dutchroll

Some odd things to have in a pilot-orientated store, for sure. Maybe they should be in the "miscellaneous" category? In any case, there are more than one or two blokes here for whom I'm certain no amount of beauty product will help........(yes by default I'm already speaking for myself).

Yes it's cringeworthy Robyn, but I agree with Downunder that it's probably not intentional. I have met fellow male pilots throughout my aviation career, even very recently, for whom even the 60's would be scary modern times as far as attitudes to women go. Why, you might even have already detected some of them on this very forum!

There you go again. Using "British" and "logic" in the same sentence.

Yeah I only picked up that typo after the edit window had already passed. I was hoping everyone would re-interpret it the way I meant it! I'd generally disagree with that. The autopilot and autothrust disconnection is purely a function of the reversion to alternate law as the computers reconfigure themselves. They get booted out at the time, but they can be re-engaged (usually). Aside from the loss of both engines which would be pretty obvious, alternate law reversion occurs when certain air data failures, inertial reference failures, or sensor failures happen. In other words, the plane says "hey I've lost some information, so I'm not 100% sure where I'm at here". However it still keeps flying normally if you sit there and do absolutely nothing. It's still attitude stabilised by the flight control computers, even in alternate law. There's more than enough info available, including groundspeed still displayed on the nav displays and getting the GPS altitude from the FMC displays is a simple matter. Yes there's a simple way to fly the plane when the computer misbehaves like this: don't touch it! The flying pilot in AF447 inexplicably decided to mess with it after everything disconnected and pulled the nose up. It took him less than 60 seconds to stall it. If he had just sat there, it would've largely sat there too. True, it was in turbulence and it did roll around a little, but if he did nothing else but keep the wings roughly level and maintain the pitch attitude (or if the other guy had taken over and done the same), we wouldn't be having this discussion. If they'd done the "unreliable speed" emergency memory actions which Airbus pilots are trained for, again we wouldn't be having this discussion. I should add the Air Asia flying pilot did exactly the same thing. He pulled the nose up at high altitude while it was in alternate law.

Yeah when I did aerodynamics at Uni we used slugs as well. We had an old lecturer who clung vehemently to imperial measurements (I'm almost certain that a portrait of the Queen must've adorned his dining room at home) on the basis that "a foot is divisible by lots of whole numbers" which struck me as a grossly illogical argument because there are plenty of imperial units which are not, and there's no consistency whatsoever between the number of "sub-units" per "unit" anywhere across the imperial measurement system.

An Airbus does not become unstable in Alternate Law. It loses some of its flight envelope protections (including angle of attack/stall protection), but it does not become unstable at all. The common thread in these accidents is that the aircraft has reverted to alternate law, lost its stall protection, and then they've managed to stall it without realising, or realising too late, that they now have to do a high altitude big jet stall recovery (which is not like a Cessna stall recovery - it chews up a lot of altitude). There have been a number of incidents where an Airbus has reverted to alternate law and the consequent flight, approach, and landing has been totally eventful. You can revert to alternate law in straight and level flight and the Airbus will just sit there fat dumb and happy. It requires mishandling to get into these dire situations.

The metre was born of the "International Metre Commission" in 1870-1872, which then led to the creation of the BIPM (International Bureau of Weights and Measures) and in turn, SI units. It is by definition metric, and an integral and original part of the metric system. How it has been precisely redefined over the years is a matter of convenience more than anything. Redefining the unit for the sake of accuracy doesn't change the whole crux of the metric system. As far as the inch being more appropriate for machine engineering, I'd be interested if you could get support for that contention from the engineering powerhouses of Germany. Or Russia. Or anywhere else except countries which have clung to imperial measurements! Maybe the Germans were never so crash hot at machine engineering after all?

No probs - just making sure we don't get tarred with the same brush! I for one would totally agree that there are some airlines with very poor training and assessment systems. The accident airline is one that I personally would not fly with (and that was before this accident). Any time mate. I don't charge. Well actually......I can't charge legally. Although I have been known to graciously accept bottles of wine in return.

"Four tenths of a thousandth of an inch". Lol.......I've always found it ironic listening to pro-imperial arguments while simultaneously talking about divisors and multiples of ten or a thousand, applied to inches! I think that's a case of the imperial measurement system wanting to have its cake and eat it too.

So........you're going to tar all professional pilots with exactly the same brush now? I'm a professional pilot (have been since I left school). Are you concerned about my flight skills?

Sounds to me like you were talking about the "feet", "nautical miles" and "knots" used worldwide in aviation before the discussion quickly drifted to metric versus imperial generally speaking. To understand this you have to go back to the end of World War 2 and the dominance of the USA around the world, supported by the British. The adoption of standardised units in aviation was a consequence of the Chicago Convention in 1944 and subsequent post-war years. The general thrust was to adopt the metric system universally for aviation. However the nautical mile was included due to it's relevance in map usage (being one minute of latitude on maps and charts). Hence also "knots" or "nautical miles per hour" for speed. Even so, there's no specific reason it couldn't be adapted to kilometres but it remains as it is for convenience. The foot for altitude was purely a result of American and British insistence. There's absolutely no reason it should be used for altitude, but he who wins the war writes the post-war rules. As to metric versus imperial measurements for other purposes, again you have to look at the aircraft and general manufacturing juggernaut of the USA after the war. There's not actually a lot about the old imperial measurements which makes logical sense in the modern day, but trying to get a powerful nation with significant world influence to change is....well....not all that easy. Technically the USA is supposed to have changed to metric (Congress authorised it back in 1975), but practically the country has largely refused to do so mainly due to the sheer cost and effort it would require. Put simply, it's "too hard". It hasn't been without consequential trauma either. NASA lost a $125 million Mars probe in 1999 as a direct result of confusion between imperial and metric measurements. In 2006 a remote NASA spacecraft rammed into a military satellite it was meant to dock with for the same reason. Interestingly I witnessed a discussion on metric versus imperial between two American engineers not long ago. One designed and built aircraft, the other was involved in precision CAD manufacturing. The aircraft guy was arguing that he found it easier to think in terms of the old fashioned imperial units (probably because that's just what he grew up with). The precision manufacturing guy argued the complete opposite, saying that in his line of business, nothing about the old system made any sense and metric was far better. When you think about it, metric measurement is a natural "base 10" system just like we use in mathematics everywhere in the world (including the USA). I personally can't see why they hang onto imperial, other than the old "it's just too hard to change" reason.

Some of the discussion didn't come across that way to me, but anyway. One of the issues that I have with this sort of thing is that correctly executed, sideslipping and rudder-only use is not an issue (though I totally agree if you can use balanced turns and balanced flight generally, you should). But it's really easy for the inexperienced to incorrectly execute it. That's a simple fact when you're talking about crossing your hands and feet up into a situation which doesn't "feel" normal. And then.......well you know the rest. With all this eagerness to espouse whiz-bang advanced flying techniques which are outside the realm of basic flying training anywhere in the world, I'm not entirely convinced this point is sinking in.

Yeah I'm just a little bit disturbed by that whole thing at the moment.

Yeah I've been desperately trying not to comment on this Kamloops because I've felt I needed a sanity break. For info, I'm a current operational A330 pilot in my day job (however my training was Air Force, as was 16 years of my flying career). But here goes: Your contention that the 3 pilots were clueless morons and that's why it ended up at the bottom of the Atlantic is unjustified. For a start the Captain wasn't even in the cockpit when the aircraft was stalled by the mishandling of the junior flying pilot, after being faced with a number of confusing system warnings and cautions pertaining to air data and airspeed. He was asleep in the crew rest. He had 2 minutes after having been awoken and greeted with a totally unexpected and confusing situation, to try to analyse and understand what these 2 guys were doing. In fact he did eventually realise what had happened but it was all too late. They were at 2000ft with a 10,000ft/min rate of descent. Even when he instructed the pilots how to correctly recover, the junior pilot pulled full back on the stick while the other pilot was trying to push forward and recover, negating any probability of doing so. In the Airbus, the flight control system "averages" the inputs of both sidesticks. The Air France training system shouldered a lot of blame for the accident. It wasn't that the pilots didn't know how to recover from a stall. It was that they didn't realise that they were in one. Their training system, approved by Airbus itself, emphasised that the aircraft is not possible to stall in normal operations. This is actually quite true as the aircraft has angle of attack protection which will simply not let it stall no matter what you do with the stick......in normal operations. For example, if we get a "pull up" warning from the ground proximity system, what do you think our trained immediate checklist actions are? It might surprise you that they are to pull fully back on the stick and hold it there, irrespective of anything else including airspeed. In a windshear recovery, it specifically states "up to full backstick if necessary". A colleague of mine recounted how a few years back they were cruising along and suddenly went into a substantial temperature gradient, which caused the speed to decay rapidly and with traffic below them. He ended up with full backstick, the aircraft sitting there at max angle of attack, protected by the stall protection system, before finally being able to descend to a lower altitude. So there has been a mentality around for a long time that the Airbus just can't be stalled. Unfortunately this isn't true. The stall protection is lost when certain computer failures occur, and that happened to AF447. There was never any proper handover/takeover of control either. The junior pilot who stalled it in the first place was poorly trained and most likely out of his depth. The other guy tried to takeover but was clearly also confused about what was happening and allowed the junior pilot to still be attempting to pull back on the stick to arrest the rate of descent. The A330 does tell you when both pilots are making inputs on the stick, but as I mentioned before, it just averages them out unless you push and hold the takeover button. If you've got a christmas tree of warning messages and other alerts going off, it's quite possible to not notice (and indeed in the accident report, there are occasions where some aural alerts are overridden by others). So it makes for a complicated analysis of what happened in an electric jet which had a number of system faults occur, design and human interface problems which have been there from the beginning, and compounded by poor training and procedures. http://www.bea.aero/en/enquetes/flight.af.447/rapport.final.en.php

I own an aircraft without flaps, I might point out. I'm not arguing that sideslipping shouldn't be taught, nor that it shouldn't be used. It is not used as a "normal" approach procedure. And if you're not happy in the circuit and want a safety margin, fly a tight circuit, not a high one. Or don't fly. Jeezus......we now have people saying it should be par for the course on every approach! Reinventing 100 years of aviation training. You heard it right here.

I'm still trying to figure out who the "3 clueless airline morons who were hired because they could tie a windsor knot" were.

Have you ever heard a test pilot advocating the use of sideslip on all approaches for more precise aircraft control? There is a reason for that.

Because you're generating high sink rates at low or idle power settings and low airspeed close to the ground. Half of all general aviation accidents occur during landing. Even AOPA extols the virtue of stabilised approaches in general aviation flying and have done for several decades.

My gliding experience is limited to single digit hours and a solo flight, but I don't ever recall being taught to sideslip it in still-air conditions on final. Let's talk still-air. Not a puff of breeze, in a powered aircraft. The only reason you should be in a sideslip under normal circumstances is if you're in a taildragger or fat-engined aircraft and you need to do that to see your aimpoint. This is common, for example, in Pitts type aircraft and some warbirds. If you reckon on a normal final approach that you need sideslip for a glidepath adjustment which can't be managed with pitch and power alone, I suggest you're way too high and it's time to go around and give it another shot. Let's add some crosswind. Ok, if it's the appropriate technique for your aircraft type, you're going to need to establish a sideslip in order to conduct your crosswind landing as described in my previous post. You would establish this sideslip once you've got your final approach track and glidepath pretty well sorted. If you go and launch into your sideslip but you've rolled out too high or low and not tracking the centreline, well you're just going to screw yourself over with having to make big adjustments while also cross-controlling. Why make life hard for yourself? It means your nose is just pointing straight down the runway, but you're tracking along the extended centreline too. To achieve that with a crosswind blowing, you must be established in a sideslip. If your nose is pointing somewhere else other than in line with your aimpoint, and you've also got a bunch of cross-control in (rudder and aileron), then you are doing a combo of both (again, disclaimer: in some aircraft you have to do that to actually see your aimpoint!). "Technically" in a crabbed approach you shouldn't need to drop the wing into wind during the flare, although clearly you need some aileron to stop the wing rise as you yaw/kick it straight (don't get me talking about the Airbus here.....that'll open a can of worms!). Practically, because getting the timing right is hard to do, you often do drop the wing a little to stop yourself drifting across the runway. During those last few seconds you are relying on the inertia of the aircraft which you've had beautifully tracking the centreline , continuing to do that while you're kicking it straight and getting the wheels on the ground in a wings level attitude. Excellent. You are streaks ahead of some others in that part of your flying then! Occasional airspeed checks but largely concentrating on the aimpoint is what you should be doing. It doesn't sound like you need to learn anew. Just sounds like you need to use one technique or the other for crosswinds, not a hybrid. With zero crosswind, there's no requirement to use either. Just normal, balanced flight is the go! (Remember my exceptions at the top, primarily involving planes you can't see out the front of!).

Something I forgot to add: With the sideslip crosswind approach & landing, people get all sexed up about "how much rudder do I use?" and "how much bank angle do I have?" and "how unbalanced do I have to be?" The answer is simple. 1. You use enough rudder to align the aircraft heading straight down the runway. 2. You use enough into wind aileron/angle of bank to stop the aircraft drifting across the centreline as a consequence of the rudder you just put in. Whatever sideslip that gives you at the time, well that's what you need! Make *small* adjustments early, not *big* adjustments later or you'll end up de-stabilising yourself. Continue to monitor your speed and approach path, which are controlled in the normal way.

I don't count weightshifters as "aircraft", but rather "loose assemblies of tubes and rags which get blown about by the wind".

My point was that this is crap. And I go through Sydney Airport security every time I go to work.

Mmmm....that's kinda grossly simplified when it comes to how a crabbed approach works. Crabbed crosswind approach & landing The aircraft is established on final, on the extended centreline, wings level. To achieve this the heading is obviously offset for drift. In a large aircraft, you must be laterally displaced slightly upwind due to your seating position and the gear geometry involved with "kicking it straight". Small, balanced heading corrections are used to adjust as required, but overall the wings remain level during the approach. At flare height the flare is commenced, and simultaneously a smooth rudder input applied to remove the drift (or crab angle) and align the aircraft with the runway. Opposite aileron is needed to keep the wings level. In a perfect world, as the aircraft reaches alignment with runway heading, the main wheels both touchdown. Regrettably the world is not always perfect. Problems: - if the flare is misjudged, the aircraft may drift across the runway excessively while being aligned using rudder. - timing needs to be very good as the aircraft may still have crab angle on at touchdown. Usually not disastrous for the plane, but makes for a rough touchdown. - difficult manoeuvre to get exactly right, and not really one for beginners. Sideslip crosswind approach and landing The aircraft is established on final on the extended centreline, wings level, offset for drift. At an appropriate height on final approach, the aircraft is established in a sideslip. Opinions on this vary, but I'd suggest get it sorted soon after you roll out on final on the extended centreline. Rudder is applied to align the aircraft heading with the runway, and aileron is used to prevent drift (resulting in a bank angle being established, low wing into wind). At flare height the flare is commenced, with the into wind main wheel touching down first. Aileron is adjusted to "gently" lower the other wheel onto the runway (yeah I know - I'm just giving you the theory, right?). Problems: - not a comfortable way to fly. - poor technique for geometry limited aircraft, ie, those which can't afford to have much of a bank angle on at touchdown. In the CT4 we were taught and used sideslip. In the Pitts I certainly use sideslip too. Believe it or not, in the C130 Hercules you also used sideslip. In a big jet you always use a crabbed approach. In some other aircraft you do too.

GG, you do realise that a female security guard who happens to have dark or olive skin isn't necessarily a Muslim, right?