Ask The Pilot

[mjt57]

Rwy 22 is the ILS and it's actually owned by Esso. It's due to be changed to Rwy 27 at some point but hasn't happened yet.

http://www.airservicesaustralia.com/aip/current/dap/MESII01-151_01MAR2018.pdf

Thanks Bill.

 

[AviatorInsight]

Any issues with transpacific air tracks with the Hawaiian volcanic activity?

Not really. VA are using PHNL rather than the usual PHKO as an EDTO alternate today. There is a NOTAM for local traffic within the HNL FIR to 3000ft that there is a temporary flight restriction with a 5nm radius of the HILO VORTAC due to volcanic activity. There hasn't been any volcanic ash detected and only minimal activity at the volcano itself. The forecast indicates no ash expected within the next 18hrs.

 

[Himeno]

Any issues with transpacific air tracks with the Hawaiian volcanic activity?

Washington VAAC stopped issuing advisories for that eruption at 1640UTC on the 5th.
The last advisory was eruption ceased, no ash detected, no ash forcast.

 

[Buzzard]

Who is allowed into the coughpit during a flight?
My understanding (probably wrong) is that it is only the flight crew of that flight.
Imagine my surprise when the pax seated in 3F on today's QF flight entered the coughpit.
I spoke to the lady when she exited and walked past my seat (1C) and she told me she usually fly's one of these so she is obviously a QF pilot.

 

[jb747]

Even within Australia, the rules vary across airlines. The only standard bit is that non staff passengers are not allowed in the coughpit in flight. We may even use a passenger seat for rest for an extra crew member, and often they'll put on a jumper so that they aren't quite as conspicuous whilst in the cabin. What was the flight number?

 

[Buzzard]

Even within Australia, the rules vary across airlines. The only standard bit is that non staff passengers are not allowed in the coughpit in flight. We may even use a passenger seat for rest for an extra crew member, and often they'll put on a jumper so that they aren't quite as conspicuous whilst in the cabin. What was the flight number?

QF 1591, Qantaslink BNE-ADL

 

[lastrow]

Recently I saw a YouTube segment that showed a compartment under the coughpit containing the avionics gear. The aircraft was a DC10 and it was certainly crammed full of equipment. It was also interesting to see several steel cables running through pulleys just under the coughpit floor which I guess were linked to the aircraft control surfaces.
Do modern aircraft still have such a room?
Are cable controls still used?

 

[jb747]

Recently I saw a YouTube segment that showed a compartment under the coughpit containing the avionics gear. The aircraft was a DC10 and it was certainly crammed full of equipment. It was also interesting to see several steel cables running through pulleys just under the coughpit floor which I guess were linked to the aircraft control surfaces.
Do modern aircraft still have such a room?

There can be a couple of avionics bays on the larger aircraft. There's one in the 380 below the coughpit, and another above and slightly astern.

Are cable controls still used?

There was a very cunning system interconnecting and separating the cable runs on the 747. The control columns were interconnected, but the cable runs were split up. For instance, roll control had cables down each side of the aircraft. These cables connected only to the flight controls on their side of the aircraft. So, for the pilot to use both control runs (as was normal) it would be partially done with a direct connection, and partially by the interconnect between control columns. My incident was possibly one of the very few that has ever happened in which a 747's control runs were cut, but because of the smart way the controls were designed, we didn't notice. In reality we had much less total control, but as we kept away from the limits, it had no effect.

I think the 320 still has a backup mechanical control link, but more modern ABs don't. But, there is still tremendous redundancy in the way the controls are powered in something like the 380. They are moved by a mix of direct hydraulics, and local hydraulic generation. It provides sufficient backup to have the aircraft fully controllable after total hydraulic failure.

 

[mjt57]

Rwy 22 is the ILS and it's actually owned by Esso. It's due to be changed to Rwy 27 at some point but hasn't happened yet.

Bill, thanks again for the info. We ventured down to ES yesterday. Managed to capture two Growlers landing on 09. But it was a 4hr wait to watch them depart. By then it was dark and even the folks with the good cameras were having problems getting enough light in to them. I have a cheap Nikon so my shots were all blurry.

But here's the question for the Pilot (probably JB as he's the camera guru that I know of). One of the photographers managed to get a really nice shot of the after burner with what appeared to be a chequered exhaust flame. A bit of discussion on why it looks like that. One guess is that it may be pressure waves resulting from the engine being a multi-stage compressor and turbine.

I'll ask the fellow who took it if I can post the photo here, and if that's alright with the forum rules.

 

[lastrow]

Thanks jb. Are the latest 747s still controlled by cables? are the cables directly connected to the surfaces or is there some sort of servo arrangement between. If the control cables were directly connected I imagine there must have been a heavy load on the controls if the aircraft became unstable.

 

[jb747]

One of the photographers managed to get a really nice shot of the after burner with what appeared to be a chequered exhaust flame. A bit of discussion on why it looks like that. One guess is that it may be pressure waves resulting from the engine being a multi-stage compressor and turbine.

The exhaust flow downstream of an afterburner is supersonic, so there are very complex shock wave formations. All you ever wanted to know here.... Shock diamond - Wikipedia

 

[jb747]

Thanks jb. Are the latest 747s still controlled by cables? are the cables directly connected to the surfaces or is there some sort of servo arrangement between. If the control cables were directly connected I imagine there must have been a heavy load on the controls if the aircraft became unstable.

The cables move the servo controls. There would be far too much load for a directly activated cable or pulley motion.

The 747-8 still has the original 747 control systems. It has fancy engines and coughpit, but other than that it's 50 years old.

 

[mjt57]

The exhaust flow downstream of an afterburner is supersonic, so there are very complex shock wave formations. All you ever wanted to know here.... Shock diamond - Wikipedia

Thanks JB. That explains it perfectly, and blew my theory out of the sky, so to speak. Here's a link to the shots that he took last night. Mine are appallingly dismal in comparison.

Benjamin Kerr Snapshot Digital Imagery

 

[docjames]

The A380 has better take off performance than the 747. The shorter runways in Oz are rarely used, because on most flights it's going such a long way, that the weights are right up near the max. In nil wind (and Sydney 25), you could go at up to 534 tonnes, whilst a headwind of 20 knots would get you to 560 tonnes.

We will take the crosswind on a long runway in preference though, as it is much kinder to the engines, and we have more options on long runways.

Found this old post from 2017 which partially answered my question (related to available payload, and in conjunction with online published performance charts).

On a day such as yesterday or today with RWY 25 the primary operating runway, would the 380 use Rwy 25 in SYD (~2500m) and if so, at the payload examples above, how big a payload compromise would be needed to achieve SYD-SIN, SYD-DXB (historically), SYD-LAX or SYD-DXB?

 

[Boca68]

Who is allowed into the coughpit during a flight?
My understanding (probably wrong) is that it is only the flight crew of that flight.
Imagine my surprise when the pax seated in 3F on today's QF flight entered the coughpit.
I spoke to the lady when she exited and walked past my seat (1C) and she told me she usually fly's one of these so she is obviously a QF pilot.

Just as an addendum to this, but in reverse.

Recently flying AKL-MEL QF152 in J. (738) . About half way through (~1.5 hours), needed to use the facilities just after breakfast service. Toilet was vacant according to lighting,
Long story short, by the time I had moved from 2F to the forward galley area, CSM had placed a catering trolley across it, blocking access. Apologised then mentioned the co-pilot was about to use the bathroom. Huh? I don't think I've ever seen this before. But I accepted it and waited. Co-pilot exited, entry still blocked by trolley. Asked CSM if she could move it. Oh no!! PIlot is now going to use the bathroom. So, waited another couple of minutes, pilot then exits coughpit and uses the toilet. All told 10+ minutes.

I've flown a lot, but have never seen this? Is this normal practice for crew? What is Qantas's policy on this?

Or have I just been lucky over the past 20 years? and never experienced it.

I certainly remember many times waiting at the toilets and a pilot exits. But never seen the area actually blocked by a galley trolley.

 

[Flashback]

Just as an addendum to this, but in reverse.

Recently flying AKL-MEL QF152 in J. (738) . About half way through (~1.5 hours), needed to use the facilities just after breakfast service. Toilet was vacant according to lighting,
Long story short, by the time I had moved from 2F to the forward galley area, CSM had placed a catering trolley across it, blocking access. Apologised then mentioned the co-pilot was about to use the bathroom. Huh? I don't think I've ever seen this before. But I accepted it and waited. Co-pilot exited, entry still blocked by trolley. Asked CSM if she could move it. Oh no!! PIlot is now going to use the bathroom. So, waited another couple of minutes, pilot then exits coughpit and uses the toilet. All told 10+ minutes.

I've flown a lot, but have never seen this? Is this normal practice for crew? What is Qantas's policy on this?

Or have I just been lucky over the past 20 years? and never experienced it.

I certainly remember many times waiting at the toilets and a pilot exits. But never seen the area actually blocked by a galley trolley.

I've had it on Qatar and BA.

 

[lastrow]

I'v just been watching a doco regarding a problem with a Lauda 767 where reverse thrust was suddenly deployed at high altitude and full speed caused when two control valves opened simultaneously. The aircraft became uncontrolable and crashed. As a former 767 pilot do recall this incident and steps taken to avoid a re occourance?

 

[Himeno]

Just as an addendum to this, but in reverse.

Recently flying AKL-MEL QF152 in J. (738) . About half way through (~1.5 hours), needed to use the facilities just after breakfast service. Toilet was vacant according to lighting,
Long story short, by the time I had moved from 2F to the forward galley area, CSM had placed a catering trolley across it, blocking access. Apologised then mentioned the co-pilot was about to use the bathroom. Huh? I don't think I've ever seen this before. But I accepted it and waited. Co-pilot exited, entry still blocked by trolley. Asked CSM if she could move it. Oh no!! PIlot is now going to use the bathroom. So, waited another couple of minutes, pilot then exits coughpit and uses the toilet. All told 10+ minutes.

I've flown a lot, but have never seen this? Is this normal practice for crew? What is Qantas's policy on this?

Or have I just been lucky over the past 20 years? and never experienced it.

I certainly remember many times waiting at the toilets and a pilot exits. But never seen the area actually blocked by a galley trolley.

It's been common on US based carriers for the last 16 years.

 

[Boca68]

It's been common on US based carriers for the last 16 years.

I've had it on Qatar and BA.

I have not encountered it before. I was thinking of the many times I'd seen a pilot/co-pilot exit a bathroom. Recall an FA stopping me once as the pilot was going to use the bathroom, but not seen the trolley done before. Anyway, not such a big deal.
Thanks

 

[jb747]

Found this old post from 2017 which partially answered my question (related to available payload, and in conjunction with online published performance charts).

On a day such as yesterday or today with RWY 25 the primary operating runway, would the 380 use Rwy 25 in SYD (~2500m) and if so, at the payload examples above, how big a payload compromise would be needed to achieve SYD-SIN, SYD-DXB (historically), SYD-LAX or SYD-DXB?

I would never use 07/25 unless the crosswind were actually outside limits. So, in excess of 35 knots. At that strength though, the wind is generally gusty, so for crosswind limits purposes, we'd need to use the maximum strength, whilst for take off performance we'd use the minimum. From the original reply, at 20 knots, you'd have to lose 9 tonnes. You may be able to achieve that by offloading cargo.

Dallas or LA are less of a problem, as take off weight in that direction is nowhere near the maximum, so even a few knots of headwind would probably be enough. Singapore is never an issue.

Last night, out of LA, the wind was a tailwind on the duty (24 & 25) runways. We couldn't accept 24L, but 25L was ok. On the other hand, the Boeings going a long way (777 and 787) could not accept the tailwind at all, and were being forced to use 07R.