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#21
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Stefan "stefan"@mus. INVALID .ch wrote in message ...
Darrell wrote: The presence of two attitude indicators is especially valuable when they disagree. That disagreement will direct your attention to the needle/ball and basic flight instruments to help determine which one is correct. With a single AI you could more easily follow a gyro error without noticing a difference in the other basic instruments until it was too late. I don't understand this. Needle/ball is always included in my basic scan. As a starting point on toubleshooting, they are more reliable than the AI. Am I the only who knows this? Stefan Stefan, You have hit the nail on the head. BRAVO!!!!!!! Many of the real good instrument pilots know that needle, ball, airspeed are the three essentials to flying. These are the most reliable instruments on the panel. Once these are mastered then the rest of the instruments will just make things easy. Too many of us have forgotten the basics or have just gotten lazy. When is the last time you flew a true NDB approach? With loran, GPS, LOC & glide slopes, and vectoring, insturment flying is not that difficult. During an ICC, have your instructor give you a real good partial panel workout. It is rare to loose a gyro but it happens. Many pilots have lost their battle with gravity during IMC because they forgot the basics. This is especially true after loosing a vac pump or electrical system. Clay |
#22
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"Sydney Hoeltzli" wrote in message ... Those Electric and Vacuum AIs come with a get-your-life-back guarantee they honestly, really truly, won't tumble, never ever, no matter what, even if I do? How do I test it, in a non-aerobatic plane not approved for spins? Sure they can tumble. And I would agree they would tumble before the turn coordinator. But certainly they won't tumble at anything less than 60 degrees bank; the whole idea of the two AIs is to stop the spatial disorientation profile way before you approach anything like an aerobatic maneuver. Also I am not saying you have to put the turn coordinator somewhere where you will get vertigo... just not necessarily in the immediate 6-pack area, perhaps instead closer to where most airplanes have their CDIs. It will still be readable if you somehow get rolled nearly inverted by wake turbulence. And in the far more likely situation of a vacuum failure, you will be very glad your electric AI is right up there in your primary scan area. -- Richard Kaplan, CFII www.flyimc.com |
#23
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wrote in message ... Our Arrow has a backup electric AI on the right side of the panel. It is turned on whenever I am in or near IMC. I do not include it in my primary instrument scan, but check it periodically to make sure it is on and stable. I think that is a really worrisome location. I just flew last month with a very experienced instrument student who had a similar arrangement in his 182RG and developed vertigo and nausea while flying partial panel with his primary AI covered up.. he literally could not manage the plane and asked me to take over for a while to let him take off the hood and relax. If you do have the electric AI in that location, it would be helpful for you to occasionally fly a fairly long cross-country flight with a safety pilot while you use a hood and cover up the primary AI... that would be helpful to ensure you are not prone to vertigo from flying with the backup AI alone. -- Richard Kaplan, CFII www.flyimc.com |
#24
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Julian Scarfe wrote:
http://www.dft.gov.uk/stellent/group...cst?n=5232&l=4 tells a similarly chilling story of a Bandeirante that lost one of its two AIs resulting in a loss of control. What do you think of the conclusions? They seem to be: 1) prevent AIs from failing 2) since 2 AIs weren't enough to keep the plane upright (combined with 2 turn and banks, 2 of every other instrument), require passenger planes to have 3 (agree, chilling) Sydney |
#25
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Richard Kaplan wrote:
A vacuum faliure with a gradual spooldown of the AI and DG at vary rates is a subtle process, very different from having an instructor suddenly cover up a gyro. You are correct that there is enough redundancy in a typical GA plane to FLY partial panel; the problem is that there is not enough information for most pilots to IDENTIFY a partial panel situation before the situation has become critical. Richard, There seem to be a number of instances where the pilot was aware of the problem -- had described it to ATC and possibly requested some form of assistance -- had been flying the plane for some time more or less under control, and then lost it. So the pilot did identify a partial panel situation before it became critical, he simply couldn't FLY partial panel. The accident Julian posted the link for more-or-less seems to fall into this case, as did a couple of local accidents. Cheers, Sydney |
#26
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"Sydney Hoeltzli" wrote in message ... There seem to be a number of instances where the pilot was aware of the problem -- had described it to ATC and possibly requested some form of assistance -- had been flying the plane for some time No doubt there will always be crashes we cannot avoid. I am sure there are people with tip tanks who run out of fuel; that does not mean tip tanks fail to increase an airplane's range. The fact is that any sim instructor will tell you many pilots have a difficult time identifying gradual loss of the vacuum system and that redundant gyro equipment helps to identify this failure earlier. -- Richard Kaplan, CFII www.flyimc.com |
#27
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On 13-Jul-2003, "Richard Kaplan" wrote: I think that is a really worrisome location. I just flew last month with a very experienced instrument student who had a similar arrangement in his 182RG and developed vertigo and nausea while flying partial panel with his primary AI covered up Our electric AI isn't THAT far to the right. Actually, it's mounted in the right-hand radio stack, right above the DME. (Arrows and other Cherokees from the late 1960s on have a double radio stack. With modern avionics typically taking up less space, there is often room left over. It is a simple matter to fashion a "blank" with a 3" instrument hole to fit in this space, and that places the backup AI within reasonable scan distance for the pilot.) -Elliott Drucker |
#28
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"Sydney Hoeltzli" wrote in message ... | C J Campbell wrote: | Newer vacuum AIs have warning flags, dual vacuum pumps, and vacuum warning | lights on the annunciator panel. If I had an electric AI and a vacuum AI and | they disagreed markedly, I would be suspicious of the one having warning | lights and flags all over it. | | CJ, | | How do newer vacuum AIs come with dual vacuum pumps? | They come with a new airplane attached to them. Not unlike the $350,000 Cessna ball cap I bought. |
#29
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Sydney Hoeltzli writes:
We have a "warning flag" on our newer AI. I note that it is really a low vacuum flag. It doesn't say a thing about how reliably the instrument itself is operating. Yup, I had one freeze but the vacuum was fine so it didn't complain. --kyler |
#30
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On 14-Jul-2003, "Richard Kaplan" wrote: Our electric AI isn't THAT far to the right. Actually, it's mounted in the right-hand radio stack, right above the DME. (Arrows and other Cherokees from the late 1960s on have a double radio stack. With modern avionics OK, that sounds fine... in fact perhaps a good location for others searching for a location for an electric AI. Yes, it works for us. Also, it should be an easy and relatively inexpensive installation (unlike swapping instruments with resultant requirements for changes in wiring harnesses). In our plane, this installation also allowed plenty of space to install an ON/OFF switch next to the electric AI. We leave it off when flying in solid VFR conditions, with the understanding that this will extend its life. So far, so good. It's required no maintenance in over 7 yrs/1400 hrs (knock on wood). -Elliott Drucker |
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