Search found 79 matches

  • 1
  • 2
by stephanwintner
Tue Jul 16, 2019 10:47 pm
Forum: Travel, Polls & Preferences
Topic: Should Lockheed get back into commerical aircraft?
Replies: 50
Views: 6189

Re: SHOULD LOCKHEED GET BACK INTO COMMERCIAL AIRCRAFT?

I can't imagine it, excepting niche products like the L100. I think Lockheed's L1011 experience and Douglas' slow decline show a need to have several products at different market segments. Clearly, until they'd developed 3 or 4 products, Lockheed wouldn't have that. That's a heck of a long term pro...

Jump to post
by stephanwintner
Tue Jul 16, 2019 10:36 pm
Forum: Technical/Operations
Topic: GE9X Record Breaker
Replies: 60
Views: 9819

Re: GE9X Record Breaker

Cold weather, alone, allows for quite a bit more thrust than, for example, a hot day takeoff. I'm not sure what precise values are used for a rating, but keep in mind that the rated thrust is not what the average engine makes. Every single engine in the fleet, worn or not, should be capable of exce...

Jump to post
by stephanwintner
Wed Jul 10, 2019 10:47 pm
Forum: Travel, Polls & Preferences
Topic: Should Lockheed get back into commerical aircraft?
Replies: 50
Views: 6189

Re: SHOULD LOCKHEED GET BACK INTO COMMERCIAL AIRCRAFT?

I can't imagine it, excepting niche products like the L100. I think Lockheed's L1011 experience and Douglas' slow decline show a need to have several products at different market segments. Clearly, until they'd developed 3 or 4 products, Lockheed wouldn't have that. That's a heck of a long term proj...

Jump to post
by stephanwintner
Wed Jun 26, 2019 7:35 pm
Forum: Civil Aviation
Topic: Inference: BA may acquire 6 x A380 ex-LH
Replies: 56
Views: 17670

Re: Inference: BA may acquire 6 x A380 ex-LH

Given Heathrow's capacity issues, I wonder if the A380 makes more sense for BA than many other airlines.

Jump to post
by stephanwintner
Tue Jun 25, 2019 11:30 pm
Forum: Technical/Operations
Topic: GE9X Record Breaker
Replies: 60
Views: 9819

Re: GE9X Record Breaker

Cold weather, alone, allows for quite a bit more thrust than, for example, a hot day takeoff. I'm not sure what precise values are used for a rating, but keep in mind that the rated thrust is not what the average engine makes. Every single engine in the fleet, worn or not, should be capable of excee...

Jump to post
by stephanwintner
Mon Jun 24, 2019 11:27 pm
Forum: Technical/Operations
Topic: Natural Gas and Aviation
Replies: 12
Views: 1464

Re: Natural Gas and Aviation

Bio fuels are much more likely than LNG. They are more stable, similar to today's Jet/Diesel, and have similar volume to power ratio. The US Navy is currently pushing very hard to become 100% bio for all aviation fuel. That could push the technology to the private sector quicker. Really? Link pleas...

Jump to post
by stephanwintner
Fri Jun 21, 2019 7:25 pm
Forum: Technical/Operations
Topic: Could the GE Catalyst be used to reengine 19-30 seaters?
Replies: 7
Views: 1283

Re: Could the GE Catalyst be used to reengine 19-30 seaters?

I hope some engine performance guru will chime in. For one, you have to distinguish between 4 approaches - where then engine is physically unchanged but the throttle is pushed up or down, it's got a different gearbox or prop, this airplane uses more bleed than that one, etc. - where the engine is ph...

Jump to post
by stephanwintner
Fri Jun 21, 2019 5:35 pm
Forum: Civil Aviation
Topic: United Announcing Something Tomorrow (Space Theme)
Replies: 100
Views: 18335

Re: United Announcing Something Big Tomorrow (Space Theme)

I still want a PanAm space clipper ticket. :)

Jump to post
by stephanwintner
Fri Jun 21, 2019 5:32 pm
Forum: Technical/Operations
Topic: RC turbine engine failing to start on the B3 helicopter
Replies: 2
Views: 983

Re: RC turbine engine failing to start on the B3 helicopter

I am struggling to understand what you wrote. I think you are saying you have a small RC turbine mounted on a test rig underneath a helo rotor, sticking out of the open door, and pointed up (turbine inlet faces up). (I guess a university project?) On one side, the turbine starts easily, on the other...

Jump to post
by stephanwintner
Thu Jun 20, 2019 4:48 pm
Forum: Technical/Operations
Topic: Benefits of a 2 blade rotor
Replies: 15
Views: 3323

Re: Benefits of a 2 blade rotor

For storage, especially on a carrier, 2 blades have some advantage as well. Else you need a folding blade - which has of course been done, but adds complexity and hence weight. Rotor inertia is NOT about weight. It is about weight distribution. A solid disk that is 1 inch thick and 12 inches diamete...

Jump to post
by stephanwintner
Wed Jun 19, 2019 11:43 pm
Forum: Technical/Operations
Topic: Concorde economics vs. 787/A330/777/A321LR
Replies: 56
Views: 10516

Re: Concorde economics vs. 787/A330/777/A321LR

With digital design and testing it would be quicker to develop. Hahahahah Clearly you've not used Catia or Enovia. Turning off the sarcasm, I'm not at all convinced modern design methods are quicker. I believe we can analyze in much greater depth, hence we engineers do. E-mail and Powerpoint are wo...

Jump to post
by stephanwintner
Tue Jun 11, 2019 6:49 pm
Forum: Civil Aviation
Topic: Confirmed: 777X First Flight Delayed Due GE9X Issues
Replies: 319
Views: 70239

Re: 777X First Flight Delayed to Year End Due GE9X Issues

2. CF-34 (first 'high bypass') Lightsaber, Um, TF-39 first ran in 1964, TF34/CF34 first run is 1971. I'd always regarded TF39 as the "first high bypass", which led for the CF6 first models and the JT9D a couple years later. (Granted, I got those dates from Wikipedia). Can you clarify ? Wh...

Jump to post
by stephanwintner
Mon Jun 03, 2019 4:10 pm
Forum: Civil Aviation
Topic: Pratt & Whitney reduces life limits for A220, E190/E195-E2 engines
Replies: 30
Views: 7955

Re: Pratt & Whitney reduces life limits for A220, E190/E195-E2 engines

PBTH does make it interesting in that older aircraft come with expensive maintenance contracts (or no engines!). How does this benefit the engine maker? Does it benefit them to incentivize the retirement of the older airframes and their engines earlier in favor of younger airframes with newer engin...

Jump to post
by stephanwintner
Thu May 30, 2019 3:48 pm
Forum: Civil Aviation
Topic: Indigo to switch from Pratt & Whitney engines to CFM engines for A320neo.
Replies: 29
Views: 5511

Re: Indigo to switch from Pratt & Whitney engines to CFM engines for A320neo.

Does anyone have a picture of the reliability issues PW has faced across their GTFs? Most of the issues seem to be occuring in India. Off the top of my head, I am aware of one (very major) IFSD on a Korean Air Cseries and one one a Vietnam A321NEO. I think Swiss, LH, Air Baltic etc have had better r...

Jump to post
by stephanwintner
Wed May 29, 2019 9:54 pm
Forum: Technical/Operations
Topic: What is the dynamics or reason behind the turboprops rotating blades in opposite directions?
Replies: 22
Views: 4598

Re: What is the dynamics or reason behind the turboprops rotating blades in opposite directions?

P factor I guess no one read this. It is the main reason for counter rotating props on twin engine propeller aircraft. Basically, what it means is that the down going blade is producing more thrust than the up going blade at any angle of attach higher than zero. Counter rotating props, clockwise on...

Jump to post
by stephanwintner
Wed May 29, 2019 9:35 pm
Forum: Civil Aviation
Topic: Pratt & Whitney's Geared Turbofan Has A Strong Backlog
Replies: 23
Views: 6794

Re: Pratt & Whitney's Geared Turbofan Has A Strong Backlog

If I understand the history - and I may not - western firms were & are far ahead of the Soviets regarding single crystal alloys and turbine cooling techniques, as well as / and hence in hot section reliability. If you cannot compete on T4 (combustor exit temp) because of those factors then your ...

Jump to post
by stephanwintner
Wed May 29, 2019 7:25 pm
Forum: Technical/Operations
Topic: PW6000, CFM56-5A/B, LEAP-1A, PW1100G - How to distinguish them?
Replies: 5
Views: 1284

Re: PW6000, CFM56-5A/B, LEAP-1A, PW1100G - How to distinguish them?

Fan size is much bigger on the latter 2, so you should be able to distinguish between them and CFM56 by proportion. Between the V2500 and CFM56, though, it's harder. The nacelles probably look a bit different in detail. And between Leap and PW1100, you can probably also distinguish by a detailed loo...

Jump to post
by stephanwintner
Thu May 23, 2019 3:46 pm
Forum: Travel, Polls & Preferences
Topic: Why didn't McDonnell-Douglas get bailed out?
Replies: 17
Views: 2251

Re: Why didn't McDonnell-Douglas get bailed out?

As noted above, MDD had the F15, F18, and C17 in production, as well as various other government programs, and could expect to compete for more in the coming years - even if one expected pentagon budgets to shrink, there were a lot of T38s that would eventually need replacement, the F14 would eventu...

Jump to post
by stephanwintner
Wed May 08, 2019 8:36 pm
Forum: Civil Aviation
Topic: Heathrow - Legal challenge lost
Replies: 85
Views: 11975

Re: Heathrow - Legal challenge lost

Not sure how practical it would be to be confined to a 10 mile radius. If proper public transit was built, in advance of growth, one rarely needs to get into a private car - it becomes a luxury, not a necessity. While being "confined" to a 10 mile radius would be very limiting - I've used...

Jump to post
by stephanwintner
Mon May 06, 2019 3:40 pm
Forum: Civil Aviation
Topic: A220 question
Replies: 64
Views: 11941

Re: A220 question

twaconnie wrote:
I didn't know PW had the worst reliability engines out there.Will the new GTF series be better?


Not so far. But hopefully.

-ex-Pratt guy in SoCal.

Jump to post
by stephanwintner
Wed May 01, 2019 5:24 pm
Forum: Civil Aviation
Topic: Thailand fails (again) to achieve FAA safety rating
Replies: 44
Views: 10586

Re: Thailand fails (again) to achieve FAA safety rating

hz747300 wrote:
If locals won't do it, outsource it to the Germans.


I hear the former management of the BER airport project are looking for work....

;)

Jump to post
by stephanwintner
Fri Apr 12, 2019 8:40 pm
Forum: Travel, Polls & Preferences
Topic: Why so few international major carriers to Philadelphia?
Replies: 104
Views: 14368

Re: Why so few international major carriers to Philadelphia?

My parents live in Bucks county (northern suburbs of philly, for others). And I used to live in europe, so I flew international to the Philly area a bit. I always checked both PHL and EWR. JFK - no. Combined with NYC traffic jams, JFK really wouldn't enter into it. For a lot of people, it's all abo...

Jump to post
by stephanwintner
Fri Apr 12, 2019 6:57 pm
Forum: Travel, Polls & Preferences
Topic: Why so few international major carriers to Philadelphia?
Replies: 104
Views: 14368

Re: Why so few international major carriers to Philadelphia?

It’s about a 90 minute drive from Bucks County to EWR, 2 hours to JFK. My parents live in Bucks county (northern suburbs of philly, for others). And I used to live in europe, so I flew international to the Philly area a bit. I always checked both PHL and EWR. JFK - no. Combined with NYC traffic jam...

Jump to post
by stephanwintner
Thu Apr 11, 2019 7:06 pm
Forum: Technical/Operations
Topic: MAX nacelle, AOA, center of lift, and C/G
Replies: 193
Views: 14315

Re: MAX nacelle, AOA, center of lift, and C/G

https://aviationweek.com/commercial-avi ... detachment

I will leave commenting to the experts.
-->

In case anyone missed it :

https://aviationweek.com/commercial-avi ... detachment

I will leave commenting to the experts.

Jump to post
by stephanwintner
Wed Apr 03, 2019 10:43 pm
Forum: Technical/Operations
Topic: MAX certification: new systemic issues identified
Replies: 109
Views: 11132

Re: MAX certification: new systemic issues identified

"ET302 used the Cut-Out switches to stop MCAS" https://leehamnews.com/ Time for some Apologists to eat Crow, and stop being condescending towards the late Ethiopian crew. :tombstone: Also posted here : https://www.flightglobal.com/news/articles/report-that-crashed-737-crew-shut-off-mcas-r...

Jump to post
by stephanwintner
Wed Mar 27, 2019 6:58 pm
Forum: Technical/Operations
Topic: MAX certification: new systemic issues identified
Replies: 109
Views: 11132

Re: MAX certification: new systemic issues identified

In all it's 50 years of service, basically there are only two kinds of pilots that have ever actually stalled a 737 in flight. a) Boeing test pilots b) Airline pilots who left a big hole in the ground :tombstone: There might possibly be a very small group of others who survived such a rare encounte...

Jump to post
by stephanwintner
Wed Mar 27, 2019 4:04 pm
Forum: Civil Aviation
Topic: Why Are Bus Boardings so Common in Europe and so Rare in the USA?
Replies: 188
Views: 21442

Re: Why Are Bus Boardings so Common in Europe and so Rare in the USA?

You ever ride on one of our US buses? They are usually the most nondescript form of transportation known to man. ;) The German ones aren't much different. Perhaps a bit better for wheelchairs and old folks since they all kneel and have low floors. I once flew through CDG. After being bussed from th...

Jump to post
by stephanwintner
Tue Mar 26, 2019 11:28 pm
Forum: Technical/Operations
Topic: MAX certification: new systemic issues identified
Replies: 109
Views: 11132

Re: MAX certification: new systemic issues identified

This is not making a safe plane safer. It's not even maintaining par with the NG. Yes, the MAX with new improved full-disclosure MCAS v2.0™ will most of the time be safer than the aircraft our grandfathers risked their lives in, but is that enough? OK, so, please first provide a definition of "...

Jump to post
by stephanwintner
Tue Mar 26, 2019 5:33 pm
Forum: Technical/Operations
Topic: MAX certification: new systemic issues identified
Replies: 109
Views: 11132

Re: MAX certification: new systemic issues identified

This is not making a safe plane safer. It's not even maintaining par with the NG. Yes, the MAX with new improved full-disclosure MCAS v2.0™ will most of the time be safer than the aircraft our grandfathers risked their lives in, but is that enough? OK, so, please first provide a definition of "...

Jump to post
by stephanwintner
Mon Mar 25, 2019 6:30 pm
Forum: Technical/Operations
Topic: TriStar parts?
Replies: 3
Views: 1411

Re: TriStar parts?

Yes, there are some parts which are common, but it gets very complex with the exact model number, and the fact that the majority of G/Hs are actually G-T/H-T engine. A contact informs me that even RR has major problems procuring parts / engines for their own Flying Test Bed's pusher engines. Comple...

Jump to post
by stephanwintner
Mon Mar 25, 2019 4:13 pm
Forum: Technical/Operations
Topic: L1011/DC10 general questions
Replies: 20
Views: 4405

Re: L1011/DC10 general questions

Those seats look like something out of an L1049 not an L1011. I hope they are more comfortable than they look. That is a simulator, and they are not L1011 original chairs Glad to hear it ! I knew it is a simulator (the screens give that away), I'd just have expected the real seats in the simulator ...

Jump to post
by stephanwintner
Wed Mar 20, 2019 11:07 pm
Forum: Technical/Operations
Topic: TriStar parts?
Replies: 3
Views: 1411

Re: TriStar parts?

A glance at the RB211 wikipedia page suggests the -524 G/H was used on the 747 and 767. The earlier B/C/D off the L1011 might be gone, but I'd imagine some common parts between the G/H and B/C/D would still be available. Some parts may also be used in industrial RB211's. I'm sure some older engines ...

Jump to post
by stephanwintner
Wed Mar 20, 2019 10:58 pm
Forum: Technical/Operations
Topic: What drove Soviet airliner tech advancements?
Replies: 12
Views: 1939

Re: What drove Soviet airliner tech advancements?

Can anyone knowledgeable comment on the Design Bureau / Factory organization the Soviets used? It seems bizarre to me, from what little I understand. Did it hinder their efforts? separation of design and building. it should have provided for nigh perfect documentation and good interface definition....

Jump to post
by stephanwintner
Wed Mar 20, 2019 9:13 pm
Forum: Technical/Operations
Topic: What drove Soviet airliner tech advancements?
Replies: 12
Views: 1939

Re: What drove Soviet airliner tech advancements?

Can anyone knowledgeable comment on the Design Bureau / Factory organization the Soviets used? It seems bizarre to me, from what little I understand. Did it hinder their efforts?

Jump to post
by stephanwintner
Wed Mar 20, 2019 9:07 pm
Forum: Technical/Operations
Topic: L1011/DC10 general questions
Replies: 20
Views: 4405

Re: L1011/DC10 general questions

Those seats look like something out of an L1049 not an L1011. I hope they are more comfortable than they look.

Jump to post
by stephanwintner
Mon Mar 18, 2019 11:00 pm
Forum: Technical/Operations
Topic: MAX nacelle, AOA, center of lift, and C/G
Replies: 193
Views: 14315

Re: MAX nacelle, AOA, center of lift, and C/G

I cannot imagine Boeing deliberately withheld data. Certification and the related paperwork processes are (shouldn't be, but are) too complex, I'm sure it's a late change that got missed. And while management may have overridden certain engineers, I again cannot imagine they did so without some supp...

Jump to post
by stephanwintner
Mon Mar 18, 2019 5:59 pm
Forum: Technical/Operations
Topic: MAX nacelle, AOA, center of lift, and C/G
Replies: 193
Views: 14315

Re: MAX nacelle, AOA, center of lift, and C/G

MCAS addresses a aerodynamic problem in the small part of the envelope near stall AOA in clean configuration. It’s not a major problem, only a problem in that small regime. The operational problem that testing didn’t reveal was the case of sole source sensor failing or providing incorrect sensor da...

Jump to post
by stephanwintner
Wed Mar 13, 2019 7:32 pm
Forum: Technical/Operations
Topic: Why is the A330 still 8 abreast?
Replies: 26
Views: 3931

Re: Why is the A330 still 8 abreast?

stephanwintner wrote: The airframer surveys the market, and determines a range and payload that will appeal. A380 comes to mind. Somebody on a.net once said "the plane makes the market". I believe that's true to a considerable extent. I agree, A380 comes to mind. It certainly failed to ma...

Jump to post
by stephanwintner
Mon Mar 11, 2019 11:19 pm
Forum: Technical/Operations
Topic: Redundancy of sensors
Replies: 4
Views: 562

Re: Redundancy of sensors

I'm speculating. As an engineer, we like to have three measurements that should agree. When one doesn't, assume the other 2 are correct. If we only have 2, then we don't know which one is correct. One or both may be wrong. Worse, we often don't know which one is wrong. So with one bad sensor out of ...

Jump to post
by stephanwintner
Mon Mar 11, 2019 9:59 pm
Forum: Technical/Operations
Topic: Why is the A330 still 8 abreast?
Replies: 26
Views: 3931

Re: Why is the A330 still 8 abreast?

I assume that these planes were designed for the available engine power at the time.? isn't it an economic necessity to trade ever increasing range for more seats, like the 777X does? Is my assumption correct? I think you misunderstand how planes are designed. The airframer surveys the market, and ...

Jump to post
by stephanwintner
Fri Mar 08, 2019 8:13 pm
Forum: Technical/Operations
Topic: The 787 and potential weight increases, why so problematic ?
Replies: 14
Views: 1603

Re: The 787 and potential weight increases, why so problematic ?

Wiederling - well... kind of. I don't see those as two effects. Two sides of the same coin perhaps. Any engineering program works through the iterative process, both effects occur - we engineers find that early values were a bit rough, and refine both the current estimate, and possibly the targets (...

Jump to post
by stephanwintner
Fri Mar 08, 2019 5:31 pm
Forum: Technical/Operations
Topic: The 787 and potential weight increases, why so problematic ?
Replies: 14
Views: 1603

Re: The 787 and potential weight increases, why so problematic ?

Speaking as someone who briefly worked on it, I was always curious about what Boeings predicted weights vs. actuals were over the program. I suspect their early weight estimates, which drove structural design, may have underestimated the mass of some items, e.g the lightning protection system, which...

Jump to post
by stephanwintner
Thu Mar 07, 2019 10:34 pm
Forum: Travel, Polls & Preferences
Topic: What old liveries would you like to see back again ?
Replies: 20
Views: 1689

Re: What old liveries would you like to see back again ?

http://graphics8.nytimes.com/images/2011/12/09/business/airlines-livery-american/airlines-livery-american-custom3.jpg Probably never going to happen though with all of the composites on airliners today. Bare metal just doesn't work anymore. . Well, their current livery is a metallic grey paint, rig...

Jump to post
by stephanwintner
Wed Mar 06, 2019 8:04 pm
Forum: Technical/Operations
Topic: New 767-300ER/-F Avionics and Engine Options
Replies: 14
Views: 1881

Re: New 767-300ER/-F Avionics and Engine Options

Pratt's 4062 is being used on the new KC-46's, so will continue to be produced and supported for as long as Congress wishes to fund that.... going by the B-52 and KC-135, it'll be a while.

Jump to post
by stephanwintner
Fri Mar 01, 2019 9:11 pm
Forum: Technical/Operations
Topic: Future twin engines over the wing
Replies: 36
Views: 4092

Re: Future twin engines over the wing

Bah, too late to edit my last post. Meant to add this: 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 yielding in the shear, tensile, or compressi...

Jump to post
by stephanwintner
Fri Mar 01, 2019 7:50 pm
Forum: Travel, Polls & Preferences
Topic: Manufacturing-related accident or incident
Replies: 26
Views: 2744

Re: Manufacturing-related accident or incident

QF 32 is probably one of the more high profile ones in recent times, the cause being a misaligned counter bore within a stub oil pipe leading to a fatigue fracture. If I recall, it was either that the blueprint did not specify a concentricity between the two relevant diameters, so the thin wall was...

Jump to post
by stephanwintner
Fri Mar 01, 2019 6:51 pm
Forum: Technical/Operations
Topic: Future twin engines over the wing
Replies: 36
Views: 4092

Re: Future twin engines over the wing

Again - they aren't claiming an overwing design is better than an under wing design. They claim that, if they adjust positions carefully, for their particular nacelle, wing, and fuselage shapes, they can get some beneficial effect compared to a no engine configuration, and that they can also get a b...

Jump to post
by stephanwintner
Fri Mar 01, 2019 6:17 pm
Forum: Civil Aviation
Topic: Korean Air A220 Significant Engine Damage
Replies: 55
Views: 23835

Re: Korean Air A220 Significant Engine Damage

My Bad. Yes, ExMilitaryEng is correct, I should have pointed that out. They are different, but very similar engines, designed by the same guys at the same firms. I know that, but should have pointed that out for everyone.

Jump to post
by stephanwintner
Fri Mar 01, 2019 6:01 pm
Forum: Civil Aviation
Topic: Bloomberg: Rolls-Royce Offers China Engine Plant to Win Deal; Airbus Plans to Make Newest Jet in China to Win Orders
Replies: 35
Views: 4314

Re: Bloomberg: Rolls-Royce Offers China Engine Plant to Win Deal; Airbus Plans to Make Newest Jet in China to Win Orders

What could anyone learn of a FAL for an engine, that they could not also learn from an engine overhaul facility? I think there are several such in PRC. The secret sauce in an engine lies in the metallurgy (casting cored airfoils, especially single crystal alloys, is not simple), in the engineering o...

Jump to post
by stephanwintner
Fri Mar 01, 2019 5:06 pm
Forum: Civil Aviation
Topic: Korean Air A220 Significant Engine Damage
Replies: 55
Views: 23835

Re: Korean Air A220 Significant Engine Damage

https://aviation-safety.net/wikibase/wiki.php?id=222410

This incident seems to have also had a failure of the 3rd stage LPT blade...
-->

https://aviation-safety.net/wikibase/wiki.php?id=222410

This incident seems to have also had a failure of the 3rd stage LPT blade...

Jump to post
  • 1
  • 2