# The Great Ongoing Aviation Thread (general and other) (Part 1) **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [October 23, 2011, 2:17am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499 "2011-10-23T02:17:01Z")\ **Posts on this page:** 20\ **Page:** 217
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [August 8, 2023, 6:00pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4323 "2023-08-08T18:00:00Z")
> [@LSLGuy](#): > > So the 47 was well entrenched when the CH-1 came along into a very similar niche. I think the Bell 47 was more of a ‘utility’ helicopter (think: litter carrier), and the CH-1 was more of a ‘recreational’ helicopter in a time when there wasn’t really a recreational helicopter market. (These are just my impressions without doing any research.) ---
**Author:** ![Robot\_Arm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robot_arm/32/18280_2.png) [@Robot\_Arm](https://boards.straightdope.com/u/Robot_Arm)\ **Post date:** [August 8, 2023, 7:25pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4324 "2023-08-08T19:25:03Z")
> [@LSLGuy](#): > > …nowadays Cessna might be a major force in helos instead of Bell. Who in turn might have disappeared entirely given their poor record in fixed-wing aviation,… Maybe Bell didn’t have a lot of fixed-wing successes, but it’s safe to say they made one great plane. > **[Bell X-1](https://en.wikipedia.org/wiki/Bell_X-1)** > > The Bell X-1 (Bell Model 44) is a rocket engine–powered aircraft, designated originally as the XS-1, and was a joint National Advisory Committee for Aeronautics–U.S. Army Air Forces–U.S. Air Force supersonic research project built by Bell Aircraft. Conceived during 1944 and designed and built in 1945, it achieved a speed of nearly 1,000 miles per hour (1,600 km/h; 870 kn) in 1948. A derivative of this same design, the Bell X-1A, having greater fuel capacity and hence longer rocket burning time, e... ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [August 8, 2023, 11:57pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4325 "2023-08-08T23:57:34Z")
> [@Robot\_Arm](#): > > Maybe Bell didn’t have a lot of fixed-wing successes, but it’s safe to say they made one great plane. True. And not taking anything away from Bell but the British were on-track to be the first to break the sound barrier and had shared their research with the United States ([Miles M.52](https://www.nationalgeographic.co.uk/science-and-technology/2021/01/britain-through-the-sound-barrier-first)) . They were building a plane with what would be described as a ramjet engine designed by Whittle. It was very sophisticated for it’s time. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [August 9, 2023, 3:08pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4326 "2023-08-09T15:08:47Z")
Like all X planes, the X-1 was always an accident looking for a place to happen. The wiki points out how much trouble the damn things was. Ground-breaking is always hard dangerous work. And Bell had the real lead in US jet propulsion and US pre-supersonic research. Interestingly, the last updated variant of the X-1 was cancelled because the state of the art had moved far enough that production designs were already nipping at and past the original X-1 of just a few years ago. ---
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [August 9, 2023, 9:50pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4327 "2023-08-09T21:50:05Z")
> **[Hydrogen-powered planes almost ready for takeoff](https://arstechnica.com/science/2023/08/hydrogen-powered-planes-almost-ready-for-takeoff/)** > > Companies are readying hardware but differ dramatically in how they're testing it. Interesting. Being discussed is a French firm. A comment from the company: > In the case of Beyond Aero, their first aircraft will have a Maximum Take-off Weight of under 8.5 tonnes with a seating capacity between 4 and 8. > > “With hydrogen fuel cell technology we could reach a certain performance in terms of the range of our aircraft. We realized that with a range of 800 nautical miles, we could cover 80 percent of the business aircraft market.” He said electric batteries alone were not considered, as they are too heavy for aircraft. > > “Batteries alone are not an option, due to their low mass-energy density. With batteries alone, the range of the aircraft is very low. However, there will be hybridization of the fuel cell with batteries for phases where extra power is required, such as during take offs. ” ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [August 10, 2023, 11:23pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4328 "2023-08-10T23:23:54Z")
This sounds bad (for them) if true: > **[Aeroflot Deactivates Brakes on Nine Aircraft, Relies Solely on Reverse Thrust](https://aeroxplorer.com/articles/aeroflot-deactivates-brakes-on-nine-aircraft-relies-solely-on-reverse-thrust.php)** > > Russian flag carrier Aeroflot is beginning to fly some of its western-made aircrafts without properly maintained brakes due to lack of parts as a result of sanctions. Pilots: does the article make sense? Yeah, the laugh-at-the-Russians thing makes me want to believe it, but at the same time I think it warrants skepticism. ---
**Author:** ![KCB615](https://avatars.discourse-cdn.com/v4/letter/k/ea666f/32.png) [@KCB615](https://boards.straightdope.com/u/KCB615)\ **Post date:** [August 11, 2023, 12:13am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4329 "2023-08-11T00:13:19Z")
Sounds like a great idea until they suck a couple of stones or aggregate (I’m sure the runways they’re landing on have perfect pavement). I’d think brake components are likely easier to source than new fan blades or inlet cowlings. I can’t imagine trying to come to a stop at a jetbridge using only reverse thrust. Gotta be using stairs and remote parking. ETA - looks like they’ve disconnected the autobrakes, not “the” brakes. That doesn’t make me as worried, unless the antiskid went along with it. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [August 11, 2023, 12:26am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4330 "2023-08-11T00:26:24Z")
LSL can explain it better but it sounds like they’re deferring items that aren’t crucial to flight. It might mean limiting landing conditions to longer runway lengths and less vodka for the pilots. ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [August 11, 2023, 6:21am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4331 "2023-08-11T06:21:13Z")
It’s a confused article that I gather came from a Russian document originally and whoever translated it didn’t have the technical knowledge to recognise that the translation was poor. Aircraft such as the A320 and Boeings mentioned in the article have multiple brakes for each set of wheels. The Airbus A320 and A321 have four brakes, two per main landing gear / one per wheel. As some of you would know, the Minimum Equipment List (MEL) is a document that allows you to operate the aircraft with certain items unserviceable provided you comply with certain restrictions. On the A320 and A321 it is permissible to operate with one brake deactivated for a period of ten days provided that (among other things) the reverse thrust is operable, the auto brake system is not used, the runway width is at least 45 metres, and performance penalties are applied for take-off and landing. This is a common enough practice and there would be aircraft flying like this all over the world right now. Given the above, the following quote sounds a lot less sinister: > According to The Moscow Times, Russian Airlines are allowed to refuse the repair of aircraft brakes for up to 10 days, after which they must either be replaced or turned off, with a notification of the Federal Agency for Air Transport (FATA) required. Like _all_ airlines around the world, Russian airlines are allowed to _defer_ maintenance on a limited number of brakes per aircraft for up to 10 days, after which they must be repaired or replaced. Now it’s quite likely that Russian airlines are applying this MEL much more regularly now that spare parts are scarce, but that’s not such a snappy headline. Edit: If all brakes were unserviceable you wouldn’t be able to stop an A320 or A321, I don’t about the others, but certainly with the small Airbuses you need regular brake applications to keep the speed under 30 knots. ---
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [August 11, 2023, 10:34am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4332 "2023-08-11T10:34:20Z")
Is it that difficult to avoid sanctions by buying parts (including junkyard parts) from a corrupt business somewhere (particularly the third world)? Doing so would simply result in higher prices and slower deliveries. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [August 11, 2023, 1:07pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4333 "2023-08-11T13:07:54Z")
Airline parts have to go through a rigorous certification process. Mentour Pilot has talked about the serious issues Russian airlines face since the sanctions went into place last year. Here is the second of his videos on the subject. There’s a link to the first in it. [![](https://img.youtube.com/vi/xs3nja2LKIs/maxresdefault.jpg "Is Russian Aviation Becoming Dangerous?! One Year Later.") ](https://www.youtube.com/watch?v=xs3nja2LKIs) ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [August 11, 2023, 2:45pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4334 "2023-08-11T14:45:50Z")
NTSB report on the Boeing 777 that came within 800 feet of diving into the water after taking off from Maui just came out. Simplify Flying has a summary. My phone linking skills are poor. Miscommunication between the pilots as to flap settings, bad weather, and instrument readings were cited. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [August 11, 2023, 3:45pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4335 "2023-08-11T15:45:19Z")
> [@smithsb](#): > > Simplify Flying This article? > **[NTSB Says Miscommunication Led To United Airlines' Boeing 777 Dive Near Maui](https://simpleflying.com/ntsb-finds-miscommunication-fault-united-airlines-boeing-777-dive-maui/)** > > The aircraft reportedly went into a dramatic nose dive toward the ocean. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [August 11, 2023, 7:08pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4336 "2023-08-11T19:08:11Z")
I think @Richard_Pearse nailed the Russian wheel brakes situation. Now what could also be beginning to happen is they’ll look the other way on the 10 days limit. With the eventual consequence of them sharing brakes around until the whole fleet is running with 1 inop brake indefinitely. Then any further brake failures leave them with a dilemma. Paperwork or no, stopping with just 2 of 4 brakes on jets with 4 main wheels will not be good. But they will have successfully postponed the day of reckoning for 6-9 months. ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [August 11, 2023, 7:15pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4337 "2023-08-11T19:15:21Z")
> [@gnoitall](#): > > This article? Yes, thanks. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [August 11, 2023, 8:03pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4338 "2023-08-11T20:03:35Z")
> [@Richard\_Pearse](#): > > It’s a confused article that I gather came from a Russian document originally and whoever translated it didn’t have the technical knowledge to recognise that the translation was poor. Thanks for the detailed info; that all makes much more sense than the article. Like @LSLGuy says, one does wonder if they’ll stretch out that 10-day limit or push the margins in some other fashion. But this at least buys them some time. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [August 11, 2023, 10:02pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4339 "2023-08-11T22:02:28Z")
> [@LSLGuy](#): > > Paperwork or no, stopping with just 2 of 4 brakes on jets with 4 main wheels will not be good. But they will have successfully postponed the day of reckoning for 6-9 months. If they try to stop with half the brakes then that will generate twice the heat. Expect brake/tire fires if that happens. Standing on the brakes on a good day is really hard on them. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [August 11, 2023, 10:24pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4340 "2023-08-11T22:24:15Z")
Yes. Actually the total absorbed _heat energy_ from the airplane’s kinetic energy will be the same. But divided between, say two brakes versus four, the heat energy absorbed by each brake will be doubled so the _temperature_ of those brakes will be much higher too. At the limit, that’s certainly enough to start fires. But the total heat capacity of the brakes as designed is much more than is used on a routine landing. They’re sized for a rejected takeoff at max possible takeoff weight with no use of reverse thrust. Typical landing speeds are lower, and landing weights are lower as well. And reverse thrust is generally available in a landing. Even half brakes would be enough for benign-enough conditions. Given skillful diligent brake-saving pilot technique. How much the Russian airline industry can count on benign-enough conditions or skilled diligent work every day on every landing is a different question. For sure they’re going to have a surge in brake fires, tire failures, etc., if they try this on a large scale and doubly so at whichever particular airports are especially challenging. And of course, the first time an airplane with half the brakes disabled tries to reject a takeoff at high speed, they _will_ go off the end or side of the runway, guaranteed, period, amen. Gonna be a messy expensive experiment. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [August 11, 2023, 10:41pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4341 "2023-08-11T22:41:21Z")
I just dug into our brake energy charts. Early this morning I happened to make a nearly max-effort takeoff. Had we rejected at V1 we’d have fed about 48 million foot-pounds of energy into each of the 4 brakes. And would probably have come close to destroying a brake or tire. The brake cooling time would be measured in hours, not minutes. We were right up against the limits where we’d expect melted fuse plugs and deflated tires after that max effort stop. We landed the same jet 4 hours later under more favorable airport conditions with ~20K# of fuel burned off. Using proper brake-saving technique, the chart suggests we fed about 8 million foot-pounds into each brake. One sixth the energy vs the rejected takeoff. Had we been willing or able to roll far enough, we could have done even better. Which suggests that for that landing we could have gotten stopped with just one of the four brakes working. I sure wouldn’t want to plan to do that regularly, but purely from a brake energy absorption perspective it seems doable. In good conditions. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [August 11, 2023, 10:48pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/4342 "2023-08-11T22:48:19Z")
Do any aircraft use bleed air (or some other gas system) to help cool the brakes? Forced convection cooling is typically way faster than radiative and normal convection. Plus, it could help get the heat away from the tires. [Previous page](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499.md?page=216) [Next page](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499.md?page=218)