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Porpoising leads to gear collapse accident


kortopates

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5 hours ago, DXB said:

I’d like to think I know my bird pretty well, but compared to you, not so much.  Maybe there’s something to be said for keeping a ‘lil mystery in the relationship with the mistress? :lol:

My PP instructor made sure I knew the "why" for everything we did. And the answer was never "the POH says so". There has to be a reason for everything.

For example, what is the purpose of trim? To relieve control wheel pressure. So it's good to know how much control wheel pressure it takes to overcome an out of trim situation.

The POH says cowl flaps open for take-off. Why? To keep the engine cool at full power and slow airspeed. So it might be useful to know how quickly the engine heats up with the cowl flaps closed. My 252 will climb at full power for a couple of minutes before reaching 380 on any cylinder with the cowl flaps closed. This lets me know that on an emergency go around, I can concentrate on flying the plane, handling trim, flaps, gear and worry about cowl flaps later once stable in the climb. I like to leave my cowl flaps closed on landing so that the turn limit labels are visible if the plane has to be towed.

I usually land with full flaps and take off with "one notch" of flaps. But I also know I can easily land without flaps and anything in between. This also means that on a go-around, I should know how well it will climb with full flaps. It's not very good, but practice has showed me I should get the trim, gear, flaps, in that order if I haven't touched down. If the wheels are on the runway then it's flaps, trim, gear, for me.

I'm an engineer, mysteries are there to be solved. :huh:

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I'd just like to say, if your fancy "FAA Certified" mechanic suggests that you need some expensive gear donuts and he needs some tool to install them, I suggest you come out to Oregon. Here a sawzall and a couple 2x4s is a good enough replacement.

(Obviously, this is just to keep the gear in place long enough to tow it into a hangar.)

IMG_20180228_145711099s.jpg

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  • 1 month later...

Well, the quote from the mechanic is in, and the insurance company has accepted. So repairs start next week, so in just a few short years(months?) I'll have a plane again.

Now to go procure a new engine monitor and engine heater so I can help get that installed while the engine is off.

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3 minutes ago, thinwing said:

Is that nose gear truss actually cracked?

I don't know exactly what parts are cracked/broken, but the assembly that held the pucks in is totally destroyed, I believe the plan is simply to replace the entire thing.

If you're talking about the spot on this side next to the wood, no, that was just where I scratched it up it when I was removing the pucks with the sawzall.

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3 hours ago, Steve W said:

Well, the quote from the mechanic is in, and the insurance company has accepted. So repairs start next week, so in just a few short years(months?) I'll have a plane again.

Now to go procure a new engine monitor and engine heater so I can help get that installed while the engine is off.

Well, that took forever, but I suppose that's good news, right?  Hopefully the repairs go quickly enough that you don't go insane in the meantime.  I was grounded for about 4 months last year and my wife almost killed me.

Where did you end up going to for the repairs?  Keep us up to speed!

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1 hour ago, thinwing said:

Yeah I see one of the pucks in the background....don't they have dry hangars up there in Newport?Also best crab sandwichs in town are at Local Ocean!

"Dry", sounds like you've never been to the coast... Actually my hangar is much dryer now that I've improvised some rain shields and sealed some of the bottom of the walls.

The problem was that the night of the event they got it off the runway on a tow truck, but it was the wrong way around to try and put it into my T hangar, so it ended up on the ramp for a while.

31 minutes ago, jaylw314 said:

Well, that took forever, but I suppose that's good news, right?  Hopefully the repairs go quickly enough that you don't go insane in the meantime.  I was grounded for about 4 months last year and my wife almost killed me.

Where did you end up going to for the repairs?  Keep us up to speed!

The problem was that the mechanic is Tom from Reliant Aircraft up at Starks Twin Oaks since there's really no mechanics at Newport for a project like this(or know Mooneys that well) so he had to come down to help get it on the gear and inspect it, etc. He'll be doing the repair. Tentative plan is to pull the engine and prop in the next week or 2, get that work done(well, ok, throw the prop away and get a new one) then repair the gear and rest of the damage enough at Newport so it can be flown gear down on a ferry permit to his shop where he has the tools to do the rest of the work.

Current 'upgrades' planned include moving back to a 2 blade prop, replacing the Tanis with a Reiff and adding a JPI EDM 900. (As much as I like EI, the CGR-30p doesn't have enough primaries to replace the cluster gauge, and moving to the CGR-30p and 30c adds $1000 over the JPI)

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  • 2 weeks later...
  • 4 weeks later...

OK guys, cut me a little slack since I’m three sheets to the wind on cheap bourbon.  My prop strike (described on this site, but my google-fu is too weak to bring it up) was on the first bounce.  I’ve been beating myself up about it ever since and probably always will. I’ve been ready to hang it up more times than I can count since. But the one sign of hope that I’m not the screwball pilot I think I am is that was the only time I had more than one bounce in my Mooney.

Indeed, on my last landing I saw a deck angle that was uncomfortably high. A little blip of power and it was just fine. And I was still stopped on the first third of the runway (though it was a pretty big runway).

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8 hours ago, steingar said:

OK guys, cut me a little slack since I’m three sheets to the wind on cheap bourbon.  My prop strike (described on this site, but my google-fu is too weak to bring it up) was on the first bounce.  I’ve been beating myself up about it ever since and probably always will. I’ve been ready to hang it up more times than I can count since. But the one sign of hope that I’m not the screwball pilot I think I am is that was the only time I had more than one bounce in my Mooney.

Indeed, on my last landing I saw a deck angle that was uncomfortably high. A little blip of power and it was just fine. And I was still stopped on the first third of the runway (though it was a pretty big runway).

It sounds as if you are too fast on approach to landing?  Bouncing plus taking up so much runway.?  Maybe an aoa plus a cfi can help?  Plus if you are to fast just let it float as long as it wants to rather than try and land before it wants to.

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13 hours ago, steingar said:

OK guys, cut me a little slack since I’m three sheets to the wind on cheap bourbon.  My prop strike (described on this site, but my google-fu is too weak to bring it up) was on the first bounce.  I’ve been beating myself up about it ever since and probably always will. I’ve been ready to hang it up more times than I can count since. But the one sign of hope that I’m not the screwball pilot I think I am is that was the only time I had more than one bounce in my Mooney.

Indeed, on my last landing I saw a deck angle that was uncomfortably high. A little blip of power and it was just fine. And I was still stopped on the first third of the runway (though it was a pretty big runway).

The only way to strike the prop on landing is to allow the nose gear to touch down first and hard. This happens when coming in too fast and getting anxious of diminishing runway and forcing the airplane to land by pushing it down. Depending on a few things including airspeed one of two things will happen: the prop will strike on first contact of nose gear with the runway or it will bounce if not too fast to strike the prop. If it bounces the bounce will be encouraged by the gear pucks because they don’t absorb much energy. If you have too much airspeed the cycle repeats itself and may strike the prop on the second bounce. Certainly if you insist on bouncing it will strike on the third bounce.

If lucky enough to touch down on the mains first it will still bounce if too fast. Then if forced down it will strike the prop just the same.

I see a spectrum in pilots transitioning to the Mooney from more forgiving airplanes. Some will land on the nose gear first and bend the prop. Some will do a little better and be at the proper attitude to touch down on the mains but being too fast will bounce a couple of times before they force it down and strike the prop. Some will do sttill better than that and will recognize a bad transition to landing. This group will go around. Eventually it sinks in: proper airspeed and attitude control. And if the approach just does not look good go around. 

The Mooney needs to touch down on the mains first when it’s ready holding the nose off until it's ready. All it asks of the pilot is to have it in the proper attitude and airspeed during the transition to do so.

 

 

 

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13 hours ago, steingar said:

OK guys, cut me a little slack since I’m three sheets to the wind on cheap bourbon.  My prop strike (described on this site, but my google-fu is too weak to bring it up) was on the first bounce.  I’ve been beating myself up about it ever since and probably always will. I’ve been ready to hang it up more times than I can count since. But the one sign of hope that I’m not the screwball pilot I think I am is that was the only time I had more than one bounce in my Mooney.

Indeed, on my last landing I saw a deck angle that was uncomfortably high. A little blip of power and it was just fine. And I was still stopped on the first third of the runway (though it was a pretty big runway).

Everyone has a bad day, I have had several so has Maverick (Top Gun).

Cruiser:  The simple fact is you feel responsible for "a prop strike" and you have a confidence problem. Now I'm not gonna sit here and blow sunshine up your ass, "Steingar". A good pilot is compelled to always evaluate what's happened, so he can apply what he's learned. Up there, we gotta push it. That's our job. It's your option, "Steingar". All yours. (as adapted from Top Gun)

 

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4 hours ago, PTK said:

The only way to strike the prop on landing is to allow the nose gear to touch down first and hard. This happens when coming in too fast and getting anxious of diminishing runway and forcing the airplane to land by pushing it down. Depending on a few things including airspeed one of two things will happen: the prop will strike on first contact of nose gear with the runway or it will bounce if not too fast to strike the prop. If it bounces the bounce will be encouraged by the gear pucks because they don’t absorb much energy. If you have too much airspeed the cycle repeats itself and may strike the prop on the second bounce. Certainly if you insist on bouncing it will strike on the third bounce.

If lucky enough to touch down on the mains first it will still bounce if too fast. Then if forced down it will strike the prop just the same.

I see a spectrum in pilots transitioning to the Mooney from more forgiving airplanes. Some will land on the nose gear first and bend the prop. Some will do a little better and be at the proper attitude to touch down on the mains but being too fast will bounce a couple of times before they force it down and strike the prop. Some will do sttill better than that and will recognize a bad transition to landing. This group will go around. Eventually it sinks in: proper airspeed and attitude control. And if the approach just does not look good go around. 

The Mooney needs to touch down on the mains first when it’s ready holding the nose off until it's ready. All it asks of the pilot is to have it in the proper attitude and airspeed during the transition to do so.

 

 

 

As a rule of thumb, as has been mentioned before, for every 1 knot of airspeed over nominal airspeed, the landing distance will be increased by 100 feet.  So 10 knots too fast and you will be taking up an extra 1,000 feet of runway.  Your landing distance had been determined by the time you hit ground effect.  You can't expect to force it on any sooner and expect things to "work out".  They won't.  It's critical to touch down in the landing attitude (about 8° nose up) no matter what speed you come over the threshold.  You can't have a prop strike if the nose it up.  So it is incumbent on you to come over the threshold at the correct speed, especially on a short field.

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4 minutes ago, Cruiser said:

Everyone has a bad day, I have had several so has Maverick (Top Gun).

I believe that every Mooney pilot can profit from the skills acquired flying a tail wheel airplane and becoming proficient at full stall landings.  Not full stall landings where you stall and come crashing down the last foot, but full stall landings timed to gently land on all three wheels.  Those are skills that can transfer directly to landing the Mooney.

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44 minutes ago, Cruiser said:

Everyone has a bad day, I have had several so has Maverick (Top Gun).

In my opinion not true.  Proper slope and airspeed coupled with a smooth transition to the landing attitude will practically guarantee a perfect landing.

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8 hours ago, donkaye said:

In my opinion not true.  Proper slope and airspeed coupled with a smooth transition to the landing attitude will practically guarantee a perfect landing.

Unless your having a bad day.  All kidding aside as humans we are none of us perfect and sometimes things can go bad.

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That's why I learnt to have a short final call out and the first item on the list is "on speed" And if the air speed is more than 80 knots I do everything I can to get below it unless I have lots of runway plus it's a windy day. Follow by "gear down" "full flaps" "full prop" "runway XX clear to land"

I also trim it to reduce the amount of pulling back needed as I transition to flare. Yes it does mean that I need to push in hard if I need to go around - difficult but not impossible - but I am much rather enjoying the benefit of having some degree of finesse 99 landings than of slightly easier go around in 1 landing out of 100. 

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1 hour ago, Tommy said:

That's why I learnt to have a short final call out and the first item on the list is "on speed" And if the air speed is more than 80 knots I do everything I can to get below it unless I have lots of runway plus it's a windy day. Follow by "gear down" "full flaps" "full prop" "runway XX clear to land"

I also trim it to reduce the amount of pulling back needed as I transition to flare. Yes it does mean that I need to push in hard if I need to go around - difficult but not impossible - but I am much rather enjoying the benefit of having some degree of finesse 99 landings than of slightly easier go around in 1 landing out of 100. 

Not sure what you mean by “transition to flare.” It gives the connotation that you can come in fast and flare to slow down. That’s not how it works and it’s the wrong connotation. The space shuttle flares but it has a parachute to slow it down. In my Mooney I transition to ground effect. 

Ground effect comes into play when within one wingspan off the ground. Low wings have less induced drag (i.e. more reduction off their normal induced drag) in ground effect than high wings. It will cause our slick low wing to float if too fast. Incidentally It is this ground effect that folks try to beat by pushing the nose down and striking the prop. 

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6 hours ago, PTK said:

Not sure what you mean by “transition to flare.” It gives the connotation that you can come in fast and flare to slow down. That’s not how it works and it’s the wrong connotation. The space shuttle flares but it has a parachute to slow it down. In my Mooney I transition to ground effect. 

Ground effect comes into play when within one wingspan off the ground. Low wings have less induced drag (i.e. more reduction off their normal induced drag) in ground effect than high wings. It will cause our slick low wing to float if too fast. Incidentally It is this ground effect that folks try to beat by pushing the nose down and striking the prop. 

Of course flare is also for slow down. It's also to put the main wheels on the tarmac first. I don't want to sound like telling you how to suck egg like what you just did but, with same power setting, a flare with increasing AOA WILL slow you down (and you will either climb "ie. ballooning" if you have excess airspeed or maintain level flight if you don't have excess air speed ie. "holding off"). Once you slow down to stall speed (critical AOA) - hopefully it's only a few inches above the runway - you plant your wheels. If it doesn't slow you down, then what else is slowing down at the final stage of your landing. You are already at idle power and full flaps.

Ground effect simply means it will take longer for you to bleed off that airspeed - ie SLOW DOWN. 

I have never come across with any instructors that says "now you are transitioning to ground effect" during landing as if it's a deliberate act. You can be in the ground effect whether you flare or not and at any speed but flaring to slow down and ready the wheels is a deliberate act that takes good judgement.

The POH has already taken that into consideration when it publishes the landing distance required.  So it's our job as pilots to fly the number and flare at the right time not thinking about "ground effect." 

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4 hours ago, Tommy said:

Of course flare is also for slow down. It's also to put the main wheels on the tarmac first. I don't want to sound like telling you how to suck egg like what you just did but, with same power setting, a flare with increasing AOA WILL slow you down (and you will either climb "ie. ballooning" if you have excess airspeed or maintain level flight if you don't have excess air speed ie. "holding off"). Once you slow down to stall speed (critical AOA) - hopefully it's only a few inches above the runway - you plant your wheels. If it doesn't slow you down, then what else is slowing down at the final stage of your landing. You are already at idle power and full flaps.

Ground effect simply means it will take longer for you to bleed off that airspeed - ie SLOW DOWN. 

I have never come across with any instructors that says "now you are transitioning to ground effect" during landing as if it's a deliberate act. You can be in the ground effect whether you flare or not and at any speed but flaring to slow down and ready the wheels is a deliberate act that takes good judgement.

The POH has already taken that into consideration when it publishes the landing distance required.  So it's our job as pilots to fly the number and flare at the right time not thinking about "ground effect." 

We differ in opinion. “Flare” doesn’t accurately describe or teach much about what’s happening. The skills that take good judgement and practice to perfect are: a deliberate transition from approach attitude to landing attitude followed by slow flight in ground effect followed by the mains touching down. (in a tailwheel touching down level.) One of the most valuable exercises during primary training, and my primary instructor long ago had me do lots of these, is to practice slow flight a foot or so above the runway. Isn’t this the main reason why we teach slow flight and the MCA maneuver in the landing configuration? 

In my mind this transition to slow flight is a separate phase which happens prior to the  round out with the airplane gently stalling and mains touching down. 

 

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3 hours ago, PTK said:

We differ in opinion. “Flare” doesn’t accurately describe or teach much about what’s happening. The skills that take good judgement and practice to perfect are: a deliberate transition from approach attitude to landing attitude followed by slow flight in ground effect followed by the mains touching down. (in a tailwheel touching down level.) One of the most valuable exercises during primary training, and my primary instructor long ago had me do lots of these, is to practice slow flight a foot or so above the runway. Isn’t this the main reason why we teach slow flight and the MCA maneuver in the landing configuration? 

In my mind this transition to slow flight is a separate phase which happens prior to the  round out with the airplane gently stalling and mains touching down. 

 

Isn't this called the "flare"? Or is it colloquially known as "transitioning from approach attitude to landing attitude"? My CFIs and CFIIs have all called it "flaring". Maybe NJ is a special case?

In your final paragraph, you describe rounding out and say it's different from your TFAATLA, which it is. First, the plane rounds out to level flight, then flares to landing attitude. This is how we were all taught as primary students. With experience, these merge together. In my Mooney, it's a deliberate act to hold off just above the runway and continue raising the nose as speed bleeds off (i.e., I gently flare the plane) until the stall horn chirps followed by the tires. 

In the Mooney, the flare is less pronounced than in Cessnas, because the airframe has so much less drag. Pay attention on your next flight, you also flare . . . .

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