Performance / obstacle clearance

[camps]

In our manuals it says that in case of an engine failure :our performance calculations will take into account all obstacles within 600 meters of either side of the runway extended centreline.
Our manuals also state that for the Sim check we need to fly headings/tracks within the tolerance limits of +\- 10 degrees for single engine.
On a wide body jet if you deviate +\- 10 degreee you will not stay within the 600M "protected area " for long !
I know that the limitations -/+ 10 degrees are for skill test/Check and the obstacle clearance limits of 600 M are for the Pan Ops regulatory but aren't they suppose to compliment each other ?

[FlightDetent]

Not to mention that many a present day L-NAV systems struggle to keep a magenta line within 0.3 NM if conditions are less than ideal.

Hopefully your obstacle / escape route specialist allowed for more error than the regulatory 600 m. Anybody ready to calculate how wide is 1 deg angular of a VOR-radial, let's say, at 5 miles out?

[GearDown&Locked]

0.087269 miles :}

[aterpster]

Fortunately, most Part 121 operators voluntarily used AC 120-91, "Airport Obstacle Analysis."

https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/22479

[camps]

I forgot to mention that our aircrafts are old 1984 classics WITHOUT GPS - we are only RNAV 1 compliment !
According to my calculations if you are very heavy and it's a hot day it will take you about 10 NM to climb to 1500' AAL. According to my calculations ( using TANgent ) you need to ensure that you track with an accuracy of 1.8 degrees to ensure you do not exceeed the 600meters wide protected area for the 10 NM climb to 1500' ! Am I correct ?

[aterpster]

camps:

Back in the 1980s we challenged our company's performance assumption. An honest VP agreed to provide the pilot's union with performance data for OEI on Runway 25 at KLAS. We picked the temperature that would just permit a MGTOW for the 727-200 with the 14,500 thrust engines. It took 31 miles to reach 1,500.

[megan]

It took 31 miles to reach 1,500:eek: And here's me thinking you guys could leap tall buildings with a single bound. :eek:

[john_tullamarine]

According to my calculations if you are very heavy and it's a hot day it will take you about 10 NM to climb to 1500' AAL

VERY optimistic ...

MGTOW for the 727-200 with the 14,500 thrust engines. It took 31 miles to reach 1,500.

I have a relevant AFM in the files somewhere but I don't think I'll go searching. This is a bit more realistic. Now, if you go to the twins, where things are abysmally worse .. it can be a LOT more .... DC9, for instance, with a long third segment .. could take 50-odd nm. This is why we continually keep pushing the "don't try to wing the obstacle clearance visually on the fly ..".

And here's me thinking you guys could leap tall buildings with a single bound.

.. that's a skill reserved for you flingwing folks ..

[aterpster]

J.T.:
This is why we continually keep pushing the "don't try to wing the obstacle clearance visually on the fly ..".

Well, if the crew does that on a nice clear day, they may get a spectacular view of the forthcoming point of impact.

[megan]

.. that's a skill reserved for you flingwing folks ..We don't even get a mention John.

The Airline Transport Rated Pilot

Leaps tall buildings in a single bound
Is more powerful than Concorde
Is faster than a speeding bullet
Walks on water
And discusses policy with God.

The Multi Engine Rated Pilot

Leaps short buildings in a single bound
Is more powerful than a VC10
Is as fast as a speeding bullet
Walks on water on a calm day
And talks to God.

The Instrument Rated Pilot

Leaps short buildings with a running start and a favourable wind
Is almost as powerful as a 1-11
Nearly as fast as a speeding bullet
Walks on the water of a deep puddle
And talks to God, if specially requested.

The Commercial Rated Pilot

Leaves nail scratch marks at the top when trying to leap short buildings
loses a tug of war with a 152
Can fire a speeding bullet
Swims well
And is occasionally addressed by God.

The Private Pilot

Barely clears a scout camp tent
Is run over by a single engine aircraft
Sometimes recognizes a speeding bullet
Can dog paddle
And talks to animals.

The Soloed Student Pilot

Runs into buildings
Recognizes a Cessna 152 twice out of three times
Has never seen a speeding bullet
Can stay afloat under instruction
And talks to the wall.

The Non-Soloed Student Pilot

Trips over door sills entering buildings
Says "gosh, look at the aeroplanes" a lot
Doesn't know what a speeding bullet is
Only stands in the shallow end
And mumbles to himself.

The Aircraft Engineer - that's you John

Lifts buidings and walks under them
Kicks aircraft out of hangar
Catches speeding bullets with his teeth and chews them
Freezes water with a single glance
And talks to everybody
THE AIRCRAFT ENGINEER IS GOD

I was actually thinking 727 performance in my post, didn't realise it could be so dismal.

[camps]

Sorry guys I should have mentioned the type of aircraft : it's the 767 with the old vintage A1 engines

[john_tullamarine]

they may get a spectacular view of the forthcoming point of impact.

Granted ...

We don't even get a mention

Hadn't seen that particular version previously .. love it.

it's the 767 with the old vintage A1 engines

Long time since I looked at 767 performance so the memory is a tad scratchy. If you have an AFM, perhaps you could redo the sums and see what the story might be ? Twins don't go all that well at WAT limited weights.

[RAT 5]

Megan: It's been a while since I heard/read that old soliloquy. Love the dreams & wishes.

[camps]

Would appreciate if anyone would shed some light on how are we are suppose to keep that aircraft within the allocated protected area ( 600M left and right of the runway centre line ) during the single Eng climb ? Our HSI is not calibrated / scaled in 100s of meters ? The minimum range setting is 10NM . We also don't have GPS :(

[Pugilistic Animus]

Under 14CFR 121 obstacles must be cleared vertically by 35' or 200' horizontally within the airport boundaries and at least 300' horizontally after passing the boundaries

[Willie Everlearn]

camp
I think you're over thinking this.
Most 767s will depart on a runway analysis that accounts for obstacles in the departure. If there is a special engine out procedure it's usually stated on the runway analysis as well. They usually cover PANS-OPS or TERPS.
If you lose one on takeoff, fly the Boeing profile, clean up and climb to a safe altitude (refer to the runway analysis, SID, or mark 1 eyeball)
Also, on one engine you're likely a pan pan or a mayday so all bets are off. The regulator says do what you need to do. Anyone taking measurements in this circumstance can get stuffed. Unless you can't control your heading and yaw manually within reasonable tolerances. If you can't, center-in-command, heading mode. LNAV, VNAV works too.

[john_tullamarine]

shed some light on how are we are suppose to keep that aircraft within the allocated protected area

That comes under the title of training and proficiency which comes down to sim practice .. if you are fortunate enough to have an employer who puts dollars into extra training in the box.

Forget the eyeball .. gradients are too small to estimate and, with the body angles, how do you see over the nose in any case ?

Other boxes can be useful .. eg, backcourse LLZ tracking (a very useful sim training exercise to get the stick and rudder skills up ... try a min weight, aft CG, failure during the rotation with a requirement to so track) ... and, these days, preprogrammed FMS escapes may be useful.

I think you're over thinking this.

I don't think so at all. There be dragons outside the splays

fly the Boeing profile,

However, the Boeing profile doesn't put you in the middle of the splay, that's a pilot task and responsibility.

Anyone taking measurements in this circumstance can get stuffed.

Of course they can.

However, the aforementioned dragons can be right on the splays. It is not at all uncommon to run the splay up the side of the mountain so that the sums work out. If Captain Speaking allows his/her aeroplane to diverge too much then it's all over, Red Rover.

[aterpster]

J.T.

That comes under the title of training and proficiency which comes down to sim practice .. if you are fortunate enough to have an employer who puts dollars into extra training in the box.

I believe most U.S. Part 121 carriers' Performance and Engineering departments use the dimensions in AC 120-91 (Post #4), rather than the lateral limits of 121.189.

I know that APG uses the lateral areas of AC 120-91.

[john_tullamarine]

There exist various standards for splays but the skill matter remains critically important.

Many years ago, a local Regulatory certification/ops engineer (Ian C, if my recollection be correct) organised for a simulator study to be run with the two major domestics over here. Typically, a minimal briefing on the exercises he wasn't interested in .. and, I suspect, no mention of any engine failures. I note that Ian, for whatever reason, had missed out on getting into the airlines as a pilot ... but he was certainly a sufficiently experienced flyer to understand the significance of the study.

In amongst the distraction exercises, V1 failures were introduced and the subsequent flight paths tracked. I still have a report on the exercise tucked away somewheres and the graphed tracks are interesting, to say the least.

I don't recall the sample size but it was more than reasonable for drawing some inferences. While the great majority were fine, there was a fairly small number which indicated that the pilot flying was away doing something else at the time or, for whatever reason, just having a bad day ... it wouldn't have mattered what the splays were ..

Now this was with two airlines (in a commercially protected environment) both of which indulged in significant "over training" compared to what we see these days ...

Obviously there was some post study navel gazing to the airlines' benefit ...

... food for thought in our current minimalist training environments ?

[aterpster]

j.t.:

There exist various standards for splays but the skill matter remains critically important.

Even TERPs and PANS-OPs normal operations criteria cannot protect for errant blunders.

Having said that, the more modern birds that automatically input the correct amount of rudder for an engine failure on takeoff, and which are capable of both RF legs and RNP accuracy, integrity, and continuity as low as RNP 0.10, could have RNAV/RNP OEI flight-paths that could eliminate the need for splays. Just linear step-up in 2xRNP containment areas, similar to what is done today for RNP AR missed approach procedures.

[john_tullamarine]

Even TERPs and PANS-OPs normal operations criteria cannot protect for errant blunders.

.. but the training dollar can go a long way towards reducing such to a reasonable minimum ..

Until there be NO dinosaur aeroplanes with which the Industry has to contend, the problem remains extant.

.. and, indeed, there remains the potential problem that the gee-whizz JB stuff has a day off whereupon the pilot comprises the last line of defence ....

[LeadSled]

Folks,
Many moons ago now, I was sitting at the holding point of 15 in Cairns (when it was a lot shorter than now) and a TAA DC-9 went off ahead of us.
Somewhere past V-1, his thrust was reduced by 50%, and as per SOPs, he started to turn for the all engine/engine out profile ---- for only a few second, then the wings leveled --- now headed for the hills around Awaba mission.
Then a second go at a turn, same result ---- then decided to head straight down the valley past Gordonvale visual ---- where the overcast was about 1500 with scattered heavy showers.
As there were no headlines next morning, the "change of plan" to a visual departure OCTA obviously worked, but I was glad it wasn't me.
An aeroplane with seriously "modest" performance was the 747-100/200 with Pratt -7A engines --- 2000' at 20 miles from Bahrain down the Persian/Arabian ( name of choice or prejudice) Gulf ---- and that was on 4.
After a bird strike off RW 16 in Sydney, one of the QF as above flew visual through the Botany Bay Heads, the SID over the sandhills was out of the question. The comments of the Captain immediately after ( an old Sunderland/Sandringham pilot) was quite "instructive".

[aterpster]

j.t.

.. but the training dollar can go a long way towards reducing such to a reasonable minimum ..

You would think so, yet TWA 514 and AAL 965 happened.

Until there be NO dinosaur aeroplanes with which the Industry has to contend, the problem remains extant.

Time is overdue to not drag the high-tech birds down to the lowest common denominator.

.. and, indeed, there remains the potential problem that the gee-whizz JB stuff has a day off whereupon the pilot comprises the last line of defence ....

A risk worth taking, because the gadgets failing at the same time as an engine failure on lift-off is down in the statistical weeds.

[john_tullamarine]

d'accord. I am only raising some concerns ...

[aterpster]

Oui monsieur. Nonetheless, I have no doubt your concerns are shared by the very slow moving ICAO OC panel. And, correctly so...to a point.

[john_tullamarine]

.. at day's end, there be only the one hard and fast rule .. "Don't crash". All else is stylistic.

[aterpster]

J.T.:

In the Land of Oz they are already way ahead of the rest of the world. Great example is at Cairns. For the airplane that is RNP capable, they extend the missed approach track to become the OEI track. In the example the missed approach ends at KABUT all engines operating. But, with an engine failure the track extends much further to UPOLO.

I don't know whether they use it for takeoff or just for OEI on the RNP AR missed approach.

[underfire]

Aus had a great start with all of the RNP-AR procedures that Naverus designed for QANTAS. This laid the groundwork, obstacle clearance, the waypoints, and the aircraft performance. The last thing we did was work on converting them to multivariant, but that was not too difficult as all of the turns were pretty big anyways and there werent any short finals.

These tracks are just for the missed. As you are aware, there is no criteria for DEP. Within the Naverus designs, we did provide some custom DEP, but given the lack of benefits to the airline, few were used.

I remember these 2.85 degree approaches with the temperatures, these go down to the 2.5 minimum, much lower than the FAA allowable.

Also thinking that with a max temp of 36 in Cairns, this wont get used much!

[aterpster]

underfire:

These tracks are just for the missed. As you are aware, there is no criteria for DEP.

I meant an OEI path for takeoff. That doesn't require criteria.

Also thinking that with a max temp of 36 in Cairns, this wont get used much!

That doesn't make much sense. KPHX, for instance, has a max of 46 degrees at 3.00 degrees. In any case, my point is about the RNP OEI flight track.

[underfire]

Because in Cairns, (chart shows NA above 36) it is below 36 for about 2 months out of the year!

If DEP does not require criteria, what would be the foundation of the design? (especially OEI?)

[oggers]

The mean maximum temperature is 29°C and peaks at 31.5º in June.

Climate statistics for Australian locations (http://www.bom.gov.au/climate/averages/tables/cw_031011.shtml)

[Judd]

In the 737-300 simulator at max structural take off weight ISA sea level, with engine flameout at V1 and level acceleration height 1000 ft, it takes around 11 miles to reach flaps up single engine clean speed before resuming climb OEI.
Some operators do not assess obstacles more than 15 miles out and runway analysis charts do necessarily state how far the obstacle survey is valid. One European charter operator I worked for stated they expected the pilot to use "Airmanship" beyond the stated survey path:ugh:

[aterpster]

Underfire:

If DEP does not require criteria, what would be the foundation of the design? (especially OEI?)

All engines operating uses either TERPS or PANS-OPS departure criteria. (or, the operator can submit its own all engines operating departure procedure for FAA approval.) OEI is a different matter, it becomes the domain of the operator's performance and planning department. In the U.S. that means adherence to 14 CFR 121.189 as at a minimum.

Most operators use AC 120-91 for area containment, but the use of the OEI RNP tracks, such as used as Cairns, would be quite acceptable for OEI planning and performance compliance. It would, however, require a certified RNP AR airplane and an RNP AR qualified flight crew.

[aterpster]

Judd:

Some operators do not assess obstacles more than 15 miles out and runway analysis charts do necessarily state how far the obstacle survey is valid. One European charter operator I worked for stated they expected the pilot to use "Airmanship" beyond the stated survey path.

That is fool hardy and would violate 121.189 for a U.S. air carrier.

[oggers]

...yes, and I think it would violate the rules anywhere that has an ICAO compliant policy.

Also:

All engines operating uses either TERPS or PANS-OPS departure criteria. (or, the operator can submit its own all engines operating departure procedure for FAA approval.) OEI is a different matter, it becomes the domain of the operator's performance and planning department. In the U.S. that means adherence to 14 CFR 121.189 as at a minimum.


...quite right.