Search found 60 matches

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by AirBoat
Sun May 24, 2020 6:21 pm
Forum: Technical/Operations
Topic: Parking airliners. question?
Replies: 5
Views: 1314

Re: Parking airliners. question?

thanks for that most informative post.

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by AirBoat
Sun May 24, 2020 1:30 pm
Forum: Technical/Operations
Topic: Parking airliners. question?
Replies: 5
Views: 1314

Re: Parking airliners. question?

I am curious about the tyres and brakes.
On a car, after standing for a few months the tyres are flat spotted, and gives a bumpy ride for a few days.
The brake fluid tends to gain moisture and then corrode the pistons in the brake callipers in a car. How soon is this an issue for an aeroplane?

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by AirBoat
Thu May 21, 2020 7:28 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounding, General Discussion Thread, Q2 2020
Replies: 607
Views: 57362

Re: Boeing 737MAX Grounding, General Discussion Thread, May 2020

What happened to the manual trim wheel issue?
Do the Europeans still want a second electric trim motor?

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by AirBoat
Tue May 12, 2020 9:01 am
Forum: Civil Aviation
Topic: Boeing CEO: A major US airline likely will go out of business this year,
Replies: 308
Views: 41549

Re: Boeing CEO: A major US airline likely will go out of business this year,

There is unfortunately a new factor in play. A lot of companies who have been having their employees work from home via skype etc. plus vpn The bosses are now thinking, why do we need these big office buildings The next thing they are going to think is: why do we need to air travel to all these meet...

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by AirBoat
Sun Mar 15, 2020 9:54 pm
Forum: Civil Aviation
Topic: Coronavirus Aviation Related News & Discussion Thread - March 2020 - Part II
Replies: 1993
Views: 336770

Re: Coronavirus Aviation Related News & Discussion Thread - March 2020 - Part II

with immediate effect travel from USA, UK, ITALY, IRAN CHINA ETC into south Africa is forbidden. see speech by sa president Ramaphosa this evening. Schools are closed from next Wednesday until after Easter. Total infections detected so far in south Africa is 51. It was only 7 a week ago.The first 7 ...

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by AirBoat
Mon Feb 17, 2020 9:53 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounding, General Discussion Thread, February 2020
Replies: 708
Views: 95423

Re: Boeing 737MAX Grounding, General Discussion Thread, February 2020

MCAS does not start up only when high AOA is reached, it is continuously active in the background, checking the AOA multiple times per second. (this might be where the bit flip requirement comes from) Disabling electric trim did not switch off MCAS 1.0. What is not clear is if MCAS acts on the eleva...

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by AirBoat
Sat Feb 15, 2020 10:44 am
Forum: Technical/Operations
Topic: CPT - Alternate/Diversion Airport Question
Replies: 20
Views: 1961

Re: CPT - Alternate/Diversion Airport Question

The winter rainfall at cape town is mostly coming from the west. the winds are north west so runway 01 would be in use. if the weather system has been going for a few days then all the coastal airfields will have the same weather ie Overberg, PE, east London and Durban. the best alternates would be ...

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by AirBoat
Thu Jan 16, 2020 1:32 pm
Forum: Civil Aviation
Topic: SAA trying to sell 9 A340s
Replies: 125
Views: 30626

Re: SAA trying to sell 9 A340s

Lufthansa still flies A340-600 to cape town.

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by AirBoat
Wed Jan 15, 2020 6:59 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounding, General Discussion Thread, January 2020
Replies: 1740
Views: 190492

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

I will assume that boeing can optimize a structure to be as light as possible, ie all parts are near maximum allowable stress. This is the problem. If aero changes are now made which cause increased loading, they are overstressed and up the creek. This is why any changes which lead to additional loa...

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by AirBoat
Wed Jan 15, 2020 5:55 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounding, General Discussion Thread, January 2020
Replies: 1740
Views: 190492

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

I remember when I thought after 3 years in my profession I knew everything..... I don't think I know everything. I think I'm perfectly capable of sitting at the adult table and reasoning through issues just as complex as they do. Do you know what another good word for experience is? Codified bias. ...

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by AirBoat
Sun Jan 05, 2020 6:03 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounding, General Discussion Thread, January 2020
Replies: 1740
Views: 190492

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Once the dust settles with the MAX, would the FAA 'go-back' and look at previous certifications provided for lets say, the 787-8, 787-9, 747-8i, etc? i.e basically going on full CYA mode..... The minimum action on all current types (including 737NG) per NTSB recommendations, if not already complete...

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by AirBoat
Sat Jan 04, 2020 7:41 pm
Forum: Technical/Operations
Topic: When is too much wing flex bad?
Replies: 33
Views: 6823

Re: When is too much wing flex bad?

The main problem with using carbon as wing structure is although it is much stronger than steel, the modulus of elasticity (or the amount of deformation per load) is the same or slightly better than steel. This results in a wing, for the same strength as the steel one, deflecting much more. As long ...

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by AirBoat
Thu Jan 02, 2020 6:43 pm
Forum: Civil Aviation
Topic: Is the South African market big enough for UA?
Replies: 6
Views: 1901

Re: Is the South African market big enough for UA?

JNB TO CPT is a 2hr flight.
The other destination that CPT is also used for is flights to Antarctica, mainly freight I think.

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by AirBoat
Thu Dec 05, 2019 1:32 pm
Forum: Civil Aviation
Topic: South African Airways to enter bankruptcy protection
Replies: 23
Views: 7766

Re: South African Airways to enter bankruptcy protection

The business rescue will probably point out that the airline is heavily overstaffed. The strike a few weeks ago was in part due to a proposed 20% staff cut. If you look at the check in counters at jhb airport. Comair(british airways) will typically have 2 staff at counters. SAA will have up to 7. Th...

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by AirBoat
Mon Nov 25, 2019 12:31 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q4 2019, Production suspended
Replies: 5670
Views: 739161

Re: Boeing 737MAX Grounded Worldwide Q4 2019

I notice on flightaware that on Saturday, Boeing was still doing what looks like stall testing on a 737max. What could they be testing if everything was handed over? As for testing with MCAS switched off. Just the switches wont do it, because mcas is still running in the background. It would take a ...

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by AirBoat
Mon Nov 11, 2019 11:15 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q4 2019, Production suspended
Replies: 5670
Views: 739161

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Unfortunately these days big projects are driven by project managers, who don't always appreciate engineering consequences, and mostly look at time lines. If new computer hardware takes years to certify and just re-using and old one with some updates takes a few months, then that is what they will c...

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by AirBoat
Fri Nov 01, 2019 7:27 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q4 2019, Production suspended
Replies: 5670
Views: 739161

Re: Boeing 737MAX Grounded Worldwide Q4 2019

For the Lion air case: the question is why did they stop trimming nose up? there are 2 possibilities: 1. they did not know how. 2. the electric trim drive motor failed. There are signs of intermittent trim action just before the final moments. This could open up another can of worms. What was the du...

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by AirBoat
Wed Oct 30, 2019 7:20 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q4 2019, Production suspended
Replies: 5670
Views: 739161

Re: Boeing 737MAX Grounded Worldwide Q4 2019

The Lion air pilot with the flu was pulling 105lbs on the yoke at times. That is pretty impressive for a sick guy. The answer is maybe more simple. The pilots simply got tired of pulling back on the yokes. When you have to pull that hard on the yoke, I do not think you are in a position to think of ...

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by AirBoat
Fri Oct 25, 2019 6:28 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q4 2019, Production suspended
Replies: 5670
Views: 739161

Re: Boeing 737MAX Grounded Worldwide Q4 2019

I still don't understand how a larger stabilizer would have helped with this issue. Because destabilizing surfaces in front of CG can be compensated with larger surfaces behind the CG. But how would it help maintain a constant stick force gradient when the destabilization is non-linear with increas...

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by AirBoat
Thu Oct 24, 2019 8:38 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q4 2019, Production suspended
Replies: 5670
Views: 739161

Re: Boeing 737MAX Grounded Worldwide Q4 2019

The larger stabilizer was never going to happen.
The implication is that the structural design of the rear half of the aircraft would have to be redone, due to larger stabilizer forces, and possibly the structure strengthened. That late in the process, this was not going to happen.

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by AirBoat
Sun Oct 13, 2019 9:44 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q4 2019, Production suspended
Replies: 5670
Views: 739161

Re: Boeing 737MAX Grounded Worldwide Q4 2019

for mcas 1.0 working correctly, at high AOA the stick force would increase and the stabilizer would trim nose down. when AOA had reduced it was supposed to return to the previous trim setting. One of the JATR comments was whether, when trimmed nose down, there was enough elevator authority to mainta...

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by AirBoat
Wed Oct 02, 2019 8:40 pm
Forum: Civil Aviation
Topic: 737NG Pickle fork issue
Replies: 565
Views: 138335

Re: 737NG Pickle fork issue

The fuselage also flexes by bending downwards, as it cantilevers forwards and backwards. See the Hawaii 737 that had part of the forward roof break off in mid flight. This was found out to be high cycles on aircraft parked in salt air So a few hard landings will work the pickle forks in the fore aft...

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by AirBoat
Tue Oct 01, 2019 7:29 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q4 2019, Production suspended
Replies: 5670
Views: 739161

Re: Boeing 737MAX Grounded Worldwide Q4 2019

I believe the 120 hours per aircraft is mostly for purging all fluids, cleaning the systems and tanks and refilling. The potable water system needs to be clean and free of bugs.. Then something non-aircraft: the heating elements in the stoves could have absorbed moisture, which is going to make them...

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by AirBoat
Wed Sep 25, 2019 8:43 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q3 2019
Replies: 4380
Views: 663328

Re: Boeing 737MAX Grounded Worldwide Q3 2019

It would be interesting to know what the duty cycle is on the stabilizer trim motor. (where 100% duty cycle is continuous max torque on motor) normal operation near in trim would only require a fraction of full torque, but in the mcas failure mode you might need full torque for a long period when tr...

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by AirBoat
Thu Sep 05, 2019 4:00 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q3 2019
Replies: 4380
Views: 663328

Re: Boeing 737MAX Grounded Worldwide Q3 2019

just my 2c engineers are not poets, they write in simple English so that their fellow workers can understand them properly. so mcas means: helping the aircraft to pitch up or down. there is nothing in there about stick force. so is this a hidden active control system? as for never needing the manual...

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by AirBoat
Tue Jul 23, 2019 1:16 pm
Forum: Civil Aviation
Topic: Flight detours due to geopolitical instability
Replies: 26
Views: 4589

Re: Flight detours due to geopolitical instability

any flight from jhb to Frankfurt flies around Libya on the west side

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by AirBoat
Wed Jun 12, 2019 2:11 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411819

Re: Boeing 737MAX Grounded Worldwide Q2 2019

how about this idea.
the max needs extra training, but its the same as the ng
therefore ALL 737 pilots need extra training....
I am sure Boeing does not want to go there.
maybe the FAA is thinking about this, and is trying to find the best middle ground.
if its different, then re-certify.

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by AirBoat
Tue Jun 11, 2019 8:04 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411819

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Ok so possibly the aero wind tunnel model testing and the computer cfd modelling showed up an anomaly and they hoped for the best. From the above effects of MCAS one item that is being ignored is: it leads to increasing control forces ,i.e. it trims nose down and forces the elevator down as well and...

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by AirBoat
Tue Jun 11, 2019 7:03 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411819

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Can anyone confirm when MCAS was implemented. I got the idea the light control forces were noticed during flight testing. This is a bit late in the day. It leaves only one option. A software fix. Any structural or aero fix would have taken years to do. As for the higher mounted engine causing more p...

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by AirBoat
Tue Jun 04, 2019 3:48 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411819

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Control forces in the max are not directly related to aerodynamic forces. There is a FEEL system that provides stick forces decided on by the flight computer. The magnitude of the forces are affected by the systems such as mach trim , speed trim and possibly mcas. when MCAS needs to activate, the no...

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by AirBoat
Mon Jun 03, 2019 1:55 pm
Forum: Travel, Polls & Preferences
Topic: Should Airports Stop Building for 380 sized Aircraft?
Replies: 56
Views: 7874

Re: Should Airports Stop Building for 380 sized Aircraft?

Johannesburg has 4 gates for A380 (I think) with double boarding ways. This can be used on any aircraft, like the LH 747-8 and speeds up boarding, so will definitely be a benefit to any airport. On domestic flights at JNB they use the one jet-way for the front and the back half pacs walk down the st...

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by AirBoat
Mon May 27, 2019 6:55 pm
Forum: Technical/Operations
Topic: Do the MAX 7 and 10 require MCAS?
Replies: 35
Views: 4533

Re: Do the MAX 7 and 10 require MCAS?

Can someone confirm the following: MCAS only operates approaching stall. therefore for the rest of the flight envelope it does nothing. Should it not be called 'Approaching stall help system' Then if it does nothing for the rest of the flight envelope, how can it make the plane feel the same as a NG...

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by AirBoat
Sat May 25, 2019 8:30 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411819

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Note the sentence below: The FAA is reassessing the extent of force required to manually counteract nose-down commands in extreme circumstances, by turning a wheel—known as the trim wheel—located between the pilots. This is the hidden "approaching train smash" The utube video from the Amer...

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by AirBoat
Mon May 20, 2019 2:55 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411819

Re: Boeing 737MAX Grounded Worldwide Q2 2019

agree with above. I was taught to fly where trim is used to enable the plane to fly hands off, not to reduce forces. The 737 has software protection to prevent overstress of the elevators, which shows itself has higher control forces. The parts of the flight envelope where this happens should be poi...

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by AirBoat
Fri May 17, 2019 1:57 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411819

Re: Boeing 737MAX Grounded Worldwide Q2 2019

The 737 has hydraulically powered elevators. Why should the stick force become higher at high speeds? I searched and found an article on: Elevator Feel and Centring system. my take on this: its a system that increases the required force on the control stick at high speeds ( is this to limit any exce...

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by AirBoat
Mon May 13, 2019 10:09 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411819

Re: Boeing 737MAX Grounded Worldwide Q2 2019

The MCAS software update does not make sense. The logic of disabling MCAS if the two sensors disagree by more than 5 deg, assumes that the faulty sensor is the high value. What if the low value is the faulty one. You are then approaching the edge of your flight envelope with no protection.(According...

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by AirBoat
Thu May 09, 2019 9:08 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 411819

Re: Boeing 737MAX Grounded Worldwide Q2 2019

my take on this: MCAS was put in to prevent a certain AOA value being exceeded, due to more powerful engines. (does anyone know this value, and what can the NG do?) When there is an AOA disagree MCAS is deactivated. Now there is no safe way to fly this aircraft as the pilots have no idea as to what ...

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by AirBoat
Mon Mar 11, 2019 4:54 pm
Forum: Civil Aviation
Topic: Ethiopian Airlines 737MAX crashes enroute to Nairobi Q1 2019
Replies: 5479
Views: 743062

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

being an eyewitness is an acquired or learned skill. as a structural engineer with a degree and close to 40 years experience, when I visit a building site, I can very quickly see most big errors. this is due to the fact that I have a frame of reference. i.e. I know what to expect and any missing or ...

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by AirBoat
Mon Mar 11, 2019 3:24 pm
Forum: Civil Aviation
Topic: Ethiopian Airlines 737MAX crashes enroute to Nairobi Q1 2019
Replies: 5479
Views: 743062

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Is it possible to load a 737 max to aft of aft cg limits? It should not be possible. I was on a 737 800 with a delay due to luggage being offloaded and the LCG being recalculated. is this correct? If you are loaded tail heavy, the aircraft could fly ok with flaps out when the Longitudinal centre of ...

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by AirBoat
Tue Dec 19, 2017 4:48 pm
Forum: Civil Aviation
Topic: BA 380 stuck in JNB
Replies: 98
Views: 35444

Re: BA 380 stuck in JNB

thanks for that ( apologies for off topic)
have not been on board for a while. how do I upload an image.
I have a nice foto of the a380 at jnb, but can not figure out how to attach it.

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by AirBoat
Tue Dec 19, 2017 4:17 pm
Forum: Civil Aviation
Topic: BA 380 stuck in JNB
Replies: 98
Views: 35444

Re: BA 380 stuck in JNB

was on SA317 JNB-CT on 16 dec:
Saturday morning 16 dec there was a 787 parked next to the service hangar at cape town int airport. could not see the airline.
The BA A380 was parked at the service hangars opposite the domestic departures side of JNB airport

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by AirBoat
Tue Jan 03, 2017 9:39 pm
Forum: Technical/Operations
Topic: Can an Airplane be Painted With a Matte Look?
Replies: 29
Views: 7117

Re: Can an Airplane be Painted With a Matte Look?

the reason most aircraft are painted white is to keep the temperature down. A black aircraft will see a skin temperature of more than 100 deg c where as the white one will probably be above 30 deg c. having a black aircraft is burning money, in extra fuel burned for aircon. (these temps are obviousl...

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by AirBoat
Thu Oct 13, 2016 8:15 pm
Forum: Technical/Operations
Topic: How Often Are Planes Weighed?
Replies: 18
Views: 5999

Re: How Often Are Planes Weighed?

How is this for margin...
A c130 was loaded kg instead of pounds and it still flew.....(2.2 x max load) this is from incident reports.

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by AirBoat
Sun Sep 18, 2016 9:22 am
Forum: Civil Aviation
Topic: Remote pax loading coming to SFO
Replies: 67
Views: 13472

Re: Remote pax loading coming to SFO

Remote pax unloading can be much quicker for the pax.
at cape town or jhb, the bus drops you at the baggage claim.
If the plane was at a docking station, you could have a very long walk to baggage claim. I would not call that a premium experience.

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by AirBoat
Sun May 22, 2016 7:20 pm
Forum: Civil Aviation
Topic: Egypt Air 804 Paris-Cairo Missing
Replies: 1187
Views: 75120

RE: Egypt Air 804 Paris-Cairo Missing Part 4

just a question?
I assume there are vents in the passenger cabin floor so that cabin pressure can equalize with the cargo hold to prevent a floor collapse when a cargo door opens in flight.
Does the cabin air con pressurize the cabin and then bleed through to the cargo hold?

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by AirBoat
Fri Sep 18, 2015 3:09 pm
Forum: Civil Aviation
Topic: Concorde 'could Fly Again'...
Replies: 120
Views: 28219

RE: Concorde 'could Fly Again'...

The Concorde at Manchester airport is in a hangar and in good condition.

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by AirBoat
Fri Sep 11, 2015 11:48 am
Forum: Civil Aviation
Topic: Malaga Airport Flooding
Replies: 13
Views: 7319

RE: Malaga Airport Flooding

That buss jet is going to have water in the wheel bearings, which can lead to seized up bearing down the line.

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by AirBoat
Thu Aug 06, 2015 5:00 pm
Forum: Travel, Polls & Preferences
Topic: Stupid People On Planes
Replies: 51
Views: 17480

RE: Stupid People On Planes

Most dangerous for me is when the plane is about 20m or so from the gate and the pilot stops for a moment, and some idiots get up and reach for their bags in the overhead bins, and then the plane move again. These bozos then grab at anyone and anything to prevent taking a fall. This can lead to seri...

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by AirBoat
Thu Jun 11, 2015 4:40 pm
Forum: Civil Aviation
Topic: Math Professor B777 Dive Claim
Replies: 23
Views: 14464

RE: Math Professor B777 Dive Claim

The paper does not claim the fuselage stays intact.
It clearly shows points of failure and explains various failure modes for the vertical dive.
Some high level engineering computational fluid dynamics effort went into this.

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by AirBoat
Mon Mar 30, 2015 3:40 pm
Forum: Civil Aviation
Topic: Germanwings A320 Crashed Enroute BCN-DUS - Part 14
Replies: 207
Views: 46729

RE: Germanwings A320 Crashed Enroute BCN-DUS - Part 14

In my company in South Africa, they can ask for a doctor's examination if they notice a pattern of excessive use of sick leave. The doctor then will only say, you are fit for work or unfit. The details remain confidential. I would think that its the same in Europe. It would take quite a number of si...

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