Ask The Pilot

[jb747]

Re: How many engines can you fly on?

Do you run/exercise "unwinnable" scenarios in the sim ?

No. We'd be too likely to turn around and solve the problem by punching the instructor; we are problem solvers by nature, after all.

Pointless. Something might be demonstrated, but it won't be taken to any conclusion.

 

[casanovawa]

Re: How many engines can you fly on?

No Starfleet Kobiashi Maru simulation eh...

 

[Flying Fox]

Re: How many engines can you fly on?

On the other hand, if I've got an engine failure, and a fire on another, I haven't lost two engines until I shut down the one that is on fire. I can delay that as long as required to ensure it will fly. Deal with the fire issues later. If you look at the Concorde crash, they were doomed when the engineer shut down an engine with a fire warning, without the captain's command. He would have wanted the power, and wouldn't have cared if it melted giving it.

Wow, so you are saying that it would be better for the pilot to have power from the engine on fire vs putting out the fire immediately?

Not being in aviation at all, I clearly have no ideas but at what point does the fear of the fire from the engine burning into the fuel tanks etc come into your decision set when considering having the engine power vs putting out the fire?

 

[jb747]

Re: How many engines can you fly on?

Wow, so you are saying that it would be better for the pilot to have power from the engine on fire vs putting out the fire immediately?

It certainly MIGHT be. An engine fire is nowhere near as scary as a cabin fire. And it's not as bad as the non flying public think. Engines are pretty tough, and being 'on fire' simply means that it's hot in the 'cold' section of an engine...it isn't necessarily all that dramatic.

Not being in aviation at all, I clearly have no ideas but at what point does the fear of the fire from the engine burning into the fuel tanks etc come into your decision set when considering having the engine power vs putting out the fire?

The only reason you'd keep a burning engine running is because you NEED, not want, the power. It is the lesser of two evils. If I shut down a second engine at max weight after taking off from Sydney 34, you're going to end up in the suburbs. Almost anything is better than that....

 

[markis10]

Re: How many engines can you fly on?

In a recent incident the final report mentions "alpha prot" What exactly is that ?

Incident: Air France A321 at Paris on Jul 20th 2012, speed drops to alpha prot on approach

(this incident also reinforces my decision to still have AF on my no fly list)

This question may have been missed?

 

[jb747]

Re: How many engines can you fly on?

In a recent incident the final report mentions "alpha prot" What exactly is that ?

Incident: Air France A321 at Paris on Jul 20th 2012, speed drops to alpha prot on approach

(this incident also reinforces my decision to still have AF on my no fly list)

Alpha protection is the angle of attack or stall protection system. When in normal law, if you decelerate the aircraft it will eventually reach the angle of attack limit, and it will stay there, even with full back stick. To stop the speed decaying, it will simultaneously select TO/GA, even if the autothrust is disengaged...basically an automatic stall recovery.

There are actually a number of ways of making it activate, one of which is simply to select the speed brakes whilst relatively slow...not particularly dangerous, and an overreaction from the aircraft as a response.

It's interesting to note that this response is what the ANZ 320 people were expecting, when it all went wrong on the test flight.

The AF 330 people thought that ALPHA PROT would keep them out of trouble, which is almost certainly why the flying FO thought that back stick was a good idea...they simply didn't realise that the behaviour in different laws is totally different.

Protections are great when they work, but also have the effect of decoupling the pilots from the aircraft. Nobody would pull into a deep stall if they realised they were doing so, but if, at the back of your mind, you think you can't stall an Airbus, then the opportunity is being made. The non moving thrust levers disconnect the pilots from the engine power settings...it's a silly idea. But, it's a couple of Boeings that have had the most recent problems with power control causing an accident....

 

[Flying Fox]

Re: How many engines can you fly on?

It certainly MIGHT be. An engine fire is nowhere near as scary as a cabin fire. And it's not as bad as the non flying public think. Engines are pretty tough, and being 'on fire' simply means that it's hot in the 'cold' section of an engine...it isn't necessarily all that dramatic.

Yep, I'm proof of the non-flying public thinking that an engine on fire is worse than shutting down an engine.

Thanks for your explaination.

 

[Awesom Andy]

Re: How many engines can you fly on?

The only reason you'd keep a burning engine running is because you NEED, not want, the power. It is the lesser of two evils. If I shut down a second engine at max weight after taking off from Sydney 34, you're going to end up in the suburbs. Almost anything is better than that....

Same scenario, but you're on 16 instead, is trying to get airborne still a good idea, or would you smack it onto the tarmac, kill off whatever speed you can, and have a swim in the shallow waters just past the runway?

 

[jb747]

Re: How many engines can you fly on?

Same scenario, but you're on 16 instead, is trying to get airborne still a good idea, or would you smack it onto the tarmac, kill off whatever speed you can, and have a swim in the shallow waters just past the runway?

Fire or failure. Failure it won't fly....decision made. Fire...take it flying. The other option is still the worst of the choices.

 

[mjt57]

Re: How many engines can you fly on?

Yep, run the engine to destruction if it'll save the day.

Back to destroyed engines, on Sunday night Nein showed another special on QF 32. This time they had actors playing the roles of Richard, Matt and the other fellows. Did you see it, JB? If so, thoughts?

I saw the first few minutes before the missus commandeered the TV...

 

[jb747]

Re: How many engines can you fly on?

Yep, run the engine to destruction if it'll save the day.

Back to destroyed engines, on Sunday night Nein showed another special on QF 32. This time they had actors playing the roles of Richard, Matt and the other fellows. Did you see it, JB? If so, thoughts?

I saw the first few minutes before the missus commandeered the TV...

There's a thread elsewhere on the forum about it. Much worse than appalling.....

 

[power71]

QF510 SYD-BNE Aborted take off Tues 18 Feb

My first ever aborted take off this morning at Sydney airport. 767-300 on roll down runway till the breaks were slammed on. Now back at Gate with engineers. Captain said a high pressure value did not close. Any idea what that means or would do? irony is i was put on an earlier flight after international flight from BKK

 

[markis10]

Re: QF510 SYD-BNE Aborted take off Tues 18 Feb

My first ever aborted take off this morning at Sydney airport. 767-300 on roll down runway till the breaks were slammed on. Now back at Gate with engineers. Captain said a high pressure value did not close. Any idea what that means or would do? irony is i was put on an earlier flight after international flight from BKK

I have moved your question to a place I expect will provide the best answer

 

[jb747]

Re: QF510 SYD-BNE Aborted take off Tues 18 Feb

My first ever aborted take off this morning at Sydney airport. 767-300 on roll down runway till the breaks were slammed on. Now back at Gate with engineers. Captain said a high pressure value did not close. Any idea what that means or would do? irony is i was put on an earlier flight after international flight from BKK

Sounds like an HPSOV (high pressure shut off valve).

The aircraft engines provide bleed air for lots of services. When the engine is running at high power, this air is taken from a low pressure source, and at low power settings from a high pressure source. When you start the take off roll, the HP valve should close, and the supply switch to low pressure. If that doesn't happen, you'll get an EICAS that says L/R HPSOV. I forget at which point the message is inhibited during the takeoff, but probably at around 80 knots, which means that it could cause an abort at relatively low speed, but not at the high end of the scale.

If the take off were continued, it's not a danger to the flight, but it's likely to cause damage to the bleed system.

The abort itself, irrespective of speed, would always start the same way. Once the take off has started, RTO will engage if you close the thrust levers, and it applies all 3,000 psi to the brakes, and just lets the anti skid control things. Whilst that might seem overkill, one of the hardest aborts to actually handle happens at very low speed, so it's always best to start with max stopping effort, and then reduce it as you can.

 

[Maca44]

Re: QF510 SYD-BNE Aborted take off Tues 18 Feb

This thread started in June 2011 and now has 137 pages.

At this point jb747 has 2590 posts and I can't thank you enough to imparting your extensive knowledge of flying, your experience flying prior to QF and answering all the questions from us 'unwashed' who (the majority of whom) have essentially no comprehension of how aviation works or the technical aspect of flying one of those big birds.

I have kept up with the threat and read every page, and appreciate the considerable time you spend on the forum answering our questions. Thank you again, what a great thread.

 

[harvyk]

Re: QF510 SYD-BNE Aborted take off Tues 18 Feb

I don't know if this gets more into ask a FA, but with an aborted takeoff, is there a specific speed which the brace command will be given at if the aircraft is going faster than, or is that up to the CSM?

 

[jb747]

Re: QF510 SYD-BNE Aborted take off Tues 18 Feb

I don't know if this gets more into ask a FA, but with an aborted takeoff, is there a specific speed which the brace command will be given at if the aircraft is going faster than, or is that up to the CSM?

Like anything to do with cabin procedures, I'm sure it will vary from airline to airline.

The cabin crew have no access to speed information, and have to base any calls they give on whatever they feel is happening. Whilst it would be nice to think the pilots would make a brace call over the PA, the reality is that if things are getting that extreme, they'll be too busy.

The basic rule down the back is that once one person calls it...they all call it. That will be overkill in some circumstances, but it's always better to be wrong on the safe side.

 

[jb747]

Re: QF510 SYD-BNE Aborted take off Tues 18 Feb

This thread started in June 2011 and now has 137 pages.

At this point jb747 has 2590 posts and I can't thank you enough to imparting your extensive knowledge of flying, your experience flying prior to QF and answering all the questions from us 'unwashed' who (the majority of whom) have essentially no comprehension of how aviation works or the technical aspect of flying one of those big birds.

I have kept up with the threat and read every page, and appreciate the considerable time you spend on the forum answering our questions. Thank you again, what a great thread.

Thank you for that...

I enjoy meeting my passengers, and I go into the cabin as much as I can. Some of you I met in the good old days, when passengers in the coughpit were not only allowed, but welcomed. (And, I must add, you're still welcome, just not airborne).

The point of this thread was always to try to counter the myths of aviation...the media tales of aircraft 'plunging', or the 'dropped thousands of feet in turbulence', and all the other rubbish that passes for aviation stories.

I love going flying, and I'll freely admit that I'm a lucky cough to have had the career that I've had. If I can make one unhappy passenger feel a bit better about coming flying with me, then it's a good day.

 

[legroom]

Re: QF510 SYD-BNE Aborted take off Tues 18 Feb

Thank you for that...

I enjoy meeting my passengers, and I go into the cabin as much as I can. Some of you I met in the good old days, when passengers in the coughpit were not only allowed, but welcomed. (And, I must add, you're still welcome, just not airborne).

The point of this thread was always to try to counter the myths of aviation...the media tales of aircraft 'plunging', or the 'dropped thousands of feet in turbulence', and all the other rubbish that passes for aviation stories.

I love going flying, and I'll freely admit that I'm a lucky cough to have had the career that I've had. If I can make one unhappy passenger feel a bit better about coming flying with me, then it's a good day.

For more than one occasions where a choice was available, I have made the decision to fly QF feeling secure that its pilots are at least as competent as you are, JB.

Reading your posts fills me with confidence in my choice.

You are one of the finest ambassadors for QF.

Keep up the good work (and put up with more silly Qs from time to time incl. some from yours truly !).

 

[petercr]

Re: QF510 SYD-BNE Aborted take off Tues 18 Feb

JB, probably a bit of a silly question but I'll anyway...

Who / what /why determines the route a plane travels on take-off (apart from the obvious of flying into the wind to get extra lift)? On the weekend, I was watching planes take off from BNE on FlightRadar24 and they were departing on runway 01 out over Moreton Bay. Domestic flights going to places such as Cairns, Townsville, Gladstone etc seemed to do a left turn on take-off and then follow the coast line but international flights to Singapore and points in that general direction turned right heading south and did a big loop to the north west taking the 'scenic route' over Brisbane. I would have thought it would have been more fuel efficient to go the same route as the domestics and then turn north-west a bit further north...

Thanks,