Ask The Pilot

[por930]

Re: Perth alternates

Thanks Aviator. I guess my original surprise was the QF Singapore flight I mentioned earlier didnt carry any fuel for diversion to an alternate, and while the original forecast had no prediction of Fog plenty of other reasons could have caused the airfield to close. Particulary since Perths two runways intersect, completely possible an aircraft due to arrive immeidately before the QF flight became disabled and blocked both runways.

I get the point Clazman made about various mine sites have a long enough stretch of runway but if the aircraft is low on fuel, the last thing I think the pilots would want to do is having to quickly determine which minesite has a long enough runway, does it have lighting etc. Most certainly they wont have an ILS so given the foggy weather conditions I think most of those minesites within a short distance from Perth would have been unavailable anyway to the crew.

Will be interesting to see what improvements, if any, are made to Kalgoorlie airport to support the upcoming 787 operations.

Because of Perth's isolation from other airports capable of landing a A330, you would think it would be a requirement to carry sufficient fuel for an alternative, in case Perth YPPH is closed at the last minute for what ever reason. I am sure JB will have the answer.
For interest, Perth=3,444m & 2163m, Kalgoorlie=2000m & 1200m, Learmonth= 3047m. A330 requires approx 2700m Take Off, and 1750 Landing, depending on a zillion things. All well and good landing in say Kalgoorlie, but it has to be able to leave again.
Note the ATSB report link, The summary appears below the link....

https://www.atsb.gov.au/publications/investigation_reports/2006/aair/aair200605473/

[FONT=&quot]On 16 September 2006 at 0038Western Standard Time, an Airbus Industrie A330 landed on runway 21 at PerthAirport in weather conditions that were below the applicable landing minima.The aircraft, registered VH-QPJ, was being operated in accordance with theinstrument flight rules (IFR) on a scheduled passenger flight from Singapore toPerth, WA.
[/FONT]Before departure from Singapore, the aerodrome forecast (TAF)for Perth Airport predicted a 30% probability of fog after 0200. The aircraftwas due at Perth at 0020 so in accordance with the operator's fuel policy; fuelwas not specifically carried for a diversion from the destination to analternate aerodrome. While the aircraft was in cruise, the TAF was revised toforecast fog from 2400, but the trend type forecasts (TTF) which superseded theTAF trended fog from 0030.
At about 2350, when the flight crew commenced descent, theaircraft passed the point where it had the fuel to divert to Learmonth, WA.About 10 minutes later, the TTF was amended to forecast fog to occur before theaircraft's arrival time. The fog occurred at about 0015. The crew attempted twoInstrument Landing System (ILS) approaches before they used auto land to landon runway 21 in weather conditions that were below the prescribed landingminima for the ILS
The ILS at Perth (and other Australian airports) was approved tothe Category I standard that did not allow landings where the visibility wasless than 800 m. The Perth runway 21 ILS glide path critical area was not fullyprotected from multipath effects during low visibility operations.
Perth and Learmonth were the only aerodromes in WesternAustralia that could be classified as suitable for the A330, and Learmonth was599 NM (1,110 km) from Perth.
[FONT=&quot]As a result of this occurrence, the operator implemented aninterim flight planning fuel policy specifically for Perth.[/FONT]

 

[jb747]

Re: Perth alternates

Ah, the myths about the amount of fuel aircraft carry.

There is no requirement whatsoever to habitually carry an alternate.

Legally (it varies a bit, but not much), all you need is to have 30 minutes of fuel remaining at the end of the landing roll.

The amount of fuel you require varies depending upon whether you are in the planning stages or actually in flight.

Planning, you need:
Fixed fuel reserve (i.e. that 30 minutes).
Approach fuel (a figure that varies from aircraft to aircraft) but is designed to get you from 1,500' to the end of the landing roll
Flight fuel - the amount you need to get from the start of take off to 1,500' at destination.
Taxi fuel - the amount you'll use getting from the gate to the end of the runway.
Variable fuel reserve - nominally 10% of flight fuel, but that will be to an arbitrary (regulator approved) maximum. For an A380, that's 5,000 kgs.
ATC holding fuel - any fuel required for nominated ATC holding.
Weather holding fuel - whatever you need to cover any TEMPO or INTER periods where the weather is below the nominated holding criteria.
Diversion fuel - required if the weather holding periods exceed your ability to hold.

There are a bunch of others that apply en-route as well. For instance you must be able to get somewhere and land after a depressurisation, or loss of an engine. They may require additional fuel just for that requirement (the depress situation causes quite a substantial fuel addition on the routes to LAX), but in most cases there are runways close enough that they don't need extra.

Once in flight, things change. Now, I simply need:
a) Fuel to go somewhere (anywhere)
b) 10% of (a)
c) approach fuel
d) minimum reserve
e) weather holding (and in some cases, but not all, ATC holding)
f) alternate fuel, but only if I can't handle e)

In most places, there are numerous acceptable airports within only a few miles of destination. Basically the alternate is almost in the circuit. For instance Heathrow/Gatwick/Stansted LAX/Ontario, or even Tullamarine/Avalon. The upshot is that you can have an alternate, basically without carrying any extra fuel. The downside is that these aren't 'real' alternates as they are almost certain to have exactly the same weather conditions.

When you get to places like Tahiti, which is the only decent runway within a long way, you cannot reasonably carry an alternate, so generally there's some form or remote fuel allowance. Basically something like 90 minutes of holding on top of anything else that might be required.

For the 787, the trip towards Europe will be the range limiting sector. But, that doesn't matter too much, as there are untold runways within Europe that can handle any early landing. Heading the other way, because of the winds, you're looking at a dramatically shorter flight. The upshot is that if needed, even Adelaide is likely to be within reach. Perth, like most Australian airports, is under serviced by decent approach aids. Hopefully either (or better, both) CAT IIIB ILS and GBAS will be installed. Both would allow operation in fog. Kalgoolie is certainly viable - its biggest issue was the limited parking.

As to when any decision must be made..that varies on every flight. For instance, arriving at Dubai, I could have sufficient fuel to fly to Muscat. But, if I'm held for any length of time, that alternate option will disappear. I may still be able to carry a closer airport, but eventually, you're left with only one choice. Managing just when you hold, when you divert, and if you'll let options disappear, is what we do every day. On the 94, Sydney normally disappears as an option about the time you pass Albury. It's not impossible that you might not be able to consider Sydney, and so Brisbane may be of interest. The option to go to Avalon may exist right to the gate, or it could disappear whilst still airborne. What's the weather at all of these places. What requirement do they have. There is NO fixed answer.

If you want to play the 'what if' scenario game, then it's easy to come up with ones that are difficult to comply with. Generally if a runway is closed, you'll use another. If the situation is dire, even a taxiway might become interesting. But, you don't need to have aircraft disabled on the runway to make things sporting. How about this scenario.

Destination Wellington. Wind calm. Drizzle. 767. On selecting landing flap, you get a flap asymmetry warning, and the flaps are frozen...they can't be moved at all. Dirty go around. Checklist action gives approach speed of Vref 20 + 20...somewhere around 165 knots. The runway length required is well beyond the length of the runway. Even with alternate fuel, diversion is not possible as alternate fuel never assumes the aircraft will be dirty (and limited to F200). Real situation BTW.

You can't plan for everything. It's a very dynamic world, and sometimes a bit of lateral thinking goes a long way.

 

[OZDUCK]

Re: Perth alternates

The current diversion airports for Perth are luxurious compared to the previous one.When I worked at Perth Airport in ancient times (early 1970's) the diversion airport was Meekatharra - which had very basic services hence Tammy Fraser's (in)famous quote about it being "the end of the earth" after her plane was diverted there.

On this question of fuel reserves I remember Malaysia Airlines introducing the then modern A300 on the KL/Perth run and then after a week or so having to take it off the route because of range problems. They replaced it with some wet leased Laker DC10's for a short time. This was at the height of the DC10 panic after the various crashes and incidents. One flight had landing gear warning lights and did several low passes, at night, to confirm the gear was down and then landed with all the fire appliances alongside the runway with lights flashing etc. When I was talking to some pax after the drama, I mentioned that it was DC10 and they almost fainted - it confirmed to me that many people haven't a clue what type of plane they are flying.

Perth Airport is being upgraded to Cat111 status - [FONT=&amp]Perth Airport has announced that it has begun upgrading its infrastructure and navigational aids to permit Category III Low Visibility Operations by early 2018. [/FONT]Perth Airport upgrade to reduce delays and diversions – AviationWA

 

[por930]

Re: Perth alternates

Jb, so, for airports that are isolated from alternate airports by considerable distance, you will rely on getting in with flight planning fuel loads, not carry extra fuel to make the only gazetted alternative, but will carry extra for anticipated bad weather The basis being, we have always landed there ok for the last x years. Maybe need to circle for a bit longer, or as in Perth incident, we can still do it, just need to move the CAT rules somewhat due to the emergency nature. I suppose in instances like this, you put a tad more thought when you pass over the last point of no return waypoint when you can divert?

 

[jb747]

Re: Perth alternates

Jb, so, for airports that are isolated from alternate airports by considerable distance, you will rely on getting in with flight planning fuel loads, not carry extra fuel to make the only gazetted alternative, but will carry extra for anticipated bad weather The basis being, we have always landed there ok for the last x years. Maybe need to circle for a bit longer, or as in Perth incident, we can still do it, just need to move the CAT rules somewhat due to the emergency nature. I suppose in instances like this, you put a tad more thought when you pass over the last point of no return waypoint when you can divert?

The company provides a flight plan that is minimum legal fuel. Sometimes there are rules that adjust the load, but the outcome will be the minimum. That's perfectly ok, as it gives me a baseline against whatever fuel order I actually want.

We consider lots of things when looking at the weather. Not just today's forecast, but what has been happening over the past few days. What happens if we divert (i.e. will there be support, hours, etc). How familiar am I with the possible diverts. Lots of things.

Sometimes you simply cannot get more fuel on board. There aren't many flights that are affected that way, and they have some 'fall short' options.

My personal fuel order could vary anywhere from the minimum to going right up to max landing or take off weight. Varies every time. On very rare occasions, I've even offloaded items to get a bit more fuel.

The most important factor for me is that the order is decided by the captain. Dispatchers do not order the fuel, though that is not the case everywhere.

 

[RooFlyer]

Re: Perth alternates

<snip>
You can't plan for everything. It's a very dynamic world, and sometimes a bit of lateral thinking goes a long way.

... which is why I have a standing instruction to my Travel Agent not to book me on Dodgy Air. Legacy carriers please, with those horrid expensive (well trained) crew. You never know when ya gonna need 'em until its really important!

 

[straitman]

Re: Perth alternates

TOD - top of descent?

Yes. (......... filler)

 

[andmiz]

Re: Perth alternates

The requirement not to carry alternate fuel seems unless weather forecast dictated is somewhat an Australian peculiarity, but even with the QF & VA emergency landings into Mildura it doesn't seem that CASA will require the industry to catch up to the rest of the world (or at least the ICAO world). Reassuring however to hear that VA does do so for international flights.
Perth's an interesting location in Australia as there are no suitable alternates anywhere nearby, and we'll either carry Adelaide as the alternate, or it gets treated as an 'isolated island airport' and carry 2 hours of holding fuel to allow any un-forecast weather or runway blockages to be clear.

 

[Cheatah]

Re: Perth alternates

The requirement not to carry alternate fuel seems unless weather forecast dictated is somewhat an Australian peculiarity, but even with the QF & VA emergency landings into Mildura it doesn't seem that CASA will require the industry to catch up to the rest of the world (or at least the ICAO world). Reassuring however to hear that VA does do so for international flights.
Perth's an interesting location in Australia as there are no suitable alternates anywhere nearby, and we'll either carry Adelaide as the alternate, or it gets treated as an 'isolated island airport' and carry 2 hours of holding fuel to allow any un-forecast weather or runway blockages to be clear.

Thanks andmiz for your comments. Yes, the main point I was trying to get across in my earlier posting is that aircraft may need to divert for non weather reasons. It seems the QF SIN>PER flight in 2006 that landed below legal minimums was lucky that it was "only" fog. If the airfield was closed for whatever reason then I guess everyone would have hoped that Pearce was available. If not, then maybe a taxiway as JB mentioned earlier. Either way it seems more sensible for aircraft to carry enough fuel for an alternate regardless of weather conditions.

I'm surprised this is an Australian regulatory "thing". Seems like quite a commercial advantage to Australian carriers if they are flying routes in competition with foreign aircraft who do need to take on additional fuel to cover a potential landing at an alternate. I just read up on the Mildura incident and again it appears another close call. I get JBs point that there is potential infinite combinations where fuel may become a concern, and not every possible situation can be planned for. But having enough fuel for a designated alternate is what every other regulator around the world thinks is appropriate I wonder why CASA doesnt think the same.

Given Australia's airfield infrastructure is less developed compared to other countries I would have thought our regulations/policies on alternates would have been stricter than the rest of the world not more lenient!

 

[jb747]

Re: Perth alternates

There are lots of variations to the rules. Even ICAO and the FAA don't specify it as mandatory, except in defined cases. The upshot though, is that in the vast majority of cases, alternates are so close as to be covered under the normal arrival fuel. Australia suffers from having a lack of decent alternates, and then large distances between them.

Many of these 'alternates' are anything but. Changi and Paya Lebar are so close as to likely be under the same thunderstorm. All three of the major London airports tend to have identical weather, with the only saving grace of Stansted being that its direction might help if crosswind is the issue at the others.

My understanding of the Mildura event is that the aircraft did have alternate fuel. In both cases their destination was Adelaide. The logic of diverting away from an airport at which you could do an auto land (irrespective of the actual category of the ILS) to a place with virtually nothing in the way of aids is classic aviation 'make it legal'. If they'd landed at Adelaide they would have been hung. What happened was legal, but dangerous. Common sense just doesn't exist in aviation when there is a rule that a paper pusher can hang you on.

 

[yohy?!]

We flew from HKG-BKK on UL891 on the 26/12, I was hoping to get your opinion, JB on how the flight was handled - on arrival the descent seemed to be quite unstable with some weather over BKK (which I have experienced many times). This time however we experienced periods of heavy turbulence with the plane dropping out below us for sustained periods of time (10-15 sec), there was also a lot of noise coming from the ceiling of the cabin that sounded like impacts hitting the airframe (no hail or rain). As we neared BKK the turbulence cleared and we seemed to stop descending before making a long turn out to sea then back to the airport. Many on board were distressed as we landed - there was more noise/screeching from the ceiling on landing.

 

[oz_mark]

there was also a lot of noise coming from the ceiling of the cabin that sounded like impacts hitting the airframe (no hail or rain).

Was it like a crackling sound? I've heard that on the Qantas and Virgin A330s - no idea what it is.

 

[yohy?!]

Was it like a crackling sound? I've heard that on the Qantas and Virgin A330s - no idea what it is.

yes kind of but more of thumping sound, i hadnt previously heard it on qf332s - perhaps its to do with age

 

[lastrow]

Where do you think the two major aircraft manufacturers will head over the next ten years? At present Boeing seems to be playing second fiddle to Airbus especially in the short haul market where Airbus is selling three times as many A320s as Boeing is selling B737. Also Boeing has virtually given the extra large long haul market to Airbus and it wouldn't surprise me to see Boeing loose B777 market share to the Airbus A350. It all seems pretty gloomy for Boeing at the moment however we are yet to experience the TRUMP factor. How long will the new US president put up with US airlines ordering and flying Airbus aircraft whilst US jobs at Boeing are drying up. Witness Trump's order to Ford to set up their new factory in Detroit and employ American workers rather than invest in much cheaper Mexico.
What do AFF members predict?

 

[N860CR]

Was it like a crackling sound? I've heard that on the Qantas and Virgin A330s - no idea what it is.

Ice crystals forming in the air con ducts and breaking off. You'll occasionally cop one in the face.

 

[petercr]

Possibly more an 'ask the ATC'... Sitting at gate 6 in SYD T3 and in the space of about 5mins, runway 16R had gone from being inbound to outbound... How long does it take for changes to be notified to pilots?

 

[Orca]

Possibly more an 'ask the ATC'... Sitting at gate 6 in SYD T3 and in the space of about 5mins, runway 16R had gone from being inbound to outbound... How long does it take for changes to be notified to pilots?

A runway change can be planned well in advance, particularly with regards to noise sharing or in advance of a forecast wind change. The pending configuration change will be broadcast on the aerodrome ATIS about an hour in advance.
If the change is due to wind direction change, this can usually also be planned in advance as per above with reference to MET forecasts. However on some occasions the wind may swing around earlier than forecast and result in an immediate RWY config change. Often this may be the result of a couple of aircraft having to go round. Such a change in YSSY results in a short notice delays for inbound traffic as they are generally vectored for the other end. Aircraft a little further out (i.e more than 45nm from YSSY) may need to orbit/hold briefly depending on traffic capacity at the time.
Notification to pilots is fairly swift, either via ATIS but for aircraft close in the controller will immediately reissue the new clearance via voice

 

[Dale Eastham]

Re: Perth alternates

If you want to play the 'what if' scenario game, then it's easy to come up with ones that are difficult to comply with. Generally if a runway is closed, you'll use another. If the situation is dire, even a taxiway might become interesting. But, you don't need to have aircraft disabled on the runway to make things sporting. How about this scenario.

Destination Wellington. Wind calm. Drizzle. 767. On selecting landing flap, you get a flap asymmetry warning, and the flaps are frozen...they can't be moved at all. Dirty go around. Checklist action gives approach speed of Vref 20 + 20...somewhere around 165 knots. The runway length required is well beyond the length of the runway. Even with alternate fuel, diversion is not possible as alternate fuel never assumes the aircraft will be dirty (and limited to F200). Real situation BTW.

You can't plan for everything. It's a very dynamic world, and sometimes a bit of lateral thinking goes a long way.

I've thought about this one a bit & am dying to know what the answer was - only close alternate that I can think of would be Ohakea AFB - I dont know for sure but suspect the Regional airport at Palmerston North wouldn't have a runway long enough, and others would be too far away. Possibly Ohakea is too far in 'dirty' configuration too?

I can't think of any other solution other than ignoring the normal approach/ landing requirements based on experience - depending on wind conditions into wellington that could also not be an option though... the curiosity is killing me!!

 

[jb747]

We flew from HKG-BKK on UL891 on the 26/12, I was hoping to get your opinion, JB on how the flight was handled - on arrival the descent seemed to be quite unstable with some weather over BKK (which I have experienced many times). This time however we experienced periods of heavy turbulence with the plane dropping out below us for sustained periods of time (10-15 sec), there was also a lot of noise coming from the ceiling of the cabin that sounded like impacts hitting the airframe (no hail or rain). As we neared BKK the turbulence cleared and we seemed to stop descending before making a long turn out to sea then back to the airport. Many on board were distressed as we landed - there was more noise/screeching from the ceiling on landing.

To be honest it's pretty hard to comment on a flight that I wasn't on. The FR24 trace for it is quite normal.

Realistically, the aircraft can't drop out from under you for any sustained time...though I'm sure it feels like it. Some approaches are rough. Rare enough that people are bothered when they experience one, but it's not always possible to avoid all of the potholes.

I don't know what the noise was. If it stops it probably means something has fallen off. I very much doubt the ice in the aircon ducts theory.

 

[jb747]

Where do you think the two major aircraft manufacturers will head over the next ten years? At present Boeing seems to be playing second fiddle to Airbus especially in the short haul market where Airbus is selling three times as many A320s as Boeing is selling B737. Also Boeing has virtually given the extra large long haul market to Airbus and it wouldn't surprise me to see Boeing loose B777 market share to the Airbus A350. It all seems pretty gloomy for Boeing at the moment however we are yet to experience the TRUMP factor. How long will the new US president put up with US airlines ordering and flying Airbus aircraft whilst US jobs at Boeing are drying up. Witness Trump's order to Ford to set up their new factory in Detroit and employ American workers rather than invest in much cheaper Mexico.
What do AFF members predict?

Both makers have had odd aberrations over the years. Airbus, has a pretty solid line right now, with the 320, 330, 350. The 380 was designed for a world that no longer exists, and I doubt that it will see any second wind.

Boeing seems to have made some strange moves. The 737 dates back to the 60s, and no matter how much they polish it, it's suffering increasingly in the modern market. They had an 80s era replacement in the 757, and they really need a modern version of that now. I'm sure the 747-800 is a wonderful aircraft, but they threw their money away in developing it. The 777 is a modern success story, but it really needs the X version to arrive sooner, rather than later. People aren't buying the classic, with that in the wings. That leaves them with the 787, which is more a 767 replacement than anything else. I'm sure it will mature into a wonderful aircraft, but they desperately need something of it's ilk in the 737 size market...

Right now though, Airbus seems to have a much more consistent family of products...Boeing's seems a bit of a mess.

As for Trump..well Boeing sells its products around the world. Airbus do make 320s in the USA. Any aviation trade war could well lock Boeing out of most of the market...so they would seem to have much to lose.