Ask The Pilot

[Tortuga]

And this goes for a sea going ship too. Get a cabin in the centre of the ship if prone to sea sickness.

Not just the centre - make sure it is as low as possible.

 

[jb747]

12 years in the navy....and I still can't get away from ships.

 

[mjt57]

12 years in the navy....and I still can't get away from ships.

I take it then, that you're not into cruises...

 

[por930]

JB,Boris..I will be traveling to Canada soon, and visiting Yellowknife. Looking at the web site flightaware, they show the routes flown by my aircraft Westjet-WS109. flight between Yellowknife to Edmonton route as only TETAG, TETAG1 STAR. As TETAG is some 1000km from Yellowknife, I would have thought using some airways and fixes would have been more appropriate than 1000km between fixes. Or maybe Flightaware have simplified the route for some reason, and in some cases leave out the actual route?

What distance between fixes do you mostly get provided by your dispatch guys and would you often fly between them direct, rather than via airways?

Looking at the Flightaware site for today's QF9, (which is currently holding at BUBLIN) shows many fixes....DCT NEVIS H345 BOR DCT MTP DCT ISLAV DCT FRT DCT 28S124E DCT EZDON DCT GOKUP DCT VETEL/M084F340 DCT TIPAM DCT 17S111E 14S107E/M085F360 10S102E 08S099E 06S096E DCT MUTMI DCT ELATI/N0496F360 N640 EKASU/N0493F380 N640 KAT P570 CI/M085F380 P570 LATEB/M085F400 P570 KITAL/N0488F400 P570 ITURA M762 BUBIN

 

[Boris spatsky]

Por930, i will take a stab but i must caveat that i have not flown in canada for over 10 years. Most of the continental US and Canada has good radar coverage at high level. Whilst you need to plan via approved routes, frequently once you get airborne they track you direct to a fix hundreds of miles down track (very common in the US). There are also no published direct high routes from TETAG to Yellowknife - so i can only assume that there is an approved direct route from Nav Canada or they have an approved company route for that sector.

Outside of radar coverage, the longest distance between waypoints is meant to be 200 nm (few years ago, anyway). We would insert lat longs at 200 nm intervals if needed to meet that requirement (for example, Perth to Diego Garcia where there is no published route). If there is a route, then you are supposed to fly it, to the extent that in Aus, ATC have started to disallow direct tracking if there is a suitable route nearby as it makes management much easier if you are on an air route.

 

[andmiz]

JB,Boris..I will be traveling to Canada soon, and visiting Yellowknife. Looking at the web site flightaware, they show the routes flown by my aircraft Westjet-WS109. flight between Yellowknife to Edmonton route as only TETAG, TETAG1 STAR. As TETAG is some 1000km from Yellowknife, I would have thought using some airways and fixes would have been more appropriate than 1000km between fixes. Or maybe Flightaware have simplified the route for some reason, and in some cases leave out the actual route?

What distance between fixes do you mostly get provided by your dispatch guys and would you often fly between them direct, rather than via airways?

I had a quick look and there's no airways between Yellowknife and Edmonton, and likely no published requirement to use one between those ports unless the aircraft's navigation capability required ground-based aids. It's only 550nm, so not excessive; along the NOPAC (North Pacific) routes there's 300+nm between waypoints, and upwards of 500nm between PACOTS routes along the Pacific.

 

[jb747]

JB,Boris..I will be traveling to Canada soon, and visiting Yellowknife. Looking at the web site flightaware, they show the routes flown by my aircraft Westjet-WS109. flight between Yellowknife to Edmonton route as only TETAG, TETAG1 STAR. As TETAG is some 1000km from Yellowknife, I would have thought using some airways and fixes would have been more appropriate than 1000km between fixes. Or maybe Flightaware have simplified the route for some reason, and in some cases leave out the actual route?

Interesting route. Almost exactly true north/south, so no turns required once established prior to TETAG. Generating waypoints along the route actually complicates what is a perfect great circle track. There isn't an airway that logically joins the two places. TETAG is simply the start point for the standard arrival, so including that makes sense.

What distance between fixes do you mostly get provided by your dispatch guys and would you often fly between them direct, rather than via airways?

In some of the less populous parts of the world (for instance, much of Australia and over some oceans), free tracking may be allowed. That means the flight planning system does not have to use pre existing waypoints, but can generate them as desired. There are very substantial fuel savings from this practice. Obviously it requires an ATC system that is up to it, and systems that have enough computer power behind them are relatively recent. Waypoints will obviously have to happen at any point where there is a turn, and may also be there as reporting points.

Looking at the Flightaware site for today's QF9, (which is currently holding at BUBLIN) shows many fixes....DCT NEVIS H345 BOR DCT MTP DCT ISLAV DCT FRT DCT 28S124E DCT EZDON DCT GOKUP DCT VETEL/M084F340 DCT TIPAM DCT 17S111E 14S107E/M085F360 10S102E 08S099E 06S096E DCT MUTMI DCT ELATI/N0496F360 N640 EKASU/N0493F380 N640 KAT P570 CI/M085F380 P570 LATEB/M085F400 P570 KITAL/N0488F400 P570 ITURA M762 BUBIN

You can see that the flight uses the airways structure in the busy sections of the trip, but reverts to free tracking over the western half of Australia, and the Indian Ocean. Most of the long range flights enter, and leave, the airways structure a number of times during the journey. The onwards journey from Dubai will be totally planned via the airways, but European controllers will normally issue direct clearances at each control area boundary, so you're rarely on the airway, once past Turkey.

The distance between waypoints varies enormously. It does not necessarily represent the points at which you talk to ATC. With data links that happens regularly anyway. On the overwater flights, they're generally about an hour apart. If ATC want, we can generate points along the track that occur at given latitudes or longitudes.

 

[ChrisGibbs]

Here in AKL waiting for the departure of the Qantas Codeshare service with Emirates (EK413) the A380 service from AKL - SYD. We were midway through the boarding process when the Captain came on the PA and requested everyone to deplane due to a faulty windshield wiper on the Captains side. The Captain explained that everything would need to be reset to a "dark and cold" state to try and fix the problem. I was also surprised to hear that a faulty windshield wiper could stop a plane departing. I guess its one of those parts that doesn't have any inbuilt redundancy. The weather here in AKL has been raining most of the day so I would imagine it could make taxiing a challenge?

 

[cambriamarsh]

Here in AKL waiting for the departure of the Qantas Codeshare service with Emirates (EK413) the A380 service from AKL - SYD. We were midway through the boarding process when the Captain came on the PA and requested everyone to deplane due to a faulty windshield wiper on the Captains side. The Captain explained that everything would need to be reset to a "dark and cold" state to try and fix the problem. I was also surprised to hear that a faulty windshield wiper could stop a plane departing. I guess its one of those parts that doesn't have any inbuilt redundancy. The weather here in AKL has been raining most of the day so I would imagine it could make taxiing a challenge?

I'm in Devonport in Auckland and it's been clear here for a couple of hours. Did you get away tonight?

 

[Deleted member]

I'm in Devonport in Auckland and it's been clear here for a couple of hours. Did you get away tonight?

It's always sunny in Devonport, my old stamping ground

 

[jb747]

Here in AKL waiting for the departure of the Qantas Codeshare service with Emirates (EK413) the A380 service from AKL - SYD. We were midway through the boarding process when the Captain came on the PA and requested everyone to deplane due to a faulty windshield wiper on the Captains side. The Captain explained that everything would need to be reset to a "dark and cold" state to try and fix the problem. I was also surprised to hear that a faulty windshield wiper could stop a plane departing. I guess its one of those parts that doesn't have any inbuilt redundancy. The weather here in AKL has been raining most of the day so I would imagine it could make taxiing a challenge?

I must admit that I hadn't realised that a reboot could affect the wipers...but then that's the initial cure for anything on the aircraft, so perhaps I shouldn't be too surprised.

"Dark and cold" means that they are going to totally power down the aircraft. All of the systems will reboot, but it's a slow process that can easily take over an hour. During that time, the use of almost any system on the aircraft (for instance PA) can cause the reboot to fail, so getting everyone off is the only option.

Wipers can, in some circumstances be MELed, but they will always require the Captains side to work. Try driving your car down the road in a rainstorm without wipers to see what it might be like. Then triple the speed.

 

[marki]

Yep effectively you will see very little at car speeds with working wipers in a proper downpour at night.

 

[ChrisGibbs]

Wipers can, in some circumstances be MELed, but they will always require the Captains side to work. Try driving your car down the road in a rainstorm without wipers to see what it might be like. Then triple the speed.

Would the fault with the Wipers be picked up as part of a pre-departure check or would the fault have been logged by the inbound crew? The reason I ask is we were about 20 minutes out from the scheduled departure when the offload started. The time from CTRL-ALT-DEL to departure was around 100 minutes which pushed our departure time by about 80 minutes. We picked up just over 10 minutes on the trip across the Tasman arriving into SYD around 67 minutes late courtesy of a kind approach onto 16R by tracking to the north of Sydney via what looked to be a BOREE STAR rather than having to overfly the field and join a right downwind for 16R (not sure what STAR that would have been)...

 

[jb747]

Would the fault with the Wipers be picked up as part of a pre-departure check or would the fault have been logged by the inbound crew? The reason I ask is we were about 20 minutes out from the scheduled departure when the offload started.

The wipers aren't touched as part of the preflight, as using them on a dry windscreen causes scratches. Presumably the issue was found on the previous flight. The engineers most likely had a few things to look at (including the MEL possibility) before jumping to the reboot option. The crew would have continued loading on the assumption that they'd be fixed. Sometimes, you're damned if you do, and damned if you don't.

 

[por930]

We picked up just over 10 minutes on the trip across the Tasman arriving into SYD around 67 minutes late courtesy of a kind approach onto 16R by tracking to the north of Sydney via what looked to be a BOREE STAR rather than having to overfly the field and join a right downwind for 16R (not sure what STAR that would have been)...

Hi ChrisGibbs,
I would think they would have used the Marlyn one STAR(which covers the Eastern approach) towards TESAT until ATC radar vectored them to the North of the field for a visual approach, or an ILS into 16R. I am sure JB, being a A380 driver would be better able to comment.

 

[jb747]

Hi ChrisGibbs,
I would think they would have used the Marlyn one STAR(which covers the Eastern approach) towards TESAT until ATC radar vectored them to the North of the field for a visual approach, or an ILS into 16R. I am sure JB, being a A380 driver would be better able to comment.

I expect it was just a MARLN STAR. You can be vectored for either a right or left hand circuit onto 16R depending upon the traffic.

 

[747sp]

When the flaps are extended is the plane flying at the speed it will land at or is the plane constantly slowing down before it lands ?

 

[jb747]

When the flaps are extended is the plane flying at the speed it will land at or is the plane constantly slowing down before it lands ?

The flaps are extended in stages (and retracted the same way).

First stage will normally be at about 15 miles, and depending upon the aircraft type, will probably be just leading edge devices (which could be slats or leading edge flaps). At that point we really just need them to allow us to slow below our minimum clean speed (190-230 knots roughly). The next stage will normally incorporate be a small amount of trailing edge droop, but very likely a large extension rearwards, which increases the wing area. That comes at about 12 miles, and with it a reduction to 160-180 knots or so. Glide slope interception happens at about 10 miles...depending upon the speed at that point, you may be able to leave the flaps as they are until about 7 miles. If you're fast, you'll need a bit more drag, so either early gear selection or more flap, or both.

Landing gear selection happens at about 6-7 miles, and is immediately followed by (in the 380) flap 3, then flap full. The 747 call was "gear down, flap 20" and then "flap 30". Each selection allows a lower speed, so you won't be able to target the final approach speed until all of the flap has run...so about 5-6 miles.

Whilst the flap run is sometimes almost continuous, there will often need to be a pause as the aircraft is slowed to below the max speed for the next stage. For instance, flap 3 has a max speed of 196 knots (A380), whilst full is 182. So, if you've selected F3 at the top end of the scale, you'll have to wait until the aircraft slows below 182 knots before you can take the next. These limits are shown dynamically on the airspeed displays.

We actually don't have to hit the final approach speed until 500' or 1,000' (depending upon the conditions), and even then wind gust adjustments could be applied until very close to the flare.

 

[clazman]

In a recent air crash investigators it mentioned not all commercial aircraft have the ability to dump fuel. What sort of aircraft can't, is this a by design or sold as a optional extra?

 

[andmiz]

In a recent air crash investigators it mentioned not all commercial aircraft have the ability to dump fuel. What sort of aircraft can't, is this a by design or sold as a optional extra?

Hi Clazman, I suspect the misconception out there is that fuel is dumped to minimise the risk of fire during an emergency landing. The reason why fuel jettison systems are included however is on aircraft which have a large weight difference between its maximum takeoff weight (MTOW) and it's maximum landing weight (MLW). Far less of a problem in narrow-body aircraft like the B737 or A320, which is why these aircraft don't have fuel jettison systems, but on a wide-body like the B747, its MTOW is 447.7 tonne and MLW is 346.0 tonne, so if the crew had to immediately return to the airport after takeoff, the aircraft would be close to 100 tonne heavier than its certified MLW. The issue surrounding this then is stress placed upon the landing gear and airframe upon touchdown, and potentially the aircraft would not have enough runway to stop on. We'll carry 100+ tonne of fuel for long-haul flights, so if we did have to come back to land quickly, dumping the fuel to lower the aircrafts weight is the option given to us. We can land overweight when we have to, however of course the risk increases.