Bounced landings - aft CG ?

[jaylw314]

You don't have to pull the power on the space shuttle, but they flare and land the same way nonetheless  

I'd hate to see someone bounce in the space shuttle 

Edited May 15, 2019 by jaylw314

[steingar]

  On 5/15/2019 at 8:01 PM, Bravoman said:

FWIW, the owner of my MSC, Joe Cole, who has flown them all, thinks that the long bodies are the best landing of the Mooneys because of additional rudder authority.

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Joe Cole is much of the reason I bought the Mooney I did.  He is one heck of a stand up individual.  Gave me a whole bunch of his time explaining things on the phone.  I ever get back that way I just hope I have the chance to buy him a beer.

[midlifeflyer]

  On 5/15/2019 at 5:17 PM, steingar said:

All I can say is for the first year or so my landings all sucked.  Oh, I had some good ones, but I think those were mostly accidental.  I know you come over rate numbers at 75 mph, hold it off and let it land.  That's what I'd been trying to do since I started.  Fro whatever reason it seems to be working these days.  I bounce the occasional landing, but not by much, and most are greasers.  I have no idea what changed or why. But if an ugly bald old fat greaseball like me can land a Mooney well, I'm certain anyone reading this can do so as well given a bit of time.

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Here are literally the two things I see the most.

1. Vertical Sight Picture. What does it look like to protect the nosewheel? Just enough nose up to have the nose off the runway without over-rotating? That is very different between models even within a make. 

2. Horizontal Sight Picture. Many pilots have learned to find little things on the cowling to give us the centerline and lack of drift. For those who learn that way, they have to work on a new one. Until they do they get those little swerves (that often feel like last second drops).

[Shadrach]

  On 5/15/2019 at 8:01 PM, Bravoman said:

 My fixed gear Saratoga will fly like a refrigerator if I  completely chop the power once  over the fence and need to keep power into the flare. In my opinion, it is a much harder plane to grease on. In the Mooney, I shoot for 75 to at most 80 if I am heavy over the fence, and then pull the power when I know I have the runway made.   I do the best in the Mooney compared to any other aircraft I have ever owned or flown for consistently good landings, although I will say that I have no experience other than in my long body. Don’t know how the others compare. FWIW, the owner of my MSC, Joe Cole, who has flown them all, thinks that the long bodies are the best landing of the Mooneys because of additional rudder authority.

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This surprises me... Is the additional rudder authority supposed to be due to leverage from the extra length of the fuselage? 

[Bob_Belville]

  On 5/15/2019 at 10:35 PM, Shadrach said:

This surprises me... Is the additional rudder authority supposed to be due to leverage from the extra length of the fuselage? 

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I seem to remember Wolfgang Langewiesche (Stick and Rudder) teaching that the shorter fuselage made the vertical stabilizer and the rudder more effective. 

[Shadrach]

  On 5/15/2019 at 10:43 PM, Bob_Belville said:

I seem to remember Wolfgang Langewiesche (Stick and Rudder) teaching that the shorter fuselage made the vertical stabilizer and the rudder more effective. 

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I haven’t read it in a while but it seems logical all other things being equal. Given the Rudder was as big as it ever got with the into of the F model, I’m trying to figure out what extra rudder authority a long body has.

[Bob_Belville]

  On 5/15/2019 at 11:05 PM, Shadrach said:

I haven’t read it in a while but it seems logical all other things being equal. Given the Rudder was as big as it ever got with the into of the F model, I’m trying to figure out what extra rudder authority a long body has.

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Where's our resident mathematician? @aviatoreb

[carusoam]

202kias on final, and a heavy plane...

If off by a hair... landing in the next county might be a possibility...

 

Another interesting piece of information for people that fly many different airplanes...  the ASI markings are standardized in terms of meaning and location... white arc in particular for this discussion...  See if your approach speed is generally at the 3:00 position?

The white arc of the ASI kind of indicates when the plane will stop flying... make sure to understand what weight the markings are associated with, and that the ASI is calibrated before using it....

Best regards,

-a-

[Hank]

  On 5/15/2019 at 11:05 PM, Shadrach said:

I haven’t read it in a while but it seems logical all other things being equal. Given the Rudder was as big as it ever got with the into of the F model, I’m trying to figure out what extra rudder authority a long body has.

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Long bodies are heavier, so will fly faster, giving more rudder authority. The long body rudder may also move further each way, I'd have to check the TCDS.

[aviatoreb]

  On 5/15/2019 at 11:17 PM, Bob_Belville said:

Where's our resident mathematician? @aviatoreb

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Yoohoo!

[bradp]

Probably the arm being further aft from the vertical axis confers additional yaw force and authority  

Sounds like the OP hasn’t mastered short / obstructed approaches.  Not like that would be anything I’d be ready for home field or not with that level of experience in a new to me Mooney.  Especially at a <3000 ft field.  Would go out with an instructor and practice chopping power once clear of the obstacle , carrying about 5 MPH additional airspeed above your *calculated* weight-based approach speed and aim for prior to the line if your displaced threshold is unusable for landing. You should be able to touch down consistently just past the start of the runway bar.  

Personally if I couldn’t master that task over and over, I wouldn’t consider myself proficient for landing or departing on a runway of that length with obstructions. Close in obstructions are serious business especially when you start getting to the corners of the performance or aerodynamic envelope (search this site for Patrick or W78 crashes and you’ll get a sense of how wrong things can go so quickly at short or close in fields).  

My suggestion would be to do as your doing - work with the instructor. But you’re going to have to master landings on a less demanding runway before considering home base your home base.

I say this from experience- I bald spotted a tire at N07 2700 ft in my first week of Mooney ownership.  That airport has close in obstructions.  I decided last week when up in that neighborhood - operating at max gross on a hot day with my family on board - that I wasn’t up to that task. Especially with regard to a planned departure after dark.  I’m not current / proficient / recently familiar enough with that field to make it past my risk assessment.  I have about 750 landings in my J - not inexperienced by any means but not to a point where I’d consider myself a master of all performance demands unless throughly practiced and proficient. 

I’ve also considered that flying with small children is some of the most demanding flying I’ve done.  It’s riddled with potential for distraction or worse.  If you can manage a four year old who wakes up in your copilot seat with a night terror on your base to final turn, or decides when she’s in the back seat she’s going to kick your seat like a brat when you’re flying an ILS... you can probably handle a G-V full of drunk and out of control Rock stars.  At least a few of the Mooneyspacers have met my oldest daughter Olivia - who does long cross countries, ILSs, and flies formation with me.  She’s an amazing kid but not always perfect so a plan A, B, and C is in order for every flight.  Make sure you can bring your A-game and a half and have a child mitigation plan before doing anything but the lowest risk flying.  But learn the how to bring the A game without the baby on board.  

[PT20J]

  On 5/15/2019 at 11:05 PM, Shadrach said:

I haven’t read it in a while but it seems logical all other things being equal. Given the Rudder was as big as it ever got with the into of the F model, I’m trying to figure out what extra rudder authority a long body has.

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Longer moment arm from rudder to CG allows same size rudder to produce greater yawing moment. 

[PT20J]

  On 5/16/2019 at 12:47 AM, bradp said:

 

Probably the arm being further aft from the vertical axis confers additional yaw force and authority  

 

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That’s backwards. There is less rudder authority with aft CG due to shorter moment arm. That’s why highest Vmc speed for a twin is at aft CG. 

[bradp]

@PT20J  I was thinking about rudder authority for a short/med body F versus a long body.  Given a similar CG location, the longer arm from the yaw axis to the control surface would confer greater authority in the long body, correct? 

Edit - I see your first post - were on the same page for this one. 

[PT20J]

  On 5/15/2019 at 8:01 PM, Bravoman said:

Joe Cole, who has flown them all, thinks that the long bodies are the best landing of the Mooneys because of additional rudder authority.

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OK, I’ll bite: why would rudder authority make for better landings? The only thing you need the rudder for is to keep it straight. Which reminds me: one of the not so great aspects of the Mooney design is that the nose wheel doesn’t disconnect from the rudder when fully extended as in many airplanes. And, since the steering is rigid (no bungees) you have to relax rudder pressure when the nose wheel comes down during a crosswind landing or you head for the grass. Bet that’s why the nose wheel deflection - and hence the turning radius - is limited. And, since the nose wheel pivots less than other airplanes, it’s more easily damaged by towing. 

Skip

[jaylw314]

  On 5/16/2019 at 2:08 AM, PT20J said:

OK, I’ll bite: why would rudder authority make for better landings? The only thing you need the rudder for is to keep it straight. Which reminds me: one of the not so great aspects of the Mooney design is that the nose wheel doesn’t disconnect from the rudder when fully extended as in many airplanes. And, since the steering is rigid (no bungees) you have to relax rudder pressure when the nose wheel comes down during a crosswind landing or you head for the grass. Bet that’s why the nose wheel deflection - and hence the turning radius - is limited. And, since the nose wheel pivots less than other airplanes, it’s more easily damaged by towing. 

Skip

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All the various Cherokee's, Archer's and Arrow's do that too, though, and their nose wheel travel is significantly greater than Mooney's

[Bravoman]

Well, thinking about it Joe may have said elevator authority as opposed to rudder. The conversation was a while back  I’ll ask him next time I talk to him.

[Bob_Belville]

Well, if several of you think the longer arm gives more authority and since Prof. Bolt is not giving us the answer I will have to find my copy of “Stick and Rudder” and refresh my memory of what struck me as counterintuitive when I read it.


Sent from my iPad using Tapatalk

[DXB]

  On 5/16/2019 at 2:08 AM, PT20J said:

OK, I’ll bite: why would rudder authority make for better landings? The only thing you need the rudder for is to keep it straight. Which reminds me: one of the not so great aspects of the Mooney design is that the nose wheel doesn’t disconnect from the rudder when fully extended as in many airplanes. And, since the steering is rigid (no bungees) you have to relax rudder pressure when the nose wheel comes down during a crosswind landing or you head for the grass. Bet that’s why the nose wheel deflection - and hence the turning radius - is limited. And, since the nose wheel pivots less than other airplanes, it’s more easily damaged by towing. 

Skip

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Very interesting Skip - I've never given this aspect of the system much thought. I have swerved a bit in the past after landing when using a lot of rudder in a strong crosswind, though it's been easily corrected. I guess I know why now. Thinking about getting off the rudder once the mains plant has never been part of my routine, nor has anyone has ever taught me to do this...do other people think about this as a deliberate step?  I  imagine one could put quite a side load on the nose wheel if it touches down at the extremes of rudder travel.  Also partial flap and no flap landings would seem to be more susceptible to problems because they tend to touch down in a flatter attitude.  @Shadrach always has detailed ideas on landing technique - I wonder what his thoughts are on this issue...

[PT20J]

  On 5/16/2019 at 2:49 AM, jaylw314 said:

All the various Cherokee's, Archer's and Arrow's do that too, though, and their nose wheel travel is significantly greater than Mooney's

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According to my old PA28 service manual, you are correct regarding early Cherokees. Beginning in 1974, bungees were added to the steering system. The nose wheel fairing aerodynamically centers the nose wheel in flight. There's a service bulletin #291 that details the addition of springs if the fairing is removed. I'm not sure how the retractable Cherokees work w.r.t. nose wheel centering. Usually, some sort of mechanism is required on a retractable to keep the nose wheel from getting cocked during retraction. 

[PT20J]

  On 5/16/2019 at 3:26 AM, Bob_Belville said:

Well, if several of you think the longer arm gives more authority and since Prof. Bolt is not giving us the answer I will have to find my copy of “Stick and Rudder” and refresh my memory of what struck me as counterintuitive when I read it.

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It's just physics: Moment = Force X Distance. Yaw (controlled by the rudder) is a rotation about the vertical axis that passes through the CG. Rotation is caused by an applied moment.

[PT20J]

  On 5/14/2019 at 4:21 PM, ChrisV said:

I still want to know what exactly I did wrong, but I will never really know.  Next I am going to mount a virb under the tail to maybe next time, I can use video evidence to learn from.

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Chris, this has been a long and interesting thread. From your description in your posts, here's what likely happened:

Your airspeed was too high on short final and, perhaps due to the obstructions, you were maybe a bit high also. At some point, as you started using up runway, you forced the plane down to the ground before it was ready. That's the only way to get it to land on the nose wheel, and that's why it bounced. It's also very common, so don't feel bad. This didn't happen with your instructor because an instructor would have seen this coming and had you correct or go around. 

You only need to satisfy two conditions for a good landing: 1) The airplane needs to be aligned with the centerline, flying level and decelerating a few inches above the runway,  and 2) the airplane needs to be in a nose high attitude. If you do that, it will land itself. There are numerous techniques to get the airplane to a point that satisfies those two conditions, and pilots will argue endlessly about which technique is best.

Fly safe,

Skip

[PT20J]

  On 5/16/2019 at 3:46 AM, DXB said:

Very interesting Skip - I've never given this aspect of the system much thought. I have swerved a bit in the past after landing when using a lot of rudder in a strong crosswind, though it's been easily corrected. I guess I know why now. Thinking about getting off the rudder once the mains plant has never been part of my routine, nor has anyone has ever taught me to do this...do other people think about this as a deliberate step?  I  imagine one could put quite a side load on the nose wheel if it touches down at the extremes of rudder travel.  Also partial flap and no flap landings would seem to be more susceptible to problems because they tend to touch down in a flatter attitude.  @Shadrach always has detailed ideas on landing technique - I wonder what his thoughts are on this issue...

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It's not quite that bad. The geometry of the nose gear provides a significant amount of positive caster. Caster is what keeps your car - or shopping cart - going straight. So, if you hold the rudder when the nose wheel touches, you will get an initial swerve, but - unless you continue to hold the rudder - it will self correct and the swerve will end. All you have to do is steer it back to the centerline.

[ArtVandelay]

Most of my bounce landings is at strange airports after long flights...either my visual clues are off or I’m tired.


Tom

[steingar]

If Joe Cole says the long  bodies land better, I believe him.  They do have greater stability in the pitch axis, could aha something to do with it.