Ask The Pilot

[harvyk]

If by 'just in case' you're referring to 'standby duties'...they are not done at the airport. In fact you have to be careful about doing any work as that might start the clock from CASA's point of view, and so limit what you could be called out for.

Yes, by just in case I meant flying to SYD for standby duties...

 

[reductionist]

I'm interested to know what factors are used to determine what the rate of climb will be after the wheels leave the ground.

Sometimes the aircraft seems to climb very steeply and it feels like I'm being pushed back into my seat quite a lot (almost uncomfortable).

Other times the climb into the sky is quite gentle.

If I had to have a stab at answering my own question I'd say steeper climbs are used when: a) Airports are close to residential areas. b) The pilot wants to spend less time flying in low winds. c) The distance to the destination airport is quite short.

Also, JB, will you be flying the A380 on the SYD-HKG route?

 

[jb747]

I'm interested to know what factors are used to determine what the rate of climb will be after the wheels leave the ground.

Sometimes the aircraft seems to climb very steeply and it feels like I'm being pushed back into my seat quite a lot (almost uncomfortable).

Other times the climb into the sky is quite gentle.

Basically the initial pitch attitude is a result of the power used vs the aircraft weight. So, the more power is used in the take off, the steeper the initial climb. More power could be used for lots of reasons...short runway would be the most likely seen in Oz domestic ops.

A specific target speed is required (around V2 plus 15 to 25 knots) from lift off to clean up (when the flap retraction is started). That gets you away from the ground, with very clearly defined obstacle clearance requirements. The angles required for the obstacle clearance (and some of the statutory climb angles) will be as likely to define the maximum take off weight as the runway length. There are two techniques controlling just when the power reduction from take off to climb happens. Normally clean up starts at 1500, with the pitch being reduced to control acceleration as the flaps are retracted, and the power changed from take off to climb once clean. The second method is mandated for noise reasons (note it doesn't make any less noise, but has the different spread), and that involves power reduction at 1500 feet, and clean up at 3000.

If I had to have a stab at answering my own question I'd say steeper climbs are used when: a) Airports are close to residential areas. b) The pilot wants to spend less time flying in low winds. c) The distance to the destination airport is quite short.

Residential areas can throw up different departure procedures for noise control, though, more than anything else, that normally involves a thrust reduction at 1500' and clean up at 3000'. So, it certainly doesn't make the initial climb steeper.

Low level winds can certainly be a factor. If you have any thoughts at all about possible wind shear, then it's best to use no derate for the take off. In a 767 that will give pitch attitudes that are up around 20 degrees, and perhaps appreciably more.

Short sectors imply light fuel loads, and so lighter overall weight. There is a limit to just how much power you can derate. Aircraft like the 767 have to be able to fly on one engine, generally at much higher weights than what they are operated at on most occasions. Upshot of that, is that the big twins tend to be very powerful, and so need quite high pitch attitudes to keep the initial climb speed under control. In the the 767 the initial pitch targets is around 20 degrees, vs, 15 in the 747 and 12 in the 380.

Also, JB, will you be flying the A380 on the SYD-HKG route?

Probably, though it won't be high on my list. I prefer longer trips, that either start or finish in Melbourne...which basically means London or London.

 

[harvyk]

Just seeing V-speeds mentioned, I’ve gotten the following basic information on V-Speeds from the web, of course as with most aviation things on the web I think it comes from a microsoft flight simmer who plays the basic aircraft (or “point and shoot” aircraft as I call it because provided you aim in the general direction of a runway the aircraft will fly).

So would the following be an accurate?

V1 = Maximum speed which take-off can be safely aborted, although I have heard that beyond V1, a take-off could still be aborted albeit with much greater risk.

VR (Rotate) = Rotate speed, the front wheels lift off the ground
V2 = Takeoff speed, speed which the aircraft lifts off the ground

I’ve always heard that V2 was then the initial climb speed, although V2+15 as you mentioned with V2+15 \ V2+25 would seem like a much better speed to do things at

Vref = Target landing speed, ideally landing is done at this speed.

 

[jb747]

V1 = Maximum speed which take-off can be safely aborted, although I have heard that beyond V1, a take-off could still be aborted albeit with much greater risk.

In terms of energy, runway length, etc, there are occasions from which you could abort at speeds beyond V1. But, it is almost always safer to take a problem into the air than it is to execute a very high speed abort. V1 is generally the first speed from which the aircraft could continue the take off with an engine failure, and once you reach it you should continue.

VR (Rotate) = Rotate speed, the front wheels lift off the ground

It's the speed at which the aft stick input is initiated...with the aim being to achieve V2 at 35'.

V2 = Takeoff speed, speed which the aircraft lifts off the ground

The target speed that we'll use for the initial climb with an engine out.

I’ve always heard that V2 was then the initial climb speed, although V2+15 as you mentioned with V2+15 \ V2+25 would seem like a much better speed to do things at.

V2 engine out. V2+15/25 (or so, varies with aircraft) gives you a comfortable range. You really don't want to be chasing every speed excursion just after take off. Pick an attitude, and if it gives roughly the right speed, then live with it. It also lowers the pitch attitude a bit, which should make it a little more comfortable. And you want to be faster because if the engine failure happens there, then you have a little bit of a speed buffer to use in the first few moments.

Vref = Target landing speed, ideally landing is done at this speed.

The target speed flown on approach will be a few knots faster than Vref, but touchdown should happen at around that speed.

And there are many more Vspeeds. Vmax. Vmca, Vmcg, Vmost of the alphabet.

 

[harvyk]

I've heard that the visual glidescope and the ILS glidescope can be different?
When coming into land (assuming a manual land, not an autoland) would pilots typically follow the ILS in or would they still do a visual landing ie using the glidescope lights (sorry don't know the technical term for those lights) at the end of the runway to judge the glidescope?

 

[jb747]

I've heard that the visual glidescope and the ILS glidescope can be different?
When coming into land (assuming a manual land, not an autoland) would pilots typically follow the ILS in or would they still do a visual landing ie using the glidescope lights (sorry don't know the technical term for those lights) at the end of the runway to judge the glidescope?

Whilst they are both normally 3 degrees, they will almost always have slightly different final touchdown points. Generally close enough to make no difference. PAPI and VASI are the two terms that cover most of the visual glideslope indications. Australia has moved from T-VASIS installations to (the more widespread) PAPI system over the past couple of years...though as usual, I'm a heretic, and prefer the T-VASIS.

If you take an extreme example...an ILS with its 3 degree glideslope, might have to be adjusted upwards to allow for an obstruction quite some distance from the runway, and that will have the effect of moving the touchdown point further in. The visual approach might not have to allow for that, and would be aimed at around the 1,000 feet markers as usual.

The PAPI/VASIS is more useful outside a mile or so from touch down - it's a relatively crude aid. In close, you should be able to just look at the runway, and hold an aim point and glide path without aids. (The mirror systems used on aircraft carriers are not really related, but are much more accurate and have extremely limited angles of view.) In practice, if there's an ILS tuned, then people look at it, but will mostly have converted to totally visual by a few hundred feet...from which point it's just like any light aircraft..aim point, line up, speed.

 

[juddles]

... Aircraft like the 767 have to be able to fly on one engine, generally at much higher weights than what they are operated at on most occasions. Upshot of that, is that the big twins tend to be very powerful.....

JB, how much flexibility is there for the pilot on climb rates, power, etc? The reason I ask is that a while ago I had an amazing experience on a 767. I do a fair bit of flying (as a pax) on most aircraft types, and also have a strong aviation interest, so I probably have a bit better perspective than the average punter. I tend to notice when a flight is not the usual.


Anyway, a few months ago I was on a short hop from BNE to SYD on a Qantas 767. The flight was quite empty (-30% load? I have never had such a wonderful takeoff and climb experience. The 767 did the steepest, most effortless, climb I have ever experienced on a commercial flight. It was almost as if the pilot was having fun and the aircraft was showing off.


Was it just my joy at leaving BNE, or can the pilot take advantage of an almost empty plane and have a bit of a play? How much flexibility is there?

 

[harvyk]

Apart from 2 extra engines, and a wider variety of sizes, is there anything substantially different between the A330 and the A340?
Could the decision to stop selling them be easily reversed at a later date? (In other word simply wack on a couple of extra engines onto an A330 and call it an A340) or would there be more to it than that?

 

[jb747]

JB, how much flexibility is there for the pilot on climb rates, power, etc? The reason I ask is that a while ago I had an amazing experience on a 767. I do a fair bit of flying (as a pax) on most aircraft types, and also have a strong aviation interest, so I probably have a bit better perspective than the average punter. I tend to notice when a flight is not the usual.

The 767 is easily the most powerful of the airliners...a real sports car at times. All you need is for ATC to ask you to expedite a climb, and to hold the speed back a bit, and you can easily make 10,000' downwind after taking off to the north out of BNE. Even with a derated climb, the performance of an aircraft that was meant to operate at 185 tonnes is quite spectacular at 100 tonnes.

Was it just my joy at leaving BNE, or can the pilot take advantage of an almost empty plane and have a bit of a play? How much flexibility is there?

Well, there are lots of rules, but none say that you can't have fun.....not that I've found anyway.

 

[jb747]

Apart from 2 extra engines, and a wider variety of sizes, is there anything substantially different between the A330 and the A340?
Could the decision to stop selling them be easily reversed at a later date? (In other word simply wack on a couple of extra engines onto an A330 and call it an A340) or would there be more to it than that?

I've never flown either...but as far as I can tell, a 340 is simply a 330 onto which they've already whacked a couple of extra engines. It was fairly widely known as the 170, as it was supposedly half the aircraft that Airbus promised. If production has been cancelled it might also have something to do with trying to steer buyers towards the 350 and perhaps the 380.

 

[harvyk]

The 767 is easily the most powerful of the airliners...a real sports car at times. All you need is for ATC to ask you to expedite a climb, and to hold the speed back a bit, and you can easily make 10,000' downwind after taking off to the north out of BNE. Even with a derated climb, the performance of an aircraft that was meant to operate at 185 tonnes is quite spectacular at 100 tonnes.

Well, there are lots of rules, but none say that you can't have fun.....not that I've found anyway.

QF811 is a perfect example of that (when it's a B767 ops). It almost always operates empty, thus it seems the pilots bearly touch the throttle and the thing does a Rodger Ramjet style takeoff...
Loads of fun and one of the reasons why if I'm doing a CBR-MEL in the morning I'll chose that flight.

 

[serfty]

811/804 generally takes a lot of freight, one way, the other or both! (most of it non self loading)

 

[Awesom Andy]

811/804 generally takes a lot of freight, one way, the other or both! (most of it non self loading)

Would I be correct to make a guess that most flights take off with similar weights? I mean, if I was running flights across the country, I would look at how many pax there are, then add in roughly how much fuel they are planning on taking, and then fill the remaining available weight with freight.

 

[jb747]

Would I be correct to make a guess that most flights take off with similar weights? I mean, if I was running flights across the country, I would look at how many pax there are, then add in roughly how much fuel they are planning on taking, and then fill the remaining available weight with freight.

It varies a fair bit. About the only flights that have consistent weights are those like the 94, which tend to be at max take off weight every day. Fuel loadings are available as averages of the past, but actual the actual order isn't made until about an hour before departure, when the Captain sees the flight plan. Boxing him in, by filling all of the available weight with cargo (and so allowing no extra fuel above the minimum) could certainly be done...except that he could then simply offload whatever weight of cargo he felt like removing to make way for fuel...the fuel order is legally his, not an anonymous planner.

Domestically, most 767 flights land around 20 tonnes under the maximum landing weight (and are nowhere near the max take off weight), so in theory that much would be available on every flight.

 

[harvyk]

This is probably more a question for ATC type people, how much control do you guys actually have over military \ VIP aircraft? I’m thinking specifically with Air Force 1’s arrival into CBR this afternoon, but also in general. For example could an ATC controller ask it to slow down, or to change direction slightly etc... Or would it be a completely different system \ group of people directing such operations?

 

[ajw373]

I've never flown either...but as far as I can tell, a 340 is simply a 330 onto which they've already whacked a couple of extra engines.

This was true for the -200 and the -300, probably more than anyone even realises. Ie Same body, same basic wing etc. However the -500 and -600 differed quite a lot from the A330 by gaining new and bigger wings, but the body was pretty much the same.

 

[jb747]

This is probably more a question for ATC type people, how much control do you guys actually have over military \ VIP aircraft? I’m thinking specifically with Air Force 1’s arrival into CBR this afternoon, but also in general. For example could an ATC controller ask it to slow down, or to change direction slightly etc... Or would it be a completely different system \ group of people directing such operations?

I expect that they would control as normal, but it would go to near the top of the priority list.

Military aircraft (in my day) obeyed where they could, but would often have a flight plan that specified anything significantly different. For instance the Macchi had very limited fuel/comms/nav, and would not normally accept holding. It was sometimes hard to get people to understand that our version of 'reserves' meant that the engine was still running...and that we often took off with less fuel than the minimum civil reserves.

 

[markis10]

This is probably more a question for ATC type people, how much control do you guys actually have over military \ VIP aircraft? I’m thinking specifically with Air Force 1’s arrival into CBR this afternoon, but also in general. For example could an ATC controller ask it to slow down, or to change direction slightly etc... Or would it be a completely different system \ group of people directing such operations?

Good question, generally heads of state get priority above RPT traffic, however medivac flights or those involving possible loss of life have priority, case in point being the arrival of air force one where Med1 was given clearance to depart ahead of its arrival while AF1 was given a traffic advisory as part of its visual approach.

 

[markis10]

Noticed yesterday at SYD T1 the A330s seem to have faded red paint on the tail yet the rudder was not faded, it would suggest the tail is in fact need of a wash but it did get me thinking as to the real reason why it appeared so, any ideas??

In the last year I have noticed many faded red tails, quite frankly it looks terrible, perhaps QF got some cheap red paint, it certainly seems worse than ever when it comes to fleet appearance?