Benign Spiral-Anyone ever try this in a M20J ?

[epsalant]

I was watching a video (below) describing a means of descending in IMC with no instruments.  Basically power at idle, trim all the way up, full flaps and hands off the controls until you enter VMC (hopefully well above terrain).  I went up to altitude slowed down with power at idle, put full flaps down, trimmed way up (not quite full), I didn't like the way things felt, chickened out and ended up practicing garden-variety stalls.

I'm a glider pilot and never learned this maneuver when I got the rating many years ago.  I believe it's called a benign spiral.  Anyone every try this in a Mooney (201 or other model) ?

 

[Mooney in Oz]

No.  I have a better recovery system and it's called standby instrumentation.

Good decision in stopping it when you felt the need to.

Something like that would be best attempted with an experienced Mooney instructor beside you.

[Hank]

Never heard of such a thing. But I don't see how idle throttle, full flaps and gear down will make you spiral.

When I went VFR into IMC (took off on a clearing forecast, headed to pick up mom for the reunion; waiting to see would have been too late ), all it took to get out was eyes on the panel, standard rate 180° turn, and watch the altimeter. 

If in IMC and somehow lose all instruments (how in the world?), just reduce throttle some and descend straight ahead. You can hold heading with the magnetic compass, right? If you were trimmed level before, you should stay pretty level; feet off the rudders, trimmed level, throttled back a little, you should descend fairly wings level if the compass isn't changing.

Lose the entire panel and the compass in IMC? Put your head in your lap and kiss your ass goodbye, assuming whatever took out everything didn't take you out with it. Even glass panel planes have backup instruments not requiring electricity . . . . .

Edited May 21, 2018 by Hank

[Stephen]

I have heard of this manuver and done it once. One of my advanced instructors demonstrated it in a PA28 Warrior; dont know if it translates to any  mooney/ your mooney/ my mooney. That time it  put the plane in a stabalized descent a few knots above stall. Worked in smooth air on that airframe  ... YMMV. Was explained to me as a last ditch way for non-IR rated person to get down theough IMC (vs panicking & killing yourself) or as a way to crash (sorry land “off airport”) if you lost instrumentation and/or night or whatever, at the slowest possible vertical and forward speed. Would depend on airframe, rigging, idle speed and who knows wat else. 

[toto]

15 minutes ago, Stephen said:

I have heard of this manuver and done it once. One of my advanced instructors demonstrated it in a PA28 Warrior; dont know if it translates to any  mooney/ your mooney/ my mooney. That time it  put the plane in a stabalized descent a few knots above stall. Worked in smooth air on that airframe  ... YMMV. Was explained to me as a last ditch way for non-IR rated person to get down theough IMC (vs panicking & killing yourself) or as a way to crash (sorry land “off airport”) if you lost instrumentation and/or night or whatever, at the slowest possible vertical and forward speed. Would depend on airframe, rigging, idle speed and who knows wat else. 

Yep. I was taught this maneuver during primary training, and my instructor demonstrated it a couple of times as a way to descend out of inadvertent IMC. (The demonstration was in a Cessna 150.)

I've never heard the term "benign spiral." Afaik this is meant to be a non-turning maneuver. 

 

[Stephen]

11 hours ago, toto said:

Yep. I was taught this maneuver during primary training, and my instructor demonstrated it a couple of times as a way to descend out of inadvertent IMC. (The demonstration was in a Cessna 150.)

I've never heard the term "benign spiral." Afaik this is meant to be a non-turning maneuver. 

 

I cant remember if the thing turned or not when we did it. Would be interesting for one our MS mooney specialist CFIs to weigh in... 

[Hank]

When discussing inadvertent IMC, the only spiral that I'm familiar with begins with "graveyard" . . . . .

[Jerry 5TJ]

I have read that early air mail pilots - and we are talking 90-100 years ago — would put their biplanes into a spin to descend out of IMC.  A spin can be stable especially in a draggy plane.  

I’m unconvinced a Mooney will stabilize itself into a spiral.  What is the source of that stability?  

During a MAPA PPP session my instructor had me trim for level flight at low cruise power, then release the controls.   The spiral that develops is not stable or benign.   Recovery is easy — in VMC and when you know exactly what’s happening.  

[Stephen]

1 hour ago, Hank said:

When discussing inadvertent IMC, the only spiral that I'm familiar with begins with "graveyard" . . . . .

Correct ; this was proposed spacifically as an alternate to that outcome

[aviatoreb]

My previous airplane the diamond da40 would do a beautiful “falling leaf” in that configuration.  In fact the forum at the time (10 yrs ago) was bragging it descended slower that way than a cirrus under parachute and the debate was if it might be use by a spouse in an emergency.

[epsalant]

2 hours ago, Hank said:

When discussing inadvertent IMC, the only spiral that I'm familiar with begins with "graveyard" . . . . .

Hey, I'm not advocating this--I'm just asking if anyone is familiar with this maneuver in a Mooney !

I was, until a few days ago, unfamiliar with this as a maneuver.  I saw this video and then read about this.  Apparently a useful maneuver in gliders.  In sailplanes sometime the problem is you can't come down, you're getting sucked up into a cumulus or some other such situations.  The gliders I have flown had no power source and  little in the way of instrumentation-ASI, compass, altimeter and a piece of yarn on the windscreen--to help you in IMC.  So maybe this works in gliders.  Heck, in airplanes certified to spin, spinning is a stable, relatively benign maneuver which can get you down in a hurry with the wings firmly attached !!!

[steingar]

I have read harrowing things about spin recovery in Mooneys and have no desire to experience it first hand.  I can get a reasonable facsimile of a panel out of my iPad, certainly enough to fly by.  I think that's my plan B.

[markejackson02]

I was taught this in a 172 but there was no spiralling.  Idea was to mush forward using the rudder to keep the ball centered.

I tried it in my 67 C model but the sink rate ended up being around 1000-1500 fpm versus 400-500 for the 172.

 

[Stephen]

2 hours ago, markejackson02 said:

I was taught this in a 172 but there was no spiralling.  Idea was to mush forward using the rudder to keep the ball centered.

I tried it in my 67 C model but the sink rate ended up being around 1000-1500 fpm versus 400-500 for the 172.

 

Yeah, this may or may not translate to Mooney at all. It is not a falling leaf though; no stall involved which is why it may be a PA28 thing that kinda translates to Cessna trainer and may or may not work for Mooney or may for certain ones based on rigging, W&B or who knows what. I would look at this maneuver as transactional because it was a function of all of a set of discretely identifieable  (settings): Power OFF, Flaps FULL, Trim FULL UP, Hands and feet OFF CONTROLS. If you have to tune things (e.g. less than full trim, using feet on rudders etc.., you are flying the plane at MCA-ish. This game was about the plane flys itself at MCA-ish. May be a dynamic stability thing with Pipers and similar airframes. I think they had around 7 degrees dihedral. I'm pretty sure our M20's have less. 

[carusoam]

Where this video is right.... (sort of...)

• Dynamic stability would be required for this to work...
• large dihedral angles would help...
• Fuel level even in both tanks would help...
• Having a nicely rigged plane would help...

 

where this video is out to lunch (sort of)

• Our planes are not on the trainer list... (training planes have better stability in their design)
• Our planes are real, flying in real conditions... (not Coronado simulators of training airplanes with no turbulence)

 

Old memories of testing stability of my M20C...

letting go of the yoke while flying gives a hint to what happens...but this was at cruise conditions...

My M20C would roll to the side with more fuel in the tank... the role would steepen over time.... didn’t appear to end in a friendly manner...

Would adding flaps add to the stability?

Would trimming to a slower airspeed add to the stability?

 

Experimenting with this idea is within the skills of the plane and the PIC...

My expectation...

It would take two failures to become a valuable third option...  

• Attitude indicator failure
• Turn coordinator failure

 

Then see how well any of the ideas or back-up equipment really works in bumpy conditions...  some  TCs don’t work very well when worn and in bumpy conditions...

 

If not trained or practiced in using this technique... the problem if it occurs will be over in a few minutes... write your results on MS once on the ground...

It is better to stay in VFR conditions... know where VFR conditions are and go to them...

 

An example of stability in a training aircraft... I failed to hold altitude during the steep turns section of my PP check ride... the guy in the right seat of my C152 was quite generous...

He quickly set power, set trim, rolled into the bank, retrimmed while explaining each step as he went... the plane went around in a circle never coming off the target altitude...

 

Using ‘tricks and hacks’ doesn’t sound like using proven equipment and training... it could be the author’s method of keeping the viewer interested...

I use an iPhone, but i’m Far from being a millennial....

I get the feeling tricks and hacks are really just steps in a manual...  

 

I have to admit... I stopped watching the video after he was clear that this was in the sim only for various trainer planes...

PP thoughts only. Seek a CFI for a more appropriate answer...

Best regards,

-a-

[EricJ]

The two things in the panel that are the least likely to fail are the compass and the spirit inclinometer (ball).    You'll probably never be without at least those, unless you have an all-glass panel where even the ball is on a glass display (which I think is dumb).

In the suggested configuration, with no control input at all (as suggested in the video), it is unlikely that an airplane would be trimmed so perfectly that it wouldn't turn one way or the other, hence the "benign spiral" being a likely stable state.    It's interesting that DAs do a falling leaf.   That's pretty cool.

If somebody in such a situation bothered to at least try to keep the ball reasonably centered with the pedals it might not be a spiral or might be an even more benign one.   I can understand the idea that a panicked student might be better off not touching anything rather than even trying that, but somebody with at least some of their wits about them should be able to keep the ball centered.   I think you'd get an idea of how well or bad things were going by how much rudder you needed to keep it centered.

It is an interesting idea for the airplanes in which it works.   It sounds like it may not be well suited to Mooneys...I haven't tried it.

[carusoam]

In IMC...

picture the plane rolling into a bank...

Rudder inputs keeping the ball centered... will keep the plane coordinated in a steep turn....

The pilot notices the altitude unwinding and pulls back on the elevator... steepening the bank even more...

The pilot notices the compass flip flopping around not keeping up with what the plane is doing...

 

The pilot is going to be depending on a gyro to keep this from happening...

kind of gives good reasoning to having stuff fixed as it wears or breaks... or spending a few bucks to get some form of electronic gyro...

There won’t be time to get out a cell phone and connect it to an adhars device while losing control...

Very few people have experienced an electrical failure and a vac failure at the same time...

But not having recent partial panel experience can be disasterous for following a TC... practice with what you got...

PP thoughts only, not a CFI...

Best regards,

-a-

 

[Mooneymite]

1 hour ago, EricJ said:

The two things in the panel that are the least likely to fail are the compass and the spirit inclinometer (ball).    You'll probably never be without at least those, unless you have an all-glass panel where even the ball is on a glass display (which I think is dumb).

In the suggested configuration, with no control input at all (as suggested in the video), it is unlikely that an airplane would be trimmed so perfectly that it wouldn't turn one way or the other, hence the "benign spiral" being a likely stable state.    It's interesting that DAs do a falling leaf.   That's pretty cool.

If somebody in such a situation bothered to at least try to keep the ball reasonably centered with the pedals it might not be a spiral or might be an even more benign one.   I can understand the idea that a panicked student might be better off not touching anything rather than even trying that, but somebody with at least some of their wits about them should be able to keep the ball centered.   I think you'd get an idea of how well or bad things were going by how much rudder you needed to keep it centered.

It is an interesting idea for the airplanes in which it works.   It sounds like it may not be well suited to Mooneys...I haven't tried it.

I agree with this....

When I was just learning to fly in a PA-11, we practiced holding the plane in a stall and keeping the ball centered; the plane (at idle power) just descended wings level.  I don't recall the descent rate, but I suspect it was a lot less than a graveyard spin in inadvertent IMC!

Keeping the ball centered and trying to hold a heading might work, but once the plane fell out of wings-level, the W. Compass wouldn't be much help.

[takair]

Had an instructor ask me to try this in a BFR (when they were still called that) a few years ago.  Does not work out so well in a Mooney (at least mine...which is relatively docile in stalls).  Trainers are typically rigged to minimize the possibility of spins and even stalls, so full up trim tends to be not as upsetting and may put it into a purely mushing attitude.  I didn't let it go all the way to see where it stabilized, but it was not as described for the trainers above.  Most Mooneys will likely stall with full up trim, drop a wing and then enter a not-so-benign spiral.  Other possibilities are secondary stalls, which will be harsher and I suppose a spin.  All airplanes will find their way down in this configuration, but the Mooney won't be as forgiving.  Best bet is to have enough back-up instrumentation to keep wings level....  As someone mentioned, there is no harm in trying it with an instructor who is comfortable in stalls and incipient spins....just give yourself some altitude and don't let it develop into anything outside of the flight manual.