Search found 567 matches
- Fri Dec 01, 2023 1:40 am
- Forum: Technical/Operations
- Topic: Can some 737s not have winglets fitted?
- Replies: 51
- Views: 5963
Re: Can some 737s not have winglets fitted?
It would be kinda cool to see a 732 with winglets… taking off from a gravel strip. But alas, it’ll never happen. https://aviation.stackexchange.com/questions/43648/why-has-boeing-used-mini-winglets-on-the-737-200 Looks like there was a winglet for the 732. Must have been quite uncommon though. 7669...
Jump to post- Sun Aug 06, 2023 4:17 am
- Forum: Military Aviation & Space Flight
- Topic: Catalina II Flying Boat
- Replies: 48
- Views: 4335
Re: Catalina II Flying Boat
Is this company in possession of Catalina tooling? I want to say it’s possible to restart production without tooling, can’t believe it’s easy though. I believe the recent run of ME-262s was done without the original production tooling. They restarted ME 262 production? Link me please! Here are the ...
Jump to post- Sun Jul 16, 2023 6:30 am
- Forum: Technical/Operations
- Topic: DeHavilland Comet Aerodynamic Performance (L/D)
- Replies: 14
- Views: 2857
Re: DeHavilland Comet Aerodynamic Performance (L/D)
@dlednicer, getting back to the L/D - could you share the data/sources you used to calculate the value for the Comet 1? It would be incredibly interesting to compare the Comet 1 with the Comet 4 also! The math is: GW = 85,000 lbs Sref = 2,015 feet2 AR = 6.56 e = 0.60 (a guess - I find that e falls ...
Jump to post- Fri Jul 07, 2023 5:52 am
- Forum: Technical/Operations
- Topic: DeHavilland Comet Aerodynamic Performance (L/D)
- Replies: 14
- Views: 2857
Re: DeHavilland Comet Aerodynamic Performance (L/D)
I found a Comet I flight manual online. Working with that and other information I have on hand, I put together a performance model of the aircraft. For a M=0.732 35,000 foot 85,000 lbs cruise point, I see a L/D of 11.2
Jump to post- Sun Apr 09, 2023 1:34 am
- Forum: Technical/Operations
- Topic: Pressurisation of different plane types
- Replies: 29
- Views: 12632
Re: Pressurisation of different plane types
This website is no longer online, buy you can look at it on the Wayback Machine: https://web.archive.org/web/20140517190531/http://mrcabinpressure.com/ This page lists maximum cabin pressure differential for a lot of aircraft: https://web.archive.org/web/20140516125351/http://mrcabinpressure.com/air...
Jump to post- Sun Jan 01, 2023 9:00 pm
- Forum: Technical/Operations
- Topic: Hawker siddeley trident wing
- Replies: 41
- Views: 9214
Re: Hawker siddeley trident wing
The upper figure is from Ed Obert's book "Aerodynamic Design of Transport Aircraft". The second figure is from a Royal Aeronautical Society paper "The Development of the Trident Series" by J.P. Smith
Jump to post- Wed Nov 30, 2022 7:06 am
- Forum: Technical/Operations
- Topic: Hawker siddeley trident wing
- Replies: 41
- Views: 9214
Re: Hawker siddeley trident wing
You might notice that the root airfoil also has negative camber and camber increases as you go spanwise. On swept wings, the isobars cross the centerline with no sweep. This causes an unsweeping of the isobars in the wing root region, as they curve to go from one side to another on centerline. This ...
Jump to post- Mon Nov 28, 2022 5:34 am
- Forum: Technical/Operations
- Topic: Hawker siddeley trident wing
- Replies: 41
- Views: 9214
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- Tue Aug 23, 2022 6:11 am
- Forum: Civil Aviation
- Topic: Boeing 747-8 Production/Deliveries - 2022 - 2023
- Replies: 474
- Views: 144931
Re: Boeing 747 Production/Delivery Thread - 2022
A friend invited me along for Boeing Family Day last Sunday (8/21). Poking around, we found ln 1573 and 1574 still on the assembly line, mixed in with 767 freighters and KC-46s. 1574 is still in sections, and has not been joined yet.
Jump to post- Sun Oct 24, 2021 2:21 am
- Forum: Military Aviation & Space Flight
- Topic: Protrusions on EC-135/E-3/AC-130 and Flight Stability
- Replies: 4
- Views: 1361
Re: Protrusions on EC-135/E-3/AC-130 and Flight Stability
And sometimes, ventral fins aren't needed:
- Sun Oct 24, 2021 2:12 am
- Forum: Military Aviation & Space Flight
- Topic: Protrusions on EC-135/E-3/AC-130 and Flight Stability
- Replies: 4
- Views: 1361
Re: Protrusions on EC-135/E-3/AC-130 and Flight Stability
And, sometimes the added appendages do impact stability, so we add ventral fins:
- Sun Oct 24, 2021 1:51 am
- Forum: Military Aviation & Space Flight
- Topic: Protrusions on EC-135/E-3/AC-130 and Flight Stability
- Replies: 4
- Views: 1361
Re: Protrusions on EC-135/E-3/AC-130 and Flight Stability
Not all protrusions have the same impact. Objects with rounded trailing edges don't produce much lift or side force (depending on how they are oriented) and thus don't have much of an impact. The radome on the top of the forward fuselage of these aircraft has a relatively small impact on stability (...
Jump to post- Tue Aug 31, 2021 2:39 am
- Forum: Technical/Operations
- Topic: Question on Aerodynamic Center
- Replies: 3
- Views: 1683
Re: Question on Aerodynamic Center
The concept of Center of Pressure if fictitious. In a college course on statics, one of the first things you are taught about is a couple, which is two equal and opposite forces producing a moment with no net force. Most engineers seem to forget about this after the final exam. I was among the guilt...
Jump to post- Sat Jul 17, 2021 5:58 am
- Forum: Technical/Operations
- Topic: Pros and Cons of Flap Track Placement
- Replies: 2
- Views: 1154
This should answer your questions: https://ntrs.nasa.gov/api/citations/199 ... 052267.pdf
Jump to post- Sat Jul 17, 2021 5:32 am
- Forum: Technical/Operations
- Topic: Chart of Jetliners with and without wing vortex generators.
- Replies: 7
- Views: 1604
Re: Chart of Jetliners with and without wing vortex generators.
The DC-9, MD80 and MD90 have a vortilon, which is a vortex generator, below each wing leading edge at roughly midspan. 1410145 DC-10s and MD11s have nacelle strakes, which produce a vortex that interacts with the wing flow field. As such, you could count them as wing vortex generators. A lot of othe...
Jump to post- Tue Jun 01, 2021 3:48 am
- Forum: Technical/Operations
- Topic: Russian Aircraft and Very Tall Landing Gear
- Replies: 43
- Views: 9486
Re: Russian Aircraft and Very Tall Landing Gear
Max Q wrote:Can’t think of any negatives with a nice tall landing gear, it gives good clearance from the possibility of tail, wingtip or engine nacelle strikes and allows for easy fuselage stretches
A huge negative: weight Jump to post
- Sat Apr 03, 2021 11:01 pm
- Forum: Technical/Operations
- Topic: Why do some Stage III hush kits have ejectors in conjunction with a mixer instead of just a mixer only?
- Replies: 2
- Views: 2962
Re: Why do some Stage III hush kits have ejectors in conjunction with a mixer instead of just a mixer only?
On the GII/III you need an improved internal core/bypass mixer, an exhaust/external mixer and an ejector to meet the noise requirements. The RQLP GII hush kit started life with a retractable ejector, but they didn't meet the noise requirements, so the ejector was lengthened until they met the noise ...
Jump to post- Sat Apr 03, 2021 10:33 pm
- Forum: Technical/Operations
- Topic: Why did Boeing design the 707 to have a shorter landing gear than the DC-8?
- Replies: 10
- Views: 4842
Re: Why did Boeing design the 707 to have a shorter landing gear than the DC-8?
A Boeing old timer told me that they picked the height of the door sill above the ground on the 707 to match that of the DC-6.
Jump to post- Tue Dec 29, 2020 5:30 am
- Forum: Technical/Operations
- Topic: Technical Cheat sheet for aerospace and aeronautical engineers
- Replies: 10
- Views: 4492
Re: Technical Cheat sheet for aerospace and aeronautical engineers
I taught Applied Aero at Cal Poly earlier this year and recommended that my students become familiar with: Hoerner "Fluid Dynamic Drag" and "Fluid Dynamic Lift" Ed Obert "Aerodynamic Design of Transport Aircraft" Ted Lomax "Structural Loads Analysis for Commercial ...
Jump to post- Tue Dec 29, 2020 5:07 am
- Forum: Technical/Operations
- Topic: 747-400 vs 737 winglet size
- Replies: 10
- Views: 3881
The surviving API 747-200 winglet is on display in front of the Museum of Flight in Seattle: https://img.geocaching.com/waymarking/d ... 80b753.jpg
Jump to post- Sun Aug 23, 2020 7:13 pm
- Forum: Technical/Operations
- Topic: 747-200F with blended winglets.
- Replies: 18
- Views: 6817
Re: 747-200F with blended winglets.
https://img.geocaching.com/waymarking/d ... 80b753.jpg(I worked on the program)
One of the remaining 747-200 proof of concept winglets is on display out front of the Museum of Flight in Seattle: https://img.geocaching.com/waymarking/d ... 80b753.jpg
(I worked on the program)
- Fri Jul 31, 2020 4:20 am
- Forum: Technical/Operations
- Topic: 737 MAX Upper Fuselage Antennas
- Replies: 6
- Views: 4096
Re: 737 MAX Upper Fuselage Antennas
The picture of the United 737-9 MAX seen above shows it carrying a Boeing Tri-band Radome. Its 92.4 inches long, 11 inches high and 42.3 inches wide. Different antennas can be put below it. Gimbaled antennas are installed below it (in contrast to the semi-phased arrays used with the Gogo 2Ku). The a...
Jump to post- Mon Jul 13, 2020 1:51 am
- Forum: Technical/Operations
- Topic: 737 MAX Upper Fuselage Antennas
- Replies: 6
- Views: 4096
Re: 737 MAX Upper Fuselage Antennas
The only satcom radome available for line fit on the 737MAX is the Boeing Tri-band Radome. As Boeing notes "Sized to fit a wide range of Ku and Ka antennas from Panasonic, Honeywell, ViaSat, Global Eagle Entertainment (TECOM), and others."
Jump to post- Mon Jun 22, 2020 12:45 am
- Forum: Technical/Operations
- Topic: Fokker 60 questions
- Replies: 5
- Views: 3220
Re: Fokker 60 questions
The Fokker F60 was officially the Model 0604. It was originally civil-certified under DGAC Type Certificate T-050-87. Upon the creation of EASA, this became EASA TCDS EASA.A.036. In addition, the F60 was military-certified in the Netherlands under KLu TCDS Number 4.
Jump to post- Sat Apr 04, 2020 6:22 am
- Forum: Technical/Operations
- Topic: A320 antenna locations
- Replies: 9
- Views: 6655
Re: A320 antenna locations
2 is the LiveTV satcom dome containing a TV downlink antenna. These have now all been replaced on the JetBlue aircraft with the FlyFi domes that cover the TV downlink antenna and broadband uplink/downlink antenna. Also, you don't have them marked, but there are two ADF antennas ahead of the satcom d...
Jump to post- Thu Nov 21, 2019 1:37 am
- Forum: Technical/Operations
- Topic: L1011 Question About a Small Detail
- Replies: 31
- Views: 5388
Re: L1011 Question About a Small Detail
When you have a protrusion sticking straight up out of a surface over which air flows, an interference vortex called a "horseshoe vortex" will form around the base of that protrusion. http://3.bp.blogspot.com/-YXJa6cxzjj8/Ty1w7vk5EII/AAAAAAAACb0/lINS1vmhfUQ/s1600/Horseshoe-vortex.jpg The ...
Jump to post- Mon Jul 29, 2019 8:28 pm
- Forum: Military Aviation & Space Flight
- Topic: The C5 nosewheel
- Replies: 28
- Views: 7051
Re: The C5 nosewheel
I bought a copy of the SAE paper. It indicates that the nose gear just rotates as a unit. However, the aft main gear bogies also steer, at 1/3 of the nose gear angle.
Jump to post- Tue Jul 23, 2019 5:49 pm
- Forum: Technical/Operations
- Topic: Solar batteries on airliner skin
- Replies: 27
- Views: 3823
Re: Solar batteries on airliner skin
The fuselage skin has to be accessible for periodic inspections. Every time someone does a skin inspection, they would have to peel them off.
Jump to post- Sat Jun 08, 2019 11:48 pm
- Forum: Technical/Operations
- Topic: On Flight Internet System / Turboprop
- Replies: 6
- Views: 2424
Re: On Flight Internet System / Turboprop
I’m not sure about what providers there are. However, it should work, as there’s still internet on jets at low altitude. Also, can a Q400 for example be retrofitted with a receiver by cutting a hole in the top of the fuselage to mount the receiver? Air-to-satellite (ATS) systems are not installed b...
Jump to post- Fri Apr 12, 2019 2:24 am
- Forum: Technical/Operations
- Topic: 767-200 to 767-200ER Conversion
- Replies: 25
- Views: 6302
Re: 767-200 to 767-200ER Conversion
viewtopic.php?f=10&t=1026493&p=13615279&hilit=dlednicer#p13615279Elshad wrote:Isn’t the KC-46 fuselage slightly longer?
Nope. See my posts in viewtopic.php?f=10&t=1026493&p=13615279&hilit=dlednicer#p13615279 Jump to post
- Sun Feb 24, 2019 11:35 pm
- Forum: Technical/Operations
- Topic: Identifying Aircraft with Hushkit Installed
- Replies: 9
- Views: 2578
Re: Identifying Aircraft with Hushkit Installed
There were at least three 707 hushkit types: 1. Long-duct nacelle (N88ZL) 2. Comtran v1 with longer bypass duct, original intake (N707JT, VH-XBA) 3. Comtran v2: longer intake and bypass duct (on many 320C versions in the 90s) N88ZL has the Burbank Aeronautical/Quiet Skies hush kit for the 707. On t...
Jump to post- Sun Feb 24, 2019 11:15 pm
- Forum: Technical/Operations
- Topic: Evolution in airliners' nose shape
- Replies: 10
- Views: 3507
Re: Evolution in airliners' nose shape
Boeing engineers laid out the rationale for the design of the 787 nose in AIAA paper 2005-0422 "Optimizing Flight Deck Noise". The started with the knowledge that minimizing the flow velocity over the cockpit windows reduces cockpit noise. Then, they shaped the nose accordingly, to both re...
Jump to post- Mon Dec 31, 2018 9:59 pm
- Forum: Technical/Operations
- Topic: Air Pressure Adjacent to Fuselage Side and Tail Cone
- Replies: 11
- Views: 3248
Re: Air Pressure Adjacent to Fuselage Side and Tail Cone
As 747Whale said, its very complicated. The fuselage nose shape causes the flow to accelerate, but then it slows down aft of this. Over the wing, the flow is accelerated again, and then slows down again. Here are CFD pictures of the calculated pressure distribution on a 737-700 at cruise conditions....
Jump to post- Sun Nov 18, 2018 10:46 pm
- Forum: Technical/Operations
- Topic: Cessna Caravan 208B CAD
- Replies: 1
- Views: 2637
Re: Cessna Caravan 208B CAD
You are looking for a valuable commodity. I paid to have a CAD model of the outside surfaces of a 208B built from a laser scan and it cost $30k. Models of the internal structure are even more expensive to acquire. We scanned all of the internal structure of a GIV wing (using a wing from a scrapped a...
Jump to post- Tue Oct 09, 2018 2:31 am
- Forum: Military Aviation & Space Flight
- Topic: Imperial Iranian Air Force, pre revolution
- Replies: 19
- Views: 6564
Re: Imperial Iranian Air Force, pre revolution
747-2J9F cn 21668/ln 400 was being built for the IIAF when the revolution happened. It was stored, mostly-completed at Paine Field (I saw it there in 1983). In 1986 it was modified to a civil configuration and sold to Northwest Airlines. A friend of mine, who has flown it, tells me that it had an od...
Jump to post- Tue Sep 18, 2018 4:11 am
- Forum: Technical/Operations
- Topic: Engine over the fuselage question
- Replies: 38
- Views: 3851
Re: Engine over the fuselage question
> The Hondajet is an example of over the wing. No other business jet does this. The Scaled Composites Triumph also had an over-the-wing engine installation. It was also the first airplane to fly with FJ44 engines. I did the aero design of the nacelle installation and will say that it wasn't easy. 17...
Jump to post- Tue Sep 18, 2018 4:05 am
- Forum: Technical/Operations
- Topic: 732 Engine Addition
- Replies: 12
- Views: 2150
Re: 732 Engine Addition
Those are the original Nordam hushkits. As they added a drag decrement, a completely internal mixer hushkit was later developed.
Jump to post- Sat Aug 11, 2018 4:09 am
- Forum: Technical/Operations
- Topic: Clmax prediction at high cruise Mach (are you geek enough?)
- Replies: 6
- Views: 1528
Re: Clmax prediction at high cruise Mach (are you geek enough?)
Get a copy of Fred Obert's book "Aerodynamic Design of Transport Aircraft"
Jump to post- Fri Feb 23, 2018 5:26 am
- Forum: Military Aviation & Space Flight
- Topic: SpaceX - Tests, Launches, Developments
- Replies: 2083
- Views: 325621
Re: SpaceX - Tests, Launches, Developments
I'm joining this conversation rather late, so I apologize if someone has already commented on this. It was not commented on much, but this morning's launch out of Vandenberg AFB, besides carrying the Spanish Paz satellite, also carried SpaceX's Microsat-2a and Microsat-2b prototypes. The plan is to ...
Jump to post- Fri Feb 23, 2018 5:05 am
- Forum: Technical/Operations
- Topic: 747-200 wing vs -300 wing
- Replies: 12
- Views: 2761
Re: 747-200 wing vs -300 wing
The 747-200 and -300 wings have common OMLs. This is some information that Boeing published in an AIAA technical paper; It shows that the extended upper hump of the 747-300 and 747-400 improves the transonic area ruling of the aircraft. This increases the drag divergence Mach number of the aircraft....
Jump to post- Sun Feb 11, 2018 6:08 am
- Forum: Technical/Operations
- Topic: 737 MAX differences
- Replies: 10
- Views: 3661
Re: 737 MAX differences
APU inlet and exhaust are visually different. Split winglets. Engines of course. Many have a SATCOM dome on top. Most of the SATCOM atenna thee days are flush mounted.An example would be the BALL SATCOM on Trumps 757 which is slightly aft of the 1L and 2L doors, Hard to see, but its there. I think ...
Jump to post- Sat Jan 20, 2018 9:40 pm
- Forum: Technical/Operations
- Topic: De Havilland Comet Dimensions for FEA
- Replies: 21
- Views: 4011
Take a look at:
http://lessonslearned.faa.gov/Comet1/G-ALYP_Report.pdf
