Search found 2590 matches

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by LH707330
Wed Aug 03, 2022 2:25 pm
Forum: Technical/Operations
Topic: Question on aircraft tires
Replies: 15
Views: 1440

Re: Question on aircraft tires

IIRC there is a patent to add little scoops on the tires to spin them up from the airflow. The issue is you would also spin them when you take-off, too. You'd therefore have to brake them more on retraction and I guess brake wear is more costly than tire wear. You'd also be adding weight to the gea...

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by LH707330
Wed Aug 03, 2022 3:36 am
Forum: Technical/Operations
Topic: Question on aircraft tires
Replies: 15
Views: 1440

Re: Question on aircraft tires

What about landing on a conveyor belt? :P

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by LH707330
Fri Jul 29, 2022 2:32 pm
Forum: Technical/Operations
Topic: Why no single-engine GA aircraft with contrarotating propellers?
Replies: 40
Views: 2970

Re: Why no single-engine GA aircraft with contrarotating propellers?

The existence of the technology and lack of adoption for the use case implies that everyone who's investigated it so far concluded that the juice wasn't worth the squeeze. If you were to do an A-team B-team comparison on some light GA single, you'd probably get the following outcome: A: single-stage...

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by LH707330
Wed Jul 20, 2022 11:09 pm
Forum: Civil Aviation
Topic: Boom Supersonic new configuration.
Replies: 102
Views: 18301

Re: Boom Supersonic new configuration.

The comparison to Rekkof is so true. Permanent vaporware with just concept images. Aren't they behind schedule on the demonstrator? They claim four engines will actually decrease costs. "Additionally, the four-engine design reduces noise while also decreasing costs for airline operators."...

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by LH707330
Mon Jun 27, 2022 1:58 am
Forum: Technical/Operations
Topic: Aircraft headings, bearings, and such.
Replies: 31
Views: 2041

Re: Aircraft headings, bearings, and such.

GalaxyFlyer wrote:
Auto correct, yes latitudes, not altitudes.

Well, according to Jimmy Buffett, both change together ;)

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by LH707330
Thu Jun 23, 2022 2:35 am
Forum: Technical/Operations
Topic: Aircraft headings, bearings, and such.
Replies: 31
Views: 2041

Re: Aircraft headings, bearings, and such.

Thanks for the answers. I assume that when you say you would turn the short direction, it means you, the pilot turn the yoke. If you are on autopilot, flying due north and are told to turn to 270, you dial this in, does the flight computers also turn the short direction? Can you direct it to do oth...

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by LH707330
Wed Jun 22, 2022 4:57 pm
Forum: Technical/Operations
Topic: Aircraft headings, bearings, and such.
Replies: 31
Views: 2041

Re: Aircraft headings, bearings, and such.

I often hear "turn 10 left" in my area when we fly from one approach sector to the next. There are a few departures where they want us to turn the long way from, say, a 130 heading to 250, so we usually get a repetition, "Left turn, left turn heading 250." I recently had a "...

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by LH707330
Thu Jun 09, 2022 5:05 pm
Forum: Technical/Operations
Topic: Widebody vs Narrowbody Cruise Speeds
Replies: 25
Views: 3812

Re: Widebody vs Narrowbody Cruise Speeds

I think that faster NB speeds will only happen if they're optimized primarily for the longer sectors, which I don't see happening. The vast majority of 737s and A321s do 1-3 hour flights, and then pinch-hit on 5-hour flights a small fraction of the time. The engines and layout are optimized for tho...

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by LH707330
Mon Jun 06, 2022 2:53 pm
Forum: Technical/Operations
Topic: Widebody vs Narrowbody Cruise Speeds
Replies: 25
Views: 3812

Re: Widebody vs Narrowbody Cruise Speeds

With NB now regularly flying 5hr + sectors, it will be interesting to see if the next generation of NB will indeed fly similar speeds to WB. Well, they are faster than before. The 737 used to cruise at .74. Now they cruise more like .80. I think that faster NB speeds will only happen if they're opt...

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by LH707330
Sun Jun 05, 2022 5:26 am
Forum: Civil Aviation
Topic: A321XLR vs first generation long haul jets
Replies: 34
Views: 12979

Re: A321XLR vs first generation long haul jets

The Airbus is much more efficient even comparing a 757-200 to a 707-320B the Maximum Takeoff Weights was about 240,000 pounds for the 757 & the 707 with their 4 Pratt and Whitney engines was about 320,000 pounds. The 707 could fly about 11 hours which would do LAX to LHR and Tokyo nonstop. The ...

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by LH707330
Sat Jun 04, 2022 3:18 am
Forum: Civil Aviation
Topic: A321XLR vs first generation long haul jets
Replies: 34
Views: 12979

Re: A321XLR vs first generation long haul jets

The Airbus is much more efficient even comparing a 757-200 to a 707-320B the Maximum Takeoff Weights was about 240,000 pounds for the 757 & the 707 with their 4 Pratt and Whitney engines was about 320,000 pounds. The 707 could fly about 11 hours which would do LAX to LHR and Tokyo nonstop. The ...

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by LH707330
Thu Jun 02, 2022 3:13 am
Forum: Technical/Operations
Topic: Widebody vs Narrowbody Cruise Speeds
Replies: 25
Views: 3812

Re: Widebody vs Narrowbody Cruise Speeds

It's an optimization problem. Today's narrowbodies don't usually go as far, so speed is less important. Related to this, they usually have less sweep, around 25 degrees, versus 30-33 for most modern widebodies. That saves structural weight. Since the 737's 25-degree wings, the A320 and 737NG were ab...

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by LH707330
Thu May 05, 2022 2:11 pm
Forum: Technical/Operations
Topic: Test-pilot combine aircracft designer
Replies: 9
Views: 1119

Re: Test-pilot combine aircracft designer

Yeah, plenty of professional aero engineers build their own kitplanes and test them. If you're asking how many people at e.g. Airbus or Boeing do systems layouts and then also go and test the planes, I'm not sure.

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by LH707330
Thu May 05, 2022 2:03 pm
Forum: Technical/Operations
Topic: CFM Engine High Oil Consumption
Replies: 28
Views: 3780

Re: CFM Engine High Oil Consumption

We once had a European outstation “service” the oils on a CF6. They wrote 0 pints of oil uplifted in the logbook. It became obvious that they did not service oils to full once the plane got back to base. I'm a bit befuddled. Wouldn't the logbook entry of 0 pints make it obvious, or am I missing a t...

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by LH707330
Fri Apr 29, 2022 4:25 am
Forum: Technical/Operations
Topic: Augmented crew - logging flight hours
Replies: 28
Views: 3781

Re: Augmented crew - logging flight hours

There were guys that would bid RFO to make it easy then complain to the capt they were coming up on their 3 & 3. Then there was the issue of "hey man you knew this so why did you bid RFO? Ugly. What is a "3 & 3"? Pre-command upgrade review? People who complain like that seem ...

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by LH707330
Fri Apr 22, 2022 5:07 pm
Forum: Technical/Operations
Topic: Throttle levers on 4+ engined aircraft
Replies: 26
Views: 3829

Re: Throttle levers on 4+ engined aircraft

How many of today's engines actually regulate thrust linearly though? I know several engines use N1 as their primary parameter, and thrust scales as roughly N1^2. Do those systems linearly set N1 (so x amount of deflection gives you y amount of delta-N1)? I'd think that an old-school system with a ...

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by LH707330
Tue Apr 19, 2022 3:43 pm
Forum: Technical/Operations
Topic: Throttle levers on 4+ engined aircraft
Replies: 26
Views: 3829

Re: Throttle levers on 4+ engined aircraft

Anyway back to my original question: Why "thrust lever" and not throttle? I believe the distinction came about with computerized engine controls such as FADEC. Prior to that the throttle levers regulated the flow of fuel to the engine. With computerized controls, they regulated the percen...

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by LH707330
Fri Apr 15, 2022 8:21 pm
Forum: Technical/Operations
Topic: Aircraft positions on ground
Replies: 4
Views: 1558

Re: Aircraft positions on ground

That already exists. Even GA planes have fishfinders that show taxiing aircraft in a different format than airborne ones so you know where they are. Not that you'd want to be operating a 172 in weather so bad that you'd need something like that (where you going if engine quits...).

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by LH707330
Sun Apr 10, 2022 4:47 pm
Forum: Technical/Operations
Topic: Curious: BA Takeoff Procedures - Gear Retraction
Replies: 39
Views: 6408

Re: Curious: BA Takeoff Procedures - Gear Retraction

Thanks all, that makes sense.

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by LH707330
Thu Apr 07, 2022 12:19 pm
Forum: Technical/Operations
Topic: Curious: BA Takeoff Procedures - Gear Retraction
Replies: 39
Views: 6408

Re: Curious: BA Takeoff Procedures - Gear Retraction

Related question: to what extent does deceleration rate affect brake heating? Doesn't the same amount of energy need to get dissipated either way? The only thing I can think of that would make a big difference is using more TR or spoilers on a longer runway and thus having to do less braking.

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by LH707330
Mon Apr 04, 2022 3:07 pm
Forum: Civil Aviation
Topic: Airbus 32X NEO program: why no length adjustment?
Replies: 58
Views: 11444

Re: Airbus 32X NEO program: why no length adjustment?

Thread bump on something I've been wondering about: what factors led A and B to pick the lengths that they did? Looking back at history, I'm going to guess the following: A built the 320 as a European 727-200 replacement, and quickly realized that they could extend the range a bit and capture a lot ...

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by LH707330
Thu Mar 31, 2022 4:24 am
Forum: Technical/Operations
Topic: music/movie in cockpit on (ultra) long haul?
Replies: 20
Views: 4202

Re: music/movie in cockpit on (ultra) long haul?

This isn't a stupid question, at all. The top brands of headsets generally come with Bluetooth, and pilots of all sorts definitely do listen to music on them during non-sterile portions of flight - though that may not be strictly following the rules at some places. After that Delta MSP overflight, ...

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by LH707330
Sun Mar 27, 2022 11:42 pm
Forum: Technical/Operations
Topic: airplane gliding
Replies: 43
Views: 5378

Re: airplane gliding

The 787 glide ratio is supposedly so high it’s proprietary information. I don’t know the exact number. I assume Airbus models are equally efficient. Couldn't one infer the 787's L/D fairly accurately (+/- a few %) based on known cruise engine SFC, thrust, and burn in a variety of gross weight condi...

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by LH707330
Sun Mar 27, 2022 11:34 pm
Forum: Technical/Operations
Topic: Delta - payroll optimized luggage/overhead question
Replies: 7
Views: 3404

Re: Delta - payroll optimized luggage/overhead question

A bag in the overhead weighs nothing, since it is built into the weight of a passenger, but in the pit it counts as a bag and weighs somewhere around 30 pounds depending on what their average weight program weights are. It is fascinating how the regulations work. Sounds like the airplane may either...

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by LH707330
Mon Mar 07, 2022 10:50 pm
Forum: Technical/Operations
Topic: Cold temperatures and the flight levels
Replies: 7
Views: 2036

Re: Cold temperatures and the flight levels

Mmmm yes I'm aware everybody uses 29.92 inHg above FL180, though I'm wondering if even at that same setting do the pressure levels "condense". Basically asking if airplanes flying an IAP have to correct for cold temperatures if marked in the approach chart (and it is cold enough), does so...

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by LH707330
Mon Mar 07, 2022 6:42 pm
Forum: Technical/Operations
Topic: Cold temperatures and the flight levels
Replies: 7
Views: 2036

Re: Cold temperatures and the flight levels

Adiabatic cooling occurs as an aircraft climbs, this is due to the change in pressure. As an aircraft climbs into the flight levels all aircraft use a standardized altimeter setting to ensure separation. As an aircraft descends out of the flight levels local atmospheric pressure, from the arrival a...

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by LH707330
Fri Mar 04, 2022 4:36 am
Forum: Technical/Operations
Topic: What degree of bank angle is used by jetliners when making large wide turns?
Replies: 15
Views: 2988

Re: What degree of bank angle is used by jetliners when making large wide turns?

OP, here's a math exercise for you: watch a few of the planes turning base and final, time how long it takes, and get an approximate ground track to get the turn radius. Look up the winds aloft, and then get an idea of the airspeeds. From that, some trig: https://code7700.com/aero_turn_performance.h...

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by LH707330
Fri Mar 04, 2022 4:26 am
Forum: Technical/Operations
Topic: Right and left-handed pilots and side sticks?
Replies: 21
Views: 4443

Re: Right and left-handed pilots and side sticks?

Most CFI students, when they transition to the right seat, are able to figure it out pretty quickly. The only real issue is the steep turns, those tend to take a few flights because the sight picture looks different. As a CFI, you often seat hop a few times in a day, and it's not a real issue. Many ...

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by LH707330
Wed Feb 16, 2022 4:49 pm
Forum: Technical/Operations
Topic: Why didn't the Boeing 707 have rudder problems similar to those of the Boeing 737?
Replies: 37
Views: 7219

Re: Why didn't the Boeing 707 have rudder problems similar to those of the Boeing 737?

The original issue with the 707 rudder on the short-fin models was that it required something like 100 lb of force to move, which is why they added the taller fin, ventral fin, and boost: https://airlinercafe.com/page.php?id=72 I believe the UK regulators were going to refuse certification if they ...

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by LH707330
Mon Feb 14, 2022 4:35 pm
Forum: Technical/Operations
Topic: Why didn't the Boeing 707 have rudder problems similar to those of the Boeing 737?
Replies: 37
Views: 7219

Re: Why didn't the Boeing 707 have rudder problems similar to those of the Boeing 737?

The original issue with the 707 rudder on the short-fin models was that it required something like 100 lb of force to move, which is why they added the taller fin, ventral fin, and boost: https://airlinercafe.com/page.php?id=72 I believe the UK regulators were going to refuse certification if they d...

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by LH707330
Mon Feb 07, 2022 3:35 am
Forum: Technical/Operations
Topic: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?
Replies: 46
Views: 5280

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Fun fact: the #3 A340 flap track canoes on the starboard side is longer to accommodate the RAT: https://upload.wikimedia.org/wikipedia/commons/e/ed/A340-600_clean-wing_bottom_plan-view.jpg Interesting, I would have thought the Port one would be the same size even if not required, for symmetry/drag ...

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by LH707330
Sun Feb 06, 2022 6:05 pm
Forum: Technical/Operations
Topic: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?
Replies: 46
Views: 5280

Re: Which airliners have ram air turbines. Which power hydraulics and which provide electricity?

Fun fact: the #3 A340 flap track canoes on the starboard side is longer to accommodate the RAT:

Image

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by LH707330
Mon Jan 31, 2022 4:45 pm
Forum: Technical/Operations
Topic: High power settings on the 727 during approach and landing due to drag for dirty condition or for quick spool up.
Replies: 18
Views: 2708

Re: High power settings on the 727 during approach and landing due to drag for dirty condition or for quick spool up.

The high lift systems on the 727 created a ton of drag as a consequence of their high lift at low speeds, so you needed a decent amount of thrust to keep it stable. More modern aircraft have simpler systems that make less drag, and hence less thrust and noise. The DC10 was not as optimized for short...

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by LH707330
Mon Jan 31, 2022 4:35 pm
Forum: Civil Aviation
Topic: Boeing Hints at Next New Jet as It Weighs Tough Engine Decisions
Replies: 115
Views: 19752

Re: Boeing Hints at Next New Jet as It Weighs Tough Engine Decisions

The landing gears stores in the lower horizontal strut. That's a HUGE can of worms IMHO. For one, that totally changes force distribution in that lower strut, from mostly tensile to... to god knows what... No way can the gear be stored, nor be supported by the as pictured lover truss bracing. So I ...

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by LH707330
Mon Jan 24, 2022 4:34 pm
Forum: Civil Aviation
Topic: Korean Air looks to rebrand
Replies: 130
Views: 41529

Re: Korean Air looks to rebrand

Let's be honest. I think we all know what direction this rebrand is going. They probably paid millions of dollars to a design firm for something that resembles this thing I crapped out in 20 minutes. https://i.imgur.com/eHtS5rB.png Queue the Marketing Department: The new livery blends the cultural ...

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by LH707330
Thu Jan 20, 2022 9:25 pm
Forum: Civil Aviation
Topic: Boeing confirms higher gross weight 787-10
Replies: 401
Views: 69587

Re: Boeing confirms higher gross weight 787-10

I just hope Boeing can do it without sacrificing CASM at lower ranges. Me too, this is what Airbus learned when they thought they needed to HGW the A346 in response to the B77W, then only offered the HGW version Well Airbus did that (made HGW standard that is) because the A345/6 wasn’t selling and ...

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by LH707330
Thu Jan 20, 2022 5:31 am
Forum: Aviation Hobby
Topic: civilian aircraft what if
Replies: 68
Views: 14839

Re: civilian aircraft what if

Coming together nicely!

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by LH707330
Fri Jan 14, 2022 5:43 pm
Forum: Technical/Operations
Topic: Are holding patterns used very much anymore and at which airfields?
Replies: 27
Views: 3369

Re: Are holding patterns used very much anymore and at which airfields?

I’d love to see pilots raised on “glass” enter and fly an intersection hold with dual VORs. I wonder if they teach the TTTTT anymore.... lol My institution does this, ditto steam gauge needle flying. Automation suffers from GIGO (AA965, EK407), and raw-data flying suffers from math errors and instr...

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by LH707330
Thu Jan 06, 2022 5:40 pm
Forum: Civil Aviation
Topic: Boeing confirms higher gross weight 787-10
Replies: 401
Views: 69587

Re: Boeing confirms higher gross weight 787-10

I’m curious what more will need to be done to get the 787 up to 260T and beyond. I imagine thrust increases, and possibly increasing wing dimensions to keep T/O performance from getting out of hand. I think an increase in wing dimensions would help, but of course it's very costly. It's interesting ...

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by LH707330
Wed Jan 05, 2022 3:42 am
Forum: Technical/Operations
Topic: Do gate size restrictions matter for freighters
Replies: 19
Views: 2160

Re: Do gate size restrictions matter for freighters

Gate space is definitely a factor for cargo ops, especially the box haulers with big hubs like Fedex and UPS. Whenever you have a bunch of planes arrive, then rescramble the boxes and re-load them, travel times and distances to and from all the planes becomes an issue. From an efficiency standpoint,...

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by LH707330
Sun Jan 02, 2022 7:49 pm
Forum: Civil Aviation
Topic: Learjet Crash December 27 2021 in San Diego/ Gillespie - audio/video
Replies: 195
Views: 60196

Re: Learjet Crash December 27 2021 in San Diego/ Gillespie - audio/video

We all look at charts, but FAA 8260-5 is the document that is the source for the charts. https://www.faa.gov/aero_docs/acifp/NDBR/2017062233337302001-SEE-NDBR/CA_SAN%20DIEGO%20EL%20CAJON_LD_SEE_CORRECTED.pdf It references Part 97 making compliance with the approach a regulation, not just a suggesti...

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by LH707330
Sun Jan 02, 2022 5:26 pm
Forum: Aviation Hobby
Topic: civilian aircraft what if
Replies: 68
Views: 14839

Re: civilian aircraft what if

Got the first 2 revell boeing 747 I ordered yesterday. The cutaway, I'm now hesitating between British airways and SAS because british airways had a weird policy on modelling specific aircraft of their fleet in the 60', revell at the time couldn't put specific registration letters on their 200 deca...

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by LH707330
Sun Jan 02, 2022 3:57 am
Forum: Technical/Operations
Topic: Altimeters, static pressure, and lift
Replies: 48
Views: 2992

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...

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by LH707330
Fri Dec 31, 2021 4:55 pm
Forum: Technical/Operations
Topic: Altimeters, static pressure, and lift
Replies: 48
Views: 2992

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 upw...

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by LH707330
Tue Dec 21, 2021 11:12 pm
Forum: Aviation Hobby
Topic: civilian aircraft what if
Replies: 68
Views: 14839

Re: civilian aircraft what if

No idea, I'd give it a dark gray to make sure it's not translucent, or do a gray primer guide coat to accomplish the same.

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by LH707330
Thu Dec 16, 2021 11:46 pm
Forum: Aviation Hobby
Topic: civilian aircraft what if
Replies: 68
Views: 14839

Re: civilian aircraft what if

If you're referring to the rear door molding, that's what we in the US refer to as "engraved panel lines," as opposed to "raised panel lines" that used to be on a lot of older kits because that was easier to produce, but forced the modeler to scribe them all in afterward.

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by LH707330
Thu Dec 16, 2021 11:40 pm
Forum: Civil Aviation
Topic: United CEO Tells Senate Panel that 100 Regional Jets are Grounded Because of the Pilot Shortage
Replies: 153
Views: 17046

Re: United CEO Tells Senate Panel that 100 Regional Jets are Grounded Because of the Pilot Shortage

Let's be clear about this.... There is not a pilot shortage. There is, however, a shortage of pilots willing to fly regionals for what United wants to pay them, when so many other opportunities are available. It is not 2008, anymore. Bingo. He should go talk to his yield management team about how s...

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by LH707330
Sat Dec 11, 2021 4:11 pm
Forum: Technical/Operations
Topic: A380 lack of cargo carrying capacity versus twins
Replies: 19
Views: 3893

Re: A380 lack of cargo carrying capacity versus twins

In a nutshell: 1. Both planes are about the same length. 2. The A380 is taller/wider and thus has more taper front and rear that eats into cargo. 3. The A380 is heavier and thus has a larger wing. This wing needs to fit in an 80m box, so to get enough area, the chord is much longer, which means the ...

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by LH707330
Sat Dec 11, 2021 4:04 pm
Forum: Technical/Operations
Topic: Complicated, by design. But is it really?
Replies: 20
Views: 3911

Re: Complicated, by design. But is it really?

The first bit has already been gradually happening for decades. Very interesting, thanks! I'm not a fan of direct autoflight implementation of datalink clearances. It removes a rather significant safety net. An intermediate step, which is already happening, is automatic entry of received parameters...

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