The TMC (Thrust Management Computer 757/767) calculates the required thrust for takeoff taking into account several variables. I used to think that the pilots just firewalled the throttles until I worked on this system. If I remember correctly it monitors the engine pressure ratio (among others) and drives the throttles via a servo loop. As Astro stated, saves engine wear and fuel.
Quickest-accelerating commercial airliner at takeoff? (laden)
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We use the TMC to set a reduced takeoff thrust. We use a different system to derive flap setting and thrust for the day (spoke about it more in this thread: https://bobistheoilguy.com/forums/threads/what-its-like-to-fly-an-airliner.269078/)
And then punch that assumed temperature into the TMC, so that when we select autothrottles on takeoff, the thrust is precisely set to that assumed temperature and thus, the appropriate reduction for those conditions.
United goes to San Francisco Fleet Week every year where they're the big sponsor. Currently with the 777-300ER, but they actually had the 777-400 in the show before it was retired. Last year I went on a Saturday and the 777 was the only thing that had a regular appearance due to the fog/clouds. The Blue Angels just did a few flybys and cut the show short. Saw an F-35C briefly.
They fly it almost like the airliner equivalent of a stunt plane. No passengers and piloted by flight test pilots.
Man. That’s cool.
I love seeing airliners at low altitudes!
Saw a FDX 777 do a flyby at an air show once. I was impressed. And it was just a flyby.
Would really like to see one do some demos like that!
One of the demo pilots said they were climbing 25-30º nose up in the 2019 vid, and the video show them level then immediately hitting a 25º climb. I'm pretty sure that would be the kind of thing that passengers would complain about.
Or with a 747-400. They didn't get it to pitch up quite as fast though. I guess they're not allowed to go under the deck of the Golden Gate Bridge.
Taking off and landing in a field, or on a beach.
Taking off in under 100 feet of ground roll.
Landing on a frozen lake, or glacier.
That for me is thrilling.
Needing a 5000 foot long paved runway, just does nothing for my heart and soul.
Taking off in under 100 feet of ground roll.
Landing on a frozen lake, or glacier.
That for me is thrilling.
Needing a 5000 foot long paved runway, just does nothing for my heart and soul.
The difference between a trials bike and a Ninja or a K1600.
I get the appeal of being able to go to those places, but those airplanes are severely limited in other ways.
Yeah, those small STOL airplanes are really cool, no doubt.
But most impressive to me, in the aviation world, are airplanes that can fly vast distances at high speeds, staying in the air for the vast majority of a DAY, without refueling!
Talk about shrinking the world!
From some quick research, I can book a flight from JFK - Singapore on an A350-900ULR with Singapore Airlines, which is the current longest flight in the world.
Over 9500 miles over 19 hours, nonstop!
Less than a day to go halfway around the world!
That is truly impressive.
Yep, that´s why STOL hasn´t really made it as a primary requirment for combat aircraft. The Harrier was pretty neat, but had severe limitations and some vulnerabilities that kept it in a very niche role (Marines). I know there was a Nasa F-15 with HUGE canards that experimented with this and IIRC, it had an exceptional short takeoff ability. But it didn´t make it to service, so I can´t help but deduce that there were some significant limitations to its performance in other areas of its mission profile.
Interestingly, though, the USAF and others seem to be doing more and more work with front line aircraft practicing on roads and highways. I´ve seen stories over the past few years of US F-18´s and A-10´s doing this and now the RAF is getting ready to send Typhoons to Scandinavia for road deployment trials. Maybe some lessons from Ukraine?
That said, I´ve neither heard nor read anything about the NGAD or any new Gen 6 fighter in development that has an STOL component. But who knows? These are interesting times in which we live and like everything else, aviation might be on the cusp of some revolutionary new designs/tech and capabilities!
Isn't that more a matter of reducing weight and having a big enough fuel tank? I guess that's how one gets a short range aircraft like an MD-80 to Hawaii - just adding fuel tanks.
Hawaiian Airlines Fleet of MD80 (History) | Airfleets aviation
Hawaiian Airlines Fleet of MD80 (History) - Aviation website for aircraft and airline information (flight, photo, travel, fleet listing, production list of Airbus Boeing Douglas Embraer Dash, ATR, Sukhoi, Saab...), plane photos for planespotters, flightlog database, aviation news, aviation store.
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But yeah - the balancing of all that on modern airliners is pretty impressive. I remember when the 747SP had the longest range of any commercial aircraft. I believe it was mostly just redesigned from the 747-100 with a shorter fuselage and a taller vertical stabilizer. But the average fuel capacity (I believe dependent on configuration) was actually higher than for the 747-100. I think the wing tanks were the same and they deliberately upped the size of the tanks even in a smaller package to get all that range.
It’s a matter of fuel fraction. What percentage of the max gross takeoff weight is fuelIsn't that more a matter of reducing weight and having a big enough fuel tank? I guess that's how one gets a short range aircraft like an MD-80 to Hawaii - just adding fuel tanks.
Hawaiian Airlines Fleet of MD80 (History) | Airfleets aviation
Hawaiian Airlines Fleet of MD80 (History) - Aviation website for aircraft and airline information (flight, photo, travel, fleet listing, production list of Airbus Boeing Douglas Embraer Dash, ATR, Sukhoi, Saab...), plane photos for planespotters, flightlog database, aviation news, aviation store.
But yeah - the balancing of all that on modern airliners is pretty impressive. I remember when the 747SP had the longest range of any commercial aircraft. I believe it was mostly just redesigned from the 747-100 with a shorter fuselage and a taller vertical stabilizer. But the average fuel capacity (I believe dependent on configuration) was actually higher than for the 747-100. I think the wing tanks were the same and they deliberately upped the size of the tanks even in a smaller package to get all that range.
Adding tanks adds weight inefficiently. Yes, you can put long range tanks on/in an airplane, but after the fact they add more weight for the capacity increase than they would have had they been built in at first.
That is why the SP worked so well, same tanks, in a smaller shorter, and lighter airplane meant a higher fuel fraction and longer range.
E.G. 747-400 - 875,000 max gross with 388,000 fuel. 44% of the airplane weight at max gross is fuel. That’s a long range airplane.
MD-88 160,000 max gross. 46,000 fuel. 28% of the airplane weight at max gross is fuel. That is a short range airplane.
I believe Voyager was about 65% fuel weight at takeoff. The wings were noticeably lower from the weight of the fuel at takeoff compared when it landed.
Either that or it just wasn't deemed to be worth the money.
Interesting. Isn't that a pretty finicky jet?
Drag, too, right? Or are the drag differences among modern(-ish) airliners relatively minor?
Almost every airliner these days is a tube with minor differences like fairings. I guess we were hoping for more creativity, but I guess that basic shape works.
Drag, too. Absolutely. Like most aerodynamic topics, range can get really complicated really quickly, so I prefer to focus on one aspect, rather than describe the entire picture. We did not talk about range with the wind, or against the wind, or cruise Mach number, altitude sensitivity, etc.
Newer Designs like the A350 or the Boeing 787, benefit from much lower drag, so you can get increased range at the same fuel fraction.
The A-350is an impressive airplane. My airline has orders for the airframe, but they keep delaying delivery. Despite its technological, and operational improvements, it doesn’t offer enough “bang for the buck“.
The slight range improvement, and the slight decrease in fuel burn, compared with a 777–300, does not cover the cost of introducing a new fleet type - which has a tremendous training, spare parts, crew availability, and other overhead costs - totaling well over a billion.
I don´t know much about the Eurofighter other than it is a badass dogfighter. I´m trying to find a link to the article and will post it when I find it.
When you can walk out your back door, do a 10 minute preflight, and take off into the wild blue yonder, that for me is freedom!
Not driving to some airport, paying way too much to park your car, having to be there ridiculously early, dealing with wanna be cops who consider nail clippers and water dangerous, having to even remove your shoes, to now sit in another room and wait even longer. Then be told your flight is either late or canceled. If you do eventually get on the plane gou have to sit beside some fat smelly creature who uses up half your seat space to, and deal with yet another stewardess who hates people and her job.
Meanwhile your wondering the whole flight if the pilots are considering suicide and taking you with them, or are they drunk, stoned, hungover, actually brought along enough fuel this time, or have a clue how to navigate, or shoot an approach to minimums, or shoot an approach even on a clear day. Was that patch from a tail drag repaired correctly, or is it going to blow apart today at FL300.
If you actually get to your destination, its probably late, and who knows if your luggage actually made it, and if it did what sort of condition is it in.
But hey at least your off the plane so no more screaming kids, and someone kicking the back of your seat.
Yup I have been on enough airliners to truly hate them.
Not driving to some airport, paying way too much to park your car, having to be there ridiculously early, dealing with wanna be cops who consider nail clippers and water dangerous, having to even remove your shoes, to now sit in another room and wait even longer. Then be told your flight is either late or canceled. If you do eventually get on the plane gou have to sit beside some fat smelly creature who uses up half your seat space to, and deal with yet another stewardess who hates people and her job.
Meanwhile your wondering the whole flight if the pilots are considering suicide and taking you with them, or are they drunk, stoned, hungover, actually brought along enough fuel this time, or have a clue how to navigate, or shoot an approach to minimums, or shoot an approach even on a clear day. Was that patch from a tail drag repaired correctly, or is it going to blow apart today at FL300.
If you actually get to your destination, its probably late, and who knows if your luggage actually made it, and if it did what sort of condition is it in.
But hey at least your off the plane so no more screaming kids, and someone kicking the back of your seat.
Yup I have been on enough airliners to truly hate them.
By way of comparison, our G600 has 32,000 pounds of thrust at takeoff, and on short flights, such as HPN to SWF (a whopping 8 minutes) we will be in the upper 40's take off weight. That's a righteous ride for a luxury barge, and things inside the cabin go flying. Yes, it will climb at a steep angle (that we will not mention) and while doing so, still accelerate beyond 300Kts within seconds. Leading to a number of annoying noises designed to alert the pilot...
The 757 gets my vote as the most powerful "push" from an airliner. However the 737 max I took a short trip on recently seemed way better than JB's Airbus A320's.
No drama, just fantastic performance:
The 757 gets my vote as the most powerful "push" from an airliner. However the 737 max I took a short trip on recently seemed way better than JB's Airbus A320's.
No drama, just fantastic performance:
