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Gimli Glider


Guest ozzie

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Guest ozzie

Did anyone watch Aircrash Investigations last Saturday night?

 

Another repeat of the Gimli Glider were a Air Canada 767 was short changed on fuel and ended up dead sticking onto a old airfield that had been turned into a dragstrip.

 

I had seen this before but only picked up for the first time that the Captain was also an ultralight pilot and owned a Lazair. Must be the reason for his great flying skills :)

 

 

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I have seen that a while ago, amazing he managed to side-slip that thing and land...

I've not flown a large plane but, AFAIK, side slipping a large plane is no different from doing it on a small plane. Maybe somebody with experience can comment on size and side slipping.

 

 

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Large or small wouldn't change the process in principle, but large tails and sweepback on the wings has to be overcome. Luckily you've got spoilers that enhance the effect of ailerons. Dunno how much hydraulic power available. Sometimes they have a thing called a ram air turbine that extends into the slipstream and gives the power for hydraulics.. Nev

 

 

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As a Canadian I was embarrassed by the event. In defence of the pilots, Canada at that time was converting from Imperial to Metric and much of the confusion came from that. Great flying though once it happened (much like the Air Transit glide to the Azores - another Canadian embarrassment).

 

 

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The Gimli Glider story is one of those amazing escapes that could have gone horribly wrong if the circumstances were only slightly different. The Hudson River incident, more recently, is another one as Owi wrote in one of the posts above.

 

Yet a further instance was the British Airways flight No 9 from Jakarta. The B747 flew through a volcanic ash cloud over Indonesia and all engines stopped. The captain announced dryly (with stiff upper lip, no doubt): "Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them going again. I trust you are not in too much distress"

 

 

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I watched an Air Crash Investigation segment on the 2001 Air Transat A330 incident where a fuel leak to one engine caused some confusion and resulted in the aircraft running out of fuel at altitude well out into the Atlantic.

 

The crew then figured they could glide to a strip in the Azores, but there was no room for error. A long nail biting trip, even on TV.

 

They opted to stay high because it was only a tiny piece of land, came in fast but made the strip and just took out the landing gear.

 

306 POB, all survived.

 

Better to be born lucky than rich

 

 

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Guest basscheffers

Yeah, the "glider pilot" thing again that supposedly saved the day, just like the Hudson splash. I reckon its nonsense, any pilot will have learned to side slip at some point and every pilot would have learned how to do power off landings.

 

No mention of the pilots flying gliders in the Azores incident and they made it!

 

I hesitate to call these pilots "heros" or "great" and think of them as better than everybody else because these situations are very rare and most of the time they seem to have a good outcome, meaning that a) they most only happen to great pilots or b) most experienced pilots will be able to deal with it. I choose B.

 

In a docco about the event, Sully was also quick to dismiss it. (as well as devine intervention; hurray for Atheism!) I am sure he's a good and experienced pilot, but just like virtually every other major airline captain or high-time FO out there...

 

Incidentally, a new season of Air Crash Investigations has started, with the BA 777, Hudson, Colgen Air and some other interesting ones. The "alternative sources" are up to episode 6 at the moment. No idea where or when it will be on broadcast TV in Australia...

 

 

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Guest ozzie

The RAT (ram air turbine) provided limited hydraulic power to supply minimal electric power for instruments and other primary electrical requirements. The only hydraulic power available was for primary flight controls. Gear had to freefall but the nose gear extended forward and did not overcome the drag of the slipstream so it did not lock. No flaps no leading edge slats so they arrived well over normal touchdown speed. As was pointed out if the nose gear did extend they would have overrun the available strip and ended up in the camping area. Several tyres blew out and caused a bit of directional control but would have helped to slow the aircraft as well.

 

Canada was not the only country that had problems with going though the metric conversion. We had some as well but not to the extent of aircraft running out of fuel. Weight and balance caught a few lighties out. Considering that most aircraft have US gallons listed in their POH and at the time our pumps displayed imperial gallons to then be converted to pounds then the govt insisted on converting the pumps to litres to be converted kilograms then reconverted to US gallons and pounds to work out the engines consumption rate. Then there was some confusion i think with hectopascals and millibars.

 

Then on the road we had trucks trying to work out their load and drivers trying to work out the new KMH speed signs using speedos in MPH. But i was doing 60 officer!

 

As for sideslipping, crossing up the controls will produce a side slip. the more diheadral and sweepback will mean more aileron input to overcome the natural stability. A large fuselage will affect the sideslip making the aircraft wanting to weathercock back straight and level. He would probably have had max control input to get a decent rate of decent happening one wing would have had a high angle of attack making it close to stalling.

 

As they said at the end of the program that they put quite a few pilots thru the same scenario in a flight sim and all pranged. So it just goes to show that real basic flying skills gained in aircraft like gliders and basic ultralights do give the nessesary skills to man handle heavy tin in situations they were never designed to be flown in. Scully proved this as well. Now consider that quite a few airlines offering cadet ships will only accept students with NO previous flying experience. Luck has played a part in a few incidents that required real pilots to pull off a successfull outcome.

 

 

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Guest basscheffers
As they said at the end of the program that they put quite a few pilots thru the same scenario in a flight sim and all pranged.

It's a bit different when you're bum is actually on the line! :) A sim also has a major difference in that the images are not 3D. That's fine and very realistic in normal training, but I reckon having that extra sensory information in a situation like this will make a big difference.

Funnily, they put some pilots through the sim for what Sully and Skiles went through and they all made it back to the runway! Easy having prior knowledge that you are not going to get your engines back and turning around immediately...

 

 

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The change over time to metric led to the possibilities of problems. Prime example was when I was doing my CPL training in a M20F 30 odd years ago

 

Flight planning was done at the time in IMP gls/hr

 

Refueling in ltrs

 

Guages read in Lbs

 

W&B done in Kg

 

Tabs in tanks read in US gls

 

Although only a small aircraft with so many different measurements it was a good example of how confusion could arrise.

 

Frank

 

 

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Frank, you point out succinctly a critical problem in aviation. As the rest of the world has moved to metric (something I agree with completely), the US and aviation has not. So when I did some ultralight flying in Portugal, I saw the same mishmash as you did in the Mooney. It would be nice to set a single standard, although the US and conservative pilots will have much to say.

 

 

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Funnily, they put some pilots through the sim for what Sully and Skiles went through and they all made it back to the runway! Easy having prior knowledge that you are not going to get your engines back and turning around immediately...

Which is why an immediate turn back was the correct decision in this case. In the event of engine failure step one is to establish a safe landing and once that is done step two is to fiddle with the engines to see if they can be restarted - not the other way around.

 

 

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Guest basscheffers
Which is why an immediate turn back was the correct decision in this case. In the event of engine failure step one is to establish a safe landing and once that is done step two is to fiddle with the engines to see if they can be restarted - not the other way around.

It depends. I would not start turning anywhere (and loose height and thus options) without knowing if the options would get any better. That does leave the possibility of missing out on the option behind you, which may be gone by the time you work out it would have been best. Damned if you do, damned if you don't. I would not hold his decision making against him.

Again, the guys trying in the sim had nothing to loose. What if Sully did immediately try to turn back and didn't make it? He'd have killed hundreds of people in the aircraft and on the ground!

 

 

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Where to go on a forced landing is knowing where you are and what the plane can do, with or without turns. I was flying in Portugal and the school emphasized through many practices that you need to know your best option before the forced landing. If the best option is behind, then take it (allowing for the turn and temporary loss of direct view). Height is always taken into consideration. In Canada, we did it somewhat differently. We drew a half circle at a specific angle (45 degrees in the Rans) from side to side (the angle adjusted for wind strength and direction), and essentially ignore anything that could not be seen peripherally. But both use steps: know your spot, get the plane flying, then try and find problem.

 

 

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Frank, you point out succinctly a critical problem in aviation. As the rest of the world has moved to metric (something I agree with completely), the US and aviation has not. So when I did some ultralight flying in Portugal, I saw the same mishmash as you did in the Mooney. It would be nice to set a single standard, although the US and conservative pilots will have much to say.

I'm with you GDL. In Eastern Europe altitude is almost universally expressed in metres ASL and all other measurements are in S I (metric) Units. Eastern European countries were under the umbrella of influence of the USSR for decades and this was a major factor.

 

The problem is that once a standard is adopted, inherent conservatism will demotivate a community (e.g, the aviation community) for a change for the better. Whether the issue is AM for aircraft radio or feet above sea level, ingrained attitudes from traditionalists will nearly always result in reform being rejected. I still remember when the S I system was to become the standard in Australia in the first half of the 1970s. My neighbour said something along the lines that he could not "understand" the kilometre and would continue to talk in miles, pounds and inches. He said the kilometre and kilogram "would kill him" if the government passed that law. The government did and he lived for another twenty years.

 

The cost of new radios and/or gauges is, of course, a significant factor. But when EPIRB frequencies or Transponder modes are slated for change, few people seem to complain because there is no inherent "tradition" to maintain and protect. My feeling is that imperial measurements in aviation will not disappear until:

 

(a) the USA agrees to the change. Aviation (as well as computers) originated there and they get to choose the standards and the terminology/jargon. Everyone else has had to fit in so far. Without US support, a change away from imperial will be a lost cause.

 

(b) glass cockpits become very cheap. Such a factor may prompt many aircraft owners to install tdual measurement panels and then choose the metric units option on the day of the changeover.

 

My feeling is that in ten years time, aviation will still be utilising AM radio communication and imperial measurements.

 

 

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Guest ozzie

When i went for a fly in Italy i only really noticed that the alimeter was reading metric when i came back to the circuit area. Hmm did an eyball on the ground decided 500 meters looked like a good prominent number on the dial looked at the instructor who spoke about as much english as i did Italian, and got a thumbs up. Also did a couple of skydives and hired some gear, alti was in meters, worried about it a bit on the way up then decided that the red bit was action time and just concentrated on the jump. Really strange being still in freefall in a valley with sides way above you. Definatley a case of 'look before you leap' just in case the spot was off a bit..

 

 

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Guest basscheffers

The main issue is with volumes and weights rather than speed, distance and altitude. (Apart from the fact US aircraft can be found in MPH and Knots!)

 

There is a real good reason for using metric in daily life because all those that swore they would never "get" metric can now easily convert between milligrams, grams and kilograms and between milimeters, centimeters, meters and kilometers, where before they would not be able to tell you how many yards were in a quarter mile or how many ounces in 2.5 pounds.

 

In aviation we tend to work in whole numbers, so that is not so much an issue. The only problem seems to be (back to topic!) is converting your glide ration from altitude in feet to miles on your map.

 

My feeling is that in ten years time, aviation will still be utilising AM radio communication

I should hope so! The only significantly better alternative is a digital system and look what our overlords are doing with ADS-B! Barely works and costs a fortune. Seriously, these guys couldn't organise the digital equivalent of the proverbial piss-up in a brewery. I'd rather they don't even try...

Actually, it is too late; the Europeans are switching to voice over VDL4 (if I recall correctly) for certain airspace. Some time from now we'll have voice over (most likely) UAT. But that will of course not be compatible with the UAT transceiver you already have (dormant) on board in your American made ADS-B unit, which uses Mode-S instead here. If you want to go near airfields frequented by RPT, you'll have to shell out another 30 grand... <sigh>

 

 

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Guest Maj Millard

One of my favorite aviation events, and a damn good example of what a sideslip will do for you when you really need it.

 

This was also written up some time back in the CASA crash comic. The last paragraph stated " Had the aircraft in question been an Airbus the pilot would not have been able to side-slip it, as the airbus computer wouldn't allow it"............or words to that effect.......................................................Maj...

 

Ozzie, You and I know it was that time in that Lazair that gave him the skills !!!

 

 

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The last paragraph stated " Had the aircraft in question been an Airbus the pilot would not have been able to side-slip it, as the airbus computer wouldn't allow it"............or words to that effect.......................................................Maj...

That is a scary thought. Where is the override in the computer program??

 

 

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When a plane is originally certified the numbers tend to be rounded to whole numbers. IF you go across to metric from imperial (say with an american aircraft) you end up with NO numbers that are even, or whole. I believe the plane in question was just being introduced to the airline and the manuals were not in a state of completion. A fuel figure was loaded in pounds to a KG number so you had less than half of what was desired. The fueller really cannot be held responsible. It always rests with the PIC. The "Captain".. The buck stops with him. That's the official situation. In this case as in the Air New Zealand DC-10, there were other factors at play, but the BIG thing in aviation is to NEVER trust some factor alone if it hasn't been checked by another method, when your whole situation depends on it.

 

Gliding to a destination. The space shuttle does it every time, but there is a lot of on-ground monitoring and back-up. If you know the track miles to touchdown and the wind between you and the ground it's fine. You sit a bit high annd adjust you descent path with spoilers, flaps and gear extension point. YOU cannot get it WRONG so obviously you err on the conservative side and stay with a bit of extra height to spare. When all engines are inoperative you have a totally new situation where you have no idle thrust and some systems don't work. You have to allow for things that you have never experienced before. People who go through this and pull it off have achieved something, that I in no way would want to take from them. The margin for error over the fence is only a couple of hundred feet or about 50 knots. ( Unless it's a hell of a long runway). Nev

 

 

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