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N9156Z Minnesota crash final report


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34 minutes ago, 1980Mooney said:

Pilot had adopted an instrument flying habit that involved making turns on approach primarily with the rudder and adjusting pitch attitude with the pitch trim.

I have significant concerns the emphasized portion of the above is far more common than people realize, especially in aircraft equipped with electric trim.

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7 hours ago, Parker_Woodruff said:

Pilot had adopted an instrument flying habit that involved making turns on approach primarily with the rudder and adjusting pitch attitude with the pitch trim.

Does this actually mean what it sounds like, turning the plane using only the rudder?  
Why would one do this?  
What I mean is that doesn’t even really make sense to me in the context of an approach. I suppose that I use the trim for descents because I use VS or FLC, but usually by the initial approach fix I am hand flying so any pitch changes are primarily throttle. 
Am I missing or misunderstanding what this means?  Why would anyone advise turning with rudder only? Is there some benefit at times to this method?

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  • Brandt changed the title to N9156Z Minnesota crash final report
On 3/23/2023 at 7:16 PM, Schllc said:

Does this actually mean what it sounds like, turning the plane using only the rudder?  
Why would one do this?  
What I mean is that doesn’t even really make sense to me in the context of an approach. I suppose that I use the trim for descents because I use VS or FLC, but usually by the initial approach fix I am hand flying so any pitch changes are primarily throttle. 
Am I missing or misunderstanding what this means?  Why would anyone advise turning with rudder only? Is there some benefit at times to this method?

I’ve known more than one old school instructor that has advocated yawing toward the needle on an ILS.  It’s not uncommon. I have also seen the technique used on VFR approaches to make minor corrections for runway alignment. I  think it’s poor airmanship and have said as much in the cockpit.

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13 minutes ago, Shadrach said:

I’ve known more than one old school instructor that has advocated yawing toward the needle on an ILS. It’s not uncommon.I have also seen the technique used on VFR approaches to make minor corrections for runway alignment. I  think it’s poor airmanship and have said as much in the cockpit.

Sometimes I will use the rudders to steer the plane when I’m in cruise flight and eating a sandwich or drinking something.  How else am I to snack and fly a heading at the same time without an auto pilot?  

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8 hours ago, Schllc said:

Does this actually mean what it sounds like, turning the plane using only the rudder?  
Why would one do this?  
What I mean is that doesn’t even really make sense to me in the context of an approach. I suppose that I use the trim for descents because I use VS or FLC, but usually by the initial approach fix I am hand flying so any pitch changes are primarily throttle. 
Am I missing or misunderstanding what this means?  Why would anyone advise turning with rudder only? Is there some benefit at times to this method?

You’re understanding correctly and I can’t think of a single reason for how intentionally flying uncoordinated in IMC is a good idea. 

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12 hours ago, Schllc said:

Does this actually mean what it sounds like, turning the plane using only the rudder?  
Why would one do this?  
What I mean is that doesn’t even really make sense to me in the context of an approach. I suppose that I use the trim for descents because I use VS or FLC, but usually by the initial approach fix I am hand flying so any pitch changes are primarily throttle. 
Am I missing or misunderstanding what this means?  Why would anyone advise turning with rudder only? Is there some benefit at times to this method?

It’s actually very common, tightening up the turn by stepping on the pedals has killed many an Airtractor pilot. Many stall / spins on the turn to final are likely due to stepping on the pedals to tighten the turn, it’s sort of instinctual, something you have to ensure you don’t do if maneuvering a lot, like Ag application flights.

Some aircraft handle it better than others, on a Maule the Autopilot controls heading by using the rudder, it’s not connected to the Ailerons. Maule isn’t the only aircraft like that, but I can’t list others.

I’m 90% sure why it’s taught by some for minor corrections because an aircraft put into a bank by ailerons will maintain that bank (neutral stability) but once pressure is relaxed on the rudder the airplane will return to wings level (assuming only a slight turn is induced).

‘I’m not recommending it, just explaining its not as uncommon as you would think.

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13 minutes ago, Evan said:

I believe the FAA requires a five-day wait before flying...

From https://www.ncbi.nlm.nih.gov/books/NBK526010/#_article-20535_s3:     
“The liver metabolizes diphenhydramine via CYP450. It is excreted in the urine, unchanged, and has a half-life of 3.4 to 9.2 hours. The drug's time to peak, serum is 2 hours.”

So, going with 5 half-lives (https://www.faa.gov/pilots/safety/pilotsafetybrochures/media/meds_brochure.pdf), you get 17-46 hours.

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I have used diphenhydramine as a sleep aid. While it certainly helps me sleep, I feel groggy the next morning even though well rested. So much so that I need to be sharp, I would rather deal with minor sleep deprivation over the "hangover".  IIRC, there was also a study published not long ago that found chronic diphenhydramine use correlated with  dementia.

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47 minutes ago, Shadrach said:

IIRC, there was also a study published not long ago that found chronic diphenhydramine use correlated with  dementia.

I don’t remember seeing that study. 

Sorry, bad dementia joke.

Yes, there have been several studies linking anticholinergic drugs (like Benadryl) with dementia.

https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2736353

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9 hours ago, Parker_Woodruff said:

You’re understanding correctly and I can’t think of a single reason for how intentionally flying uncoordinated in IMC is a good idea. 

Soooo.... Are we saying on a stable approach we shouldnt use the rudder to fix a small deviation? Say 2-3 degrees? Cause thats exactly how I was taught. Something larger and the yoke gets involved. The pressure on the pedal is pretty low though and the ball doesnt really go too far away from being centered.

Normal turns I obviously dont just use the rudder though... thats kinda insane.

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16 hours ago, Shadrach said:

I’ve known more than one old school instructor that has advocated yawing toward the needle on an ILS.  It’s not uncommon. I have also seen the technique used on VFR approaches to make minor corrections for runway alignment. I  think it’s poor airmanship and have said as much in the cockpit.

A few years ago, I remember an instructor telling me to "use your pedals to keep the nose pointed towards the runway" during a VFR approach.  Now I'm wondering what I was doing before he said that.  It does seem like there's some cross controlling involved if you do that.  This part of flying seems so instinctive I actually can't tell you exactly what I do.... do.  In IFR, I'm certain I'm not using just pedals especially if I can't see the runway.  

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15 minutes ago, dzeleski said:

Soooo.... Are we saying on a stable approach we shouldnt use the rudder to fix a small deviation? Say 2-3 degrees? Cause thats exactly how I was taught. Something larger and the yoke gets involved. The pressure on the pedal is pretty low though and the ball doesnt really go too far away from being centered.

Normal turns I obviously dont just use the rudder though... thats kinda insane.

Yeah, me too. Small corrections on final approach, hold rudder until centered then relax. Call it 2º, anything more turn the yoke like always. But not on the whole approach! Just short final, especially with an ILS where the cone gets really narrow.

Use the yoke to turn, climb and descend. Add some rudder to stay coordinated in turns. Use pitch trim to eliminate yoke forces on long-ish climbs and descents, but not if you're 100' high on approach . . . .

At some point, "rules" go away and common sense must apply. In aviation, many times there is zero tolerance for using zero tolerance rules, and they usually end badly.

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16 minutes ago, dzeleski said:

Soooo.... Are we saying on a stable approach we shouldnt use the rudder to fix a small deviation? Say 2-3 degrees? Cause thats exactly how I was taught. Something larger and the yoke gets involved. The pressure on the pedal is pretty low though and the ball doesnt really go too far away from being centered.

Normal turns I obviously dont just use the rudder though... thats kinda insane.

I was taught bank angle equal to degrees of correction required.  Obviously you don’t actually think “2 degrees off heading, so i need 2 degree bank…” but that’s the guideline.  Very small bank, just pressure on the yoke for very small correction.  The airplane should stay coordinated though.

 If you’re 10 degrees off heading, you don’t need a 30 degree bank turn, 10 degree bank would work just fine.

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I think it’s interesting that nobody has asked why he wasn’t using his autopilot.  This is the same thing that killed JFK Jr. more than 20 years ago, and we keep relearning the same lesson.

Yes, an instrument rated pilot should be able to fly the entire flight by hand.  He/she should also have the good judgement to use the autopilot during challenging actual conditions.

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1 hour ago, dzeleski said:

Soooo.... Are we saying on a stable approach we shouldnt use the rudder to fix a small deviation? Say 2-3 degrees? Cause thats exactly how I was taught. Something larger and the yoke gets involved. The pressure on the pedal is pretty low though and the ball doesnt really go too far away from being centered.

Normal turns I obviously dont just use the rudder though... thats kinda insane.

Quick, tiny, coordinated bank left or right should do it.  Keep in mind we have an aileron/rudder interconnect.

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