Ask The Pilot

[Flashback]

He doesn’t really have to request one. A twin engined aircraft with an engine out is in an emergency situation, at which point all of the rules go out the window. On the other hand, telling ATC that you are going to dump shouldn’t be an issue.

If I recall correctly the recommended minimum for dumping is 6,000’. Any emergency over-rules that. The rules are fading - probably ‘cos I’m not looking at them any more.



We don’t really know just what the aircraft issue and status was. The engine was apparently compressor stalling, which almost certainly means that it’s physically damaged, most likely having thrown/eaten blades. It’s unlikely to have been a clean shutdown (of the sort you’d get with loss of the mechanical fuel pump).

There’s a balance to be struck here somewhere. Whilst the aircraft is certified by the FAA and Boeing (both of whom we trust) for a very long ETOPS period (5 hours or so) that does not mean that flying around on one engine for any longer than you have to is a good idea. So, back on the ground as soon as reasonably possible. Conversely, dumping takes time. You don’t really need to get the aircraft to MLW, but the closer you can get to there the better.

As for dumping over land, any scenario in which you want it on the ground ASAP, for instance a cargo fire with confirmation, would have me ignoring all of the rules. I’d stop the dump at around the start of finals. In that case I’m getting rid of as much weight as I can, as I want the quickest stop I can manage, so that I get people running away. If QF 30 had approached over land I would have continued the dump irrespective, as I wanted it on the ground ASAP and at as light a weight as possible.

Was it a mistake? On the very limited info we have, I don’t see the need for the hurry, so I’d say yes. Let’s see if that opinion survives a bit more information.

So if the aircraft is too heavy, what's the impact? Won't slow down in time on landing?

 

[RooFlyer]

Thanks again. The AV report noted that that they had 'brought the engine back under control' - I took that to mean they got it re-started, but as you say, it may have been physically damaged so maybe not.

 

[jb747]

So if the aircraft is too heavy, what's the impact? Won't slow down in time on landing?

A single engine landing would require the use of flap 20, and an approach speed that would be about 20 knots faster than a full flap landing. As it had just taken off, on a very long flight, its weight would be closer to MTOW than MLW, so the approach speed would be high. Chance of the landing being quite untidy (firm or even hard) would be reasonably high. Perhaps strangely, it would also be very likely to float (high speed, little drag). So, an easy landing to get wrong. The brakes would be absorbing a lot of energy, with attendant heat problems. All of this is more reason to be slow and methodical about setting things up.

Thanks again. The AV report noted that that they had 'brought the engine back under control' - I took that to mean they got it re-started, but as you say, it may have been physically damaged so maybe not.

If an engine stalls, the thrust is reduced until it stops stalling. If it’s still stalling at idle, you shut it down. These engines are not going to start stalling in steady state operations unless something is mechanically wrong. So, if you did shut it down, you don’t restart it again. Well, most of us don’t.

 

[Quickstatus]

Sorry about the Twit link

Autonomous taxi take off and landing/

https://twitter.com/x/status/1217821008369004544

Appreciate comments by aviators please

Is flying not fun anymore?

 

[Quickstatus]

If an engine stalls, the thrust is reduced until it stops stalling. If it’s still stalling at idle, you shut it down. These engines are not going to start stalling in steady state operations unless something is mechanically wrong. So, if you did shut it down, you don’t restart it again. Well, most of us don’t.

Are u referring to this:?

Investigation: AO-2016-101 - Engine failure involving Airbus A330, 9M-XXD, 445 km SE of Alice Springs, South Australia, on 16 August 2016

 

[jb747]

Autonomous taxi take off and landing.

At the moment this seems to be little more than a party trick. I really can’t see anything terribly difficult about making the aircraft automatically take off. What would be much more interesting would be to see it handle a range of problems, be they aborts or continuation of the take off. Thus far, automatic systems have been good at handling things when it’s all going well, but rapidly lose the plot when it starts going wrong.

The worry will all of these systems is that as they remove the pilot from the ‘normal‘ loop, they also make him less able to correctly intervene when they lose the plot. Anyone remember MCAS?

Is flying not fun anymore?

I’ve looked carefully through the QF manuals, and nowhere does it say you can’t have fun. Of course, QF has never really tried to control where and when people fly their aircraft, so perhaps it’s an exception.

 

[AviatorInsight]

Sorry about the Twit link

Autonomous taxi take off and landing/

https://twitter.com/x/status/1217821008369004544

Appreciate comments by aviators please

Is flying not fun anymore?

Even if they did install it, I’d probably never use it. There’s no way I’d let it fly the MARUB6 out of SYD or the SWIFT8 departure out of CNS. They’re way too much fun!

 

[Captain Halliday]

Even if they did install it, I’d probably never use it. There’s no way I’d let it fly the MARUB6 out of SYD or the SWIFT8 departure out of CNS. They’re way too much fun!

MARUB6 looks like fun until the guy behind you goes missed.

Close proximity involving Boeing 737, VH-VZO and Airbus A330, VH-EBJ, at Sydney Airport, New South Wales, on 5 August 2019 | ATSB

www.atsb.gov.au

Is it common for the published missed approach path to converge/ cross active SIDs?

 

[AviatorInsight]

MARUB6 looks like fun until the guy behind you goes missed.

Close proximity involving Boeing 737, VH-VZO and Airbus A330, VH-EBJ, at Sydney Airport, New South Wales, on 5 August 2019 | ATSB

www.atsb.gov.au

Is it common for the published missed approach path to converge/ cross active SIDs?

I have also been in that situation, although it was with a dash 8 so because they were much slower our climb was very quick. ATC expect you to fly the published missed approach. For 34R it’s track 070° and climb to 2000ft. This will essentially parallel the track off the MARUB SID.

But in pretty much all cases we get vectored further right and a climb to 3000ft. This is not limited to 34R only.

On 16R the missed is to track 170° and climb to 3000ft but again they basically give us a westerly heading and climb back up to 5000ft.

So it’s pretty rare that we’ll fly the published missed approach procedure. In all cases if a TCAS RA (resolution advisory) occurs we will follow that. It’s actually inhibited below 1000ft and won’t give you a descending breakout below 1500ft.

 

[jb747]

MARUB6 looks like fun until the guy behind you goes missed.

Is it common for the published missed approach path to converge/ cross active SIDs?

The issue with Sydney is that the departures are not built as sensible aviation tracks, but instead are purely there for noise issues. The aircraft can be quite a handful in the initial stages of a go around, so tossing in an early turn just gives that much more opportunity to get things wrong.

A more reasonable departure setup, would have 34L going straight ahead to about 6 or 7 miles, with go around traffic making an immediate turn left turn of about 20-30º. Over on the right runway, you could have the aircraft taking off making a turn of about 20º to the right, and the go around traffic about 50º.

If any go around traffic ends up on the inside of the take traffic, then you extend them straight ahead. Crossing tracks is just asking for trouble. Low level climb constraints are equally problematic.

In this instance, it really looks as if the entire thing would have been a non event if the controller had simply let the 737 land.

 

[Quickstatus]

LHR QNH 1049mb
Can an aviator please discuss how changes in QNH affect altimeter readings. does the altimeter need to be "zeroed" to account for these changes?

 

[AviatorInsight]

LHR QNH 1049mb
Can an aviator please discuss how changes in QNH affect altimeter readings. does the altimeter need to be "zeroed" to account for these changes?

Through the transition level (different for each country) we’ll change the altimeter QNH from 1013 to the local QNH for arrival. No ”zeroing” required.

 

[jb747]

LHR QNH 1049mb
Can an aviator please discuss how changes in QNH affect altimeter readings. does the altimeter need to be "zeroed" to account for these changes?

There are a number of different altimeter settings.

Above a nominated level, all aircraft use the same setting (1013, aka "standard"). The altitude for the change is called the transition altitude during a climb, and the transition level on a descent. As the actual air pressure varies as the aircraft travel, their absolute height varies, but as all aircraft are using the same setting, it changes equally for all aircraft in the same area. Altitudes measured using the standard setting are called flight levels.

Below the transition altitude/level we operate on a local QNH. QNH is the pressure setting we get from the ATIS, and when set on an altimeter, it causes it to read the aircraft's height above sea level. So, on the runway, it reads the local elevation (in Melbourne about 380', or in Sydney about 10').

Another setting system is used in some parts of the world, called QFE. In that case, when that is set, the altimeter will read the height above the airport. So, if I had the local QFE set, in the example above, both Melbourne and Sydney would read zero. I have never seen this system used.

 

[mikenz]

AI - would VA 737 pilots and crew operate on domestic/international only or is there a mix including trans tasman, south pacific, bali etc?
If they're separate which is the most appealing as a pilot? Are there any major differences?

 

[RooFlyer]

LHR QNH 1049mb
Can an aviator please discuss how changes in QNH affect altimeter readings. does the altimeter need to be "zeroed" to account for these changes?

Apologies for the non question, but if those asking questions, at least, could please avoid 'tech-speak' or obscure acronyms, then many more of us will understand and enjoy the conversations.

 

[straitman]

Apologies for the non question, but if those asking questions, at least, could please avoid 'tech-speak' or obscure acronyms, then many more of us will understand and enjoy the conversations.

[mod hat]I respectively disagree RooFlyer. That is what the forum is all about so if something is too technical then please ask it as question.

I'll post a few definitions as soon as I can get back to the computer.[/mod hat]

 

[AviatorInsight]

AI - would VA 737 pilots and crew operate on domestic/international only or is there a mix including trans tasman, south pacific, bali etc?
If they're separate which is the most appealing as a pilot? Are there any major differences?

At present, there’s dedicated VAI B737 crew operating to Bali only. There’s also some international sectors starting to creep in with Australian based pilots (AKL and NAN to be specific).

In the coming months however it’ll be open slather and all VAA (domestic based) crew will get the opportunity to operate to Bali, and throughout the Pacific.

As for which is most appealing? Well everyone is different. Some guys don’t like the challenges of international flying and only want to stay in their own backyard. Others hate long sectors...for me though, it’s very appealing. A change is as good as a holiday for me, so I’ll be looking forward to hopefully operating some international sectors again.

 

[Must...Fly!]

The Aviation Herald

Aviation Herald - News, Incidents and Accidents in Aviation

www.avherald.com

I thought this was an interesting incident in the context of the earlier discussion about the DL flight dumping unexpectedly instead of landing with the extra weight. Even if it did clear up in the cabin a bit, it would be quite distressing for the passengers, I imagine, to circle around for an hour to burn off fuel before getting back to the airfield. It would have been a decent fuel load from OTP-STN, but with the 737, is there anything (other than performance) that would come in to play about the choice of an immediate return to ground after take off?

 

[Moody]

Came across this newsreel of a failed Vulcan landing attempt at Wellington.

Fortunately the damaged plane got airborne and made a "safe" crash landing at Ohakea.

I was wondering if the SIMs ever put this scenario in front of commercial pilots (damaged undercarriage), and is there any technique for minimising the risks when landing with known issues like this?

Edit : it turns out this was one of 3 incidents that day.

 

[AviatorInsight]

The Aviation Herald

Aviation Herald - News, Incidents and Accidents in Aviation

www.avherald.com

I thought this was an interesting incident in the context of the earlier discussion about the DL flight dumping unexpectedly instead of landing with the extra weight. Even if it did clear up in the cabin a bit, it would be quite distressing for the passengers, I imagine, to circle around for an hour to burn off fuel before getting back to the airfield. It would have been a decent fuel load from OTP-STN, but with the 737, is there anything (other than performance) that would come in to play about the choice of an immediate return to ground after take off?

Nope. We always brief that if we’re making an immediate return to land whether an overweight landing will be needed...as a consideration point only. The aircraft will happily land with an inspection required after.

In this case, if the smoke is unable to be determined, I don’t think I’d like to be holding for an hour!