Lemurs From United States of America, joined Mar 2005, 1439 posts, RR: 4 Reply 4, posted (6 years 7 months 2 weeks 5 days 21 hours ago) and read 3160 times:
Well, the question is, how many airports are strictly limited to code E aircraft and the 65m wingspan? Just because there is a classification doesn't mean that there is automatically a restriction. Show me airports that regularly operate 747-400's inside of Code E boxes...and ONLY Code E, and you'll have a point. (I'm not saying there are not, I just don't know any off the top of my head.)
There are 10 kinds of people in the world; those who understand binary, and those that don't.
Ikramerica From United States of America, joined May 2005, 21027 posts, RR: 60 Reply 5, posted (6 years 7 months 2 weeks 5 days 21 hours ago) and read 3133 times:
There are some 748i limitations.
It doesn't fit in a 744 gate. The airport planning brochure shows how to compensate for this by shifting an adjacent aircraft, but if you want to line a bunch of 748is in a row at gates, you can't do so with minimum spacing.
Also, the wingspan is wider for taxiing and such.
BUT, the engines haven't moved. So unlike the A380 which has engines overhanging grass and dirt areas, the 748i engines remain over the same asphalt/concrete that the 744 hang over.
The real question is going to be the wake. Will the longer wings and engine changes be enough to keep the wake profile low? The 744 has a slightly lower profile than the 747 classics, so it's not impossible. The noise footprint will be much smaller, either way.
Of all the things to worry about... the Wookie has no pants.
Baroque From Australia, joined Apr 2006, 15380 posts, RR: 60 Reply 6, posted (6 years 7 months 2 weeks 5 days 21 hours ago) and read 3087 times:
Quoting Ikramerica (Reply 5): The real question is going to be the wake. Will the longer wings and engine changes be enough to keep the wake profile low? The 744 has a slightly lower profile than the 747 classics, so it's not impossible. The noise footprint will be much smaller, either way.
Well it is a bit bigger and somewhere between the 744 and the 380 must either be (yet) another category, or the break to the 380. So it seems possible it will end up in the same category as the 380.
Wings and wake seem to be a topic that remains to be explored more. There was a post a while ago on another thread on the results of radar tests on various aircraft. It would be great to see more on what the actual wake characteristics of these large planes really are (sorry to whoever it is I have forgotten, it was a great post, that much I do remember!).
KC135TopBoom From United States of America, joined Jan 2005, 11708 posts, RR: 52 Reply 7, posted (6 years 7 months 2 weeks 5 days 20 hours ago) and read 3060 times:
Quoting A342 (Reply 3): Maybe they had planned to use the same facility as class E aircraft, but why should an exemption be made for them ?
We are talking about two totally different things here. Airports rate airplanes by two different catagories, wingspan (aircraft design group, or ADG, for FAA it is ADG I-VI, ICAO it is class A-F, currently) or fuselage lenght (FAA and ICAO ARFF Index A-F, currently). The ADG is all about what size runway and taxiway safety areas need to be protected, thus this directly effects airport design. Simply put, the larger the wingspan, the larger the safety areas. ARFF Index is all about the fire fighting capability of the airport. ARFF means Aircraft Rescue and Fire Fighting. The assumption has always been the longer the fuselarge, the more passenger and fuel carrying capability of the aircraft. Cargo only is in this equasion if it is classified as hazardous cargo.
The new B-747-800F/I will be an ADG VI (class F) aircraft, but is currently suppose to be able to make a 90 degree turn on the same taxiway configueration as the current B-747-400/F/ER/ERF, even though it has a longer wheel base. Here the limiting factor is when and where the main landing gear wheels leave the full strenght pavement, onto the shoulders using either the judgemential oversteer method, or the cockpit over centerline method to manuver while taxiing. The B-747-800 is suppose to be able to stay on the current 75' wide taxiway system, according to what Boeing has already told airports around the world. The A-380-800, by comparison, does have a longer wheelbase and needs intersecting taxiway fillets installed on all 75' wide taxiways, in order to make a 90 degree turn. But, in this respect, simply because the wingspan of both exceeds 220', both aircraft will be classified as ADG VI, or class F aircraft.
Now when it comes to ARFF Index, the current design of the B-747-800 is still an ARFF Index E aircraft (201'-240' long), while the A-380-800 is an ARFF Index F (a new catagory) aircraft (241' +). The ARFF Index referrs to a combination of the number and types of fire trucks, amount of water, and amount of fire fighting foam initially carried to the scene of a on airport crash of this lenght of aircraft. ARFF Index also has timing requirements for the airport's fire fighters, from their normal fire stations. The FAA requires the first rescue/fire fighting capable truck to arrive within 3 minutes, and all trucks (to meet the minimum index) within 4 minutes. Additional fire fighters that arrive that exceed the ARFF Index, are not timed.
So, when comparing the B-747-800 to the A-380-800, from an airport position, they are two different classes of aircraft.
KC135TopBoom From United States of America, joined Jan 2005, 11708 posts, RR: 52 Reply 8, posted (6 years 7 months 2 weeks 5 days 20 hours ago) and read 3026 times:
Quoting Ikramerica (Reply 5): It doesn't fit in a 744 gate. The airport planning brochure shows how to compensate for this by shifting an adjacent aircraft, but if you want to line a bunch of 748is in a row at gates, you can't do so with minimum spacing.
That actually depends on the type of aircraft the gate was designed for. Currently the maximum aircraft box is 260' X 260', but not all gates have been designed to that standard. Aircraft like the A-330-200/-300, A-340-200/-300/-500/-600, MD-11, DC-10-30/-40, all L-1011s, B-747-100/-200/-300/-400-800, B-767-300/-400, B-777-200/-300, A-350XWB-800/-900/-1000, B-787-300/-800/-900/-1000, and A-380-800/-900 are all designed to fit inside the 260' X 260' box for large wide body gates.
There are gates designed to have smaller aircraft, like the A-320 series, B-737NGs, and B-757-200/-300. There are also gates that can only handle RJs.