Ask The Pilot

[clazman]

Home - Kent Street Senior High School ?

yep that is the one

 

[NM]

Not a near miss at all. Whilst the controller had cut it pretty tight, that's not abnormal. I think he went around too soon. The smaller aircraft was rotating as the 777 started to go around...so, I'd have landed.

ATC are generally masters at juggling this sort of thing.

So in this example are you suggesting the decision to go-around was most likely made by the pilots and not directed by ATC?

My concern (from my arm-chair, so totally unjustified) would be if the 777 continued and made a late go-around for an unrelated reason, would that put the 777 and metroliner in a situation where minimal separation became a problem? Or does the go-around flight path include a turn to ensure the 777 would not encroach on the metroliner route even if the go-around was initiated later and at a lower altitude?

 

[jb747]

So in this example are you suggesting the decision to go-around was most likely made by the pilots and not directed by ATC?

Yep, that's what I think has happened.

My concern (from my arm-chair, so totally unjustified) would be if the 777 continued and made a late go-around for an unrelated reason, would that put the 777 and metroliner in a situation where minimal separation became a problem? Or does the go-around flight path include a turn to ensure the 777 would not encroach on the metroliner route even if the go-around was initiated later and at a lower altitude?

The Metro is accelerating, and the 777 is at a relatively slow speed, and even in a go around should not exceed 185 knots, so they won't necessarily close up much at all. The go around path is from an instrument approach, and won't take departing visual traffic into account. The Metro, on the other hand, would almost certainly have been given a turn to complete after take off, which would move it away from the go around path. The triple could also be given a heading for the go around.

As I see it though, pilot initiated go arounds, in these cases, can cause the aircraft to get closer that they would ever have been if the approach had been continued.

 

[alieninperth]

Thanks JB, I have to say I'm a little shocked at how close you say the planes normally get. I'm sure you are all confident and well qualified and know what you are doing, it just seems very close to me. I suppose that why you fly the planes and I sit in the back.

 

[jb747]

Thanks JB, I have to say I'm a little shocked at how close you say the planes normally get. I'm sure you are all confident and well qualified and know what you are doing, it just seems very close to me. I suppose that why you fly the planes and I sit in the back.

ATC will have different rules at every airport, and for just about every occasion, but having aircraft either taking off, or landing, in front of you is the norm. If anything, previous traffic that is landing is potentially much more of an issue, especially if the runway doesn't have many exits, or the preceding aircraft misses the required exit.

Crossing runways, such as Melbourne, also make for some interesting timing exercises for ATC.

 

[Boris spatsky]

Become a banker, and buy an aircraft for fun on the weekend. I can't see the sort of career that I've had being available in a world in which pilots are becoming consumables. I wouldn't recommend it to my son. If he wants to fly, the military is the best training that money can't buy.
The shortage has supposedly been coming for many years, and perhaps it might exist in Asia. But, it really seems to be blurb that is fed to people by flying schools that are simply trying to sell their training.

Seconded - the industry in Australia is slowly eroding away. Low salaries (yes, alot of pilots flying RPT are only paid the award wage for pilots), poor job security, loss of benefits compared to days gone by. My young son desperately wants to be a pilot, but for me i will be recommending a life in the Military as the only real option.

The way of the future for a healthy airline career is to accept that you will need to live overseas for the rest of your life, and move companies as often as is required to keep flying. Easy to say that that is fine as a single person, but it becomes immeasurably harder once you have a spouse and kids.

 

[QF WP]

Just saw this video pop up in a feed and thought it was pretty ballsy flying by the AirBerlin pilots (not knowing the airport [Madeira in Spain] or actual wind conditions at the time).

[FONT=&amp]https://au.news.yahoo.com/video/watch/28097428/raw-plane-lands-in-crazy-conditions/

[/FONT]
Until he skews right (back to an almost perfect forward landing on the centreline - but it appears to be on the RHS wheels), I thought "nah, surely he should be considering a go around". To our forum pilots - is this considered a normal crosswind landing??

No way I want to be a pilot trying to do that - so thanks and hats off to jb747, Boris and all the other pilots here. I'll happily pay you more to get me on the ground in those conditions...

 

[jb747]

Just saw this video pop up in a feed and thought it was pretty ballsy flying by the AirBerlin pilots (not knowing the airport [Madeira in Spain] or actual wind conditions at the time).

[FONT=&amp]https://au.news.yahoo.com/video/watch/28097428/raw-plane-lands-in-crazy-conditions/

[/FONT]
Until he skews right (back to an almost perfect forward landing on the centreline - but it appears to be on the RHS wheels), I thought "nah, surely he should be considering a go around". To our forum pilots - is this considered a normal crosswind landing??

No way I want to be a pilot trying to do that - so thanks and hats off to jb747, Boris and all the other pilots here. I'll happily pay you more to get me on the ground in those conditions...

Here is a better reference, without the advertising.[FONT=arial, sans-serif] LiveLeak.com - Challenging Crosswinds landings during strong winds at Madeira airport
[/FONT]
Windy days can be fun (not). Aircraft crosswind limits are around the 35-40 knot region, so somewhere between 15 and 20º of drift isn't abnormal. Boeings (at least the ones that I've flown) can be landed with all of that drift intact, which makes their handling in the flare much easier. Airbus, you're supposed to get the drift below 5º.

On days like that we are happy if we stay on the black bits, and the aircraft doesn't have to be rebuilt, but you can bet that somebody will have a go at your landing if you venture out to say goodbye to the passengers. That's when you ask how his/her last landing was.

 

[RAM]

Why don't the pictures for the 777X show any winglets or rises of any sort?

Looking at the various images of the 777X one point stands out - the wings have no winglets at all on them.

Am I missing something here?

Or is Boeing waiting until it has been patented every which way before revealing the true end wing structure?

Even though they are folding back I would have thought that the tip turbulence would still be worth a 3-5% fuel saving.

Have a look at the 787 wings vs the 777X.

 

[TomVexille]

Re: Why don't the pictures for the 777X show any winglets or rises of any sort?

Looking at the various images of the 777X one point stands out - the wings have no winglets at all on them.

Am I missing something here?

Or is Boeing waiting until it has been patented every which way before revealing the true end wing structure?

Even though they are folding back I would have thought that the tip turbulence would still be worth a 3-5% fuel saving.

Have a look at the 787 wings vs the 777X.

I thought the 777X was getting a variant of the raked wingtip which features on the 77W, 77L and 787.

 

[RAM]

Re: Why don't the pictures for the 777X show any winglets or rises of any sort?

I thought the 777X was getting a variant of the raked wingtip which features on the 77W, 77L and 787.

Seems different to the 787 variants shown.

 

[TomVexille]

Re: Why don't the pictures for the 777X show any winglets or rises of any sort?

View attachment 49329
Seems different to the 787 variants shown.

The 787 seems to have a little more of an upward curve to it. What I'm seeing on the Boeing website suggest that the 777X will be somewhere closer to the 77W

 

[QFflyermelbourne]

Re: Why don't the pictures for the 777X show any winglets or rises of any sort?

I suspect the final design isn't totally signed off on. I by chance sat in J next to a Boeing engineer on QF94 a couple of months back. He was a lead designer on the 787 wing and was visiting Australia as much of the wing is manufactured here by BAE and he was making a routine visit. He told me that he was currently working on the new 777 wing so it sounded very much unfinished at this point. I guess as you would expect right up until the flight test program is complete they will be wanting to make changes and hone it.

 

[day-heg]

Re: Why don't the pictures for the 777X show any winglets or rises of any sort?

The wingtip features (sharklets, winglets, etc) are there to disrupt the spanwise flow of air that is a function of lower pressures above the wing and high-pressures below. This movement of the air creates the wingtip vortices which causes induced drag. However, the strength of the vortices and thus amount of induced drag is a function of many different factors (wing shape & size, aspect ratio, even the shape and design of the fuselage and how that interacts with airflow over the wing).

Therefore it's not a given that some sort of wingtip feature is an essential part of a new aircraft design. Remember that adding any extra pieces of bodywork at the end of the wing will always create form-drag and add weight (reducing fuel efficiency), irrespective of whatever good work the part is doing in lowering induced drag (which increases fuel efficiency). It's a balancing act...

The current 777 doesn't have any, because Boeing must have worked out that benefit they offered was outweighed by the negatives. And the technology was there - the 747-400 complete with it's winglets started commercial service in 1989, 6 years before the 777.

Note the new-ish 747-8 doesn't have any form of winglet, but the 744 did

 

[TomVexille]

Re: Why don't the pictures for the 777X show any winglets or rises of any sort?

The wingtip features (sharklets, winglets, etc) are there to disrupt the spanwise flow of air that is a function of lower pressures above the wing and high-pressures below. This movement of the air creates the wingtip vortices which causes induced drag. However, the strength of the vortices and thus amount of induced drag is a function of many different factors (wing shape & size, aspect ratio, even the shape and design of the fuselage and how that interacts with airflow over the wing).

Therefore it's not a given that some sort of wingtip feature is an essential part of a new aircraft design. Remember that adding any extra pieces of bodywork at the end of the wing will always create form-drag and add weight (reducing fuel efficiency), irrespective of whatever good work the part is doing in lowering induced drag (which increases fuel efficiency). It's a balancing act...

The current 777 doesn't have any, because Boeing must have worked out that benefit they offered was outweighed by the negatives. And the technology was there - the 747-400 complete with it's winglets started commercial service in 1989, 6 years before the 777.

Note the new-ish 747-8 doesn't have any form of winglet, but the 744 did

The raked wingtip on the 77W, 77L, 787, and 748 are all versions of a wingtip device.

 

[jb747]

Re: Why don't the pictures for the 777X show any winglets or rises of any sort?

Looking at the various images of the 777X one point stands out - the wings have no winglets at all on them.

Am I missing something here?

Yep...they aren't worth their own weight in many cases.

Even though they are folding back I would have thought that the tip turbulence would still be worth a 3-5% fuel saving.

Have a look at the 787 wings vs the 777X.

Winglets aren't the only way of reducing drag...and I'll bet that on a modern design (as opposed to the old wing designs that are having sharklets added), you'd be hard pressed to see even 1%.

The 787 wing is extremely flexible, and bends up dramatically...and I expect to see something like that on the 777X.

 

[serfty]

I know these are wiki links but there is some good detail in these pages:

http://en.m.wikipedia.org/wiki/Wingtip_device

http://en.m.wikipedia.org/wiki/Wingtip_device#Raked_wingtip

Cliff notes:

Raked wingtips work ..." in much the same way that winglets do, by increasing the effective aspect ratio of the wing and interrupting harmful wingtip vortices. This decreases the amount of lift-induced drag experienced by the aircraft. In testing by Boeing and NASA, raked wingtips have been shown to reduce drag by as much as 5.5%, as opposed to improvements of 3.5% to 4.5% from conventional winglets."

 

[Altair]

Yes but due to the extra length they give to the new 777 series Boeing need to add the complexity and weight of folding wing tips, a la naval carrier aircraft, to them so they cn fit inside the existing airport infrastructure. IIRC correctly Boeing did offer earlier 777 with a similar feature as to allow the 777 to be used in smaller domestic gates but no airline took up that option.



Article on this Folding Wings Will Let Boeing's New 777x Squeeze Into Small Airports

Here is my question, has anyone else noticed that the Airbus newer engined aircraft have dropped the cheverons (jagged teeth), seen on the 787, 777x and 747-8, on the engine bypass cowling's trailling edge. These were to reduce the noise signature but at the expense of fuel efficiency as the cheverons created that little bit of additional drag and the 787, 747-8 have not be given a lower noise grading to allow for curfew operations.

 

[jb747]

Yes but due to the extra length they give to the new 777 series Boeing need to add the complexity and weight of folding wing tips, a la naval carrier aircraft, to them so they cn fit inside the existing airport infrastructure. IIRC correctly Boeing did offer earlier 777 with a similar feature as to allow the 777 to be used in smaller domestic gates but no airline took up that option.

Everything is a balance in aviation. The folding wings will have their own complexity and cost, but if the saving from the extended wing outweighs that cost, then it becomes worthwhile.

Here is my question, has anyone else noticed that the Airbus newer engined aircraft have dropped the cheverons (jagged teeth), seen on the 787, 777x and 747-8, on the engine bypass cowling's trailling edge. These were to reduce the noise signature but at the expense of fuel efficiency as the cheverons created that little bit of additional drag and the 787, 747-8 have not be given a lower noise grading to allow for curfew operations.

Airbus can't drop what they never used. Whether the jagged edge works or not, I don't know, but Boeing don't seem inclined to dropping it. I think you'll find that they do have lower noise ratings, but that still won't necessarily allow for curfew restricted operations. Here is some actual data from London comparing various types.. https://www.caa.co.uk/docs/33/CAP1191_Noise_Data_for_Boeing787_Heathrow.pdf

 

[juddles]

Everything is a balance in aviation......f

This is exactly right.

Raked vs sharklets etc is a very dynamic field. These wingtips can vary dramatically, but you can be sure the airlines take fuel burn/drag issues very seriously. There is no single "best" solution. The same aircraft can have better configurations depending on the flight profile they fly (short vs long haul, etc)

But I do love the 787's beautiful wing