Wake Turbulence - Did you know...?
 

I fly a 747-200 in my "normal life" - and sometimes moonlighting as Learjet pilot.
So, I know about wake turbulence, and how it feels in a Lear following a "metal overcast"...
But did you know this...?
xxx
Many of us are bad guys in the 747 and other similar planes.
No more than you dislike wake turbulence, we have the same opinion.
If I follow a MD-11 on ILS, I often fly the approach above the glide slope.
At least one half dot, sometimes a dot above to avoid the wake turbulence of the guy up front.
xxx
I do not get to fly often, so I never "couple the ILS" (unless low visibility).
My landing runways are generally the 10 or 12,000 feet long "variety".
If that MD-11 up front touches down at 2,000 feet down, I might go for a point further down.
Even with very little braking, I can stop and still have plenty of concrete left.
Is it me only...? No... many other idiots do like me.
xxx
Where does that leave you...? - Well, first, now, you know about it.
Then, your Citation is also landing on that 12,000 feet long boulevard.
So you can fly an approach "1 dot above" and touch down 3,000 feet beyond threshold.
Still leaves you with 9,000 feet to "attempt" to stop your "Gucci Jet".
With a LR-31 or 35, I only need 4,000 or less to stop with only idle reverse.
So, be careful if too close behind.
xxx
:E
Happy contrails

Amazing what you can do with Microsoft Flight sim and no one gets hurt :)

Pace

Pace...... look at the posters other posts and you will probably discover that he doesn’t know what MSFS is! In fact he was flying for PanAm when i was in diapers!

BelArgUSA, Interested procedure for the 747, but if you want to avoid the wake, why don’t you slow down sooner? Why plan to waste 1500 feet of runway?

Mutt

ATC will probably have told you what speed to fly and squeeze you in so seperation may be down to minimums.

BelArgUSA is making his point about wake down the ILS so you will have set the bug speed by then for landing. if he lands behind the touchdown point of the aircraft before him, its wake will still be there as it would have sunk down onto the ground.

to avoide the wake of the aircraft before you, you land after its touchdown point therefore being above its wake turbulance all the way down the ILS as your alwase higher than it.

He's making a point that he flies a dot high; fly the glideslope and you'll be in his wake. He may also land a little longer, just like anyone else does in a light airplane. It's a courtesy message to educate others that the large airplane ahead may very well be doing the same thing that many light airplane pilots do.

When I fly an approach in a Lear behind a heavy aircraft, I tend to fly a little high, too. I land a little long.

In a 747, I tend to fly with the needles centered and if I land long it's simply because I'm a poor pilot. BelArgUSA does it becuase he's avoiding wake turbulence. Regardless, his point is valid; stay heads up for wake. Don't assume that it's settled below if flying on the glideslope, and be aware that even large airplanes take measures to avoid wake...which might include landing past the touchdown point of the preceding aircraft, in some cases.

Gracias Sr. Guppy -
xxx
Just thought about wake turbulence because of that Lear accident in Mexico.
Once got behind a ??? at LAX in a Lear... We got beyond 90º bank...
Passengers not too happy.
xxx
:ok:
Happy contrails

...... and be particularly wary of any B757 ahead of you.

It's becoming an increasingly rare aircraft in the Euro/Mid East context meaning there's a whole new generation of Biz pilots who might not have first hand knowledge of exactly what that aircraft can do to those following.

That's not some anti Boeing mini rant. I've 4000 hours on the 75 and is my career favourite transport aircraft. Be very careful - your own personal checklist of wake turbulence conditions and mitigation simply isn't good enough.

Rob

Not landing on or near the numbers especially in a heavy is surely a high risk practice to get into especially if you use the same techique on runways which are not quite so length generous.

Landing ahead of another aircraft which itself has landed long must mean that you are estimating the available runway still available visually?

I am not a large jet pilot but know that in those aircraft the technique expected is not to even go for a smooth touchdown nowadays. Rather to plant it on the numbers and not risk any float thus maximising the available runway length.

Lighter aircraft where there is loads of runway is a different matter and landing late can even be used for waiting for an aircraft to clear that has landed ahead as well as for wake turbulence but dont think such operating mode would go down too well as a principal with large passeneger jets especially by a Captain who doesnt fly too often and doesnt couple on the ILS to get some hands on practice :)

Pace

Spunky Monkey

I dont know everyone here or their hours :) Maybe he is of the old set who do things differently but dont think that advice would go down to well with the airline nowadays :)

What has happened with ATC spacing and the pilots own speed control and spacing to be in that position anyway?

Pace

As far as I know wake turbulences tends to go down with a 500ft/min Vz which means that if the guy in front of you is on the GS and that you follow the same path, you should be 500 ft above its wake when passing a minute after him.
In addition, should you be landing facing the wind (which is generally recommended), the wake should be little bit pushed back thus increasing its clearance from the glide path.

Does this make sense ?

so if you fly one dot above and I´m behind you, how much above should I fly to avoid your wake turbulence? Be serious, no one in a 747 flies one dot above, I fly a Lear60 with a proportion of 1 Lb trust = 2 Lb weight and my Vapp is 150-160 knots, I need runway to stop and if I can I always go to the numbers. Don´t f..k us and fly your needles or you will end f...ing someone behind and then be sorry because he crashed for flying one dot behind a heavy.

I do fly the G/S "right on" when not following another heavy.
If behind another heavy, no wind, I will be slightly above, up to 1 dot.
I merely get 1 or 2 landings monthly... being relegated to check captain.
Selecting "LAND" with the autopilot is not a form of practice.
I always fly at Vref+5 as speed, which is generally 140-145 knots.
It is rare that I do have less than a 10,000+ft long runway.
And yes, it is also rare, that the RVR is less than basic visual conditions.
xxx
Plenty of practice in simulators... I still love to be in the "real machine"...
Besides, I hang my hat for good at the end of the month.
So I will be out of your airspace. Share it with other nerds and geeks.
That beach in Brazil sounds better every day that goes by.
xxx
This thread was to inform bizjet pilots as to how 747s are sometimes flown.
Sadly, a Lear just "bought the farm" in MEX, 2 days ago.
Wake turbulence was likely in their case. They were behind a 767.
But, you know better than me... I am from a third world nation airline.
I fly an airplane nearly 30 years old, soon to be retired as well.
xxx
:D
Happy contrails, from the "old fart" -

BelArgUSA

Good post and thanks for bringing our attention again to the continuing hazards of wake turbulence. I go along with what you say.

I am especially vigilant when I am landing on a runway, behind other aircraft in slight tail wind/drift conditions. These conditions bring the wake of preceding aircraft "forward" of course. Wake from an aircraft of the same weight category can be unpleasant enough.

As an addition I always carry an extra 5 to 10 knots* above bug (money in bank) on approach and in some cases, until touchdown. I can easily and soon get rid of that extra 10 knots if and when I want to. Much easier than trying to gain 10 knots lost, when even more "behind the drag curve". get "slow in a Lear" and you die, as I am sure anyone who flies or has flown one will agree.

* I can't fly within +/- 5 knots at my age!:}

BelArgUsa

I am not knocking your advice as you are obviously a thinking pilot rather than a computer mentality pilot.

Your flying is real flying compared to the highly regulated and highly automated type of flying today.

Having flown third world ferries in what can only be described as "character" business jets :) I would identify with you more than the new way. I can think of some hot, high, and heavy takeoffs we made which were not even in the performance graphs but we had massive runways in Africa so more a case of needbe and estimate the takeoff figures.

My son is flying for Easy Jet on a 737 at the age of 22 in the UK. They no longer land aeroplanes but have forced arrivals for fear of using a foot more runway than need be and it made me wonder how they would take such advice? What do you do in the same situation where your runway length is more limited?

Spunky Monkey

The reason I fly corporate is the same as yours :) It was the ref to landing past a heavy which itself landed long which concerned me not so much on a massive runway but using the same technique on shorter runways, not the dot high on the glide.

BelArgUSA

Good luck with the retirement

May I humbly suggest that if one flies one dot above the glide and the other one with unreasonable excess speed all the way to touch down, the two combined could lead to disaster or not far from it.
Slippery aircrafts such as modern commercial jets, are not often of the forgiving type.
I do not have BelArgUSA's experience (and he didn't imply he was doing both either) so in my limited view, I can say that whether I flew the 75/76/73 or the smaller Citations, Vref+5 at the threshold (Corrected with half the wind + full gust to a max of 20kts), on the glide has always worked well enough.

But I do take note of other's ways to operate...

BelArgo
 

Well Paul, there are some out there Mon Brave:ok:

AMEX,
I don´t know where you fly, where I fly (mostly europe) I´ll be told either by the plate or ATC how quick to fly (yeah I´m the captain, still I like the Idea of complying to instructions). So there is not to much room for straying from speed. (especially not at airports that are served with the heavies -the 57 aside)
The seperation we get here is usually 5 or 6 nm behind heavies (depend on your own weight class)

I had 2 closer shapes with wakes, one in a CJ2 behind a 757 and one in a KingAir behind a Fokker 50. Both have been in weather when by the book, you would not have expected it.

Still I´d like the big fellows at least tell us if they fly high on the GS. I usually fly high as well.

BTW, anyone else noticed that newbies have a real trouble to fliy exactly one dot off whilst they are really good on flying on the glide? Maybe I was the same, but I don´t recall.

BelArgUSA: happy retirement! Wish I would be short before it as well...

AMEX -
xxx
The way I land a 747 to stop it on a 5,500 ft runway, or 12,000 ft is quite different.
You do not know how the idiot preceding you on the ILS is...
I am teaching constantly how the other stupid guys could be.
Call it teaching "awareness".
Who knows, I am one of them.
xxx
Do not assume that everyone is flying "by the book" in all circumstances.
If you are that perfect, ok. I am not. Just human.
Now that I leave the career, I still want to help the young ones.
I learned from my "seniors" as well, and sometimes from my F/Os or F/Es...
Pprune is great for all of us. Did not exist when I learned to fly.
All the best to all of you, fly safe.
xxx
:ok:
Happy contrails, always

Merlinxx
 

I really will write that book... nobody will believe some paragraphs...
Like going to Tel Aviv for maintenance with a plane in Saudia colors...
Coming from Jeddah, making a touch-and-go in Larnaca.
xxx
Will not forget to send you a print, if I ever publish it...
You will laugh at some of the details, and remember some of the characters.
Who was that guy with "leathers and chains" in his flight kit, passing customs...?
xxx
I raise my glass. The "sadiqi" here is tastier - "caipirinha"...!
:ok:
Happy contrails

Wake Turbulence
 

Good information and good posts.

In my aviation career I found that common sense in any situation was the best method and in particular to keep your thinking ahead of the aircraft you are flying.

Your last landing will then be a good one.

Tmb

His Dudeness I was referring to the threshold target speed only and in answer to a specific post. 160 to 4 etc, I am well aware of it but since one of the contributors mentioned that he always flew Vref+5 or +10 all the way to touchdown , I was highlighting that high on the glide and fast with a modern jet was not the safest. As an aside, you are the Captain and you are asked to fly at a certain speed. If you are unable to comply, you do not have to but you must advise ATC so they can take it into account and work out a plan B if necessary. As far as I know, nobody asks you to fly at a certain speed when passing the threshold. At least not in the Europe I fly around.

I was not pointing my finger at BelArgUSA as I have read his post and understood it too. But since we were on an educational post, it appeared fair to mention that one has to realise all the implications of doing things one way or another.

I have no doubt I would have been clearer with you and others, whilst having a few beers.

I'm just happy with keeping the needles somewhere on the dial. Dot up, couple of dots down, lurch left, stagger right, hit the tarmac. Delighted!

You could also try doing a barrel roll on the ILS and try and come out with the needles centred :)

Pace

or as my fellow cocaptain uses to say:

"more or less established"


@AMEX: "As far as I know, nobody asks you to fly at a certain speed when passing the threshold."

Well, there is a booklet that came with the airplane.... now seriously, I got you a bit wrong. Sorry.

To BelArgUSA
Actually I have a question... Say you re riding the glide one dot above behind an MD11 (example provided). How do you know the other guy ahead of you is not doing the same ? TCAS range Vs relative altitude doesn't make it easy to work out.

@his dudeness I think that Amex meant that ATC does not require you to fly a speed at threshold, at most it will be at 4Nm final... Or minimum approach speed when established, but never fly 140 to touchdown...

Nevertheless, one dot high is as useless as possible, since like amex mentionned, you have no clue if the one in front is flying one dot high as well.. I was flying out of Ontario,Ca some time ago, watching these 4 holers landing and taking off, I never saw one touching down after the preceeding mark..Could be a domino effect after 5 heavy landing in a row...

Across my carreer, i never saw either ops manual, PartB, Sop's writing that ones has to fly one dot above when following an Heavy, increase the distance , Yes, timing before take Off, yes but not this...mind you I'm quite young in the business, only 20 years..So I have a lot still to see and learn..

It’s funny how things vary!! In my airline flying one dot above the G/S would put you right on the limits of an unstable approach and you would have to G/A if you drifted any higher. Thats why we would fly on the G/S but remain 5 NM behind the heavy, so you are clear of wake turbulence.

Guess my airline thinks runway overruns happen more often than accidents due to wake turbulence so they think there is more danger of flying high and landing deep rather than just following at 5 miles.

Landing performance is calculated on you crossing the threshold at 50 ft. 1 Dot high and you are invalidating this performance. If you did over-run not sure how the authorities would view this.

We don't quite go for forced arrivals but there is very much a culture of getting it on in the right spot!

I have not come across anyone who would intentionally fly one dot high, guess our SOP's are just a lot more prescriptive. That and a very active flight data monitoring deptartment!!!

to AMEX -
 

How do I know the MD-11 is not 1 dot above G/S...?
xxx
Good question. Beware that even though I fly an old whale 747-200, following another heavy, anything 1011, MD-11, 777, is a concern even for a 747. Being in the wake of these guys, is not comfortable.
xxx
I fly generally to Barajas or Fiumicino. You know their ATC does not always provide adequate separation, their thought is that a 747 "can handle any wake turbulence better than any smaller airplane"... So they seem not to be too concerned. It has spilled my last before-landing-expresso occasionally.
xxx
I will never deliberately fly above a G/S without reason, if no "heavy traffic" in front of me. My own "manual approach" (for practice many of you seem to deny me) standards is "ON G/S, up to 1/2 dot above" as personal limit. But if I follow a pair of heavies, I often suspect one might be himself above G/S, if wind is rather calm, in ideal visual conditions and long runway.
xxx
A word also, is "how long the runway". If I think of a 12,000 ft runway as extremely long and far from limiting for my 747, it certainly is for you in a small private jet. I wrote this thread primarily for pilots of smaller airplanes, and as a courtesy for your passengers.
xxx
If BA 038 had been above the G/S when landing at EGLL, they might still have G-YMMM flying revenue. Lucky these guys made it, I admire the outcome of the way they handled the situation.
xxx
A last word from this "old fart" - when I fly, say to a 5,000 runway in my little Piper L-21, how come I do not try to touch down 300 feet behind the threshold... And why is it that my dentist friend retracts his gear of his Marchetti SF-260 right after takeoff, when he still has 3 or 4,000 feet left to land (engine failure) in front of him...
xxx
Let's be practical, friends... as circumstances dictate.
SOPs are to be adapted when required. Spells "airmanship"...
:ok:
Happy contrails

BelArgUSA

You would be shot at dawn if you posted that in some of the forums here and dared to promote thinking pilots :) Though I tend to agree with you

Pace

Señor Pace -
xxx
I have a bullet-proof vest. I do not mind getting fired by now...!
One Madrid trip left for me, so 1 landing.
I suspect I will land also on the return sector...
Will be my last, at least in a 747. Will NOT be AUTOLAND...
xxx
And I will bust another rule, after the final landing. Drinking in uniform.
I plan to open a few bottles of Moët & Chandon with the crew in the plane.
Whether some SLF still left in the plane report me... honest I do not care.
And if the chief pilot and director of operations show up, they will join us.
... to fire me maybe, or give me my gold Rolex...!
xxx
:ok:
Happy (hips) contrails (burp)

I hope the best to you, BelArgUSA. Will also be looking forward to your posts after your retirement!:ok:
Bob.

I still don't understand the pb as wake turbulences are not remaining on the preceding aircraft's path... In fact, the only reason I see for WT to be on the GS would be that the preceding is actually flying above it... or that you land with a goof tailwind.

Regarding the BA 38, why not suggesting to raise up all GS to let's say 10 degrees, this would allow loads of fuel saving as we could shut down engines passing the IAF. Of course this would just be airmanship and smart interpretation of what can't be written in the SOPs... (I'm kidding BelArg..)

Last post on that topic for me.

Because I cannot say or know what the preceding traffic is doing (such as riding high on the glide) other than monitoring his distance based on the TCAS, I cannot conclude that this is a good solution.
Then what would I do if say, I was following a friend I know who rides the glide high.... Ride it even higher ?
Also, if everybody was doing the same, then it would be just the same as when everyone is flying an ILS, on the glide. Only not as safe and getting pretty close to the limit of what is defined as an unstable approach, (with for consequence, the requirement to perform a G/A just like it was mentioned by a previous poster.

My final point and I rejoin sispanys ria's comment... That's how I see it. Basically with no certainty of "avoiding" wake turbulences, we can be pretty sure that traffic following an aircraft behind a "high Rider" is more likely to encounter some.


So as far as I am concerned, I do not see enough positive points versus the negative ones and I ll stick with my TCAS.


On that one, safe flying to all.

Amex has it right...
 

If the guy in front was riding one dot high, does that mean I have to be two dots high? What about the guy behind me? As far as I am concerned, never got wake turbulance on a 3 degree glideslope, but on a Visual behind a 737 into LAX the GIV rolled 3 times to 90 degrees, almost took the controls from the captain, he wasn't pushing, just cross controlling.....None the less...if you want to keep me happy, keep your friggin speed up....