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Why the Boeing 737 will never take the place of the 757
- WalterBright 7y agoHaving worked for 3 years designing 757 flight controls, it's a special plane for me, too. I always enjoy finding the bird I'm booked on is a 757. Some of the guys I worked with on it were an engineer's engineer. I lost my fear of flying through working on the 757.
- soganess 7y agoWould you being willing to elaborate on what makes it special to you? I'd love to know more! Years ago I worked at Ames on the ACES system (minor but fixes and a Greenfield projects involving data/flight path visualization), but I felt the airplanes themeselves were these magical black boxes. I'd would appreciate having a deeper understanding about how they differentiate from one another in a non-superfical sense.
- WalterBright 7y agoSimply, what makes it special is I had a hand in it. Every time you fly on one, you're betting your life on my parts. I know how it works, and I know why it's safe. I worked specifically on the stabilizer trim system (like the one in the news on the 737MAX), and did some work on the elevator system. In particular on the latter, I did many calculations to prove it would not flutter (dynamic instability). My very first assignment was to size the stabilizer trim jackscrew. I panicked and told my lead I had no idea how to do that. He laughed and said of course you do, it's a simple column buckling problem. Which of course it was, and I sized it. A couple years later, and the first jackscrew gearbox assembly came off the line, and was doomed to be subjected to the ultimate load test. Any buckling, cracks, deformation, etc., would be a failure. The test guys told me they were gonna bust my jackscrew. They hooked it up to this big ugly iron I-beam with a hydraulic ram to compress my green BMS10-11 painted gearbox and shiny chrome steel jackscrew (made by Saginaw Gear, who made the best kick-ass forgings). They started cranking up the pressure, while I stood around anxiously watching it. Slowly, the I-beam bent into a nice curve. We didn't have to make any changes to any of the stab trim system due to test failures. Whaddya know, the math works! So I am not a bit afraid to fly on a 757. The seating can be cramped, but that's the way it goes these days. As far as know, there have been no in-service failures of that system. The 757 itself has a fantastic safety record, of which I am proud to have contributed to. The last D conference I flew to on a 757 operated by Iceland Air, yay! At the time I bought a bunch of Boeing stock as a result of my confidence in Boeing, and it has paid off handsomely.
- taneq 7y agoMaybe a dumb question, but wouldn’t you have expected it to break at the target max load? I would have thought it being stronger than required would mean it was heavier than necessary?
- WalterBright 7y agoThat is a fun question. Boeing had two groups - the design group, and the stress group. The design group does the design, the stress group checks it. I was in the former. One day, I got called into the stress group, where they told me they were unhappy with my parts. I asked why, they said there just barely strong enough for the ultimate load, only about 1% over. They said they'd feel more comfortable with 10% extra strength. I said this was no coincidence, I used math to size the part to the load, rather than guessing at a size and checking to see if it was strong enough. The requirement was the ultimate load, which is 150% of the maximum load that could ever be expected. I asserted that I designed to the design requirement, and an extra 10% would make it overweight. Brat that I was, I said if you guys were unhappy with the design requirement, increase it. They grudgingly signed off on it. The reason it didn't break on the test stand is because all parts vary in size due to manufacturing tolerances. It was sized to pass the ultimate load test under the most adverse size allowed under the tolerances. Odds are, it'll be a little stronger. For comparison, spacecraft have (I think) an ultimate load of 110% of the max load. The margins are awfully thin, but they have little choice. If you really want a math heavy engineering job, design spacecraft. BTW, the stress group signed off on the jackscrew size. If it had failed the ultimate load test, both them and I would have had a black eye. As it turned out, the test guys were embarrassed by their bent rig :-) and fortunately that wasn't really a problem.
- munmaek 7y agoDo you have a recommended resource for reading more about the 757? I find it interesting but I’ve never dig deeper into it.
- WalterBright 7y agoI don't know of any books about its development. Looking back I suppose I should have kept a diary. We weren't allowed to take materials home, so I have no documentation. The 757 was the last airplane designed using paper drawings and wooden mockups. The end of an era :-) Some of the engineers still used slide rules. My lead engineer once said "let me show you how it's done" and pulled out a very nice slide rule in a leather pouch. I made a little show of blowing the dust off of it, and he laughed heartily. He started at Boeing on the B-47 design, and even he had already moved on to calculators. But nobody used computers yet. I found a PDP-11 in a neighboring building and sweet talked the sysop into giving me an account on it. I'd write my own numerical analysis programs using Fortran IV. My other lead was an old salt who told me he didn't trust computers, they always produced unreliable answers. But he was a good egg, and said he'd give me a chance. There was some long complex geometrical calculations to be done to prove the elevator linkage wouldn't bind up under load. The usual method was to use drafting tools to figure it out, and he put his best draftsman on the job. I wrote a program to figure it out, and came back with my column of numbers to 6 places. His draftsman compared it with his column, accurate to 4 places. One of them was off. My lead said see, I told you computers were garbage. I asked the draftsman to recheck that one, and he did, and came back and said I was right. Ever since then I got the calculation jobs, and my lead would defend me. One day, the CS dept head discovered I'd been stealing unauthorized time on the PDP-11, and I got in trouble. My lead went to bat for me, it went up 3 levels of management, and the top guy told the CS mucky-muck to piss off and give me whatever computer time I needed. I was only the vanguard of what was to come in using computers to design airplanes. My experience with that motivated me to ensure D had a first class foundation for numerical programming.
- WWLink 7y agoYour story reminds me very much of a coworker of mine. He mentioned how they'd start an analysis job on it and get a printout of the results delivered to their desk later in the day by a messenger. What a difference.
- jrockway 7y ago> I lost my fear of flying through working on the 757. That's refreshing. I have a friend who worked on the A380 and she says she'll never set foot on one.
- WalterBright 7y agoOuch!
- rapsey 7y agoDid she say why?
- Hunisgung 7y agoI have had this talk many times and it usually went something like: "You don't realize how serious it is. We discover issue#13270 during the validation of the FCDC. If it occurs after the primary flight computer had a hardware failure and the pilot is landing with heavy side winds and the thunder strikes, there is a heightened probability of hard landing. Most dangerous aircraft ever. By the way, this weekend I'm taking an Avro RJ100 to go to Brussels; no problem there."
- brownbat 7y agoThis sent me down a rabbit hole. The RJ100 (BAe 146) can apparently be kitted to take off and land on gravel: https://www.aviationpros.com/aircraft/commercial-airline/press-release/12144625/bae-systems-bae-146avro-rj-unpaved-runway-capability-gives-cobham-competitive-edge https://www.aviationpros.com/aircraft/commercial-airline/pre...
- gambiting 7y agoSo can a 737: http://www.b737.org.uk/unpavedstripkit.htm http://www.b737.org.uk/unpavedstripkit.htm
- WalterBright 7y ago
- johnmorrow 7y agoI mean the number is lower, how could it?
- smacktoward 7y agoLooking forward to the Medium article about how Boeing wouldn't be in the mess they're in today if they'd just used semver.
- dang 7y agoCould you please not post unsubstantive comments to Hacker News?
- bfrog 7y agoThe 737 max is what happens when the bean counters are in control of an engineering firm.
- loeg 7y agoThe bean counters will always be there. Alternatively, one can think of the 737 MAX (and prior new 737 models) as an example of regulation imposing perverse incentives. ( https://en.wikipedia.org/wiki/Type_certificate https://en.wikipedia.org/wiki/Type_certificate )
- rob74 7y agoInteresting point, but what would be the alternative? Are you really suggesting that pilots should be able to switch from e.g. the 737 to the A320 without any kind of additional training?
- loeg 7y agoType certificates are not about pilots; they're about airframes. Maybe skim the link? > A type certificate signifies the airworthiness of a particular category of aircraft, according to its manufacturing design (‘type’). It confirms that the aircraft is manufactured according to an approved design, and that the design ensures compliance with airworthiness requirements. And to be clear, since it seems my comment was also not totally clear: I'm not saying aircraft regulation / Type Certification is bad in general. Just that this particular implementation currently has unintended perverse incentives which lead to the 737 MAX.
- cyberferret 7y agoNever understood why the 757 wasn't more popular?? It had the best performance in its class while still being economical. Maybe back in its day there was too much overlap between it and the 767, but from talking to pilots who have flown it, the 757 handled like a fighter jet, and passengers seemed to love it too.
- tus88 7y agoIt's a narrow body. They went out of fashion.
- loeg 7y ago737s are narrow body, aren't they? And they're still quite popular.
- tus88 7y agoIt is probably infeasible to make a wide body aircraft the size of a 737 - if they could, they would. The ergonomics (and economics) of twin aisles is vastly better than single aisle planes.
- mdasen 7y agoBoeing/Aurora are kinda trying that with the D8 (aka double bubble). It’s not exactly the same since it is basically two circles next to each other rather than one large one, but it will be twin aisle. The D8 is one of the cooler projects right now, in my opinion. It isn’t too radical like many designs, but it would dramatically lower fuel consumption (50-70%), offer dual aisle boarding on a smaller craft, and a lot less noise. All in a package that doesn’t have too many unknowns from an aeronautics perspective.
- selectodude 7y agoThe 757 was too big for what airlines wanted out of narrow bodies. Now it’s the same size as a 737 MAX 10.
- ianhawes 7y agoThe 737-MAX is the plane equivalent of Windows XP Service Pack 8. > JetBlue is among airlines planning to use the [AirBus A321LR] on routes across the pond, serving Western Europe from New York and Boston. This has to be a gut punch for Southwest, who has famously relied only on the 737. They're close to hitting their ceiling on domestic expansion with the 737 and can't compete on US-EU routes because of their fleet. I like that the author points out the realities of modern 737 performance - just because it _can_ reach coast to coast destinations doesn't mean it _should_. Thats not to say that the 757 is perfect. From what I've heard, maintenance is significantly more complex than the 737. And as the article pointed out, it takes way too long to board/deplane for the short hops that the 737 dominates now.
- Aloha 7y agoSouthwest as far as I'm aware had shown no interest in transatlantic routes, nor do I think they've hit their domestic growth limits - there are still lots of places they don't fly.
- toomuchtodo 7y agoThey fly to Hawaii now, as well as Central America and the Carib with their AirTran acquisition. As you said, lots of places to fly still.
- dehrmann 7y agoOnce Southwest gets over the hurdle of flying something other than 737s, it'll have transatlantic ambitions.
- riffraff 7y agoBut flying a single kind of plane has a lot of advantages, doesn't it? It seems that switching to a new plane would mean a drastic economic change. So the transatlantic ambitions should be a cause to go past that, rather than a side effect.
- 7y ago
- ljosa 7y ago> What would it be like on the westbound leg, I wondered — a longer flight, from a shorter runway, in the face of winter headwinds? Wouldn't colder (denser) air and a headwind make the plane require less runway?
- jcampbell1 7y agoI think he is referring to the jet stream at altitude, which is stronger during the winter.
- phumbe 7y agoThe author isn’t worried about the takeoff speed in that quote; he’s thinking about the increased duration of the flight as stiff winter headwinds (at cruising altitude) decrease the aircraft’s groundspeed. Prevailing surface wind direction doesn’t vary much with season.
- jessaustin 7y agoA longer flight against with headwinds will require more fuel. Taking off with more fuel from a shorter runway will require the pilot to inflict even more bare-knuckling violence on the passengers.
- nutcracker46 7y agoSmith is spot on with his analysis of why no number of mods and modules will make the 737 into a 757. Here on HN I have ranted about the wobbly bobbly handling, obsolete hydraulics, and noisy crappy cockpit of the 73, versus the modern and comfortable 75. Pay attention to what the article says about takeoff and landing performance. We used to load the 75 heavily for trips between NY La Guardia and Chicago Midway, or Midway to Washington National. We could NOT load a 737-NG heavily due to field length or climb limits. Boeing made a bad, bad decision to push the 737 instead of advancing a fresh design. Just wait and watch. They won't abandon the 737 until one or two more are lost due to runway overruns or something else related to its shortcomings. That is WITH better than average pilots, all the sooner to happen with typical ab initio crews.
- mjevans 7y agoI also like the intellectual idea of taking an older airframe (767-200) that is suitable for the task and modernizing it once, rather than applying yet another level of patches to something already pushed far outside of it's intended design envelope.
- Gravityloss 7y agoBut why is it so hard to develop a new plane now, compared to patching an old one? One would think computers could make a single engineer hugely more effective nowadays than back then. Constraints, generative design, accurate simulations. Additive manufacturing, CNC machines and composites can make manufacturing a lot simpler too. Has it actually reduced any cost? Interest rates are really low too. Is it that new planes being developed have much stricter regulations? If so, that's a problem, the incentives result in the public being less safe. The A220 ran so much over budget that the whole program was sold to Airbus. Yet it seems like a really good airplane from what I've read. 787 and A350 were also terribly expensive. Something similar has happened with nuclear plants. They seem to take much longer to do than way back and are so expensive to be barely profitable. A friend commented that one reason is because top talent doesn't see the nuclear industry as a "cool" thing or a viable career anymore. There is one additional problem in airplanes and nukes. They are seen as prestige projects by governments. This makes it hard to make regular money in the industry as you always have subsidized competition.
- audiometry 7y agoI am sure there will be all sorts of (correct) actuarial arguments that driving my car to work is more deadly than flying in the v2 737, but I still don't want to ever fly in a 737. It's got the mark of Cain at this point. I doubt I'm the only one that feels that way.
- 333c 7y agoAs I understand it, all 737s pre-MAX are fine; you want to avoid the MAX planes because of MCAS and the new engine placement.
- inferiorhuman 7y agoAs I understand it, all 737s pre-MAX are fine; you want to avoid the MAX planes because of MCAS and the new engine placement. Yeah, just don't pay too much attention to the structural problems that Boeing is having with the 737 NG (cracked pickle forks). The inspection threshold keeps getting lower and the scope of the inspections keeps growing.
- iknowalot 7y agoWhat a branding disaster, tack on the name of reliable series of crafts to a flying suicide machine and destroy the whole line. I'm sure many customers will avoid 737s in general due to confusion.
- dredmorbius 7y agoBranding is like leverage. There's a downside that goes with the upside.
- Swenrekcah 7y agoThis will be such a confusion though. I’m reminded of my girlfriend who is not interested in airplanes and thinks all airplanes that start and end with a 7 are affected.
- 7y ago
- zeristor 7y agoIs there a way to select for the aircraft when booking a flight? Price, flight times, and minimal number of connections are the main focus; but is there a website that can add in aircraft type? I realise types can be swapped, but with historical data there should be very high probability of prediction of aircraft type at booking. I flew a 757 back in the 1980s and have fond memories of it. This article made me realise that a spate of flying in 737s might have been what put me off flying for so long.
- sleavey 7y agoI haven't seen a search filter for that but you could manually check the probable aircraft on SeatGuru once you find out the flight number from the airline's website.
- mazsa 7y agoand on https://whatsmyaircraft.com/ https://whatsmyaircraft.com/
- kenneth 7y agoMost airline websites and search engines will show you which type of aircraft a flight is on in the results. Alternatively, Google Flights or ITA Matrix can show you. You don't always get to find out easily which variant of an aircraft it is, e.g. a 757-200 vs. a 757-300 might both show as "757."
- zeristor 7y agoSo there’s a gap in the market if you want to be able to filter by aircraft. I can imagine adding another dimension for searching flights could have an impact on usability though.
- kenneth 7y agoITA Matrix is my favorite powerful flight search engine. It lets you filter by aircraft, among many other things. You have to learn what essentially amounts to a really obscure query language to use it effectively.
- Animats 7y agoBoeing has botched this so badly that the replacement for the B-737 will probably be the Comac C919. It's not clear how good an aircraft it will be, but the financing is very favorable. [1] https://en.wikipedia.org/wiki/Comac_C919 https://en.wikipedia.org/wiki/Comac_C919
- xadhominemx 7y agoNo way man. Comac is decades away from an aircraft that will be competitive outside of China.
- peteretep 7y ago> Boeing has botched this so badly that the replacement for the 737 will probably be It will definitely be the A320 family, which has none of these problems, comes in sensible size variants already, is used extensively every day around the world, is price comparable, and isn't going to spook Western consumers in the same way that a Chinese plane will.
- Nokinside 7y agoIsn't this exactly what technical debt is? The term originated in software engineering, but it seems to be exactly what Boeing has if we transfer the terminology into aerospace. > is a concept that reflects the implied cost of additional rework caused by choosing an easy (limited) solution now instead of using a better approach that would take longer 737 rated pilots are abundant, production lines are ready and paid for and orders come in as long as the product works. There is huge incentive to do just small fixes if you can't see technical debt in the books. When it shows up in the bottom line company is already paying interest.
- _ph_ 7y agoThis article raises an interesting point in the 737 MAX discussions. Far too much the press coverage about the MAX has concentrated on whether the MAX can be made to fly safely - which I think it can be, but not, whether it is actually the right design for the tasks it is meant to do. And it does not surprise that stretching a smaller design wouldn't do the trick so well. I am not an aviation expert, so the article was a bit short on details which make the 757 better than the 737 MAX, but I assume it is the wider body and probably better sized wings etc.?
- stefco_ 7y ago707, 727, 737, and 757 all have the exact same cross section. One of the advantages of the 757 is that it sits higher off the ground and can accommodate the large engines necessary for a longer fuselage. More generally, 757 is designed to be longer, with larger engines and wings, and higher fuel capacity. 737 had to have these features bolted on as it was stretched, fitted with higher bypass (more fuel efficient) engines, and given larger wings and fuel capacity.
- alkonaut 7y ago321LR will be very very successful if Boeing decides to scrap the 797 project.
- FighterMafia 7y agowell, one's a narrowbody and the other a widebody with much higher PAX, so didn't really thing this was a point that needed to be made...
- selectodude 7y agoThe 737 and 757 have identically sized fuselages. In fact, they are both basically the same fuselage as the original 707.
- duckqlz 7y ago737 < 757! The argument holds!
- PaulHoule 7y agoInstead of building an NMA with a limited market, Boeing needs to build a 737 replacement.
- jonstewart 7y agoI always like flying on a 757 because of the middle-ish door position. It breaks up the interior and makes boarding and deplaning more pleasant. I far prefer the MD-80/MD-90/717 to the 737. The rear mounted engines make most seats (except the very back) far quieter and landings always seem smoother. Obviously they’re a smaller plane than contemporary 737s, but it’s still far more comfortable than the cramped conditions of the 737.
- orlovs 7y agoWill not touch technical side of plane. I am not so proficient in this field, but it’s one of the best looking passenger jet what humankind have designed. Now only cseries/a220 have done it rigth
- arcticbull 7y agoThe points guy is a terrible source largely full of mistakes and poor information. For instance: “ If built, the 797 would bridge the range and capacity gap between the narrowbody 737 family and the much larger 787 and 777 families — a slot occupied by the now-geriatric 757 and 767.” The 787 and the 767 are the same size to a rounding error. The 787 is basically a drop in replacement for the 767 but much more efficient. And further, the 737MAX and the A321LR (and A320neo) and even the A220 are designed to replace the role of the 757 in air travel. The US market wants smaller aircraft that are more efficient and fly longer range to open up more frequencies. They’re getting them. > “ I may be biased, since I fly it, but you might undoubtedly call it the most versatile jetliner Boeing has ever built. It’s a medium-capacity, high-performing plane able to turn a profit on both short and longer-haul routes” Even a quick perusal down Wikipedia would tell you the 757s are incredibly inefficient aircraft, getting a second wind a cargo haulers due to their way outsized power to weight ratio. And even with all that they can’t make regularly scheduled east coast transatlantic flights without often stopping along the way if there are temperatures or headwinds. As for domestic travel the sheer inefficiency of the planes makes them a poor contender. Really only the full-transcon corridor made any sense at all and even those are being replaced. JetBlue went all A320. They’re by no means “able to turn a profit on short and medium haul flying” solely by virtue of them being scheduled. They’re often flying them for utilization reasons. Can you even call any of this flying “profitable” when American had a 3% margin last quarter across their entire route network, lost money on domestic and made it up on international? The 737 will absolutely take the place of the 757, and already was scheduled to prior to the MCAS issues coming to light.
- WalterBright 7y ago> the 757s are incredibly inefficient aircraft Ironic considering the genesis of the 757 was a new wing and new engines that produced a 35% improvement on fuel efficiency over the 727 it replaced.
- arcticbull 7y agoOh definitely but that was almost 40 years ago (launched in 1981, designed even earlier). Progress is a wonderful thing!