Search found 79 matches

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by stephanwintner
Fri Mar 01, 2019 4:49 pm
Forum: Technical/Operations
Topic: Future twin engines over the wing
Replies: 36
Views: 4392

Re: Future twin engines over the wing

Putting the engine above the wing would allow slightly shorter landing gear, and might reduce noise transmitted to the ground a little bit. But everyone thinks that it also reduces lift/drag ratio a slight bit (1%-2%???). Except Honda. Honda says it improved aerodynamics for them. No one is calling...

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by stephanwintner
Thu Feb 28, 2019 7:27 pm
Forum: Technical/Operations
Topic: Future twin engines over the wing
Replies: 36
Views: 4392

Re: Future twin engines over the wing

Putting the engine above the wing would allow slightly shorter landing gear, and might reduce noise transmitted to the ground a little bit. But everyone thinks that it also reduces lift/drag ratio a slight bit (1%-2%???). Except Honda. Honda says it improved aerodynamics for them. No one is calling...

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by stephanwintner
Thu Feb 28, 2019 4:33 pm
Forum: Military Aviation & Space Flight
Topic: Volga-Dnepr to withdraw from An-124 freighter contract for EU and NATO
Replies: 74
Views: 16104

Re: Volga-Dnepr to withdraw from An-124 freighter contract for EU and NATO

Do you really think either Lockheed, Congress, or GE viewed that as a weakness ? No. You reference a bunch of buddies running the hamster wheel "Military Industrial Complex". No intention to be efficient beyond funneling public money into private coffers. For commercial use the C5 wouldn'...

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by stephanwintner
Wed Feb 27, 2019 6:52 pm
Forum: Military Aviation & Space Flight
Topic: Volga-Dnepr to withdraw from An-124 freighter contract for EU and NATO
Replies: 74
Views: 16104

Re: Volga-Dnepr to withdraw from An-124 freighter contract for EU and NATO

st21 wrote:
Steep maintenance costs and poor reliabilty have always been the Achilles' heels of the Galaxy, especially the older C-5A version.


Do you really think either Lockheed, Congress, or GE viewed that as a weakness ?

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by stephanwintner
Mon Feb 25, 2019 5:22 pm
Forum: Civil Aviation
Topic: Georgia lawmaker lobs legislation for state takeover of Atlanta airport
Replies: 83
Views: 10681

Re: Georgia lawmaker lobs legislation for state takeover of Atlanta airport

qcpilotxf wrote:
I'm not sure if I would call generations of laws and lawsuits.....coexisting just fine.....


You are clearly not a lawyer then. It is working just the way they want it.

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by stephanwintner
Mon Feb 25, 2019 5:17 pm
Forum: Technical/Operations
Topic: Future twin engines over the wing
Replies: 36
Views: 4392

Re: Future twin engines over the wing

Basically an underwing engine is like a pendulum. Any lateral forces acted upon it is naturally countered by gravity and the engine will naturally want to center itself under the pylon. On an over wing engine, it’s like balancing a pencil on your finger. The moment the pencil moves ever so slightly...

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by stephanwintner
Fri Feb 22, 2019 7:45 pm
Forum: Technical/Operations
Topic: Future twin engines over the wing
Replies: 36
Views: 4392

Re: Future twin engines over the wing

To add to that: - The compression loads of an overwing pylon would result in a heavier pylon How do you figure that? Compressive failure stresses in metals are generally to equal or higher than tensile. The pylon needs to handle crash and hard landing overloads, which I expect are limited by yieldi...

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by stephanwintner
Thu Feb 21, 2019 11:07 pm
Forum: Technical/Operations
Topic: Ultrafan A350-2000 a gamechanger?
Replies: 2
Views: 2042

Re: Ultrafan A350-2000 a gamechanger?

The whole point of a GTF architecture is that you can keep the hot section more or less as is. So if RR can manage that gearbox and fan, then any gains in the hot section are more or less a bonus. GE needs CMCs and hot section advances, precisely because they didn't use a geared fan. The bypass rati...

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by stephanwintner
Tue Feb 19, 2019 4:59 pm
Forum: Technical/Operations
Topic: What is the exact definition of a "cycle?"
Replies: 14
Views: 1936

Re: What is the exact definition of a "cycle?"

Again, cycle has a number of definitions, applicable to different components. If the flight stays below 10,000' and doesn't pressurize, (though most would pressurize regardless), it's still going to have a landing, which is also a type of cycle. Generally engines have landings, and airframes have c...

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by stephanwintner
Mon Feb 18, 2019 8:27 pm
Forum: Technical/Operations
Topic: What is the exact definition of a "cycle?"
Replies: 14
Views: 1936

Re: What is the exact definition of a "cycle?"

I've worked at three different airlines, including one major, plus a stint as a contractor of the ANG. All cycles on everything were airframe cycles. Engine runs to full power did not count for anything, Speaking an a gas turbine engineer, currently working on ground power turbines, they ought too ...

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by stephanwintner
Tue Feb 12, 2019 11:38 pm
Forum: Non-Aviation
Topic: California abandons plan for LA-SF HSR; air travel continues to rule the market
Replies: 216
Views: 19381

Re: California abandons plan for LA-SF HSR; air travel continues to rule the market

Last year (so current prices) the new LGV Tours-Bordeaux, continuing the existing Paris-Tours LGV, was inaugurated. 300Km long, it cost 10 billions euros and 5 years to build. Now Paris-Bordeaux can be done in 2 hours and 4 minutes, it's about as far as SF to LA. We also have plenty of environmenta...

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by stephanwintner
Tue Feb 12, 2019 5:25 pm
Forum: Technical/Operations
Topic: Future engine improvements
Replies: 32
Views: 3635

Re: Future engine improvements

As far as the subject - as far as I understand it, within the bounds of the high bypass turbofan architecture, there is a bit or room left (CMCs, better metal materials, better cooling approaches) but the approaching limits are what drove Pratt to the GTF architecture. A higher bypass ratio improves...

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by stephanwintner
Tue Feb 12, 2019 5:04 pm
Forum: Technical/Operations
Topic: Future engine improvements
Replies: 32
Views: 3635

Re: Future engine improvements

I think that makes as much sense as saying that automobiles have not changed much in 60 years. Cars 60 years ago required the insertion of keys, did not have seat belts, and had "tune ups". If you pushed the left-most pedal, the brakes locked up. They didn't have built in maps of the worl...

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by stephanwintner
Fri Feb 08, 2019 8:25 pm
Forum: Technical/Operations
Topic: Cost recovery for a major check
Replies: 12
Views: 1553

Re: Cost recovery for a major check

Whether the aircraft is leased or owned, I imagine it also depends very much on the rest of the fleet & network. Which route pair(s) would the aircraft fly after the check, and what other aircraft in the fleet might fly that route if scrapped or sold instead (or, do you drop the route, I suppose...

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by stephanwintner
Mon Feb 04, 2019 5:44 pm
Forum: Civil Aviation
Topic: Airbus A220 Developments : more of a match for A320neo than Airbus says
Replies: 308
Views: 58495

Re: Airbus A220 Developments : more of a match for A320neo than Airbus says

Boeing's decisions are as subjective, and as prone to being poor as anyone else's.. I agree - they made some poor ones - and thus lost the CF-18 replacement and handed Airbus a gift. Granted, that's in hindsight... then again, the people making the decisions are supposed to be professionals, and we...

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by stephanwintner
Thu Jan 31, 2019 12:06 am
Forum: Civil Aviation
Topic: Airbus A220 Developments : more of a match for A320neo than Airbus says
Replies: 308
Views: 58495

Re: Airbus A220 Developments : more of a match for A320neo than Airbus says

ExMilitaryEng wrote:
They figured it was just cheaper to offer A319s/737-700s instead. And at bargain/dumping prices if need be... ([email protected]$23M)


Exactly.

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by stephanwintner
Thu Jan 31, 2019 12:05 am
Forum: Civil Aviation
Topic: Airbus A220 Developments : more of a match for A320neo than Airbus says
Replies: 308
Views: 58495

Re: Airbus A220 Developments : more of a match for A320neo than Airbus says

Boeing's decisions are as subjective, and as prone to being poor as anyone else's.. I agree - they made some poor ones - and thus lost the CF-18 replacement and handed Airbus a gift. Granted, that's in hindsight... then again, the people making the decisions are supposed to be professionals, and we...

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by stephanwintner
Wed Jan 30, 2019 11:21 pm
Forum: Civil Aviation
Topic: Airbus A220 Developments : more of a match for A320neo than Airbus says
Replies: 308
Views: 58495

Re: Airbus A220 Developments : more of a match for A320neo than Airbus says

A point that gets overlooked - given limited landing slots, gauge and frequency are not free variables (You can't just fly the smaller plane more often on many routes). At current sizes, the threat to the 737 is limited by that. When the fraction of slots at ORD, ATL, and DTW that are RJs is small,...

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by stephanwintner
Wed Jan 30, 2019 6:15 pm
Forum: Civil Aviation
Topic: Rolls gets German passport for jet engine designs ahead of Brexit
Replies: 14
Views: 3457

Re: Rolls gets German passport for jet engine designs ahead of Brexit

I don't understand how this would help Rolls Royce. IAG has all sorts of problems with IB, EI, I2, and VY and they have a "Spanish passport." None of it makes sense to me, could anyone explain the difference between Rolls-Royce's Brexit plan and IAG's debacle? If RR has switched, then the...

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by stephanwintner
Wed Jan 30, 2019 6:06 pm
Forum: Civil Aviation
Topic: Airbus A220 Developments : more of a match for A320neo than Airbus says
Replies: 308
Views: 58495

Re: Airbus A220 Developments : more of a match for A320neo than Airbus says

So . . . for Airbus it was better to just take it and own it then have Boeing grab it . . . does not seem plausible. Well, the next place BBD were going to go with it was China. That was something neither Boeing or Airbus could entertain. Boeing just didn't appreciate that risk when the offer was m...

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by stephanwintner
Wed Jan 30, 2019 5:09 pm
Forum: Technical/Operations
Topic: High Schooler interested in aviation management career
Replies: 6
Views: 1406

Re: High Schooler interested in aviation management career

Seems like there must be a small airport near you, go see if the general aviation FBO's near you need anyone. Working for a small firm will allow you to see lots of different sides of the business. Even if you think your interest lie with larger businesses, wide exposure to in a small one will help ...

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by stephanwintner
Tue Jan 29, 2019 11:54 pm
Forum: Civil Aviation
Topic: Korean Air A220 Significant Engine Damage
Replies: 55
Views: 24676

Re: Korean Air A220 Significant Engine Damage

Are you sure? I may have it wrong but I didn't think the exhaust behind the LPT was painted. Plus...the blades of the first two rows we see, (I'm not talking about the large support struts), are canted in opposite directions. It seems to me that the first row of blades could be a stator, with the s...

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by stephanwintner
Tue Jan 29, 2019 9:58 pm
Forum: Civil Aviation
Topic: Korean Air A220 Significant Engine Damage
Replies: 55
Views: 24676

Re: Korean Air A220 Significant Engine Damage

Definitely not FOD. Internal failure resulting in damage downstream. and how could you say it's NOT? The leading and trailing edges pf the turbine are torn up so the damage had to come from Forward, Since we can't see the inlet? How would you know unless you did the Borescope inspection? Which you ...

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by stephanwintner
Tue Jan 29, 2019 9:20 pm
Forum: Civil Aviation
Topic: Korean Air A220 Significant Engine Damage
Replies: 55
Views: 24676

Re: Korean Air A220 Significant Engine Damage

@ Joe, no, that's a view from the aft at the back of the LPT. Between the turbine exhaust case struts at the stage 3 blades. Well, where the stage 3 blades should be. @Wayextdi sorry didn't realize it was for subscribers. I'd agree with the summary Momo posted. (Subscribe mate, it's free! Good conte...

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by stephanwintner
Tue Jan 29, 2019 7:22 pm
Forum: Civil Aviation
Topic: Korean Air A220 Significant Engine Damage
Replies: 55
Views: 24676

Re: Korean Air A220 Significant Engine Damage

https://www.flightglobal.com/news/artic ... sa-455104/

Well, that's not adding any clarity to the matter....
-->

https://www.flightglobal.com/news/artic ... sa-455104/

Well, that's not adding any clarity to the matter....

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by stephanwintner
Mon Jan 28, 2019 8:27 pm
Forum: Civil Aviation
Topic: Emirates intends to fly HAM-JFK
Replies: 119
Views: 20052

Re: Emirates intends to fly HAM-JFK

EK would be stupid to try to resurrect this route given the political implications, regardless of whether the route is profitable or not. They should wait for 2 years until the US gets a new President. Care to elaborate what the hell Donald Trump has to do with this route discussion? I guess we won...

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by stephanwintner
Fri Jan 25, 2019 7:47 pm
Forum: Technical/Operations
Topic: Engine options on future aircraft
Replies: 5
Views: 1582

Re: Engine options on future aircraft

LH707330 is spot on.

Boeing also has what looks to me to be a clear preference for working with GE/CFM.

I'd expect the NMA to be sole source, especially since there seems to be doubt about the size of the niche.

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by stephanwintner
Fri Jan 04, 2019 10:27 pm
Forum: Technical/Operations
Topic: CFM LEAP-1A vs PW1000G: Sensor Incorporation
Replies: 9
Views: 1844

Re: CFM LEAP-1A vs PW1000G: Sensor Incorporation

I can't speak for the LeapX or Pratt, but I do know the GENX. I count 3 pressure sensors, 3 temp sensors, 2 pairs of speed sensors plus EGT sensors and vibration sensors. Not much different from previous gen engines. There are also various external sensors for accessories like T/R's fuel oil etc. N...

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by stephanwintner
Fri Jan 04, 2019 5:34 pm
Forum: Civil Aviation
Topic: Korean Air A220 Significant Engine Damage
Replies: 55
Views: 24676

Re: Korean Air A220 Significant Engine Damage

@Waterbomber - makes some sense. But, if it was a bearing, then the oil sump chip detector and/or the vibe sensors are supposed to have sensed the failure and shut it down before that sort of damage...Still it's the best theory. A flutter failure of the blades might look like that - but that'd be an...

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