Ask The Pilot

[por930]

hummel, jb supplied his schedule a few days ago....
New roster time.

"I'm on leave until the 25th of November.

26/11 93 MEL-LAX
27/11 94 LAX-MEL

05/12 9 MEL-DXB
08/12 1 DXB-LHR
10/12 10 LHR-DXB
13/12 10 DXB-MEL

30/12 93 MEL-LAX
31/12 94 LAX-MEL

07/01 9 MEL-DXB
10/01 1 DXB-LHR
12/01 10 LHR-DXB
15/01 10 DXB-MEL"
Enjoy QF F....A pleasant way to fly...

 

[jb747]

One for the Airbus guys. Pushed back last evenings (Wed 02 / 11) 1830 QF460 MEL-SYD A330-200 service. Started engines and sat stationary for 5-10 minutes. Captain came on the PA and said we just need to reset our "computers" and passengers will see / hear some strange noises in the cabin including chimes, lights flashing, etc. After another 5 minutes Captain came back on the PA and said we're being towed back to the gate and engineers will come on to reset the "flap control unit". We sat at the gate for another 20-25 minutes with the flaps being extended / retracted while we were are the gate a couple of times.

Just after engine start (and around the end of the pushback) the flaps are extended to their take off setting. Any time there is a selection change, that gives the system the chance to either fail, or to find some form of error between the various controllers. It will throw up an ECAM, and that in turn will give a procedure that has to be followed to allow you to continue. The flap position affects some other items within the cabin, which would probably explain the chimes. Repeated movement is probably just a case of 'making sure'.

Captain came on the PA and said he just needed to do a walk around down below and sign off some paperwork and we would be on our way. All up we departed / arrived about 1 hr later than scheduled. A 1hr delay was reasonable as I've had previous A330 sectors where a failed "control surface check" after pushback resulted in the aircraft going U/S and being subbed for another tech crew and aircraft with a 4 hr delay being from the 2 person tech crew being subbed for a 3 person tech crew on a SYD-SIN sector.

I've never seen a failed control surface check on the ground. It is a major issue, and one which quite rightly keeps the aircraft on the ground. I have seen it in flight...but on that day it was just one of many issues.

 

[jb747]

Is this a function of the radar physically "seeing" things, or that the pilot chooses the settings to show what they are interested in, suppressing returns that are just clutter and noise for the job at hand?

Radar, and radar tuning, is a surprisingly complex game. Some (military) radars allowed a great deal of adjustment, whilst most are quite limited. Computerised systems remove most of the complexity, but at times have a nasty habit of either removing the interesting returns, or of showing way too much. Modern airliner radars are automatic, and very few people go back to the base settings and play with them. You simply don't need to...they do their job well enough in auto. I like to fiddle with them because my background involved a complex system, so fiddling is ingrained. The A380 generates a 3d database of radar information, so, to a degree, you can look behind. Cool, and sometimes useful, but it's not really a presentation of the present, but rather a view of what it saw a few minutes ago.

What weather features can you see? Clouds, I guess, but are they differentiated at all? More subtle things like jetstreams and turbulence?

Radar has to reflect from something. That can be an aircraft, land, or moisture. Not air. Jetstreams and turbulence are basically air. There are turbulence displays (and warnings) within the system, but they need to be reflecting off moisture to able to gain doppler and density data.

Weather is generally colour coded by the insensity of the return, and we learn to interpret that. Simplistically, green is ok, yellow so-so, red bad, magenta horrible. But there are times when red can be ok, and green not....

As for other aircraft, there must be some way of knowing where they are located. Do you trust in ATC, look out the window, keep track on the radio ("Breaker, breaker, this is Roo Two, what ya haulin', good buddy?"), or do you just plow on through God's wide night sky out over the Pacific, relying on the hand of the Almighty to keep everyone apart?

Why? Keeping us apart is ATCs reason for being. If you don't trust ATC to do so, then you're going to be a very nervous wreck. There are times in non controlled airspace where we look after it ourselves, but mostly the sky is very full, and having an aircraft do it's own thing as it avoids imaginary issues is not a safe behaviour. TCAS provides a nice last ditch defence. As for radio calls..there are very defined rules as to just what is said, and when, and there is no place for 'breaker'.

 

[Wingin..it]

Ok just had first time in the 737-8.It is a nice A/C ,smooth at high alt .Just wondering are they trickier to land than a 320.I say this because the A320 seems stabler at lower alt,or was it purely the weather(as it was rolling a bit before touchdown?)Mel was pretty windy .
Is Mel easier than Sydney .Sydney is often breezy?
Also Newcastle landing was smooth as .........just missed taking the pics (4) Jets but Jb has them on plane spotters

 

[Captain Halliday]

But there are times when red can be ok, and green not....

Can you give an example of when this might apply?

 

[jb747]

Ok just had first time in the 737-8.It is a nice A/C ,smooth at high alt .Just wondering are they trickier to land than a 320.I say this because the A320 seems stabler at lower alt,or was it purely the weather(as it was rolling a bit before touchdown?)Mel was pretty windy .

You can't read anything into a lack of motion at altitude. That just means the weather was smooth. My experience of both types is as a passenger, but in general I find the smaller Airbus types to have more uncomfortable motion than the Boeings.

A low altitudes (approach), it's easy to put in lots of corrections in the non FBW Boeings, with the aircraft generally responding quite noticeably and instantly to the inputs. The Airbus, on the other hand, will become a real pain if you put in very rapid inputs, as there is the slightest of delays in the response...so you can build up pilot induced motions.

Is Mel easier than Sydney .Sydney is often breezy?

I'd say that Melbourne generally suffers from more wind than Sydney. Nastier crosswinds too, especially on 34. Melbourne 34/16 has about a degree of slope to the south, which can also make things a little more interesting (easy to float on 16 and thump in on 34).

 

[jb747]

Can you give an example of when this might apply?

Remember that the radar is only showing returns from moisture. In general, we don't really care about rain, but we want to avoid turbulence. You can sometimes see some quite interesting (nasty) cells, with lightning, which have little return. They're well worth avoiding (by 20 plus miles if you can). On the other hand (and this was often evident at Singapore), you can have the radar showing red in automatic gain, but if you go to manual and reduce the gain, the returns show the red flickering around the cloud (not staying in one spot). That's heavy rain. Whilst also worth avoiding if you have a chance, as long as everyone is seated, there won't be any issues in going through it.

 

[ChrisGibbs]

I've never seen a failed control surface check on the ground. It is a major issue, and one which quite rightly keeps the aircraft on the ground. I have seen it in flight...but on that day it was just one of many issues.

The Captain on the A330-300 service where I was a passenger said a failed control surface check was extremely rare and hadn't happened, from what he was aware of, during his time flying A330's. The ground engineers spent about 90 minutes resetting various components and even did a power down to "cold and dark" followed by a power up - but it still didn't fix things and needed a complete swap out of a number of control units - hence a replacement plane being required and a replacement tech crew as the 2 person crew would be out of hours on the way to Singapore. I'm assuming if a control surface failed during flight on a modern commercial aircraft there is some level of redundancy that would keep things as normal as possible. Would be different in a A-4 or other military aircraft. If you're able to comment can you provide insight into where you had seen it in flight?

 

[jb747]

The Captain on the A330-300 service where I was a passenger said a failed control surface check was extremely rare and hadn't happened, from what he was aware of, during his time flying A330's. The ground engineers spent about 90 minutes resetting various components and even did a power down to "cold and dark" followed by a power up - but it still didn't fix things and needed a complete swap out of a number of control units - hence a replacement plane being required and a replacement tech crew as the 2 person crew would be out of hours on the way to Singapore. I'm assuming if a control surface failed during flight on a modern commercial aircraft there is some level of redundancy that would keep things as normal as possible.

A control check involves application of nose up/down elevator, full roll input in both directions, and then rudder in both directions. There will be a page in the display systems that shows the control surface position, and you look for the controls to actually move correctly with joystick/yoke movement. On large airliners, the controls are broken up into sections, so an aileron may actually consist of a number of panels, which may be controlled by different hydraulic systems or power packs. There is a huge level of redundancy, no only with the various means of moving the panels, but also because they are sectioned, loss would only affect a subset of them.

But, this redundancy is for use in flight. It's not there to allow aircraft to fly with non functioning controls. So, whilst most failures would have little real effect once airborne, you generally don't take off that way.

Would be different in a A-4 or other military aircraft.

Military aircraft will generally have much less redundancy.

If you're able to comment can you provide insight into where you had seen it in flight?

QF30 lost all roll control from the starboard wing. So, no inboard or outboard ailerons, and no spoilers. The other wing provided plenty...sufficient that the loss wasn't noticeable. You can also get roll control as a secondary effect of rudder, though that isn't normally an airliner technique.

 

[ChrisGibbs]

QF30 lost all roll control from the starboard wing. So, no inboard or outboard ailerons, and no spoilers. The other wing provided plenty...sufficient that the loss wasn't noticeable. You can also get roll control as a secondary effect of rudder, though that isn't normally an airliner technique.

Re: QF30 - given roll control was via the port wing only was there any asymmetric condition/s created? If so were these offset via Rudder control only or via differential power settings from the port & starboard engine/s. Was the aircraft hand flown from the time of the incident and did the automatics assist and take into account the lack of control from the starboard wing?

I recall when learning to fly bug smashers the instructor would always get stuck into if you got lazy and "slip through" a turn and not "keep the ball in the centre" via rudder inputs. In the larger airliners I presumed that when hand flying the pilots use of rudder would be minimal and the automatics would "keep the ball in the centre"?

 

[Boris spatsky]

Ok just had first time in the 737-8.It is a nice A/C ,smooth at high alt .Just wondering are they trickier to land than a 320.I say this because the A320 seems stabler at lower alt,or was it purely the weather(as it was rolling a bit before touchdown?)Mel was pretty windy .
Is Mel easier than Sydney .Sydney is often breezy?
Also Newcastle landing was smooth as .........just missed taking the pics (4) Jets but Jb has them on plane spotters

I have only flown the 737 so can't comment on the A320. You'll have to find a tiger pilot as they are all about to transition to 737 (or leave and find an A320 to fly elsewhere)...

Landing conditions, terrain and runway size really dictate the difficulty - gusty and strong winds make it challenging. The big runways are all similar - Melbourne has a slightly sloping runway but you get used to it.

 

[Altair]

I have only flown the 737 so can't comment on the A320. You'll have to find a tiger pilot as they are all about to transition to 737 (or leave and find an A320 to fly elsewhere)...

Landing conditions, terrain and runway size really dictate the difficulty - gusty and strong winds make it challenging. The big runways are all similar - Melbourne has a slightly sloping runway but you get used to it.

I have spoken to 5 NZ pilots that transitioned from 737-300 to A320. All WLG based and used to the tricky winds experienced there. Without fail all reported the 737-300 was definitely easier to fly and land in difficult wind conditions. However I would also like to add that 2 of the pilots preferred the A320 over the 737-300 as a plane to fly overall.

 

[jb747]

I have spoken to 5 NZ pilots that transitioned from 737-300 to A320. All WLG based and used to the tricky winds experienced there. Without fail all reported the 737-300 was definitely easier to fly and land in difficult wind conditions. However I would also like to add that 2 of the pilots preferred the A320 over the 737-300 as a plane to fly overall.

That's a bit of a back handed compliment....40% of pilots who have flown both prefer Airbus.

Easily the best aircraft that I've flown for tricky conditions is the 767. Very powerful, and very responsive.

 

[jb747]

Re: QF30 - given roll control was via the port wing only was there any asymmetric condition/s created? If so were these offset via Rudder control only or via differential power settings from the port & starboard engine/s. Was the aircraft hand flown from the time of the incident and did the automatics assist and take into account the lack of control from the starboard wing?

I don't recall any persistent roll input, but if there was, you'd simply trim it out using the aileron trim. Even with only half working, that would easily handle anything required. Any abnormal yaw during a roll input would have been cancelled by the yaw damper. Given the amount of asymmetry we practice with for engine failures, this would be minor.

The aircraft was initially hand flown because the engaged autopilot disengaged as the aileron cables were cut. It just happened to be the one autopilot that would have been affected. The left would not engage as it had no air data source until I tidied it up. The centre was engaged about a minute into the event, and stayed engaged for most of the remainder of the flight. It was disengaged a couple of times to get a feel for the aircraft, and finally disconnected at about 2,000'.

I recall when learning to fly bug smashers the instructor would always get stuck into if you got lazy and "slip through" a turn and not "keep the ball in the centre" via rudder inputs. In the larger airliners I presumed that when hand flying the pilots use of rudder would be minimal and the automatics would "keep the ball in the centre"?

Instructors bash students over the head to keep aircraft in trim because once it becomes a habit, they'll automatically do it for the remainder of their flying career. If the aircraft is out of trim (or balance) it will always be flown inaccurately. It's a mind set. Don't aim to be near something. Aim to be right on it.

 

[Quickstatus]

What is meant by "in trim"

 

[jb747]

What is meant by "in trim"

https://en.m.wikipedia.org/wiki/Trim_tab

 

[Awesom Andy]

Instructors bash students over the head to keep aircraft in trim because once it becomes a habit, they'll automatically do it for the remainder of their flying career. If the aircraft is out of trim (or balance) it will always be flown inaccurately. It's a mind set. Don't aim to be near something. Aim to be right on it.

I still remember all those lessons. In a very brief example, if you can fly at 92 knots, you can also fly at 90 knots, so there're no excuses why you're not right on it.

 

[Melburnian1]

On Saturday 5 November for a good deal of the morning the east west runway in SYD was the sole available due to wind. The latter was at 57 kilometres an hour gusting to 65kmh at one stage.

Is 07/25 only 50 per cent as efficient as having the two north south runways available, or is only being able to use the east west even worse because of unsuitability for 'super heavies' such as an A380 at close to maximum take off weight? Didn't one of our esteemed contributors opine previously - I can't find the post - that in most or many circumstances an A380 crew would not want to use the east west runway for takeoff?

Are cross movements (if there are any from aircraft taxiing) even more inefficient when the east west runway is the sole one in use?

What is the maximum number of hourly movements that can be achieved in practice (assuming a busy mix of international and domestic flights ranging from SAAB 340Bs up to A380s) with just 07/25 operating - is it fewer than 40 (which would be half of the permitted maximum of 80 an hour or 20 in any quarter hour period)?

 

[jb747]

More appropriate to an ATC thread...but I'd expect single runway ops on 07/25 to be appreciably less than 50%.

 

[jb747]

I still remember all those lessons. In a very brief example, if you can fly at 92 knots, you can also fly at 90 knots, so there're no excuses why you're not right on it.

Or 50' off the requested altitude. Same with the centreline...you may end up off it by a few feet, but no reason to aim anywhere but right on it.