Ask The Pilot

[AviatorInsight]

I’m not sure what rates as a strong wind up at FL400 but this mornings QF611 BNE - MEL service had a few bumps in the cruise

Jet streams are usually around the 150kt mark. As shown in the photo below, this is the high level significant weather chart which is just one of the charts that are given as part of the flight plan package. This particular chart was issued yesterday afternoon and valid from 10am today.

If you have a look along the BNE-MEL track there is a fairly strong jet stream sitting at 38,000ft. It's speed there is only about 120kts. I don't have yesterday's charts for this morning's flight but this jet is moving eastward so it's possible that it could have been a bit stronger earlier.

There is also associated moderate turbulence along that track with the occasional severe turbulence up to 42,000ft that sits between BNE and SYD which explains the bumps in the cruise.

 

[MooTime]

Jet streams are usually around the 150kt mark. As shown in the photo below, this is the high level significant weather chart which is just one of the charts that are given as part of the flight plan package. This particular chart was issued yesterday afternoon and valid from 10am today.

If you have a look along the BNE-MEL track there is a fairly strong jet stream sitting at 38,000ft. It's speed there is only about 120kts. I don't have yesterday's charts for this morning's flight but this jet is moving eastward so it's possible that it could have been a bit stronger earlier.

There is also associated moderate turbulence along that track with the occasional severe turbulence up to 42,000ft that sits between BNE and SYD which explains the bumps in the cruise.

View attachment 276757

Thanks for that info & chart.

I'm fascinated by turbulence, where it is consistently , if it's related to what's happening on the group & how it affects the giant metal tube that flies so quick thru the sky. How the wings bend etc etc.

Interested watching my 3yo how he wasn't fussed by it at younger age, but now seems to dislike turbulence going up n down, yet whilst cruising he's fine.
I really appreciate when the Captain gives notice of bumps on flight or not.

thanks for yours & others constant insight, even though I understand so little.

 

[Quickstatus]

This particular chart

What are the black triangles and the lines next to them?

 

[ChrisGibbs]

There is also associated moderate turbulence along that track with the occasional severe turbulence up to 42,000ft that sits between BNE and SYD which explains the bumps in the cruise.

Assuming FR24 is accurate the maximum we encountered on the QF611 BNE-MEL service was around 210kts... The bumps continued on until we were abeam Dubbo - albeit the jet stream was still 200kts+

 

[AviatorInsight]

What are the black triangles and the lines next to them?

They indicate speed. The triangles represent 50knots each and the lines are 10knots. You add them together to get the speed along the core of the jetstream.

 

[jb747]

150 knots over Perth. I guess that's telling you not to go there.

 

[Saab34]

Gents, do many pilots smoke?

I assume smoking in uniform is a big no no, I was going last a Melbourne hotel last week and noticed a international crew lighting up in uniform down the side laneway. I can’t help to think that it would have medical challenges for the older smokers.

 

[jb747]

Gents, do many pilots smoke?

I assume smoking in uniform is a big no no, I was going last a Melbourne hotel last week and noticed a international crew lighting up in uniform down the side laneway. I can’t help to think that it would have medical challenges for the older smokers.

These days, no. Of course there's always going to be some, but the percentage would probably be single digits. I can't think of any of my friends who do.

In the past there were some shockers, who seemed to consider the coughpit to be their personal smoking room. One bloke even had a pipe, though he was just generally obnoxious for other reasons too.

For reasons I never understood, the most common smokers would have been the younger female cabin crew.

 

[747sp]

Hi all. I was looking at the following photo and I was wondering how close do the flaps get to the ground in a heavy landing?
When there is a strong cross wind would you use a smaller setting to avoid hitting the ground with the flaps?
Does each incremental setting for the flaps have same change in effect or is it a diminishing return?

Aviation Photo #6867913: Boeing 747-438 - Qantas

Low res rear port-side view of Qantas Airways First Boeing 747-438, VH-OJA Cn 24354, rolling out on Sydney's Rwy 16R (with flaps and spoilers deployed). Photo taken from taxying RAAF Boeing 707-338C(KC) A20-624, after the AAR Tanker carried out a cross-wind landing at Mascot, as part of the AAR...

www.airliners.net

 

[jb747]

I was looking at the following photo and I was wondering how close do the flaps get to the ground in a heavy landing?

There's heavy landings, and heavy landings. The sort of landing that has the passengers and cabin crew complaining is generally less than 1.2 g. You need to go to 1.4 before engineering will even have a look, and you probably won't have done anything much at less than 1.8 g

To get to the point at which you'd hit the flaps, you'd have to actually break the main landing gear. I don't know how many g that would take, but I'd expect it to be in the order of 3 or so. At that point the flaps would be the least of your worries.

On the 747 any impact will be on the aft fuselage, or an outboard engine. They will occur not so much because of any landing's heaviness, but because of selected roll or pitch attitudes being too great.

When there is a strong cross wind would you use a smaller setting to avoid hitting the ground with the flaps?

No, because hitting the flaps is not an issue. It's not a light aircraft, you can't go putting much bank in to cancel crosswind drift. 5º is about the limit.

Does each incremental setting for the flaps have same change in effect or is it a diminishing return?

Flap settings don't have the same effect. For instance the first step may only involve leading edge flaps. The next might be area increase at the trailing edge only. The next might be more leading edge, and the trailing edge starts to 'bend'. Next one more trailing bend. The last setting is almost all extra drag from the trailing edge.

 

[ChrisGibbs]

Hi all. I was looking at the following photo and I was wondering how close do the flaps get to the ground in a heavy landing?
When there is a strong cross wind would you use a smaller setting to avoid hitting the ground with the flaps?
Does each incremental setting for the flaps have same change in effect or is it a diminishing return?

Boeing Co 747-238B, VH-EBS, Perth, Aero. WA, 2 September 1999 | ATSB

www.atsb.gov.au

This one was from September 1999 where a QF 747-238 scraped a POD on landing into Perth.

 

[ChrisGibbs]

JB747 - when QF were flying the 744's there was an option on the Rolls Royce powered aircraft to carry a 5th POD. Is this capability something that was available on all RR powered 744's or just QF's? Do Airbus have a similar capability or is it reasonable to assume that replacement engines would be available at the airports QF would fly to/from...

 

[FrustratedQP]

Haha not that quite advanced. But there’s an extended motoring to prevent bowing of the N2 rotor. This is done automatically and fuel won’t be introduced until EGT is below 135° even with the fuel control switch to idle.

Still fairly warm, though I guess it's difficult to get cool with short turnarounds. Our target was 100º.

The risk if the initial temperature is too high, is that you'll get what's called "instant light-off", and will get rapidly increasing temperature and pressure in the core. That can lead to a hung start.

150º TOT in the Jetranger (Allison 250-C20B)

 

[jb747]

JB747 - when QF were flying the 744's there was an option on the Rolls Royce powered aircraft to carry a 5th POD. Is this capability something that was available on all RR powered 744's or just QF's?

It wasn't just the RR aircraft. The earlier ones (100s and 200s) could also 5th pod a P&W engine. The capability was quite widespread at one stage, with Tristars, 707, DC8, and VC10 all able to do it. As the fans got bigger, and large freight aircraft more common, it fell out of favour. As far as I know, QF and SAA were the last users. I don't have any way of checking, but I think the fittings actually existed in all of the 747-400s. I found a reference in one of the books mentioning NLH, which was a BA aircraft that QF used for a while, and it was also capable, which would imply all of BA's could.

Do Airbus have a similar capability or is it reasonable to assume that replacement engines would be available at the airports QF would fly to/from...

The engines have simply become too big to reasonably be carried. The Airbus did not have the capability, nor does the 747-800. If you need a replacement, you may be able to get a 'pool' engine, but it's more likely that any replacement will be flown in on a freighter.

 

[eric2011]

Yesterday morning at AKL flight NZ141, B787 pushed back and during the push back a medical emergency arose. The tug disconnected and disappeared and we sat there for approx 30 minutes while the flight attendants looked after the person. After that 30 mins we taxied back to the gate and shut down. Prior to departing the 2nd time the captain advised that due to the wait we needed more fuel. My question is how much fuel burn would occur during that 30 mins with the engines at idle and how much time would that amount of fuel be used during cruise. I didnt think they would have cut it so fine

 

[eric2011]

My second question relating to the above post is in this situation, prior to departing the 2nd time the coughpit door was open ( I was in 3A and had a good view into the coughpit) and it appeared they were doing a pre-departure check list. Do you need to do a full checklist in this departure scenario

 

[jb747]

Yesterday morning at AKL flight NZ141, B787 pushed back and during the push back a medical emergency arose. The tug disconnected and disappeared and we sat there for approx 30 minutes while the flight attendants looked after the person. After that 30 mins we taxied back to the gate and shut down. Prior to departing the 2nd time the captain advised that due to the wait we needed more fuel. My question is how much fuel burn would occur during that 30 mins with the engines at idle and how much time would that amount of fuel be used during cruise. I didnt think they would have cut it so fine

There is a margin, and in this case he would have burnt around 1,000 kgs of fuel. If he hadn't gone back to the gate and shut down, then he would probably have been ok to continue, but by shutting down he now needs to ensure that he has at least the minimum requirement of the flight plan on board.

Basically, if he had exactly the minimum requirement the first time (and there are plenty of Captains who order min op), then the second time he'd be the amount burnt by the first departure less than min op.

My second question relating to the above post is in this situation, prior to departing the 2nd time the coughpit door was open ( I was in 3A and had a good view into the coughpit) and it appeared they were doing a pre-departure check list. Do you need to do a full checklist in this departure scenario

Basically yes. They would have done the complete shutdown and restart. It's far to easy to forget to do something in this case, and running a different procedure is a great way to do so.

 

[Saab34]

Gents

If your on say a long domestic trip, like 4/5 days, and you get sick during that, or the kids do etc and you need to go home, does the company let you abandon the trip as such and pax you back? Would the entire crew also abandon trip and head back to base with you also?

 

[jb747]

Gents

If your on say a long domestic trip, like 4/5 days, and you get sick during that, or the kids do etc and you need to go home, does the company let you abandon the trip as such and pax you back?

I don't think domestic trips are built to that sort of length. If you get sick, you'll basically stop in situ for a while. If you need to go home, they'll most likely try to juggle the rosters so that you work your way back. But it will have to be a pretty solid reason. Kids are expected to get sick whilst you're away from home; it's part of the job. You can't just abandon the trip. You'll have to be replaced somehow or other.

Would the entire crew also abandon trip and head back to base with you also?

No.

If your sick in another city and you want to go home will they send you back or just stay in hotel?

Rather depends upon what is wrong with you. If you have a cold/flu etc, you shouldn't be flying as a passenger, so you'll most likely be left in the hotel. But, if it's something that doesn't medically preclude you from flying as a passenger, they'll send you back to your base as soon as they reasonably can.

 

[AviatorInsight]

Gents

If your on say a long domestic trip, like 4/5 days, and you get sick during that, or the kids do etc and you need to go home, does the company let you abandon the trip as such and pax you back? Would the entire crew also abandon trip and head back to base with you also?

4 Days is the maximum that can be rostered at the moment. Pilots used to opt-in for 5-day trips, particularly during the PER-HKT days. Now if you get sick down route (especially if it's affecting your ears) then you would stay in the hotel until cleared to fly.

The company is generally pretty good at helping you out if something has happened at home that you need to get back for. Has to be legit though. In that case yes the company would absolutely pax you back.

We change cabin crew almost every 2 sectors. So no, they don't also abandon the trip and go home.

I have run out of hours on occasion and in that case, a replacement just for me had to be made while I then went to the hotel, and the rest of the crew continued on (I had already done a couple of sectors prior to joining this crew). So it doesn't need to be related to sickness to get taken off a trip.