Search found 16731 matches

by zeke
Fri Dec 31, 2021 10:02 pm
Forum: Technical/Operations
Topic: Altimeters, static pressure, and lift
Replies: 48
Views: 2584

Re: Altimeters, static pressure, and lift

Anybody who thinks there are no pressure differentials on boat rudders needs to go sail a Laser dinghy. Get on a broad reach in 20 knots of breeze, let the boat heel over 30 degrees, and then pull the tiller to try and maintain course. Spoiler alert: you'll hear a "khkhkh" sound as the up...

Jump to post
by zeke
Fri Dec 31, 2021 11:16 am
Forum: Civil Aviation
Topic: Cathay Pacific Suspends 747F and Cargo-Only Pax Flights for 7 Days
Replies: 184
Views: 29935

Re: Cathay Pacific Suspends 747F and Cargo-Only Pax Flights for 7 Days

Really ? According to Dr David Hui Shu-cheong (apparently a "leading government pandemic advisor"): "Hui urged residents to get tested if they had been to any of the 60 places known to have been visited by the aircrew, and said people should avoid gathering in groups to celebrate New...

Jump to post
by zeke
Fri Dec 31, 2021 2:52 am
Forum: Technical/Operations
Topic: Altimeters, static pressure, and lift
Replies: 48
Views: 2584

Re: Altimeters, static pressure, and lift

I didn't say that the vapour pressure changes. I said the the static pressure drops below the vapour pressure, and that causes cavitation. It is not an isothermal process, hence the reason advanced weapons systems use active temperature control to reduce noise and vibration. Some weapons systems ca...

Jump to post
by zeke
Thu Dec 30, 2021 9:38 pm
Forum: Technical/Operations
Topic: Altimeters, static pressure, and lift
Replies: 48
Views: 2584

Re: Altimeters, static pressure, and lift

It is primarily a function of the static pressure of the fluid dropping below the vapour pressure of the fluid. If and where that happens, you can (or will) have cavitation. And why does the static pressure drop in certain areas? Because the dynamic pressure (i.e. the local velocity) rises, while t...

Jump to post
by zeke
Thu Dec 30, 2021 8:01 am
Forum: Technical/Operations
Topic: Altimeters, static pressure, and lift
Replies: 48
Views: 2584

Re: Altimeters, static pressure, and lift

By 'phase change' do you mean liquid turning to gas? My understanding of cavitation is that it's when the pressure over a boat/ship's propeller surface drops to the point where gas forms (it effectively 'boils'). Prop blades nearer the surface are more prone to cavitation due to the lower pressure ...

Jump to post
by zeke
Wed Dec 29, 2021 10:05 pm
Forum: Civil Aviation
Topic: Emirates serious incident on takeoff on EK231 DXB-IAD on 20 December 2021
Replies: 267
Views: 63576

Re: Emirates serious incident on takeoff on EK231 DXB-IAD on 20 December 2021

kalvado wrote:
Would you assume 40 knots tailwind for takeoff? I doubt that could be the case.


I would expect the density altitude to be above airport elevation.

Jump to post
by zeke
Wed Dec 29, 2021 9:39 pm
Forum: Technical/Operations
Topic: Altimeters, static pressure, and lift
Replies: 48
Views: 2584

Re: Altimeters, static pressure, and lift

Wait....are you saying that marine propellers, rudders, etc., do not induce a pressure differential? Then how do you explain cavitation? Cavitation is caused by a phase change, the rate of phase change depends upon local flow conditions (pressure, velocities, turbulence) as well as fluid properties...

Jump to post
by zeke
Wed Dec 29, 2021 9:29 pm
Forum: Civil Aviation
Topic: Emirates serious incident on takeoff on EK231 DXB-IAD on 20 December 2021
Replies: 267
Views: 63576

Re: Emirates serious incident on takeoff on EK231 DXB-IAD on 20 December 2021

kalvado wrote:
But they accelerated past tire speed limit, and likely past any possible Vr for any weight


Indicated speed is not what you see on FR24 data

Jump to post
by zeke
Wed Dec 29, 2021 9:03 pm
Forum: Civil Aviation
Topic: Emirates serious incident on takeoff on EK231 DXB-IAD on 20 December 2021
Replies: 267
Views: 63576

Re: Emirates serious incident on takeoff on EK231 DXB-IAD on 20 December 2021

If they set up for a lighter aircraft, my uneducated guess would be they would get early callouts and have to be on alert, possibly estimating Vr on the fly. However, they were almost driving through the houses at the end of the roll with pretty high speed. It could happen if they were programmed m...

Jump to post
by zeke
Wed Dec 29, 2021 2:26 pm
Forum: Civil Aviation
Topic: FAA to prohibit many flight operations due to risk of ‘5G’ wireless interference
Replies: 512
Views: 64228

Re: FAA to prohibit many flight operations due to risk of ‘5G’ wireless interference

Is the UK 5G Implementation any different to what Verizon, for example, plans in the US? Why don't we have the same issues in the UK also? I think the UK stop their mid frequency 5G allocation at 3.8GHz, with aircraft radar altimeters operating in the 4.2–4.4 GHz range. US frequency allocation if d...

Jump to post
by zeke
Wed Dec 29, 2021 1:51 pm
Forum: Civil Aviation
Topic: Emirates serious incident on takeoff on EK231 DXB-IAD on 20 December 2021
Replies: 267
Views: 63576

Re: Emirates serious incident on takeoff on EK231 DXB-IAD on 20 December 2021

Is it possible that, besides human factors, some obscure automation factor prevented them from rotating? It could be possible the takeoff speeds were wrong , eg setup for a lighter aircraft and as a result didn’t have the automated V speeds callouts for the correct runway/weight/altitude/temperature

Jump to post
by zeke
Tue Dec 28, 2021 8:40 pm
Forum: Civil Aviation
Topic: Emirates serious incident on takeoff on EK231 DXB-IAD on 20 December 2021
Replies: 267
Views: 63576

Re: Emirates serious incident on takeoff on EK231 DXB-IAD on 20 December 2021

Reminds me a little bid on this incident back in 2009: https://en.wikipedia.org/wiki/Emirates_Flight_407 Reminds me of an even earlier incident https://aviation-safety.net/wikibase/147120 Go work there and then we talk again. :lol: Been there, done that, etc. I've worked and lived extensively in th...

Jump to post
by zeke
Tue Dec 28, 2021 1:23 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

So in other words…QR filed in the High Court in London No, practice direction 60:states “ 3.1 TCC claims must be issued in the High Court or in a County Court hearing centre specified in this practice direction” https://www.justice.gov.uk/courts/procedure-rules/civil/rules/part60/pd_part60 This mea...

Jump to post
by zeke
Tue Dec 28, 2021 10:54 am
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

It’s not inaccurate to say that it was filed in the High Court of London. The Technology and Construction Court is part of the High Court which encompasses three divisions with various sub divisions (https://www.judiciary.uk/highcourt/). You have to file in the division applicable to your case. The...

Jump to post
by zeke
Mon Dec 27, 2021 10:33 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

Some if not most media sources shortened this to just saying the High Court in London. The correct name of the forum this was being heard has been discussed over the previous 3 pages of this thread. The name of the forum was clearly included in the title of the QR press release on the matter which ...

Jump to post
by zeke
Sun Dec 26, 2021 7:44 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

I hadn't thought about this aspect till you asked. All the reports I've read say that QR has filed a claim against Airbus in the High Court in London. I would think that if they were using arbitration, different terminology would be used, but I'm not a legal expert. QR have not “filed a claim again...

Jump to post
by zeke
Sun Dec 26, 2021 6:56 am
Forum: Technical/Operations
Topic: Altimeters, static pressure, and lift
Replies: 48
Views: 2584

Re: Altimeters, static pressure, and lift

Can you say that movement causes lift? I am not comfortable with that word, it is more of two results of the same interaction for me. You put an aircraft in a hanger to weigh it as if you to weigh it outdoors, the movement of air over the aircraft will generate lift. If you have a boat moored at th...

Jump to post
by zeke
Sat Dec 25, 2021 11:22 pm
Forum: Technical/Operations
Topic: Altimeters, static pressure, and lift
Replies: 48
Views: 2584

Re: Altimeters, static pressure, and lift

Pressure differential explanation is perfectly correct. After all, pressure is the force of air interacting with the surface, and there has to be such force in order for the wing to generate lift. Now higher pressure air under the wing is trying to escape down, and air above the wing moves down as ...

Jump to post
by zeke
Sat Dec 25, 2021 11:14 pm
Forum: Civil Aviation
Topic: AS, UA, DL and others struggle to crew flights due to Omicron
Replies: 193
Views: 47691

Re: AS, UA, DL and others struggle to crew flights due to Omicron

kalvado wrote:
Uhm... Not really. Local newspaper reports "‘Striking’ increase in child hospitalizations as COVID surges"
And Xmas travel season likely involves more kids than average business-heavy Monday


That would be unvaccinated children ? Children 5 and above can be vaccinated.

Jump to post
by zeke
Sat Dec 25, 2021 10:18 pm
Forum: Civil Aviation
Topic: AS, UA, DL and others struggle to crew flights due to Omicron
Replies: 193
Views: 47691

Re: AS, UA, DL and others struggle to crew flights due to Omicron

Yes, of course they can be positive and be asymptomatic but they can easily infect many others, so being themselves being asymptomatic is of absolutely no relevance, nor is them being either healthy or fully vaccinated. Yet you are saying that they are justified in going to work??? Data I have seen...

Jump to post
by zeke
Sat Dec 25, 2021 1:23 pm
Forum: Civil Aviation
Topic: AS, UA, DL and others struggle to crew flights due to Omicron
Replies: 193
Views: 47691

Re: AS, UA, DL and others struggle to crew flights due to Omicron

IOW, it was too late to change and the full impact of the Omicron variant was yet to be realized. I think it is not reasonable to use the data from a country with low vaccination rate like South Africa to try and project what impact it will have on a highly vaccinated community like NA. I think the...

Jump to post
by zeke
Sat Dec 25, 2021 11:21 am
Forum: Technical/Operations
Topic: Altimeters, static pressure, and lift
Replies: 48
Views: 2584

Re: Altimeters, static pressure, and lift

First, lift is caused by the differential pressure above and below the wing, the faster flow is on the upper surface, not the lower. Second static ports are placed in aerodynamically calm areas on the skin-there’s no lift, typically very flat surfaces. Whilst this is one of the popular reasons at f...

Jump to post
by zeke
Sat Dec 25, 2021 11:08 am
Forum: Technical/Operations
Topic: Very basic question for pilots: How do airliners slow down when they are already at flight idle?
Replies: 31
Views: 3114

Re: Very basic question for pilots: How do airliners slow down when they are already at flight idle?

I imagine any pilot could answer this. At the bottom of the initial descent portion of a flight and when the wings are still clean and the power is at flight idle, how do you slow the aircraft down? Does an aircraft slow when it is leveled off? Raise the nose? I think someone told me that dumping t...

Jump to post
by zeke
Wed Dec 22, 2021 3:16 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

If Qatar says a QR plane is not airworthy QR can’t fly it no matter what airspace it is in. It doesn’t matter if it is exclusively flying GRU-EZE and never touching Qatar airspace. Well they can, and have. Think about how the aircraft got from the paint shop in Ireland to TLS. The document is calle...

Jump to post
by zeke
Wed Dec 22, 2021 9:27 am
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

tomcat wrote:
updated again when new aviation-related facts will surface.


I see what you did there ;)

Jump to post
by zeke
Tue Dec 21, 2021 7:37 am
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

There is a big difference between an interim fix (containment) while the root cause is being investigated.. Here slapping another coat of paint on a surface that has adhesion issues is hardly an effective repair and if that is what the repair manual calls for, I'd question the integrity of the cert...

Jump to post
by zeke
Mon Dec 20, 2021 10:26 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

This line of argument fails in the light of the MAX debacle. Now that they know an issue exists, they have stopped taking deliver, which reinforces the back end of your argument. I am on the fence in this situation. And believe it's all about money. Which has gone beyond any technical solution to t...

Jump to post
by zeke
Mon Dec 20, 2021 9:56 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

According to QR, Airbus has delivered planes that are not fit for use; you think they won't seek financial compensations for the time they had to pay the lease and been unable to use the plane? Pleeeeease... Please cite a source for the “delivered planes that are not fit for use” or withdraw the co...

Jump to post
by zeke
Mon Dec 20, 2021 6:32 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

Seems we've now gone well past that call for an independent legal assessment. That court is the same sort of venue as ILA, the case may not even go before a judge, it might be dealt by a recorder. In any case a large part of that court is doing arbitration, and by a single member which is a similar...

Jump to post
by zeke
Mon Dec 20, 2021 6:25 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

No. They’re saying the fix proposed does not stop the problem from happening again and if does then prove it. If you have the root cause why won’t you share it and show that it won’t come up again. The same airline had an aircraft recently that had a lateral excursion from the runway taking out som...

Jump to post
by zeke
Mon Dec 20, 2021 5:55 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

So they have basically admitted that they have had offers to fix this issue however they refuse to allow the repairs because they want to know the root cause. This is known as hinderance, like locking a builder out of a building site to make rectifications. Off the top of my head I cannot think of a...

Jump to post
by zeke
Sun Dec 19, 2021 9:41 am
Forum: Technical/Operations
Topic: Which CAA’s allow A330/A350 and 777/787 common type ratings
Replies: 8
Views: 1246

Re: Which CAA’s allow A330/A350 and 777/787 common type ratings

Hong Kong also seems to think single pilot operation is acceptable on 300 passenger aircraft, another idiotic move. Hong Kong follows EASA on most things, under EASA rules the A330/A350 are the same type rating, same with the 787/777. Finnair was flying the A330/A350 as a single type. In the Middle...

Jump to post
by zeke
Fri Dec 17, 2021 11:40 am
Forum: Technical/Operations
Topic: Cost of Radar
Replies: 2
Views: 1107

Re: Cost of Radar

About US$6 million for HKG

Jump to post
by zeke
Fri Dec 17, 2021 5:58 am
Forum: Civil Aviation
Topic: 777X – VLA of the Future or another “White Elephant” A380
Replies: 390
Views: 50828

Re: 777X – VLA of the Future or another “White Elephant” A380

Have you done an engine type change on an A320? If not, why don’t we end this discussion with an agreement that while both the A320neo/ceo and 777X/-300ER have many similarities, they also have difference. Sure have, there is something like 47 engine types certified on the A320 series, with engine ...

Jump to post
by zeke
Fri Dec 17, 2021 1:56 am
Forum: Civil Aviation
Topic: 777X – VLA of the Future or another “White Elephant” A380
Replies: 390
Views: 50828

Re: 777X – VLA of the Future or another “White Elephant” A380

The wing is not interchangeable because there’s this structure called a pylon. The pylon is not part of the wing, that is evidenced by any photo you care to look at of the wing assembly transportation to the FAL. Every engine type on the A320 has its own pylon. Been that case on the CEO as well. Th...

Jump to post
by zeke
Thu Dec 16, 2021 9:33 pm
Forum: Civil Aviation
Topic: 777X – VLA of the Future or another “White Elephant” A380
Replies: 390
Views: 50828

Re: 777X – VLA of the Future or another “White Elephant” A380

The non-engine parts on CEO and NEO are not 100% interchangeable. The parts on the 777-300ER and 777X are not 100% different. The wing on the CEOs being made at the same time as the NEOs were interchangeable, you could put the ailerons, flap, rudder, THS, vertical stab from onto the other. The gear...

Jump to post
by zeke
Thu Dec 16, 2021 8:50 pm
Forum: Civil Aviation
Topic: 777X – VLA of the Future or another “White Elephant” A380
Replies: 390
Views: 50828

Re: 777X – VLA of the Future or another “White Elephant” A380

You’re playing up the changes in the 777X while downplaying changes to the A320neo program. Negative, the A320CEOs that were built at the same time as the NEOs had the same fuselage, wing, gear, avionics, parts were interchangeable. The main difference was a different engine. The parts being used o...

Jump to post
by zeke
Thu Dec 16, 2021 8:39 pm
Forum: Civil Aviation
Topic: 777X – VLA of the Future or another “White Elephant” A380
Replies: 390
Views: 50828

Re: 777X – VLA of the Future or another “White Elephant” A380

Just in case it wasn't clear, I agree with Zeke that the 777X needs a much more thorough level of certification than the A320NEO. That is not what I was trying to say, just a different engine on an existing type is a lot more straightforward. The rules that was needed for that is the same rules tha...

Jump to post
by zeke
Thu Dec 16, 2021 4:35 pm
Forum: Civil Aviation
Topic: 777X – VLA of the Future or another “White Elephant” A380
Replies: 390
Views: 50828

Re: 777X – VLA of the Future or another “White Elephant” A380

And the US will accept Airbus's treatment of A321XLR as a derivative of A320neo which is a derivative of the 1980's "classic" A320, yet we're still allowed to discuss how good an airplane the A321XLR is without a bunch of people complaining. Just as much a "having your cake and eatin...

Jump to post
by zeke
Wed Dec 15, 2021 10:15 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

Force majeure would be defined in the purchase agreement and is almost certainly limited to “acts of God.” Manufacturing failures is not a force majeure, otherwise Boeing would have called this for the MAX (hint: they didn’t). There is no hardship or interference concepts that are meaningful here. ...

Jump to post
by zeke
Wed Dec 15, 2021 8:07 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

For those who say the Qatari regulators are doing the bidding of QR, lets step back and ask, why would QR want these frames grounded? As a bargaining chip to get better pricing for the next buy? To get Airbus to pay for the re-paint and the ongoing maintenance there of? I would think that QR would ...

Jump to post
by zeke
Wed Dec 15, 2021 8:08 am
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

QR has stated they aren’t interested in the 350F, two Airbus only has an agreement with ALC for seven planes. That is not an accurate account of the position at all times. By law of Airbus if has orders they would have to be listed and they don’t have to say who but it had to be on the books as an ...

Jump to post
by zeke
Wed Dec 15, 2021 4:10 am
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

Airbus does not have any agreement committing QR to the A350F. You do not know that for fact. The integrity of the paint system certainly is a warranty issue, which would be subject to compensation by Airbus. The exterior finish is covered by warranty however these aircraft have been in service so ...

Jump to post
by zeke
Tue Dec 14, 2021 10:35 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

It’s more complicated than that. Airbus would have to come up with (and able to justify) a financial figure from the damages. How much Airbus has actually been damaged by QR’s comments is a tricky question to answer. No other CAAs have grounded the plane. How many orders has Airbus lost because of ...

Jump to post
by zeke
Tue Dec 14, 2021 5:51 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

They can call it whatever they like, but much of the material is obviously not paint, including the copper mesh used for lightning protection. I guess if it makes everyone feel better to just label it "paint" or call it a "paint" problem so be it. If you were to get your house p...

Jump to post
by zeke
Tue Dec 14, 2021 5:28 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

At no point does Danny claims to be speaking for all operators, or that Al Baker is. A majority of the article outside the new quotes is just him recapping the recent Reuters article. You are reading way too much into the statements than what is required. Readers are expected to understand that one...

Jump to post
by zeke
Tue Dec 14, 2021 5:01 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

I'm not sure what your squabble is in this case, the reporter directly quoted AAB. If you really want grounds to be annoyed, he wrote "At least four Boeing 777s will come from Cathay Pacific"... You need to be a regular reader of Dannys articles to understand, his articles would never be ...

Jump to post
by zeke
Tue Dec 14, 2021 4:42 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

The EASA talks about multiple layers up from the composite, which include many substances other than just paint, and dubs it all a "paint system.". I wasn't aware copper mesh used for lightning protection was a component of paint, but according to the EASA it is. Go figure. You should be ...

Jump to post
by zeke
Tue Dec 14, 2021 4:29 pm
Forum: Civil Aviation
Topic: Updated: Airbus goes legal as Qatar Airways jet row escalates
Replies: 1232
Views: 210008

Re: Updated: Airbus goes legal as Qatar Airways jet row escalates

Just because Airbus refused to comment or add more doesn’t mean the paper shouldn’t post Al Baker’s. A lot of information about the OEM products/sales/etc (both Airbus and Boeing) start out as leaks from customers to journalists. That’s a negotiation tactic. Danny is not known for posting those sor...

Jump to post