pchapman

I'm curious, do you have statistics or anecdotal evidence of relative reliability of Martin Baker versus United Technologies ACES II seats, for example? Which eras and seat models? Of comparable build date? Was your friend US Air Force or Navy? (US Air Force pilots recently have usually been in ACES seats while US Navy pilots in Martin Baker. Except the F-35, which is Martin Baker for all I believe.) Or is it just a saying, like, "If it's not Boeing, I'm not going!"? Yes I'm holding you to a higher standard than just a rhyming phrase. :-)

'Deep' is relative to whatever the stall point of the canopy is. Which could be with toggles past full arm extension, or chest level, or whatever applies to you and your arms in that particular harness with that particular canopy. So you can fly with no brakes, shallow brakes, moderate brakes (or medium or whatever term you want), or deep brakes. There's no specific definition (eg, "75-99% of the usable brake range before the first pre-stall rocking"). It's just "a lot of brake, getting closer to the point where you would stall the canopy or have arms fully extended". In deep brakes the canopy will fly a steeper line towards the ground, a steeper descent. The canopy might be dropping vertically faster than in moderate brakes, although possible less than when in no brakes, if it is a ground hungry canopy with a high descent rate in normal flight. It is easier to hit a target on the ground when coming down steeply, rather than skimming by at a shallow angle. Deep brakes is good for that. If too deep, you are getting closer to a stall, and thus susceptible to added danger from turbulence or accidentally stalling the canopy. You also won't have much energy left in the canopy for a flare, which isn't a big issue if doing accuracy with a big canopy onto a soft tuffet. If you do need to descend steeply (e.g., landing into a small field surrounded by trees), but would hit the ground too hard without much flare, you might need to have the room to pick up some speed again (out of deep brakes) before doing a flare with more effect. You might also fly in deep brakes when learning about and practicing approaches to stalls and doing stalls, while up high. Flying in deep brakes is therefore something with some added risk if not done appropriately, and not generally needed for normal flying and landing (excluding the dynamic activity of the flare), but is useful in specific situations.

Students don't need to deal about buying a jumpsuit -- that's normally supplied by the dropzone. When you are going off student status, then you can start worrying about all that. Jumpsuits for flying on one's belly also have grippers so one can dock for formations. Still useful for students, if doing AFF, or learning to fly one's first formations with an instructor or coach.

True, stuff happens and the focus is on your jump, not getting the camera footage. Still, at the DZ I'm at, I'm used to the idea that on most AFF style jumps, at least one of the instructors will always plan to have video. These days one expects to have video as a training tool that greatly improves feedback for the student. It is part of the whole teaching process. All video gets uploaded to the computer system where students can review it (and bring a USB stick to download their own at their leisure). So occasionally a student doesn't get video of a particular jump, but ideally there's a copy of every jump available to the student.

Ok I'll bite, you do present an interesting case! If the DZ has some good rental gear for downsizing, maybe you can at least convince them to allow a rapid downsizing. Back in the old days, early in the zero-p canopy era, if you were good you might do a couple jumps on a particular size canopy, then downsize a size, and repeat. If going to a sportier canopy, have a few jumps on a more docile canopy of the same size. Anyway, that was my experience in the early 1990s as someone who also thought they were a special case -- a pilot in my case. Try to borrow rigs as well, if needed to help with the downsizing. At least then you might have an idea what works for you before you spend money on gear yourself. If you're already on a 180 at 2 jumps that's just one 1 to 2 more downsizes to a 150 anyway. I'm not a great source of advice as I don't speedfly (only paraglide). I'm not sure of the glide ratios current speedflying or riding canopies are built for, but I'd warn you to be careful of the more ground hungry skydiving canopies until you worked your way into them. At the same wing loading, there can be canopies of widely varying flight characteristics. I guess they aren't really common at say 150 size, but at 135 and under they start to be more common. They have a steep descent (say, glide ratio of under 2.5) and dive sharply in turns. So be careful of the model of canopy and not just size. Whether you end up buying a 150 or whatever, it is just very difficult to know what to look for (in a rig, reserve, and main) when you've only barely started skydiving. You could probably fly and land smaller than a 150 easily enough, but you would also be learning to deal with packing, body position on opening, and dealing with other skydivers on opening and in the landing pattern. So who knows, maybe a 150 at 1.25 loading or thereabouts might be reasonable to stay at for a little while.

Well, they do better than the walruses! That's referring to the video in the recent "Our Planet" series, where walruses end up lumbering from a rocky beach up slopes. Then, being somewhat poor sighted and not being used to cliffs or backing down from anything they can't handle, try to take the shortest way down -- and fall off the cliffs. NSFW: (Not Safe for Walruses) Good old square-cube laws for surface area and mass...

From an Aviation Week article, detailing some of the changes: (my bolding) They're also planning more sim sessions for pilots -- Getting practice with dealing with the sort of situation where the stick shaker is going off and the airspeed value is unreliable, making things a bit chaotic in the cockpit. (Airspeed gets somewhat wrong if the AOA is wrong, as the AOA on is used to correct smaller errors in the pitot tube readings.) Some of the new memory items for pilots for situations like that are basic "power and pitch" rules. If you are unsure of airspeed, and your flaps and slats are retracted, then for example set the engines to 75% speed and pitch the nose up at a 4 degree angle. That should give a reasonable climb and airspeed whatever the aircraft weight. The Airbuses also have stuff like that -- If some sensors are unreliable, there are rules of thumb to use. The Ethopian pilots, for example, were distracted enough that they kept the same takeoff power during the whole flight, which put the aircraft at the very high end of the airspeed envelope and even led to overspeed warnings, during flight prior to the final dive. The high speed also made the trim issues and forces on the control wheels worse. It would all have been more manageable at a more moderate speed.

If Trump had nothing to hide, why did he & associates keep lying about all their Russian contacts? Maybe it has turned out that all they did was lie and be sleazy and lie some more and hope & ask indirectly for support from Russia (without actively colluding). But their actions certainly helped get the whole investigation momentum going. Hiding your contacts with Russia when asked about your contacts with Russia might make someone suspicious about your contacts with Russia, amazingly enough.

If Trump had nothing to hide, why did he & associates keep lying about all their Russian contacts? Maybe it has turned out that all they did was lie and be sleazy and lie some more and hope & ask indirectly for support from Russia (without actively colluding). But their actions certainly helped get the whole investigation momentum going. Hiding your contacts with Russia when asked about your contacts with Russia might make someone suspicious about your contacts with Russia, amazingly enough.

I'll have to agree. I hate it when people take things out of context, or misinterpret minor slips of the tongue or awkward use of language, no matter what side. The conman Trump was in a conversation about people like MS-13 members, and unfortunately then said " We have people coming into the country, or trying to come in — we’re stopping a lot of them — but we’re taking people out of the country, you wouldn’t believe how bad these people are. These aren’t people, these are animals." He put his foot in his mouth there, and the media took it too far. Trump did the next day clarify he meant MS-13 people. God knows there are a million legitimate ways to attack Trump. Of course, Republicans are at least as bad. Witness their harping on about Obama talking about "you didn't build that" -- which was in the context of all the things that a government provides, that assists someone in the US who has 'built their own business'. It's also one thing to snicker at a verbal gaffe that doesn't reflect actual knowledge (e.g. Obama's '57 states', or some things George Bush #2 said), and another to claim it to be a serious political issue.

This is a decent design I jump. The key here is that there is a downwards facing tuck tab just below the main tab to hold the brake line. It is resistant to coming out when simply pushed in one direction along the riser -- like by a slider grommet slamming down. Too many toggles have only upwards facing tabs. (Source for mine is a Canadian rigger, Al MacDonald at Flying High. He was already making these 15 years ago.) Mirage for years had toggles with up and down facing tabs but a later one I saw had both facing up. The Racer design with the snap fasteners seem like they would be even better at avoiding accidental release. @gb1 who wrote " they elected to install the ones with an inside diameter of 15/16 in. Real bright. The old style #8's have an ID of 1 1/6 in. ". I had figured that diameter was all that was available for lightweight stainless grommets. Otherwise the full #8 size would certainly have been preferable....

1. The "second problem found" - The WaPo article has Boeing saying it is minor and easily fixed. Well, obviously we'd like a second opinion. 2. I've looked more through the preliminary report on the Ethiopia crash. It looks like the crew turned the electric trim system back on. That's weird. They initially had the problems, discussed turning off the electric trim (Stab Cut-out switches), and did so. MCAS even tried to trim nose low using the electric trim after that point, but nothing happened to the actual trim because the electric trim was disabled. Good, they had followed procedures! They they keep flying OK for quite a while. Although it would be a high stress situation with back pull on the controls, stick shaker, and later overspeed clackers too for a small overspeed (since they left a lot of power on from the early climb). There's a discussion where the first officer says manual trim not working -- But did he actually try to use the wheel and not try to mash the trim button on the electric system that wasn't working now? Was the 360hr pilot really familiar with forces that could be on the manual wheel? Did he actually fold out the handle to increase leverage? Anyway, over a minute later something unexpected happens, that could only happen if the electric trim were turned back on, assuming no bizarre electrical faults we don't know about) The data shows a couple very short upward trim activations of the electrical trim buttons. The actual pitch trim position is hard to see on the graph, but it looks like it moved up a little -- but only a little, as the activations were very short. Then the MCAS kicks into effect one last time, trimming significantly more nose down. That's when the pilots lose effective control and nose over. So someone, without discussing it in the cockpit, turned electrical trim back ON, but only used it to make a couple short and ineffective up trims. I figure the first officer tried to fiddle with things, and turned the trim back on without discussing it, made short useless up trim activations, didn't immediately turn electric trim back off, so they then lost control as MCAS kicked in again with a bunch of down trim. That's my best interpretation with current data, although who knows who actually did what. Was the electrical pitch having trouble getting the stabilizer to actually pitch, given the air loads at speed with columns pulled back? Who knows but the aircraft was flying OK, not the much different from earlier when trim worked fine. And the trim attempts were very short, too short to have much effect. Although the Airworthiness Directive from last time mentions keeping the Cut-out switches off for the rest of the flight, I could see that turning electric trim back on temporarily might be a way to help the situation: Turn the electric trim back on, hold electric trim UP until control forces are neutral again, and select the Cut-out switches again to stop MCAS from then pitching the plane down again.

That issue of trim and control column forces has long been a background issue for some aircraft in general. You don't want the trim to be effective both slow and fast, but then it is easy for it to have too much authority at higher speed. So it might overcome full back elevator, or cause pitch forces to be too high to realistically hold and fight against the trim. A small plane might have just a small trim tab that's easy to counteract, but on airliner jets with large speed ranges the whole stabilizer (with the elevators attached) moves, so it can have a lot of authority. If an aircraft is trimmed nose low and picking up speed, to lighten the trimming, one would have to unload the stabilizer, such as by slowing down, or by unloading the elevator, by not pulling back hard on it. But that's just what one can't do easily when there's too much speed or too low. Looks like they might have had to get on the issue quite quickly to avoid getting into the trouble they did. But it'll take some careful reading of the flight recorder traces, and understanding of control column and trim wheel forces, to sort this all out. I'm starting to wonder if Boeing had really simmed this very well after the first accident. When alarms are going off, and one stick is shaking because of the messed up AoA sensor, real world pilot reactions aren't going to be instant. We're still caught up with this whole issue of it on the one hand being a really messy situation, but on the other one should supposedly be able to get ahead of it by killing the electric trim ... if one can do that before the stabilizer trim & flight angle get to be too bad. And what the heck is going on with Boeing's AoA sensors & associated electrical system? They had confidence in it during the design phase, and the sensors are by Rosemount, who have built AoA sensors for a long time for many aircraft. Although I have no idea about any associated black boxes, it would likely be an electrical failure somewhere in the Boeing & Rosemount & any other supplier's system, not the actual vane on the outside of the plane somehow jamming in a weird position. With a large fleet of aircraft out there, does one really expect a failure in the fleet every 6 months? It would still be bad enough on non Max 737's, where it could presumably still cause a stick shaker to go off because of the bad data. Going by the graphs in the prelim report: When the Ethiopian Airlines pilots lost the plane, they really lost it. Although they had some altitude loss early in the flight when the emergency started (and had Ground Proximity Warning System alerts), they fought it and then managed a slow climb for a long time. Then they got one last automatic nose down trim of maybe 4 seconds, which despite hauling back on the sticks even further than during rest of the flight, pitched the nose from above to below the horizon. There were no more pilot input electric pitch trims, and the thing just nosed over -- they lost their roughly 5000' above ground in 15 or 20 seconds, pitching down to -2g's and 45 degrees dive. I'll have to read the rest of the report later.

Interesting (and annoying) that they want to enforce their rules by Nationality and not simply by Residency. Someone might not have set foot in the homeland of their passport since they were a kid, or since they started skydiving, and suddenly would be required to get all the local licences -- even if just visiting for a weeked and not moving to the country permanently. I wonder to what degree they actually check passports, if you show up and say, "Guten Tag, I'm from Amerika and want to jump!".... but it doesn't sound like the DZ or national organization are very flexible...

From the article Ryoder referenced about the whole shitshow, I think these are a couple key quotes: The new DA who decided to drop all the charges (edit - talking about how nothing was done for ages about actually getting bikers into court):

Just ask about your weight. It may or may not be an issue depending on the school. Each will have their own student weight limit. Some gear (harnesses, emergency parachute) is only certified to 254 lbs for example, and that's person plus all their gear. That used to be a common standard, which also means that plenty of people technically overloaded their gear. But nowadays there is more gear that's rated to a higher value, so ideally you would find a place that has such gear. It can also depend on the instructors available. For example, for the AFF method of instruction, if they don't have any big burly instructors (or maybe super high experienced ones), they might cap the student weight at a level below yours. An instructor might have a personal limit on how big a fellow they want to try to move around in freefall, especially in the rare occasions when things aren't going all smoothly...

Re: Billyvance writing about McCain pretty much blowing up the Forrestal and practically being a Colonel in the North Vietnamese Air Force. I do try to give the right wingers on this forum a chance. After all, sometimes the news focuses too much on one story or one idiot, without putting things in historical context or looking at other sides of issues enough. But then I check on the right wingers' info, to give them a chance, and sometimes it's all such utter bullshit. Stuff that's totally wacko and repudiated by Snopes and PolitiFact and other decent sources. Stuff that's copied once off some crazy blog and spread around unquestioningly in right wing circles. (There are always things that aren't well known or come to light later, but some stuff is just out there with the flat earthers and moon landing deniers. We individually don't have perfect knowledge, but we're talking about stuff that's almost certainly false, not just "this is a bit out there but there may be some truth to these accusations".) It's hard to see logic in the other side when one doesn't see much of the moderates, but instead one has to fight off the most outspoken crazies. I mean Billy, why do you even try with that stuff? Do you honestly believe it? And that something like Snopes (good, but not infallible) is all a big conspiracy against your kind? Or do you spread this stuff like Putin, as long as it spreads doubt and dissent and inflames people, no matter what the truth? Did you just forget to do any fact checking?

20 years of heavy use, getting fuzzed up from wear or heavily faded from sunlight, sure one could have webbing lose half its strength. Look for the "Wilcox Webbing Tests". (Old Skydiving Magazine article and also a PIA presentation. Might still be kicking around the web. ) But there's also data from government and military testing suggesting that one might lose only say under 2% of strength per decade, if not stored in too hot conditions. That's the closet queen scenario, without sun and dirt and wear. (This has been in older threads I've been involved with, but I'm not dredging up the data right now.) Nylon does degrade and oxidize over time, and the chemical processes are speeded up with heat. But it is a slow, slow process.

Good point. Although first the rule is given, then it talks about voluntary compliance. So it is a bit vague on what exactly is voluntary -- the rule, or the compliance. E.g., "Murder is a crime. Voluntary compliance with this law will protect everyone."

Ok. Even there it just talks about applying to "all jumps" from aircrat, except military or emergency. While that technically sets no limits to location or time, it is still really only USPA's interpretation if they expect it to apply globally 24/7. Mike Mullins seems to believe it does, so as a director, his opinion has some weight. I would want to see it clarified what the USPA really want. Most organizations' rules are intended only to apply to activity relating to that organization. But I've spent enough time on this issue that really doesn't affect me anyway, although it would for other jumpers I know....

To go back to the origin of all this, where is it stated, that USPA members must always follow the BSR's, as Mike Mullins suggested? Any argument depends greatly on what the actual rule happens to be! It really is supposed to apply all over the globe, 24/7? Or is it mainly aimed at the USA? I can see why the USPA might have done it, to try to fight back against non USPA DZ's, sketchy or not, within the US. I can see the USPA not wanting someone to have fun at a USPA DZ (where the USPA membership is needed) but also teach at the sketchy Pecos Parachute School at other times. One might or might not agree with that. So if a BASE jumper with a BASE rig has some fun from a balloon or ultralight in the US, yeah that's violating the FARs. But if he is a USPA member, should the USPA consider it a violation of their BSR's too? He has to maintain his squeaky clean USPA standards 24/7? Thanks. So I'm not quite as concerned as I initially was. If the USPA is attempting global 24/7 control of a jumper, there seem to be some exceptions. It's easy to misunderstand the "follow the FAR's" rule. It isn't about following the TEXT of the FAR's but about not actually committing an FAR violation -- which can't normally happen when in another country. So it doesn't stop a USPA member from jumping from an ultralight aircraft with a BASE rig, in another country. Whether or not that is legal in another country. The BSR's are good that do try to take some account of foreign operations, such as allowing jumps below age 18 outside the US, if OK with the local rules (although a USPA license won't be granted until 18). What specifially would let one interpret all the USPA student training BSR's to only apply to students being trained in the USA? And thus try to control USPA DZ's, plus non-USPA DZ's (even if FAA legal), but not foreign DZs? The BSR's after all say "All student training programs must be conducted under the direction and oversight of an appropriately rated USPA Instructor until the student is issued a USPA A license". If so, it would stop a CSPA instructor from instructing CSPA students, if the instructor happened to have a USPA membership. Or does one wave ones hands around and say, "Well, the USPA doesn't really mean to shut down training around the world if someone happens to have a USPA membership, so don't worry about it. "?? But if one does that for outside the USA, why wouldn't that apply inside the USA too, and thus not interfere with non-USPA DZ's? The BSR's don't have that many other requirements once one gets past the student stuff -- Much of it is stuff like no alcohol, opening altitudes, max winds, and deployment altitudes. The details of those rules tend not to be too restrictive compared to many countries in the world. So there this USPA-global-control idea doesn't actually cause that many problems. Still, conflicts will occur: In Canada, a jumper not jumping under voluntary CSPA rules, but jumping over some farm field, could legally pull low. But the USPA BSR's would try to restrict him from doing that. Or, a while distances to obstacles are similar for the USPA and CSPA, the USPA happens to be stricter than the CSPA for a C licensed jumper. So the USPA wants its rules to apply, even on "a CSPA jump" if the jumper is dual rated? And the water jump question is still open. Again, unless one waves ones hands around and claims some common sense exception, "Well, there are no USPA S&TA's at most places elsewhere in the world so that doesn't really apply." The whole issue could still use some clarity about what exactly the USPA requires in its rules, and what it really intends the rules to do.

I'll kind of agree with you here Westerly. Pitching in a track isn't inherently bad. It can be, and might OFTEN be, depending on the tracking situation, but isn't necessarily so in all cases, so it can be perfectly fine. Now if one has a fairly short track, as is typical in a quick breakoff from an RW jump, then one might not be slowing down all that much vertically, and one is adding horizontal speed -- so the total velocity might be higher. And some people don't track all that efficiently. And dumping in a track means the opening starts with one 'less upright' or body in line with the canopy deployment -- so it can be snappier on the neck and feel worse, if the canopy is already snappy to begin with. So there are many cases where yes slowing down from the track before pitching is the right thing to do. But on the other side, I've done long tracks where my vertical speed went way down. (Measured by Protack, with data on a computer so I wouldn't be fooled by any short term data fluctuations from body position changes.) With a canopy that opens reasonably well, pitching from that track tended to produce nice smooth openings, at least as smooth as normal. I love pitching in a track on that canopy! Even though I had some decent forward speed going, I think my total speed was lower or no faster than in normal freefall.

Just a brief comment to add to your good post. I've heard the above on the news too but I've started to get the impression that that was mainly overeager reporting by unknowing media. For all I know MAYBE there were cases, but some of the "control problems" the media discovered from the NASA ASRS confidential incident reporting system (I guess) were unrelated to MCAS. If a pilot had some finger trouble with autopilot settings and accidentally busted an assigned altitude, it doesn't necessarily make it the airplane's fault.

Nice to have someone from industry comment. I think though that the 737 Max does have an AOA vane already on each side, used to drive left and right side display systems in some way in addition to the left and right side pitot tubes. Think that is standard and not an option but not absolutely sure. But the MCAS was tacked on using only one side's AOA vane. [Edit: Ryoder's link also gets at the issue of comparing data from the 2 sensors.] At least already having 2 vanes already should help speed the fix -- as you talked about, with 2 inputs one can at least put up a big warning when they disagree, even if it doesn't help with deciding which data is bad, as one might with 3 inputs.

This is always fun. NZ Aerosports are the "designers and makers of Icarus canopies" as they state, yet but don't make the "Icarus Reserve" or the "Icarus Nano" as they are called on the Icarus World website, names that don't include the World part. The companies don't help in reducing the confusion.