Ask The Pilot

[WheelieBagWanderer]

Thanks, JB... and sorry for confusing you as an A330 Captain in a previous life!
Will go and wash my mouth out with soap immediately upon writing this post.

(Having said that, as a passenger - mostly in Y - I *do* like flying on the A330 with it's 2-4-2 config! Much better as a passenger with only 1 person next to you!)

Oh - two more quick questions if I may...

I've noticed on my Flight Radar 24 app on my phone, and when flying, aircraft that take off from runway 16R at Sydney always seem to make a slight right-hand turn quite quickly after take off when over Botany Bay. Always before the Kurnell Oil refinery. They then seem to "adjust" and turn left again (mostly, but not always) to get back on to a track that was in-line with 16R again. Is this for noise abatement? Or some other reason?

Also, I guess this pertains more to when 767's were flying a lot of the A330 routes, were the flight crews utilised for both dom and intl operations? ie. Could you find yourself one week doing SYD-MEL-BNE-PER domestics and then the next week off to MNL, HNL, SIN etc?
Is is still the same today for the 767 crews or is it separated into dom/intl crews?

Thanks again!

 

[Bjet]

Most people I have heard that they really want to be an airline pilot so badly. I am positive sure that it's not that easy to get that job. It's like a lucky draw and pick it up. Then you are very lucky to work for the airlines. Virgin Australia is now hiring cadets (not this time)... maybe few months later. Qantas and Qantaslink will also hire cadet soon. Good luck!

"Follow me" car.... When I flew with Emirates to Hamburg, it was operated by B77W. I couldn't believe that it's so huge to move around that small Hamburg aerodome. That's why pilots have to follow the "Follow me" car. It's useful cos pilots don't have to worry or don't need to check out whether there's enough room for the plane (with long wings) to move between two small planes (737 and A320). B77W is taller than 737 and A320 planes though.

 

[jb747]

Qantas and Qantaslink will also hire cadet soon.

I have my doubts about that....

..... That's why pilots have to follow the "Follow me" car. It's useful cos pilots don't have to worry or don't need to check out whether there's enough room for the plane (with long wings) to move between two small planes (737 and A320).

Not even close. The only time you aren't responsible for wing tip clearance is when the aircraft is being towed. If you drive the wing tip into something, whether following a 'FW' vehicle or not, it is solely your fault. Like everything else in aviation, the aids are there to help the pilot, but never to take any responsibility. The buck stops in the coughpit.

 

[Batesy]

I have my doubts about that....




Not even close. The only time you aren't responsible for wing tip clearance is when the aircraft is being towed. If you drive the wing tip into something, whether following a 'FW' vehicle or not, it is solely your fault. Like everything else in aviation, the aids are there to help the pilot, but never to take any responsibility. The buck stops in the coughpit.

Is Bjet a pilot? I thought that we wanted the pilots such as JB747 and Straitman to be the ones who aswered questions and provided factual information for this thread....

 

[RooFlyer]

Hi again BJ

This isn't precisely in your bailiwick I think, but perhaps you can comment.

One thing that irritates me greatly when flying is pax - most commonly in J - who talk loudly during the safety demo. As well as being rude to the FAs doing the demo, you just know its going to be those oafs who don't know what to do when the sh$t hits the fan.

Only once I think have I seen the FA gently 'shush' the talky pax during the demo.

Does Qantas have any policy regarding quieting noisy pax during the safety demo, or are you aware of any guidelines?

 

[Skyhigh777]

Hi, is there a formula for calculating your V1, Vr and V2 speeds? Does runway length and slope come into play at all?

Thanks

 

[smeacs]

Jb has just been flying around for a holiday when landing I assume the process is to fly the plane onto the ground. As such at what point do you aim to hit your stall speed ?

 

[jb747]

This isn't precisely in your bailiwick I think, but perhaps you can comment.

One thing that irritates me greatly when flying is pax - most commonly in J - who talk loudly during the safety demo. As well as being rude to the FAs doing the demo, you just know its going to be those oafs who don't know what to do when the sh$t hits the fan.

Only once I think have I seen the FA gently 'shush' the talky pax during the demo.

Does Qantas have any policy regarding quieting noisy pax during the safety demo, or are you aware of any guidelines?

I'm not sure what they actually teach the cabin crew with regard to this. I've seen a few variations, ranging from ignoring the perpetrators (for much of the flight actually), a stare that could just about kill, through to a quiz on completion. Plus, of course, that gentle reminder.

 

[jb747]

Hi, is there a formula for calculating your V1, Vr and V2 speeds? Does runway length and slope come into play at all?

It's a complex process, that used to use pages and pages of tabulated data, or multiple graphs. Now, the numbers are generated by a laptop (and soon, the iPad).

Wind, temperature, pressure, all of the runway conditions (slope, wet, dry, contaminated), departure obstacles, aircraft weight, flap setting, packs on or off. Icing. Any runway modifications (i.e. works which temporarily change the runway length). If you can think of a parameter, it will be in there somewhere.

Basically we now fill in all of the blanks in the performance application, and it will generate Vspeeds, power setting, optimum flap setting, and also give us maximum weight for the conditions.

 

[jb747]

Jb has just been flying around for a holiday when landing I assume the process is to fly the plane onto the ground. As such at what point do you aim to hit your stall speed ?

When I first learnt to fly (in a Piper at Canberra aero club) I was taught to land with the stall warning going off at touchdown. That was the last time I ever saw that technique. The jets are all landed at about 20% over their stall speed for the configuration.

Getting anywhere near the stall speed would have tails being dragged along the ground...probably not a good idea.

 

[mjt57]

When I first learnt to fly (in a Piper at Canberra aero club) I was taught to land with the stall warning going off at touchdown.

My first flight in a Victa Airtourer was like that. A horn going off just as we crossed the threshold. Scared the cough outta me, but the pilot was cool and explained what it was (and how it worked). The landing seemed smooth enough, though.

 

[anat0l]

It's a complex process, that used to use pages and pages of tabulated data, or multiple graphs. Now, the numbers are generated by a laptop (and soon, the iPad).

Wind, temperature, pressure, all of the runway conditions (slope, wet, dry, contaminated), departure obstacles, aircraft weight, flap setting, packs on or off. Icing. Any runway modifications (i.e. works which temporarily change the runway length). If you can think of a parameter, it will be in there somewhere.

Basically we now fill in all of the blanks in the performance application, and it will generate Vspeeds, power setting, optimum flap setting, and also give us maximum weight for the conditions.

But you would have a general idea of how to do it so you can check mentally that the numbers generated are in the right ballpark, right? (i.e. in case someone has "fat finger syndrome", or it's new software and someone fouled up the calculation procedure, etc.)

I suppose if the software that generated these numbers fouls up for any reason, you would have the calculation pages handy to get the numbers you need (though the equipment required to generate the numbers could be considered part of the MEL)?

 

[kiwi1972]

G'day jb,
Love the information here.
I was wondering how you descend into an airport. I fly every week but I also live near the flight path from Perth Airport.
it appears that the nose is in an upward attitude? I was told once that square winged aircraft descend nose down but swept wing aircraft nose up? If this correct you must descend with throttle movements to keep the correct glide path. How do you do this and not stall? I no there is the auto throttle but it all amazes me how these big birds seem to float along nose up when they are so close to the airport.
Thanks very much for your time!!!

 

[NM]

It's a complex process, that used to use pages and pages of tabulated data, or multiple graphs. Now, the numbers are generated by a laptop (and soon, the iPad).

Wind, temperature, pressure, all of the runway conditions (slope, wet, dry, contaminated), departure obstacles, aircraft weight, flap setting, packs on or off. Icing. Any runway modifications (i.e. works which temporarily change the runway length). If you can think of a parameter, it will be in there somewhere.

Basically we now fill in all of the blanks in the performance application, and it will generate Vspeeds, power setting, optimum flap setting, and also give us maximum weight for the conditions.

Have you ever looked at the calculated parameters and said "that doesn't look right" and gone back and noticed that something has been entered incorrectly (by the FO of course ), just from your experience? I am thinking of a few notable example of tail strikes where data was entered incorrectly where it very nearly ended badly. I would expect that an experienced Captain (and even FO) would have a pretty good idea of what looks right and what is not right for a particular sector based on the basic parameters like distance (hence fuel loaded and take-off weight), wind, runway length etc.

 

[banger2]

What a fascinating thread this is. As a lurker to it...I found many of my questions already asked and answered.

However, recent flights prompted a question(s) for JB....

Whilst I know my question relates to an aircraft I don't think you flew as a pilot... I'm sure you would have a good idea of the answer to my questions.

Yesterday I took a return flight on a Qantas 737-800 with the same flight crew. I noted 2 things out of the ordinary (in my passenger experience), but dismissed as I am sure you have mentioned these previously as "usually only perception from the passengers". Possibly these have been answered in part before, but my search didn't fully uncover the answers....

The taxing on 2 out of the 4 taxi's seemed rather faster than "normal" (certainly faster than the remaining 2). This part of my question... is there a normal sequence (or guideline) as to who handles the take off sequence (i.e flies the plane)...and who subsequently handles the landing sequence (this was a flight under 1 hour to put it in some context)? Would different crew use different speeds to taxi (within the set speed limits)?

The second part to my question is regarding autoland (I trust this is correct terminology, or descriptive enough!). In this flight I noted both the landings were more solid (read in passenger terms "hard") than many other of my recent flights (mostly widebody I might add, with no 737's). I dismissed this perception as really just a normal landing, from yours (and others) previous comments on the subject. But what prompted me to ask, 1 gent across from me mentioned to his friend it was hard due to the "autopilot" landing the plane. I understood his meaning to be the plane was landed using autoland. Markis10 previously gave a good account of autoland in Australia (but that info is a bit dated now - 2009), and from that I thought neither the aircraft (737-800) nor the airfields (Sydney and Gold Coast) would have been equipped to facilitate that function. Is my understanding correct, neither of these could have been done using autoland? Would you think the 737 would be more likely to produce a more solid landing than a widebody (ie A330/A380), or the perception of a more solid landing?

I trust my descriptions and questions make sense!

JB, Thanks for the time and effort you put into answering this thread in particular!

Ash

 

[jb747]

But you would have a general idea of how to do it so you can check mentally that the numbers generated are in the right ballpark, right? (i.e. in case someone has "fat finger syndrome", or it's new software and someone fouled up the calculation procedure, etc.)

Whilst you'll have a very general idea, the number of variables is simply too great to say that flight X will have a V1 of x and an thrust of Y. We could use any of 3 flap settings, weights vary by up to 50 tonnes. The software chases an optimum profile, and minimum power usage. Previous manual methods simply take far too long to work out for other than quite standardised setups. You do become used to some settings though. Obviously, departing 24L in LAX you expect to see TOGA as the power setting. Out of Europe around 85-90% would be normal...so on a ferry that I did a few months ago, seeing 67% gave us all a momentary pause.

The best protection against an error is simply to have all of the crew work out their answers in total isolation (i.e. get the ATIS yourself, and don't compare any part of the input). We then compare the excess runway, which is a somewhat esoteric output, but which is extremely sensitive to any input variation. Only if we agree on that number, do we then compare all of the other outputs. FMC inputs are checked individually, and there is then a software based cross check.

I suppose if the software that generated these numbers fouls up for any reason, you would have the calculation pages handy to get the numbers you need (though the equipment required to generate the numbers could be considered part of the MEL)?

I very much doubt that the software would generate an incorrect answer. The testing and certification regime for that sort of program is extremely complex, so changes take place very, very slowly indeed. But, no, there is no alternative method. If we lose the ability to work it out (and it exists on three laptops that are part of the aircraft, and on our personal devices as well), then the only alternative would be to have it worked out in Sydney and sent to us.

 

[Skyhigh777]

JB, have you done any interesting flight sims as of late?

 

[jb747]

I was wondering how you descend into an airport.

it appears that the nose is in an upward attitude? I was told once that square winged aircraft descend nose down but swept wing aircraft nose up?

One of the first thing told to all budding pilots is that POWER + ATTITUDE = PERFORMANCE.

To descend from the cruise, we simply lower the nose by about 2º (to about zero pitch) and reduce the power to idle. That will give us a descent at about the same speed as we were cruising.

There is only one combination of power and attitude for any given performance. So, if, for instance, you want to fly at 250 knots and level you will need a specific attitude (probably about 3º nose up) and power (in our case about 50%). If I then wanted to fly at 300 knots, I would need more power, but a lower pitch attitude (about 2º). Going the other way, as you slow down, you'll need an increasing pitch attitude... The power required will reduce until you get to the minimum drag speed (which varies dramatically, but about 210 knots for an 380 at landing weight). If you go below that speed the nose continues to rise, but now the power needed will increase, until eventually you could end up very slow, with a very high pitch attitude and full power...that's if you don't actually stall before that point. Stalling simply means that the airflow over the wing is now breaking away, instead of flowing smoothly from the leading to trailing edge. Stall is related solely to angle of attack, which is the angle that the air is striking the wing. The stall speed that people talk about is always a specific case...in level flight. You can actually stall an aircraft at any speed or attitude, it's possible to stall at 300 knots and it's equally possible to fly at almost zero airspeed and not be stalled (not for long of course).

Flaps and slats have a number of effects, but the main one is that they increase the curvature of the wing, which makes it more of a low speed device. That lowers the min drag speed and stall speeds (in the order of 50 knots).

The upshot of all of this is that I could fly the 380 in level flight, with all flap/slat extended, and gear down, at approach speed, with an attitude of about 5º nose up, and about 40% power. As a glideslope is a -3º, to fly the approach I'd need to lower the nose 3º (i.e. the approach angle), and reduce the power....end result is that we fly down finals at about 2º nose up, and 23% power. Other configurations have other solutions...with limited flaps, the pitch attitude would be higher, the speed higher, but with less power.

If this correct you must descend with throttle movements to keep the correct glide path. How do you do this and not stall?

Power is used to control the speed. The stalling angle of attack is somewhere around 13-15º. On approach the angle of attack is probably around 6-7º...so a long way from the stall.

I know there is the auto throttle but it all amazes me how these big birds seem to float along nose up when they are so close to the airport.

Autothrust exists in all of the airliners that you'll see, but there is no guarantee that it's actually being used on any given approach. Whilst in the 380 we tend to use it all of the time, the general method in the 767/747 was to disconnect it if the autopilot we disengaged. It's really just like the cruise control in a car...useful, but you don't need to use it.

 

[jb747]

Have you ever looked at the calculated parameters and said "that doesn't look right" and gone back and noticed that something has been entered incorrectly (by the FO of course ), just from your experience? I am thinking of a few notable example of tail strikes where data was entered incorrectly where it very nearly ended badly. I would expect that an experienced Captain (and even FO) would have a pretty good idea of what looks right and what is not right for a particular sector based on the basic parameters like distance (hence fuel loaded and take-off weight), wind, runway length etc.

I've seen things that I didn't like and rechecked them, but (touch wood) thus far they've always been correct. Having both pilots make all calculations independently avoids most nasties. A very simple rule in aviation is that if something crosses your mind as something you aren't sure of, then stop and check it. 99 times out of 100, you'll find the doubt was unnecessary, but you only have to be right once.....

 

[jb747]

The taxing on 2 out of the 4 taxi's seemed rather faster than "normal" (certainly faster than the remaining 2). This part of my question... is there a normal sequence (or guideline) as to who handles the take off sequence (i.e flies the plane)...and who subsequently handles the landing sequence (this was a flight under 1 hour to put it in some context)? Would different crew use different speeds to taxi (within the set speed limits)?

QF 737s are always taxied by the Captain. For some reason, TAA never installed the nose gear steering controls on the FO's side in their aircraft, and that has been carried on with all of the later 737s as well. All of the bigger types are taxied by the pilot who is doing the sector. There are lots of things that affect the speed used. Sometimes you need to waste a bit of time, as the gate isn't ready, or heading out to the runway to give the cabin crew time to get the cabin ready. In close to terminals, it's a good idea to slow down. On long straights you can accelerate up to about 30 knots. Perception varies too. The little jets always seem to taxi faster than the big ones, but that's often an illusion, caused by the fact that you're a lot closer to the ground. The Captain chooses who is doing a given sector, more or less at his whim, though most simply do alternate sectors.

The second part to my question is regarding autoland (I trust this is correct terminology, or descriptive enough!). In this flight I noted both the landings were more solid (read in passenger terms "hard") than many other of my recent flights (mostly widebody I might add, with no 737's). I dismissed this perception as really just a normal landing, from yours (and others) previous comments on the subject. But what prompted me to ask, 1 gent across from me mentioned to his friend it was hard due to the "autopilot" landing the plane. I understood his meaning to be the plane was landed using autoland. Markis10 previously gave a good account of autoland in Australia (but that info is a bit dated now - 2009), and from that I thought neither the aircraft (737-800) nor the airfields (Sydney and Gold Coast) would have been equipped to facilitate that function. Is my understanding correct, neither of these could have been done using autoland? Would you think the 737 would be more likely to produce a more solid landing than a widebody (ie A330/A380), or the perception of a more solid landing?

There is an extremely wide range of what pilots consider an acceptable landing. Smooth isn't even in the first few criteria, even though it's what passengers and cabin crew judge by.

Autolands are generally very smooth. If fact we actually allow extra distance on the landing calculations as they tend you use up more runway than manual landings. The 'gent' was almost certainly wrong. Autolands can be done on some runways in Sydney, but I don't know about Coolangatta. In years past it didn't even have an ILS, but I haven't been there in a long time.

Different aircraft do land quite differently. The 747 generally settled down very smoothly. The 380 is a little firmer, but still quite smooth. The 330 seems very 'floaty', and the 767 is, like all sports cars, very firm.

My criticism of Australian runway aids in the past wasn't so much that you couldn't do an autoland, but that doing so got you to no lower a minima than a normal manual landing. CAT II/III and GLS autolands are slowly appearing here now (well Melbourne has the CAT II/III, and Sydney the GLS, though it's minima are still extremely high).[/QUOTE]