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How fast in feet per minute does the BRS float a CTSW down?


Acensor

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His thought on setting a minimum altitude, if this option might exist for me, makes sense.  Do all I can do to set up for a deadstick but have a set AGL for "go/no go" if I don't see hard packed, friendly terrain down below.

I agree that it's a good practice to have a decision height when making an approach to an emergency landing where you want to decide to use the BRS or not. However, I would not want to be locked into that decision. If my decision height is 500ft, and for some reason I see a ditch at 300ft that I could not see from 500ft, I'd still pull.

 

One thing that seems to come out of that Cirrus video Eddie posted, is that the chute can have some benefits at *any* altitude, and rarely if ever seems to lessen your survival chances. I think you should have some pre-set decision points, but use them as guidelines and not as hard rules.

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VFR pilots might want to rethink their chute strategy. There was a study awhile ago that was entitled "178 seconds to live". A summary from the Australian aviation agency: From the FAA, 76% of VMC into IMC accidents involve a fatality.

 

I'm not saying one should pull the chute immediately upon entering IMC. A 180 is typically the first move. After that, the chute should figure into the decision process.

Dynon offers training on their SV system at various aviation events.  I attended their first of these at Sebring in 2012 and one of the first things the instructor said (he is a CFII) was that folks should really invest in an autopilot and to have a 2 axis system.  Folks building their planes and only planning on a pitch servo should reconsider adding a roll servo.

 

Based upon this and my training if I were to get into IMC, I would first engage the autopilot (if I wasn't already using it) and hit the 180 button and let the system fly me out with me probably fixated on the artifical horizon.

 

Do you all think this is a reasonable approach?  I did some IMC flying with my flight Instructor and completely understand that me hand flying in IMC would not remain  level without the artifical horizon.  I got "crooked" in far less than 178 seconds until I glanced down at the instruments.

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Another IMC strategy that I heard the US Navy teaches is to keep the plane level and go into a climb.  It keeps you away from terrain and eventually you should pop out of the IMC on top.  Of course, that strategy works faster (and higher) in a Super Hornet than it would in a CT or Sting Sport...

 

My one brief IMC encounter was me saying "oh hell, that haze is actually a cloud," and starting the turn before actually going IMC.  I was IMC for about five seconds as I finished the 180 and popped out, staring at the EFIS attitude indicator the whole time.  Scared the crap out of me though.

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What I teach students is to keep the airplane trimmed. If you have inadvertant flight into IMC hands off the stick and fly a heading with rudder. You can make a nice 180° turn using only rudder. By hands off I don't mean you shouldn't touch the stick. Sometimes it will need a gentle nudge, but the less you move it the better off you are. If you need to go up or down adjust the power.

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No one has mentioned the use of the autopilot in reference to IMC. Hold altitude or climb and use the heading to make the 180. I have not practiced this, but doesn't it make sense?

I would think unless there is icing or some other mitigating factor, putting the autopilot in control would be the first thing you'd do if you have one.

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The autopilot is a great tool in many cases and inadvertent IMC is certainly one of them, just remember you have to set it correctly and it doesn't know about terrain and can fly you right into it. A good reason to keep your audible terrain alerts turned up in your intercom. Inadvertent IMC is a good thing to practice during your next flight with an instructor.

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I am NOT advocating against the use if the autopilot as a last resort - it could be a valuable tool and save your life someday.

 

But...

 

...if you have not experienced vertigo in a plane, you may not realize it's power.

 

IOW, sitting here it's easy to say one would trust it.

 

But how about when you set a standard rate left turn to do a 180° turn to exit IMC, look down for a second and when you look up there's absolutely no doubt that not only has the turn stopped, but now you're actually falling into a descending right spiral.

 

Sure, sure, you've been trained to trust the gauges, but until you've been there, you have no idea how powerful the illusions can be.

 

If it was easy, we would not have even experienced and trained pilots succumbing to LOC in IMC.

 

And if they fall victim, it's kind of presumptuous to think you could definitely do better.

 

Maybe you can - and if you survive I'd love to hear the story.

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No illusions here (no pun intended). I have not experienced IMC. I have been under the hood and know the best bet is not to look outside but fly the panel. With the auto pilot another possibility would be to set the course back to the last waypoint. Having never tried this I don't know how well the 696 and autopilot would do with a 180. Any input?

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In the "Engine Out" case, I also like the idea of delaying the chute deployment if I'm high. Our descent rate is lower under wing than under canopy and I want as much time as possible to try a restart (maybe after sloshing the fuel around in the wing a bit); to make sure my "Mayday" is accurate and understood; and to maneuver away from power lines and other hazards as described previously.

So I've amended my chute deployment criteria once again:

  1. Fire
  2. Loss of control
  3. 700' agl or less without thrust or glide to a safe landing

I'm going to print a placard to this effect.

 

By the way; under "Emergency Procedures" my operator’s manual specifically states that in the event of a fire the chute should not be used at "higher altitudes" and instead "the airplane should be flown down to 700 ft. and then the system operated."

 

Mike Koerner

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By the way; under "Emergency Procedures" my operator’s manual specifically states that in the event of a fire the chute should not be used at "higher altitudes" and instead "the airplane should be flown down to 700 ft. and then the system operated."

 

Mike Koerner

Interesting.

 

Does anyone know the descent rate of a CT under canopy?

 

BRS gives this general info, not CT-specific:

 

"Once under canopy and descending in a stable condition, the rate of descent will be about 15 - 28 feet per second (fps) at 5,000 feet density altitude under rated weight capacity of canopy."

 

source: http://www.brsaerospace.com/faq.aspx

 

That results in a vertical descent rate of between 900 and 1,680 fpm.

 

If eager to get on the ground, I suppose one could dive at or near Vne and exceed that rate. Might be an interesting experiment to try next time someone is up - check rate of descent in fpm at Vne, that is.

 

And if the fire was in the engine compartment, it sure seems to me that diving would have the possibility of "fanning the flames"' resulting in a hotter fire as a result of increased air being fed to it.

 

Best to generally follow POH recommendations. Just trying figure out the rationale behind them in this case.

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What is the minimum descent rate in a power off glide?

At the book 62kt at 15 flaps, I think it's 400-600fpm. But that's deceptive when comparing to BRS decent rate, because you also have 62kt forward speed, which is 6,274fpm. That forward energy also has to be dissipated in some way, whether by rolling out on a successful landing, or in breaking stuff in a less successful landing. It all works out in favor of the landing if it works out, if not the energy numbers favor the chute deployment by a large amount. Hard to know which you will get before touchdown.

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I have never tried allowing the GPS and autopilot turn me 180 degrees. (I know in normal situations if I am off by much it will overshoot the mark.) I wonder what the max bank angle the autopilot will take? You would have to pay close attention to power to allow the turn without loss of altitude.

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Thats what the moving map is for, the color coded terrain and in the case of the Garmin, touching anything on the ground gives you the elevation of that spot.  still, the higher the better, esp if you cant reference outside.

 

Regarding inadvertent IMC, the terrain feature of the moving map is a good tool for flight planning and "forecasting what's coming up ahead during day VFR," but it is not intended to be used as an "escape tool" to navigate during IMC or during extremely dark nights (with little or no ground reference).  Under that scenario, flying the terrain on the moving map, could lead to a trap, where the display looks like a way out, but in reality, it leads to a flight path decision which may have catastrophic consequences, like flying down a boxed canyon.  Keep in mind, during descent . . . the red gets bigger.  And if the airplane is inverted, that moving map display will still display terrain above you . . . .or below you, depending on your airplane attitude.

 

The point being, during inadvertent IMC . . . fly the airplane man!  Be careful with getting fixated on anything.

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The TruTrak Autopilots have internal accelerometers. It will not allow a bank angle more than 30 degrees, assuming that during power up, you were not banking or turning on the ground.
 

Some tidbits about the D100 and TruTrak:

 

If you encounter disorientation, you can hold the autopilot button, and eventually "CWS" (control wheel steering) will show up on the autopilot screen. This sets a course in the computer when you let go of the button, so you can let the autopilot level you out.

 

Do note, it is very possible to fly without realizing the gyro (accelerometer calibration) is not centered, probably because I was moving at the time it was booting up. I've had occasions where I've activated the autopilot, and it began turning very hard and was not able to hold a course. Holding the autopilot button on the trutrak resets the gyro, but you must be very still and flying straight and level.

 

During flight tests, I've pulled maneuvers quickly enough to see if I can cause the dynon D100 to be thrown off. This is an issue with mechanical attitude indicators. Basically, mechanical attitude indicators can precess with aggressive maneuvers. The D100 has an algorithm which will adjust the artificial horizon as a way to correct instrument error that is introduced over time (if accelerometers had an infinite resolution, this problem wouldn't exist), but it also throws it off if you are very uncoordinated.

 

 I do not believe the TruTrak has a self correcting algorithm (I was not testing the autopilot's ability to self correct at the time). It's good though if it doesn't, at least if the dynon gets thrown off, there's a good chance the TruTrak will correct your attitude if it was calibrated correctly on startup.

 

 

 

To be honest though gentlemen, if you end up in IMC, fly with gentle maneuvers. In instrument flight, you are not supposed to turn more than standard rate, and keep the pitch changes small. This keeps instrument error to a minimum, and also reduces the amount of disorientation that can occur to you.

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No box canyons where I live. :) And, if I am into IMC I am making a 180 immediately and unless I was already in a box canyon, I shouldn't have that problem.

Having said that however I don't want to be spending time playing with stuff. I do think that using the autopilot to make the 180 while maintaining, or gaining, altitude, especially if I was already using it makes sense.

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With the new dynon autopilots there is a "level" button.  If you get yourself into an unusual attitude or disorientated, just push the "level" button and it recovers the aircraft to straight and level.  Some parameters of course.  You have to have flyable power on and I'm sure there is a limit to it's abilities.  Don't know about a spin either but it is a slick feature.  Right next to it is a "180" button that will give you a 180 deg turn.  During the turn you can view the terrain feature and avoid the ground.  A couple buttons and a little common sense should help if you have inadvertently entered IMC conditions.

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I'm Sorry. I don't buy this approach.

If I had a autopilot (I don't) I might let it fly me around on a sunny day (if I wasn't feeling the tiniest bit sleepy). But I'm sure as hell not going to defer to it in an emergency.

Needle (EFIS), ball, airspeed.

Needle, ball, airspeed.

If you are not comfortable with that, spend a hour or two under a hood, either with an instructor or just a safety pilot. Or just ask that it be added as part of your bi-annual. I think it would provide a better option than hoping the autopilot keeps working.

Mike Koerner

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I'm Sorry. I don't buy this approach.

If I had a autopilot (I don't) I might let it fly me around on a sunny day (if I wasn't feeling the tiniest bit sleepy). But I'm sure as hell not going to defer to it in an emergency.

Needle (EFIS), ball, airspeed.

Needle, ball, airspeed.

If you are not comfortable with that, spend a hour or two under a hood, either with an instructor or just a safety pilot. Or just ask that it be added as part of your bi-annual. I think it would provide a better option than hoping the autopilot keeps working.

Mike Koerner

I think if you are confident in the equipment (based on lots of sunny day operation), it makes sense to use the autopilot. That doesn't mean flip the switch and then take a nap. Set a straight and level, 180, or whatever you need to do with it, then watch your instruments to make sure it is doing what you expect. Once you verify that the gear is working as advertised, you can split your attention a little to read a chart, set up your GPS, talk to ATC, or do what you need to get out of the soup.

 

The (maybe sad) fact is that a properly functioning autopilot is going to do a better job than a VFR pilot of flying the airplane in IMC than a purely VFR pilot like myself for more than a few minutes, especially if I need to do *anything* else like tune a radio or program a GPS. IMO of course, others will disagree.

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Not trusting your instruments has killed a lot of pilots and passengers over the years and they are there just for that reason. You're right VFR verses IMC can make some AP features a mute point, but only up to a point. These new generation Dynon and Trutrak AP's are really something. If you have not seen one or used one you may not grasp how well it performs or what's its capabilities truly are or how efficient it is. I would trust it and use it in an instant if need be. The AP's that have these high end capabilities weren't even available to us at our level just a few years ago. You can take off and on climb out turn it over to the AP and it will fly you to your destination and put you right back on a final. Couple these new generation AP's with a Garmin 796 or better and there almost isn't anything they can't do. These new generation AP's really shine in IMC conditions and this is where they out perform the PIC.

 

 

Before you knock these new generation AP's you really should research them and go fly with someone that has one. You will be duly impressed. Many can fly overall better than the PIC.

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Not sure anyone is knocking modern autopilots.

 

The STec in my Cirrus was a wonderful device, and later Cirrus's got even better ones. I assume the ones you mention are about as capable, if not more so.

 

And yet...

 

...many, many pilots have died from spatial disorientation over the years - many in airplanes with fully functioning and engaged autopilots.

 

The problem is that when your body is screaming at you that you're rolling off into a spiral and your attitude indicator says otherwise with the autopilot engaged or not, a pilot's "lizard brain" and panic and adrenaline can make "trust the instruments" a quaint thing you learned but not applicable right now because I'M SPIRALLING DOWNWARD AND I BETTER DO SOMETHING ABOUT IT NOW!!!!

 

Instrument training, both initial and recurring both reinforce "trust the instruments", yet experienced instrument pilots periodically succumb to spatial disorientation regardless. 

 

Low time VFR pilots with just a modicum of instrument training have to be very, very conscious of their limitations if and when the **** does hit the fan.

 

That's all I'm saying.

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That is exactly why I am asking about using the autopilot to get me out of trouble. I am not saying to set the autopilot and ignore the instruments.

I know that when I set my autopilot to hold altitude (or climb) it does just that, as long as has an appropriate amount of power. I also know I can use the heading seeing to turn the 180. Again, by trusting the instruments, I would think that this method would help combat the reaction to spatial disorientation. I don't see "trust your autopilot" much different than "trust your instruments."

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I don't see "trust your autopilot" much different than "trust your instruments."

 

Its not.

 

Its just very, very hard to do.

 

Like in "A League Of Their Own":

 

"It's supposed to be hard. If it wasn't hard, everyone would do it. The hard... is what makes it great!"

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Its not.

 

Its just very, very hard to do.

 

Like in "A League Of Their Own":

 

"It's supposed to be hard. If it wasn't hard, everyone would do it. The hard... is what makes it great!"

I agree with all of that. It seems like maybe if you turn things over to the autopilot, the two instruments you might want to start watching more closely are the tach and the airspeed indicator. If you get disoriented and think you are in a spiral dive, looking at those two instruments will confirm or deny it immediately. If RPM has not changed, and speed is the same, you cannot be in a dive. Still not easy to do when disoriented, but as Shelock Holmes says:

 

"Once we eliminate the impossible, whatever remains, however improbable, must be the truth."

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