure calls for an immediate return to the departure airport or a diversion to the departure alternate in the event of an engine failure during takeoff. b. When determining the limiting takeoff weight, the obstacle analysis should be carried out to the end of the takeoff segment as defined in paragraph 9a above. Operators should note that the end of the takeoff segment is determined by the airplane’s gross flightpath, but the obstacle analyses must use the net flightpath data. c. In the event that the airplane cannot return to and land at the departure airport, the takeoff flightpath should join a suitable en route path to the planned destination or to another suitable airport. It may be necessary to address extended times and alternate fuel requirements when climbing in a holding pattern with reduced climb gradients associated with one-engine-inoperative turns. |
Originally Posted by JammedStab
Once again, a totally useless post that adds nothing to the thread similar to what a quick search shows for virtually all your posts. I asked on this thread because there are some very knowledgeable people on this forum who I would think would know the answer, and speak English as a first language clearly as compared to engineering people where I work. It appears that I have discovered that there may be no regulation covering this subject. Useful replies appreciated. Similarly, if there's no regulation, where do you go from here? Do you stop flying or at least stop flying out of anywhere there's any granite or what? |
Hazelnuts has added some very useful info. Concerning an engine out turn, it appears that it is not a set distance to always analyze off the end of the runway but varies from runway to runway and depends on terrain and I suppose climb capability of the aircraft on that particular flight.
So nice to have useful information provided, Thanks |
I guess it depends on the company. In our company they look at the obstacles within the MSA-sector.
If our EO procedures says straight ahead, it means you will always reach MSA before the end of the MSA sector (25NM). If the above is not possible, our engine out procedure will include turns to remain within the MSA-sector and ends in a holding where we can climb to the MSA. There are exceptions to deal with airports like INN but this requires training prior to operating in those airports. I like this procedure as it is always the same: Do the Engine failure procedure climb to MSA |
I like this procedure as it is always the same
Having flown for an operator with a similar philosophy, I concur regarding the usefulness of the standardisation - (a) super simple runways - a standard simple recovery according to the operator's preferences - SOP preflight review and easily flown from memory (b) modest terrain/airspace problems without any significant problems - relatively simple standard recovery - simple preflight review and flown without any problem (c) nasty places - detailed escape - detailed preflight review and one (or both pilots) has the procedure document to hand for the departure. |
If our EO procedures says straight ahead, it means you will always reach MSA before the end of the MSA sector (25NM). If the above is not possible, our engine out procedure will include turns to remain within the MSA-sector and ends in a holding where we can climb to the MSA. |
BOAC,
Unfortunately, just the opposite is true. The agencies usually prevent publication of EO tracks other than straight ahead until 1500 because of the outcry from the general public. Think the public complains about noise, just wait until you show a track over their home where an engine has failed.... (one a side note, there are some missed procedures that are straight ahead, but if you are EO, you begin a turn at 400' before the end of the runway) |
Originally Posted by JammedStab
As usual the expected useless post from someone who appears to incapable of adding anything useful to this forum. Try the Jetblast forum. Hazelnuts has added some very useful info. Concerning an engine out turn, it appears that it is not a set distance to always analyze off the end of the runway but varies from runway to runway and depends on terrain and I suppose climb capability of the aircraft on that particular flight. So nice to have useful information provided, Thanks |
On a note of curiousity, when you are EO, how do you adjust your DA/MDA to account?
I am sure that all of you realize that if you go EO at the DA/MAP, you had better just suck it up and land... |
That's a good question, underfire. At my airline there is one aircraft type (Q400) that goes into Eagle County Airport (EGE). Their 10-7 pages specifically instruct them that should they lose an engine anywhere outside of the MAP they are to go elsewhere, unless they have a time-critical failure (uncontrollable engine fire). Of course, how one is to decide, say 2 mi outside of the MAP if something is time-critical or not is not immediately clear. Furthermore, the MDA is 8330'. The missed approach procedure is to turn right, join the SXW 001 radial and track it 24nm to JESIE intersection. Now, the terrain along that radial in the vicinity of the airport is 8,000-10,000', so even EO they would likely clear the terrain, but would not be within legal requirements. I suppose that would be where emergency authority of the PIC would come into play. Do what you have to do, 14 CFR Part 121 be damned, if the situation is dire enough.
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I used the Q400 and EGE as one example, I'm sure there are others.
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Flyboyike....much improved.
Underfire....the question was actually referring specifically for takeoff procedures. Consideration for EO on a missed approach would be covered by reducing weight if the requirements can't be met. As well, I find it difficult to believe that a takeoff EO procedure would not be made somewhere due to noise issues as the routing in reality, never gets used. Maybe once every few years if that frequently. |
The tread was initially indeed about takeoff terrain clearance.
An EO for an approach requires a different set of performance criteria, notable the Missed Approach Climb Gradient requirement and the Approach Climb Gradient requirement. Both are described in subsequent areas of legislation (JAA/FAA) regarding aircraft performance and can be found/quoted here if needed by others. In simple terms, an airport may instruct aircraft outside a MAP to execute the missed approach procedure if from the MAP any aircraft requires the minimum legal gradients required to fly the defined missed approach procedure, as these are defined and each aircraft is certified to be able to achieve them, this would be safest option in general. Think of the alternative, an aircraft proceeds beyond the MAP and then executes a missed approach for whichever reason and cannot achieve terrain clearance due to being incapable to achieve the required climb gradients... Pilots are to ensure that missed approach climb gradients and approach climb gradients can be met before proceeding on an approach. Some airport define different minima based on an aircraft's achievable climb gradient, always measured from the MAP, thus achieving the use of lower operational minima if you can achieve e.g. 4.0% instead of 2.5%, raising your chances of completing a successful approach, especially in non CAVOK conditions. This can be a very useful feature if the aircraft on the actual flight is light enough and thus be able to use lower operational minima. |
jammed, sky...
It seems most places, the engine out procedure is to fly runway heading(track) as the engineers have analyzed the surrounding terrain for obstacle clearance. But how far out are they required to analyze. |
the engine out procedure is to fly runway heading
I think that the various previous posts have indicated that the original statement is not quite right - (a) Type As and the like (generally, but not invariably) are straight out but they meet airport requirements, not operational performance (b) Such charts provide some terrain information in a specific area but not information regarding the match of a specific Type to that terrain - that's a matter for the operator to figure out as the engineers have analyzed the surrounding terrain for obstacle clear Generally, this statement is not reasonable Not sure how the original question was specific to takeoff Most of us had presumed that to be the case. However, it really doesn't matter - the ground will kill you every bit as dead during the takeoff or the missed approach so there is merit in considering both. Logically, the takeoff is the more pertinent as every flight involves one whereas the miss involves much reduced frequency. An EO for an approach requires a different set of performance criteria Not quite. Approach and Landing Climb requirements are WAT matters and have naught to do, necessarily, with terrain clearance. Any specified missed approach gradient requirements generally are regulatory and related to procedures design rather than EO escape. More particularly, none generally has any interest in the clean up phase. Rationally, the only practical way to address the missed approach terrain clearance is by adopting an implementation of the takeoff data. While this presents some interesting bits, it is generally not a major difficulty, especially with the more reliable tracking information the black boxes can now provide. |
Original post modified to make clear it is about takeoffs.
Runway track is what is done for most runways after an engine failure at my company. Heading Select and compensate for wind. |
Originally Posted by JammedStab
Runway track is what is done for most runways after an engine failure at my company. Heading Select and compensate for wind.
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Just to make sure I'm on the right line
Let’s say you had a climbing CAS of 90kts with a 15kt headwind, where your pressure height is 4,000’ and temperature is 12C, how many feet per minute (FPM) do you have to achieve to ensure obstacle clearance using 6% gradient? Using a flight computer, enter PH 4,000, Temp 12 and CAS 90. TAS = 86kts Now deduct the headwind: 86 - 15 = 71kts ground speed (GS) Using the rule of thumb GS / FPM = Climb gradient (in %) 6 x 71 = 426FPM To check the answer is correct (assuming slight error in rule of thumb), let’s work it the long way. 71kts = 71 x 6076 (feet in NM) / 60 (minutes is hour) = 7190 FPM (horizontally) 7190 x 0.06 (gradient) = 431FPM Copy copy? |
Originally Posted by JammedStab
(Post 8063051)
In regards to a takeoff, it seems most places, the engine out procedure is to fly runway heading(track) as the engineers have analyzed the surrounding terrain for obstacle clearance. But how far out are they required to analyze.
If someone decided to take a really long time with all their procedures and continue straight out, they could go quite far. There are some locations with distant mountains as we all know. What criteria is used to provide obstruction clearance during departure? The 40:1 obstacle identification surface (OIS) begins at the departure end of runway (DER) and slopes upward at 152 FPNM until reaching the minimum IFR altitude or entering the en route structure. This assessment area is limited to 25 NM from the airport in non-mountainous areas and 46 NM in designated mountainous areas. Beyond this distance, the pilot is responsible for obstacle clearance if not operating on a published route, if below (having not reached) the MEA or MOCA of a published route, or an ATC assigned altitude. http://tfmlearning.fly.faa.gov/publi...5/aim0502.html I wonder what it is for engine out procedures? |
Most charted perf data ends at 30nm. Here’s the FAA AC, but it doesn’t specify a limiting distance.
https://www.faa.gov/documentLibrary/...r/AC120-91.pdf |
Thread unlocked at OP's request.
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Here is a document with page highlighted explaining how far there is an analysis for terrain after which point, there could be a tall mountain...like Calgary or Denver don't go straight out forever. Look at Fig. 5-2-1
https://books.google.ca/books?id=x8j...0miles&f=false or google faa ocs 25/46 miles to get to the exact page on the appropriate link provided. (Note: The AIM can be linked somewhat more easily at https://www.faa.gov/air_traffic/publ.../media/aim.pdf The book reference is at page 5.2.7 - JT) |
Just read Post No. 8
We are paid to take care of things and given a manual to assist us but not handicap us. 25 yrs of doing this with no violations, write ups by anybody and no scraped metal worked for me 25 years of trouble free operations means SFA. It means you have just had good fortune where your doubtless superior airmanship was not needed:ok: |
Originally Posted by JammedStab
(Post 10012321)
Here is a document with page highlighted explaining how far there is an analysis for terrain after which point, there could be a tall mountain...like Calgary or Denver don't go straight out forever.
or google faa ocs 25/46 miles to get to the exact page on the appropriate link provided. The assumption: with all engines operating you will be level at a legal IFR altitude within those distances. With OEI it becomes the operator's responsibility to assess the takeoff and en route-climb flight path. At a places such as Calgary or Denver the operator's performance department needs to design OEI routes that don't go straight-out into high terrain.. |
Thanks, but at what distance should they become concerned and make a turn? Sounds like there is no written rule.
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at what distance should they become concerned and make a turn?
Depends on the rocky bits and pieces. Can't reasonably be done on the fly (unless the local terrain be quite benign) but, rather, needs to be done back in the office. Hence the usual deal that the operator gets the work done and schedules any requirements for crew use. |
I guess the final answer to the original question will be....it varies by airline.
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This is entirely correct...
U.S. TERPS is only for all engines operating. In non-mountainous areas the IFR obstacle departure procedure (ODP) is assessed out to 25 miles. In regulatory Designated Mountainous Areas (DMAs) the assessment is to 46 miles. If a 40:1 performance surface cannot be maintained in all directions, then a route ODP must be developed for publication. The assumption: with all engines operating you will be level at a legal IFR altitude within those distances. With OEI it becomes the operator's responsibility to assess the takeoff and en route-climb flight path. At a places such as Calgary or Denver the operator's performance department needs to design OEI routes that don't go straight-out into high terrain.. The ONLY answer is that is varies very specifically by aircraft. Performance in a turn OEI is usually far less that anyone anticipates, especially when it is warm. |
There is NO criteria for EO. NONE.
Not absolutely correct. The normal take off weight limits cover WAT requirements for climb OEI. However, when it comes to terrain clearance, you are correct .. it's up to the operator/pilot to make sure that the data has been acquired and the sums done to establish a suitable maximum weight for the day to ensure that, at the very least, the minimum terrain clearances for the net flight path are met. The ONLY answer is that is varies very specifically by aircraft. To some extent, the numbers will have some similarity for twins, triples, and quads as the WAT requirements vary with the number of engines. |
Here’s what the FAA puts out:
https://www.faa.gov/documentLibrary/...r/AC120-91.pdf Under fire. Not entirely true, this AC referenced above is not regulatory ( I believe) but is the guidance used by most operators or perf engineers. |
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