Hyperthetical for all you IFR people.

[Guest basscheffers]

Alternatives:Well, if the plane carries 'X' fuel and can make it from A to B, but C - an alternative - is outside the range...... I guess that would make it the wrong plane for the trip?

The Westwind has plenty of range to go to Auckland if Hamilton was closed, they just didn't put enough gas in the thing before they left Samoa.

 

 

[flying dog]

So "who's" fault would that be - for not putting enough petrol in the plane?

 

The pilot's or the company's?

 

 

[Guest check-in]

Back on original subject. HSI = Horizontal Situation Indicator. For those not familiar with it, a clever little jigger that displays heading - usually from an electrically-driven gyro but some crude ones may possibly be vacuum driven; however for the bearing info (see next sentence) they will require electric power as well. HSI also has a course display that can show VOR radials, Localizer (for ILS) and these days GPS tracks. The really nice ones also super-impose the ADF needles so you can get bearings from NDBs.

 

Most good ones will also have a glideslope indicator for the ILS and a VNAV indicator for GPS/RNAV approaches, so they have evolved beyond just showing the horizontal situation.

 

Therefore if you have an HSI, an ASI and an altimeter you can survive in IMC quite comfortably with no artificial horizon, but it does take some practice.

 

Another common term for Artificial Horizon these days is ADI = Attitude Deviation Indicator. Then we go EFIS and get PFDs, MFDs, etc etc where all this stuff is on one screen. It's all too hard for an old bloke. I still call the HSI the 'compass' and the other gadget the 'horizon' for short.

 

The little golf ball thingy swimming in its own booze supply to me will always be the 'wet compass' but my more professional colleagues like to call it the standby compass.

 

 

[Mazda]

Dog, your scenario says there is a vacuum problem, which is very likely to mean your AH wouldn't be working. There are electric units available which are sometimes used for standby instruments, but they are not all that common.

 

There's no need to climb to 10,000, the highest terrain in Oz is below that and many aircraft would not be capable of climbing at a good rate anywhere near that level. From planning the pilot would have a very good idea of the grid LSALT and could check that on the chart. No torch? How about a mobile phone?

 

As I've said before though, it isn't a feasible scenario. (Especially with failed vacuum and a working AH).

 

 

[flying dog]

Maz,

 

Fair enough.

 

I think part of the confusion was me confusing the "HSI" with the artificial horizon.

 

So my "idea" was you don't have a compas (visible) but the artificial horizon is working. (Deja vous here)

 

 

[Guest check-in]

FD, the odds are that the horizon would fail but the wet compass would not. However, in the highly unlikey scenario where you still have a good AH but no compass, all is not lost. Use the AH to climb with wings level, or if you need to bail out of uncertain terrain, fly a rate one turn* for one minute which will reverse your course near enough. Someone said no need to climb to 10,000 but I was giving worst-case for Australian east coast. Also 10,000 is an altitude where you just might get out of cloud. Obviously without oxygen you can't safely go higher and there are lots of situations in Australia where 5000 ft might get you out of trouble - if so, good oh.

 

But in reality you will likely always have a compass and hopefully an altimeter. With these and enough knowledge about what power produces what performance, a skilled instrument pilot could survive the loss of all other instruments and fly for quite a while in cloud or at night. The weekend warrior likely would not - even with everything functioning. The message is - by all means try this at home with Microsoft FlightSim but don't believe for one minute that you could do it for real.

 

* Rate one turn: indicated airspeed (less the zero) plus 7 = angle of bank, so for my little bugsmasher at 110 knots indicated: 11+7 = 18 degrees. One minute at rate one reverses heading 180 degrees (3 degrees of heading change per second of time). Try it using a stopwatch and you will find it is quite accurate if you hold the bank angle steady.

 

 

[Guest Howard Hughes]

IFR People

 

Hi Doggie,

 

It seems people round here have been a bit hard on you, I'm one of those 'IFR People' so l'll have a go!:thumb_up:

 

Whenever I find myself in a situation where I think "I don't want to be here", The first thing that I do is to make sure the aircraft is under control.

 

Secondly I reduce power back to the lowest possible power setting, which instantly buys you more time. In the situation above things like minimum speed in icing conditions, maybe a factor.

 

Then I would check my altitude, I would like to be at 8700 feet or above (this is the highest lowest safe altitude in Australia).

 

From there you need to come up with a plan. My next priority, would be to get 'VISUAL', by any means necessary, yes even at night! Once you are visual you have many more options! This could involve decending to LSALT, making a 180 degree turn back to where you came from. As a last resort, if you were near the coast, you could try heading out to sea and descending until 500 feet.

 

Should things suddenly go quiet there is only one important thing to remember...

 

STAY IN CONTROL!

 

 

 

 

 

 

 

Maintain wings level, maintain a constant heading and maintain your glidespeed, this is all that will save you and will give you a chance to take action should you become visual prior to hitting the ground!

 

Of course given that your aircraft has a stall speed of 150 knots, it probably has two crew, in which case you could just say "handing over"!;)

 

Cheers, HH.:thumb_up:

 

PS: Forgive me if I have rambled, this was written at 1am.

 

 

[flying dog]

Howard,

 

Thanks very much for that. Yes, you got a few good points for which I was looking/fishing and no one else seemed to get.

 

 

[Relfy]

Great advice Howard. :thumb_up:

 

 

[Guest Howard Hughes]

As most IFR pilots will attest, we spend most of our time trying to stay out of IMC!;)