To Face Plant or Not?

should say face plant.. Wiith bush wheels and extended gear. plus 3 only. Not extended forward.

how does the tendency to face plant under heavy braking compare to standard gear and 8.5s?



1. Higher
2. Same
3. Lower

Your opinion please.

Lefoy84 said:

should say face plant.. Wiith bush wheels and extended gear. plus 3 only. Not extended forward.

how does the tendency to face plant under heavy braking compare to standard gear and 8.5s?



1. Higher
2. Same
3. Lower

Your opinion please.

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Less likely to "lantern".

The brakes are less effective with larger diameter tires and the tail can remain lower with taller tires and extended gear. Your prop is also higher off of the dirt with the first scenario.

With the front end raised, the CG is farther behind the wheels. So takes more braking force to raise the tail. For the same reason, also less available friction between tires and ground. Bottom line - less nose-over tendency.

The above is my experience,

but the counter to that is that you will have the tendency to take the bird into softer/rougher places, so need to be careful not to brake hard in rough/soft lest you have a hard break!

Oh, George .......

If you think you may face lantern, be sure to have your two pound negligee ( MTV can explain that one).
Seriously Eddy the taller gear and big tires make it want to keep its tail planted, all else being equal. The larger tire diameter reduces the braking effectiveness so you have to get into the pedals pretty good to slide a tire, compared to 8.50's. With double puck Clevelands and high pressure boosters you'll have PLENTY of brakes on 31" tires, that's not an issue. You just have to use them harder to get the same effect as with smaller tires.

I would say lower, but as aktango said what you are landing on matters. Once you get a prop or two you will get the hang of it. There is a advantage to running a wood or carbon fiber prop. They will come off pretty fast as you start plowing the ground. This will make you feel better if you decide to just put on another prop and keep flying. If you run a metal prop you can usually bend it back into shape or cut off both ends to get you home. But you know that it was a hard strike and it make you think about paying for the teardown a bit harder. Not that anyone would ever do a prop strike on a 0320/0360 and keep flying!!! But in the old days when you got a prop you just dialed the crank (which was done in the field by bucket on the ground and if the prop was the same distance tip to tip, looked good from side when running, and no vibration at RPM) you where good to go. I have had a prop that looked a bit rough after some bad wind as the prop was turning. I got a new prop out of the deal and a good close look at all the parts of my motor. You can get a prop pretty easy just trying to turn on real rough stuff. It is usually better to just shut down and push plane around if needed. I have done it more than once to protect prop from nose over and picking up rock on high power spin. Full nose up trim will help when you are trying to get the tail back down!!!
LIFE ON THE EDGE CAN COST A BIT BUT THE VIEW IS WORTH IT!!!
DENNY

The physics favor the longer gear and bigger tires but there is a phenomenon when the trees get close and the water is coming fast where for no known reason, the brakes suddenly lock up and you join the "Flip Flop Flyer" club. Had many an insurance adjuster tell me that same story. 8)

It depends. The distance between the ground (the point of friction) and the CG is longer with bigger tires. As stated above, when the tail is on the ground, there is more weight on the tail and less nose-over tendency. When the tail is up, say more less horizontal, the CG is nearly over the wheels (little tail-down force) and the longer arm works to make it easier to nose over. So, if you brake hard enough to raise the tail up to horizontal, it will be a lot easier to keep on going over. If you're slow when you do this, there is little airflow over the tail to counter it.

Steve Pierce said:

The physics favor the longer gear and bigger tires

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How so?

While from experience I'd agree when the tail is down but with the tail up and get on the brakes it would seem that with that significantly longer moment arm (taller tire and longer gear) is now acting against you (get past the top of the arc and Gravity is no longer your friend) as the "lantern plant" begins to develop but that may be offset by the apparent reduced breaking effect (equal breaking energy available/surface area adjusted by the tire difference in friction coeficient). Hum, I'll pose this to the budding aeronautical engineer in the family...

Doesn't matter. What matters is to be proficient enough to know where that magic tipping point is in any given situation in your airplane.

OLDCROWE said:

How so?

While from experience I'd agree when the tail is down but with the tail up and get on the brakes it would seem that with that significantly longer moment arm (taller tire and longer gear) is now acting against you (get past the top of the arc and Gravity is no longer your friend) as the "lantern plant" begins to develop but that may be offset by the apparent reduced breaking effect (equal breaking energy available/surface area adjusted by the tire difference in friction coeficient). Hum, I'll pose this to the budding aeronautical engineer in the family...

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This is true. Once it reaches the slippery slope and starts going over it will become unsalvageable real fast. I geared my response to getting on the brakes from a tail down, flaps up, stick back condition. I've slid tires on hard dirt and packed gravel quite a few times and never had it feel like it wanted to come up on me. That being said, once landing on a short gravel bar I got on the brakes while the tail was still up and light, and got a nice little adrenaline rush for my efforts. I didn't have it adequately planted and was arresting the bounce with a little forward pressure when I started into the brakes. I now have a pretty good feel for where my tipping point is and stay away from it.

DENNY said:

... Once you get a prop or two you will get the hang of it.......

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Sounds like a pretty expensive learning curve.

Good point on the flaps, but also remember power.

Power means wind over the tail, which gives you authority.

Flaps will channel more of the wind from power to the tail.

Change either of these, and you change the 'point' of tip.

Next we should talk about tail winds... caution on brake action then.

One issue to remember is INERTIA. Tail started up and over tends to want to continue up and over; Tail remaining down behind tends to remain down and behind.

So when you are touching down with brakes or add lots of brakes and the tail starts up, that is your clue. Once it is to level flight you had better be releasing breaks. (usually I have the stick sucked into your belly while braking on landing).

Is there a finer edge: yes, it is all feel.

If you use the level spot as the need to be correcting, it will come higher at times, and you might learn to work it up a bit. That does bring the prop close to the ground, and adds to the chances of asking on here for used propellors.

I like to release the brakes (sometimes only a little if the tail is slow rising), but you can also hold it down with power in some conditions.

Go play a little in sand or wet grass, it will become obvious.

sjohnson said:

It depends. The distance between the ground (the point of friction) and the CG is longer with bigger tires. As stated above, when the tail is on the ground, there is more weight on the tail and less nose-over tendency. When the tail is up, say more less horizontal, the CG is nearly over the wheels (little tail-down force) and the longer arm works to make it easier to nose over. So, if you brake hard enough to raise the tail up to horizontal, it will be a lot easier to keep on going over. If you're slow when you do this, there is little airflow over the tail to counter it.

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Yep, completely agree. My comment assumed 3-point attitude. I don't do that tail-high-stopping-magic so didn't even think about it.
Thanks for a more complete answer.

Gordon, I suspect you are the guy to do the math. Make a couple of assumptions, like where the CG is, and raise the mains eight inches or so, and tell us how far aft the CG moved?

Here is one it took me almost a half-century to realize: if you are going really fast, it is tough to get it to go over. If you are moving really slow, slamming on those brakes can be catastrophic, and it really doesn't make any difference what size tires you have. Fortunately, I learned is by watching folks, but I did have a rather startling revelation one day when the tower said "cancel take off clearance, hold short . . ." I wasn't moving very fast, but my instinctive jab at the brakes had that tail a foot off the ground!

As Mark and Steve point out above, when that tail starts up, it is a really good idea to get off the brakes. It is not an automatic reflex; it takes experience.

As always, opinion.

I have noticed more DAMAGE, bent tubes under boot cowl/engine mount damage with long gear & big tires, instead of just flipping over without much damage

mike mcs repair said:

I have noticed more DAMAGE, bent tubes under boot cowl/engine mount damage with long gear & big tires, instead of just flipping over without much damage

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That is interesting. Did you get a feeling for reasons? Some thoughts about this: is the damage because big tires/long gear means the pilot has abused the plane off airport; is the damage because where the plane was flipped was in a miserable spot that would only be attempted with big tires/long gear; did the big tires and long gear actually create the damage due to the arm?

You guys that are inside these planes all of the time have lots of knowledge that can help us pilots be better on our aircraft.

aktango58 said:

.. did the big tires and long gear actually create the damage due to the arm?

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THAT, I think...

Yep, a longer handle on the same hammer with the same swing will do more damage!

OLDCROWE said:

Yep, a longer handle on the same hammer with the same swing will do more damage!

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if you go over slowly, there is not much pressure on the gear I would think. But once you have put her on the nose, maybe some of the damage is getting her back on her tires?