Flaring becomes a mision

[z06z33 763]

.......blah blah........

 

As Boeing say, FLY it onto the runway. The flare is merely supposed to arrest a 700 ft/min rate of descent to something around 300 ft/min.

 

Greasing it on *IS* bad practise, because you want those WoW (weight on wheel) switches in the bogies to actually *DO* something, like say, cause the spoilers to extend, so you can get the weight of the aircraft on those wheels so the brakes can actually do their job of stopping the aircraft.

 

If you have a contaminated runway, you have many more reasons to put it down firmly, not least so the tyres can break surface tension of standing water (for example) and get some grip.

 

This video here is an example of how *NOT* to do it!!!!!

 

 

 

Look how long it takes for the spoilers to extend, he keeps the nose up for what seems forever, and meanwhile he is unable to start slowing the aircraft. A great way to run off the end of the runway. It's Air France. 'nuff said. <_<

 

Best regards,

Robin.

You know you can deploy the spoilers manually right? I try to land as smooth as possible my touch down is usally under 150fpm and Ive never had trouble stopping.

[martin-w 3,235]

Indeed you can deploy spoilers manualy...

But the cockpit is a busy place during landing, hence why Mr Boeing gave us auto spoiler deployment

 

Last thing you want to be doing the instant of touchdown is fumbling for the spoiler lever.

[japascoe 98]

You know you can deploy the spoilers manually right? I try to land as smooth as possible my touch down is usally under 150fpm and Ive never had trouble stopping.

 

Flight simulator doesn't simulate aquaplaning (or even the effect of a runway being wet AFAIK).

 

Look how long it takes for the spoilers to extend, he keeps the nose up for what seems forever, and meanwhile he is unable to start slowing the aircraft. A great way to run off the end of the runway. It's Air France. 'nuff said. <_<

 

Best regards,

Robin.

 

Actually keeping the nose up increases the surface area exposed to the airstream, maximising aerodynamic braking (just make sure you gently lower the nose before running out of elevator authority). Keeping the nose up for a long time is fine, as long as you are also maximising your other forms of braking.

 

Okay, now both of these paragraphs are what I try to achieve. In my entire simming days (back to glorious FS5), I have always had a tendency with big jets to kind of "pre-flare" at around 40-50 ft. I always got away with this until the PMDG MD11 came along and I found myself either floating or going 50..40..30..20..(*oh ######*)..10....bang, bounce, porpoise, etc. With the MD11 it takes a smooth full pull starting at 50ft to accomplish 100-150 fpm. Then the NGX happened and I started floating all over the place. I've found that starting a normal flare at 30 feet along with simultaneous reduction of power to idle gives the best results. This is very hard to do correctly though. I "cheat" a little if the runway is long enough and reduce VS to about 500 or so at the threshold then finish the flare starting at 20 in conjunction with idle reduction. This is much smoother and easier only if runway allows. I'm not afraid to touch down on the aiming bars at 200 fpm if it's somewhere like HOU or MDW though.

 

As for the 777...it seems to very much need the "perfect" technique. Start a "preflare" at 50 feet and you'll float float float. It really takes a perfect 2-3 degree pitch up starting at exactly 30 feet to get an optimal touchdown profile. I do think the idle reduction starts late though as well. I remember when the NGX came out and everybody was up in arms about how hard it was to land and lo and behold, PMDG found an issue with the dynamics. I'm wondering if something needs to be tweaked with the T7 as well because it seems as if the power stays on forever when using the A/T as Boeing recommends.

 

Have you ever looked through the FCTM that came with your NGX? It has some suggestions on proper flaring technique, might be worth a read.

[pilotresponse 3]

When you fly the real aircraft flare height is a funtion of sink rate, not just a number. If you listen out for altitude auto call outs with a tailwind component, or an upsloping runway you will have a bad day. Incredibly enough when to flare in the 777 is much like the same seat of your pants gut feeling that I got when I flew a Cessna 172 around, it simply feels right. The way to land a 777 is just as boeing recommends in the FTCM, but we don't forget the basics, which they do not mention because they expect you already come equipped to fly the aircraft with that knowledge. In my personal experience on the "200" variants the "20" callout helps you judge the point, in the "300's" 30 feet is better, but I never flare solely based on this. Smooth landings are always desirable, but not necessary. As was mentioned, you must look at the terrifying physics of how much inertia something weighing over 200 tons has. That is why a "firm" touchdown followed by rapidlly selecting reverser and making absolutely sure the spoilers are out is sometimes so important. Happy flying :-)

 

K

[ESzczesniak 128]

This is the first thread I've seen an actual Boeing/real life recommendation for touchdown.  VA's have indeed screwed perception with the competitions for V/S at touchdown, although admittedly not all VA's do this.  I am glad to hear that -120 to -240 fpm is the Boeing recommendation...at least most of my touchdowns are by the Boeing books then.  I'd love to hear what an the typical airliner touchdown as measured by telemetry would be.  I am getting a feeling we as sim pilots are pushing too far towards 0 fpm.

 

In regards to the OP, I am finding very different flare behavior based on landing weight.  I have flown almost exclusively circuits practicing flying the aircraft.  I kept the aircraft empty for this.  Today I did my first true "long haul flight from Dulles to Dubai with some 200,000 lbs of payload.  The flare required much less back pressure and I ended up about 6 degrees ANU instead of about 4 ANU to achieve what subjectively I thought was the same flare profile.

[pilotresponse 3]

Eric just as a note in the real aircraft, at light weights, it is a handful to land and the flare must be more agressive as the CG is much farther forward and stab position is less affected by the elevator making it more difficult to fly the 777 on to the runway, which is what boeing want you to do. You should never hold the airplane off, as you do on light airplanes (risking tail strike or causing a porpoising bounce), if you have flared to early just hold the attitude you have and add power to arrest your descent rate. If you flare early and then lower the nose to correct you are risking putting an enormous lifting surface back into ground effect (the wing) and this will extend your landing distance considerably. Instead keep your attitude constant and use power if you have to arrest rate, the induced drag being produced by that big wing and flaps will simply fly airplane to the ground. (unless you really flared early in which case a go around is the only recommendation)

 

Late Flares always lead to bounces, if it's a shallow bounce hold what you have and again arrest rate with power if necessary always mindful of how much pavement you still have ahead, if its a deep bounce a go around is the only answer! just remember though to follow through your selection of TOGA as the auto throttle may have not function as you would expect.

 

When the 777 200LR is heavy she is very docile in landing and much less flare is required, by judging your flare point according to the FCTM, she seems to come down more gently, though now stopping distance is really an issue, so as I said you should never make a smooth landing a must, its desirable but as I said not necessary. As was said before in this forum, spoilers are key to stopping, reverse thrust adds little to stopping distance especially on dry runways, but can make a huge difference in the brake energy required to do so.

 

One last thing, a damp or slightly wet runway are a pilot's favorite as smooth touchdowns are almost always generated, though I'm sure those of you excellent flight sim enthusiasts know why, something to do with friction and momentum I'm sure. For me and all other pros "greasers" are always a treat rather then an objective.

 

cheers,

K

[martin-w 3,235]

Very interesting post. Nice to hear it from someone with real world experience of the 777.

 

Pilotresponse... How do you feel about autothrust on landings in the PMDG 777? Seems to me it may not be throttling back automatically soon enough. Thus, there seems to be a tendency for very little flare requirement, and a float. Its entirely different to autothrust off landings where a bigger flare is required and no tendency to float.

 

Seems to be throttling back at 15 feet, shouldn't it be 25 or so?

 

Or maybe it's because the engines in the PMDG version are too slow to spool down?

[pilotresponse 3]

Martin, I find it works pretty true to life, again I think that PMDG has done a great job considering this is a desktop simulation. In the real aircraft an autoland does eat up about 400 to 500 meters of runway, which is what I'd say it's doing in FSX, but can't really tell, it's close enough in my opinion.

 

The A/T BEGINS to move to idle at 25ft RA and should ideally reach idle at the same time the wheels touch. So says the book. When the A/T is off (and for a reason which has never been explained to me, and which I disagree with and don't understand, at my airline we fly ALWAYS ALWAYS with the A/T engaged and are not allowed to disengage it, unless it is failed or malfunctioning.) thrust reduction should be timed just after initiating your flare, while holding a constant pitch with back pressure on the column making only small pitch changes to adjust your rate, and again idle should be reached as the wheels touch.

 

I find that it's quite well simulated and I'm happy with it. Though you are right about the spool down, being a somewhat lethargic, as is spool up I find, but I'll let you know for sure in the next month as I fly the sim more often.

 

 

regards,

 

K

[martin-w 3,235]

Martin, I find it works pretty true to life, again I think that PMDG has done a great job considering this is a desktop simulation. In the real aircraft an autoland does eat up about 400 to 500 meters of runway, which is what I'd say it's doing in FSX, but can't really tell, it's close enough in my opinion.

 

 

I was referring to a manual landing, but with autothrust on. Not an autoland.

 

The A/T BEGINS to move to idle at 25ft RA and should ideally reach idle at the same time the wheels touch.

 

 

 However, I did try an autoland and it appears to be moving to idle at 15 feet, not 25. I'm assuming it does the same with a manual landing.

 

PMDG are adding the option to override the autothrust in the flare, which will help.

[martin-w 3,235]

Edit: Actually I've just checked with a manual landing with A/T on. It's moving to idle at about 20 feet. So not much out.

[pilotresponse 3]

that's within reason, but I haven't noticed a tendency for the airplane in the sim to float, or the A/T to do strange things on landing, pretty much behaves as in real life to me. Enough said. 

 

enjoy

 

K

[scandinavian13 5,192]

Is why im trying to get landings smoother because some VA's penalise on high V/S touchdowns, is it realistic?? I dont know.???

Was on aprroach to OPLA one minute in the clouds next min....bang on the runway didnt have time to flare or anything....VS was recorded as -768FPM landing,which is bad I know - and as I was taxiing actually had a Tire Pressue warning on the 777 again its realistic, however smooth landings is somethng I have always aim for for the very reason above.

 

Well there's big difference between hitting so hard that you break something and trying to get at close to 0 V/S when you touch down.  If you look at VA websites, too many of them have a "top landings" board with landings with vertical speeds so close to zero that they either ate up a ton of runway, or they just got lucky.

 

That's what I'm getting at.  I'm not saying you should land as firmly as possible.

[M_Sauce 6]

Wow, it is funny to hear some of you talking about stuff that you have no idea of. Sorry guys, but so much garbage is being spouted on how to land a wide-body airliner by so many people that have never landed a wide-body airliner. It is the equivalent of someone claiming they can perform emergency surgery because they watched a whole season of ER. 

 

First of all, the comparisons of a swept wing heavy airliner with a small straight wing Cessna are hilarious. Swept wings behave completely differently from a straight wing, hence they require completely different landing techniques. The cues you use to judge your alignment and height above ground might be the same, but you are talking completely different animals. So please, don't compare the two. You will never hear such talk from a professional.

 

 

 

Soft landings are bad practice in an airliner. This has been debated before and real world airline pilots have confirmed as much. 

Again, spoilers can fail to deploy and floating is more likely.
By definition, a minimal sink rate landing extends the landing distance. And the "attempt" to execute a greaser can increase the risk of floating.

 

Wow, really, where do you guys get this stuff? Soft landings are a bad practice? I've never heard such garbage. Every landing you make is with the aim of making it soft. You know, planes break above a certain G-load. Sure, you don't want to "float" by holding off a bad flare trying to turn it into a soft landing, but you also don't want to carrier-land you transport category certified aluminum tube. It does not take much to break them (see multiple MD-11 landings, DC9s breaking in half, EMB-145s breaking in half) so you aim for your landing point, usually the actual aiming point markings, and you accept a little flare distance - just like Boeing and Airbus do in programming their auto land systems. Not to mention your landing performance figures from the manufacturer that include a certain amount of flare time. It is factored, it is expected.

 

And auto-spoilers, along with other various related systems, do not just depend on WoW switches. You also have wheel spin-up sensors from the anti-lock braking systems, as well as throttle lever angle sensors. i think you will find the lack of spoilers on landing is often caused by landing with the thrust not at idle, which can come from poor technique but could also be cause by sudden shear over the threshold. You are not gonna affect your WoW sensors from just landing soft. They will either compress, or not compress. 

 

As far as hydroplaning, there are so many factors involved, not just touchdown G. Sure, it is recommended to have a slightly firm landing, but no more than slightly. We are not talking about a landing where the passengers say "ouch", but just not one where they say "are we on the ground yet?". And that is not so much to prevent hydroplaning, but to increase the wheel's time-on-pavement. The sooner the wheels are on, the sooner the systems that slow you down start to work (reverse, spoilers, ABS). Keep in mind the ABS system on most airliners will not let you put brakes on (cycles pressure back to the reservoir) until sensible wheel spin-up, just like the system in your car.

 

Last thing, as far as VS on landing, really - where did this come from? Every airline pilot I know (including myself) could not tell you what the VS is on landing because - none have ever looked at a VSI below 100ft. It is just not part of your scan, and if it is, then you sir have no business sitting in the front seat of an aircraft. Even in a CAT3B landing where the outside is soup, you would still be looking at more important things than the VSI on landing. On a normal manual landing your eyes should not be looking inside at all below 100ft. If you are, you are setting yourself up for a hard landing - guaranteed. It is one of the most common causes of hard landing inspections at my airline.

 

Sorry, had to say that, it is hard to read some of the posts on here and get past all the nonsense. 

 

Having said that, I would like to return to the original reason I opened this thread in the first place - I do agree that the flare on this aircraft does not feel right. I can only guess as to why this is, since I have no clue at how hard it must be to design a FBW aircraft like the triple. My guess is that PMDG designed the flight model to be flown for how the majority of airlines fly them - with AT engaged for landing. I don't fly the 777, but that is the policy at my airline as well.  This probably means that some compromises where made to achieve that most common technique in the triple-7, and these compromises are accentuated when you do a full manual landing. I'm guessing FBW simulation is probably the hardest aspect to simulate in FS, which is probably why there are no good PMDG-like quality Airbus add-ons out there.

 

As someone already explained, I think this is expected when you push a leisure piece of software that is several years old and clearly not designed to do the things that wizards like PMDG and others are asking it to do. We are talking about a 70 USD platform which is being asked to do what a 22 million dollar Level-D sim does (minus the motion of course). Hopefully, they are able to come up with some tweaking - I think that if it can be done, they would do it. If they don't, then I am sure it is not for lack of trying and I am still massively impressed with the aircraft.

[japascoe 98]

Wow, really, where do you guys get this stuff? Soft landings are a bad practice? I've never heard such garbage. Every landing you make is with the aim of making it soft. You know, planes break above a certain G-load. Sure, you don't want to "float" by holding off a bad flare trying to turn it into a soft landing, but you also don't want to carrier-land you transport category certified aluminum tube. It does not take much to break them (see multiple MD-11 landings, DC9s breaking in half, EMB-145s breaking in half) so you aim for your landing point, usually the actual aiming point markings, and you accept a little flare distance - just like Boeing and Airbus do in programming their auto land systems. Not to mention your landing performance figures from the manufacturer that include a certain amount of flare time. It is factored, it is expected.

 

And auto-spoilers, along with other various related systems, do not just depend on WoW switches. You also have wheel spin-up sensors from the anti-lock braking systems, as well as throttle lever angle sensors. i think you will find the lack of spoilers on landing is often caused by landing with the thrust not at idle, which can come from poor technique but could also be cause by sudden shear over the threshold. You are not gonna affect your WoW sensors from just landing soft. They will either compress, or not compress. 

 

As far as hydroplaning, there are so many factors involved, not just touchdown G. Sure, it is recommended to have a slightly firm landing, but no more than slightly. We are not talking about a landing where the passengers say "ouch", but just not one where they say "are we on the ground yet?". And that is not so much to prevent hydroplaning, but to increase the wheel's time-on-pavement. The sooner the wheels are on, the sooner the systems that slow you down start to work (reverse, spoilers, ABS). Keep in mind the ABS system on most airliners will not let you put brakes on (cycles pressure back to the reservoir) until sensible wheel spin-up, just like the system in your car.

 

 

What exactly do you mean by soft? Because quite a few simmers seem to think that the optimum landing is one where you touch down with 0.1 fpm. That is the soft landing people are arguing against here, obviously you don't aim to break your passengers' spines. Boeing recommends you land between 120 to 240 fpm, so I think you'll find that that is the vertical speed trained pilots will put the plane down at, although as you pointed out they will do so by relying on the outside view, rather than on the VSI.

 

Incidentally, per the FARs a plane breaks if you touch down with -600 fpm or greater at MLW (times a safety factor for ultimate load).

[martin-w 3,235]

Wow, it is funny to hear some of you talking about stuff that you have no idea of. Sorry guys, but so much garbage is being spouted on how to land a wide-body airliner by so many people that have never landed a wide-body airliner. It is the equivalent of someone claiming they can perform emergency surgery because they watched a whole season of ER. 

 

First of all, the comparisons of a swept wing heavy airliner with a small straight wing Cessna are hilarious.

 

You will never hear such talk from a professional.

 

 

Wow, really, where do you guys get this stuff? Soft landings are a bad practice? I've never heard such garbage. Every landing you make is with the aim of making it soft.   

 

Last thing, as far as VS on landing, really - where did this come from? Every airline pilot I know (including myself) could not tell you what the VS is on landing because - none have ever looked at a VSI below 100ft. 

 

Sorry, had to say that, it is hard to read some of the posts on here and get past all the nonsense.

And "wow" to you too my friend.

 

I find it sad that you have arrogantly dived into this thread while it seems not bothering to read all of the posts, taking comments out of context, ignoring real world 777 pilots comments and misinterpreting.

 

The term "soft landing" was in reference to a particular poster's insistence that a pilot should "aim" for a -50fpm greaser landing. It was nothing at all to do with avoiding a comfortable landing. If you had bothered to read further, you would have noticed that there was no objection at all to 100, 150, fpm landings, which I'm sure "you" would define as soft.

 

First of all, the comparisons of a swept wing heavy airliner with a small straight wing Cessna are hilarious. Swept wings behave completely differently from a straight wing, hence they require completely different landing techniques. The cues you use to judge your alignment and height above ground might be the same, but you are talking completely different animals. So please, don't compare the two. You will never hear such talk from a professional.

"Hilarious" you say. This is the mention of a Cessna...

 

From Pilotresponse, who just happens to be "a real world 777 pilot".

 

Incredibly enough when to flare in the 777 is much like the same seat of your pants gut feeling that I got when I flew a Cessna 172 around, it simply feels right.

 

 

This again from Pilotresponse...

 

Smooth landings are always desirable, but not necessary. As was mentioned, you must look at the terrifying physics of how much inertia something weighing over 200 tons has. That is why a "firm" touchdown followed by rapidlly selecting reverser "and making absolutely sure the spoilers are out is sometimes so important". Happy flying :-)

Boeing recommend -140 to -250fpm... which no one here has disagreed with. So please go somewhere else and throw around terms like "garbage" while simultaneously making sure you have not misinterpreted and taken comments out of context.