Ask The Pilot

[Quickstatus]

We don't compare the plan to the great circle track. The plan distance is used as a crosscheck against the FMC load. Any FMC error will also show up as an erroneous arrival fuel figure..which is also checked.

Looking at a pair of 93/94 plans (on the same day). The great circle distance between Melbourne and LA is 6883 NM. The 93 has a distance of 6954 and a time of 13:25, whilst the 94 has 6948 and 14:55. Arrival and departure tracking is not accounted for on the plan.

With modern flight planning, Does the actual distance flown change much? 5-10%?

 

[jb747]

Sim time again. I was originally scheduled for two sims this week, but one was cancelled, and will happen when I get back from leave...a sort of 'welcome back'!

This exercise was mainly a LOFT (line oriented flying training), which means that it will be a flight from A to B, with any events happening in real time. Events can pile on top of each other, so you may simultaneously end up with something happening in the cabin, some weather to be avoided, and then aircraft issues. As usual, the instructors have a menu of items they can use, so not every exercise will be exactly the same, nor will the outcome.

The scenario was a charter from Singapore to Bangkok. Night time (aren't all sims) and the weather at Singapore was misty with visibility reduced to 350 metres. En-route weather was typical tropics. Isolated storm cells.

Take off and initial departure were normal. During the climb the autopilot disconnected, and the aircraft rapidly rolled left and pitched down. I grabbed the sidestick and put in control inputs to correct that. During all this a 'dual input' warning was heard. When I asked the FO if he'd made any inputs I found that he hadn't, so that indicated that we had some sort of random input from his controller. I held the override button down on my side (for over 30 seconds), and that locked his side stick out of the system. Autopilot back in, and back to 'normal'. Because of the weather, we hadn't turned the seat belts off, so the excursion caused no issues down the back.

CSM rings up to tell us that a passenger is sick. It's just a nuisance item for the exercise.

As we're avoiding a cell (by flying about 20 nm to the east of it), Master Caution, 'main electronics bay smoke'. No smoke in coughpit or cabin. FO starts to deal with the ECAM, which very quickly instructs him to pull out his paper checklist (because the next actions may well take away the electronic system). In the meantime, I declare an emergency and point the aircraft at KL (the nearest place, but also with better weather than Singapore). The procedure has the FO turning off lots of electronics that we can do without, isolating the electrical system into left and right halves, and then turning off the generators for one side. This leads to a very long list of failures. Smoke warning eventually goes out. For obvious reasons, we're not going to re-power that side, so we just have to live with the failures. The aircraft redundancy handles it well. Proceed to KL and carry out an automatic landing on 14R, in reasonably heavy rail. During the approach, ECAM comes up telling us that we've lost anti skid to all of the body gear. Blow all of the body gear tyres during the landing.

Next part is to fly from KL back to Singapore, FO doing the flying. Before take off told that there is some flooding on taxiways at the far end. They just want to hear any discussion about intentions if we abort the take off, and how the flooding could change that. Don't use the taxiways, and no U turn on the runway. So, if we stop, we'll need a tug.

Departure starts out normally. Another false side stick input, FO grabs it. This time there is no 'dual input' warning. We can still assume that it wasn't the autopilot, as that has disconnected. The lack of dual input indicates that it's the FO's controller again. Normally you'd lock him out again, but as it's his sector, it's miraculously cured. Continue climb. Airspeed displays start to diverge, and that gives us 'unreliable airspeed'. All you need to do to control this is to disconnect the automatics and set a sensible attitude and power. He just levels off. Warnings appear for two air data computers, and somewhere in there, the aircraft reverts to alternate law. No hurry, it's easily handled. Those amazing engineers fix it again. Head on to Singapore for an arrival we know well, and from which you'd often be turned in quite high (if you were prepared). That's exactly what happens, and FO calls for gear very early (it's a really good way of getting rid of energy). The gear is normally down in about 30 seconds, but after 120 seconds, master caution for unsafe gear. As he hasn't even started the ILS yet, he levels off and we get some radar vectors. I run the checklist, which involves retracting the gear, and then doing an alternate extension. All locks down just as we join finals again. Apparently the lesson plan actually called for this to happen later, and to cause a go around, but the FO's reaction to the early turn circumvented that. Of course, he had some prior knowledge, as he was only there to support me, and had already done his own sim.

Next we set up for a take off. At 100 knots, there's a speed check...FO's airspeed did not match mine, so I rejected the take off. Park brakes. Exercise over.

 

[Captain Halliday]

Ignoring the fact that this was a SIM, would the problem with the FO side stick be something that would pass as a MEL or if it happened for real, would the aircraft be grounded until engineers sorted it out?

 

[jb747]

Ignoring the fact that this was a SIM, would the problem with the FO side stick be something that would pass as a MEL or if it happened for real, would the aircraft be grounded until engineers sorted it out?

It would ground the aircraft.

 

[Quickstatus]

Do these scenarios have a real life back story?

 

[jb747]

With modern flight planning, Does the actual distance flown change much? 5-10%?

SIDs and STARs can add about 20 miles to the track. Biggest issue isn't so much extra miles, but being forced into an early descent. Down low the jets are thirsty. This is a regular happening at LA and Dubai, and there's normally a fuel allowance to cover it.

Distance variation would likely be under 1%.

 

[jb747]

Do these scenarios have a real life back story?

They want to work through most items in the checklist over a 3 year period. They use interesting events that happen anywhere in the world. My depressurisation changed the way that was exercised. The focus on air data would have most likely come from AF447. A law reversion, and the inability to deal with it, caused Air Asia 8501. Asiana drove a look at vertical offsets and visual approaches. I expect the Emirates accident will lead to more late go arounds (in the sim).

Sometimes they are almost prescient...it's promulgated in a sim exercise, and then happens for real.

 

[Melburnian1]

Sim time again. I was originally scheduled for two sims this week, but one was cancelled

The scenario was a charter from Singapore to Bangkok. Night time (aren't all sims) and the weather at Singapore was misty with visibility reduced to 350 metres...
so I rejected the take off. Park brakes. Exercise over.

An incredible amount of detail, jb747.

How on earth do you remember all that to record for we AFF members?

Or does the airline give you an electronic or paper copy of the scenario so that you can remember what the problem(s) were and importantly, how you solved them?

 

[jb747]

An incredible amount of detail, jb747.

How on earth do you remember all that to record for we AFF members?

Or does the airline give you an electronic or paper copy of the scenario so that you can remember what the problem(s) were and importantly, how you solved them?

It sticks. I can't remember where I left my wallet, but aircraft stuff.... I think there's even some Macchi recall items still rattling away in my head.

There's a computerised training report, but it doesn't say much...unless you make a mess of it. The briefing sheets for the exercise sometimes contain a breakdown of what will be done, but these LOFT exercises are thinly scripted.

 

[JohnM]

What was the duration of that sim exercise?

 

[Skyring]

The briefing sheets for the exercise sometimes contain a breakdown of what will be done, but these LOFT exercises are thinly scripted.

Does that mean that the sim staff have flexibility to alter the events? I mean, if the flight crew seem to be handling the various crises well, would they throw some extra excitement into the mix to really give you a workout?

I'm thinking that it's one thing to be able to do things by the book if you've got enough time, but time-related stress management might be something that is regularly tested on the ground, and the only real way to do that is to keep on throwing disasters at the crew until something snaps.

 

[jb747]

What was the duration of that sim exercise?

The sessions are normally 4 hours, with a 45 minute briefing beforehand.

 

[jb747]

Does that mean that the sim staff have flexibility to alter the events? I mean, if the flight crew seem to be handling the various crises well, would they throw some extra excitement into the mix to really give you a workout?

There's basically a menu of items that can be chosen, but for reasons of standardisation, they have to stay within that.

I'm thinking that it's one thing to be able to do things by the book if you've got enough time, but time-related stress management might be something that is regularly tested on the ground, and the only real way to do that is to keep on throwing disasters at the crew until something snaps.

That's an utterly pointless thing to do, and results in negative training. Mistakes are made, and hopefully fixed, within the sessions. There's plenty of load. Loading something until it breaks will just as likely result is a session from which you remember nothing.

 

[Wingin..it]

We seem to have a choice between between a 737-800 or a320 on some routes .Virgin 737,Jetstar a320.Q 737-800.Do you have the pros and cons for both and is the newer 737 better.They seemed to have many incidents (older 737's )Thanks !

 

[Walter_Plinge]

During the approach, ECAM comes up telling us that we've lost anti skid to all of the body gear. Blow all of the body gear tyres during the landing.

I gather this is not regarded as adverse. Replacing the tyres would be costly in terms of lost time, manpower, and materials. Is this a usual outcome with loss of anti-skid, i.e., it's not possible to brake by feel, stop safely, yet avoid blowing the tyres?

 

[jb747]

I gather this is not regarded as adverse. Replacing the tyres would be costly in terms of lost time, manpower, and materials. Is this a usual outcome with loss of anti-skid, i.e., it's not possible to brake by feel, stop safely, yet avoid blowing the tyres?

Sometimes the sim doesn't replicate the aircraft correctly, and at others it generates faults all by itself. With the electrical systems that we'd turned off for the exercise, we should have had alternate brakes with anti skid. I was about to go around to give us time to look at it, but the instructor hadn't added the fault, and didn't want to spend the time. So, for the purpose of the exercise, he said to continue the landing.

The brake pedals have no feel, and unless you don't use them at all, you'll be pretty much bound to blow tyres landing on a wet runway without anti skid. The technique is to apply a mid level of pedal pressure, and to not modulate the brakes at all. If they blow, they blow.

Anti skid was one of the failures on QF30, and on that landing, on a damp runway, we didn't blow any.

 

[jb747]

We seem to have a choice between between a 737-800 or a320 on some routes .Virgin 737,Jetstar a320.Q 737-800.Do you have the pros and cons for both and is the newer 737 better.They seemed to have many incidents (older 737's )Thanks !

Go with the airline that you like. Both aircraft are fine.

 

[Wingin..it]

Good advise jb the one I like .The one I like has to make a connecting flight but great the 737 has thumbs up.Must admit have shied away from it for supposedly safety ratings.

 

[Foreigner]

Scary aborted landing in Prague:

http://www.dailymail.co.uk/news/art...owly-avoids-crashing-wheels-graze-runway.html

 

[Captain Halliday]

Scary aborted landing in Prague:

Plane aborts landing in Prague and narrowly avoids crashing as wheels graze the runway | Daily Mail Online

This video has sparked some questions from me:
1. What, if any, is the difference between wind sheer and a strong cross wind? Is wind sheer intermittent/lees predictable and cross wind more contstant?
2. Is the incident wind sheer or something else not evident from the video?
3. In a go around, how quickly might you typically raise the gear and reconfigure? The gear appears to be left down longer than for a standard departure. Is that typical for a go around? Is the delay likely just the crew attending to other tasks associzted with the go around, or could there be another reason(s?
4. Are there circumstances in a go around in which you might leave the gear down?