Pitch during touchdown

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Scott - A2A
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Re: Pitch during touchdown

Post by Scott - A2A »

pushpak123,

You talk about "real world experience" yet to Dudley's point, your comment of the left turning tendency speaks to experience. You should know, from experience, prop airplanes turn left almost all the time. This isn't really a jab as we all suffer from this - we basically remember things wrong. This is why we video record everything. My reason for saying this is I think you need to just take a step back and cross check things you think you are experiencing against objective analysis.

The issue here is a bit beyond this, it really speaks to respect for others. You keep making claims without backing it with anything - almost like you feel entitled for us to run around trying to make our case. That post you pasted in here, I took an hour to do exactly what you thought couldn't be done, did it, and illustrated it for you. As you can see from my response, showing graphically that our aircraft is at or even below the standards of ground roll set by the manufacturer over a 50 ft obstacle, it's proof positive that if there was any tendency to float, my landing example would have been impossible.

Then Ozzie here does the same thing I did, takes the time to demonstrate his point and did such a great job doing it.

So we have one side taking the time (working) to back up things with facts, and another side just.... not doing anything really other than saying "I disagree" and expecting others to do the heavy lifting.

Pushpack, it's about respect really. You disrespect people who do the work while you just sit there doing nothing in return. In other words, you put more weight in your opinion over other's opinions with both more experience than you and also have backed up their opinions with objective facts. This is where people can think, "who does this guy think he is?" If you want to make changes in anything, you have to do the work.

Scott.
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Re: Pitch during touchdown

Post by aprewett »

Great Ozzie,
A question; from the landing recording, how do you judge the time to pull the power?
From what I had read, is was as you cross the airfield, or the fence in other words. That is what I have been doing. Can't remember where I got this idea, it was from several sources, but maybe I was missunderstanding the wording.
But you pulled to idle maybe 200m's out.
The question, is there a set point that you do this?
Or is it, once you are at the point in the recording with the plane is set up (lined up, speed right, descent right), be that 200m or 500m you can pull the power.
Then I suppose you could add some power if required.
Thanks again for your time in doing the leg work, much appreciated.

Allan

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Re: Pitch during touchdown

Post by Great Ozzie »

Hi Allan,

It is a judgement call. Having the right airspeed and being on the proper glidepath - that is easier to assess with practice. So in that instance, I turned to final, saw I had plenty of altitude, then added that third notch of flaps - and wasn't long when I decided to carry just a smidge of power (around 1000rpm in that case). If I have the field made, no sense in carrying power; that is why you saw me pull power out completely. Just not needed. A slight adjustment in pitch may be necessary.

I think it was dvm that mentioned a friend of his makes most (all?) of his landings power off. Maybe Scott mentioned his too were power-off. I'd have to go back to the logbook, but I am certain I had to learn "accuracy landings" or power-off landings for the PPL (I think this now just a Commercial pilot maneuver - no longer required in the PPL PTS). Point is, you do not need power, and years ago (so the story goes) all landings were power-off because of the possibility of engine failure.

So the "set point", if you will, is when you determine power is not necessary to be where you believe you are supposed to be in the landing process (altitude and speed wise). I think Dudley referred to these points as "windows"... and, in fact, FSX does use the red window frames in certain missions (and you have to hit them to proceed to the next). You can, in a sense, look at it in the same way... thru-out the landing process, you don't want to be too high, or too low... too fast or too slow... but "just right" within a certain window. Not too far out (where an engine failure you'd land short) or too close where you going to have to make some drastic maneuvering to get down. That a bad thing too. This is why you hear me say, "I'm on glidepath, on airspeed" because I am continually (every such and such moments) re-evaluating where I am in the process and am I where I should be (again, in terms of altitude and airspeed). How often do I check? Well, it becomes a matter of judgement. Like when you go to bake cookies... how often do you check? Well... as often as you think you need to so that you don't burn them, but that they do get baked well enough.

Some airplanes you may use power longer. The Cherokee (w/ the hershey bar wing) I remember (at times) carrying a bit of power into the transition. I am 99% certain, you are going to see on some pilot forums where guys / gals carry power into the flare to help grease them on. I reckon this is "ok", as long as you know your airplane and have a mile of concrete ahead of you (there are other times when it can be useful). It really is going to depend on the airplane. But as I said in this case, going into a "short field" like Flora, I do not want to carry any more power (energy) than necessary to safely get me in. Goes for altitude too, as that also energy - or will be coverted to energy - that I need to get rid of to get stopped.

Let me know if this doesn't make sense or further questions.

-Rob

btw welcome... and also btw regarding "the fence" and power... probably a typical instruction i.e. "have power out by the fence" (I reckon it assumes the field is made by then). But the thing is, if you need it (unexpected loss in lift) use it. Or if you recognize you are lower than you thought and need a touch of power, use it - or go around.
Last edited by Great Ozzie on 11 Oct 2014, 11:29, edited 1 time in total.
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Re: Pitch during touchdown

Post by Oracle427 »

I aim do all my landings essentially power off from the abeam point. The only time I don't is when the tower extends my downwind as they did yesterday for 3 miles for traffic on a long final. I was number 3 to land. I hate dragged in long approaches, you feel very vulnerable especially when the only landing sites are shopping malls and highways.

Of course, always hand your hand on the throttle whenever you are near the ground, and always use pitch and power to adjust your glide.
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Re: Pitch during touchdown

Post by DHenriques_ »

aprewett wrote:Great Ozzie,
A question; from the landing recording, how do you judge the time to pull the power?
From what I had read, is was as you cross the airfield, or the fence in other words. That is what I have been doing. Can't remember where I got this idea, it was from several sources, but maybe I was missunderstanding the wording.
But you pulled to idle maybe 200m's out.
The question, is there a set point that you do this?
Or is it, once you are at the point in the recording with the plane is set up (lined up, speed right, descent right), be that 200m or 500m you can pull the power.
Then I suppose you could add some power if required.
Thanks again for your time in doing the leg work, much appreciated.

Allan
The Oz is giving you "Wizard" advice.

The main thing to remember about landings generally and power specifically is NOT to get yourself too bogged down in regimentation. Exactly where you will "pull the power" prior to landing will be a function of your airspeed and altitude as you reach the final stage of your final. Remember, in close you will transition completely out of the panel and into hand flying the airplane using your visual, audible, and physical cues.
In close take a final glance at the airspeed and make a judgment on the remaining altitude. Then based on this input, make a decision on the power. It's really not rocket science. At that point on through touchdown it's all common sense and flying the airplane.
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Re: Pitch during touchdown

Post by computerflyer »

I've often heard that the Cessna C172 is, in real and in simulated life, a "boring" airplane. So I was quite surprised that, after having mastered landing all of the A2A WWII fighters, I was having difficulty landing the C172. I expected the lowly C172 to be very easy. I'm glad that no one was watching, seeing me bouncing down the runway, stalling out 5 feet off the ground, etc. :oops:

But I have always felt that simulated planes in general have let me get away with too much when landing. I could screw up and often not much bad would happen. Not so with the C172. Any mistake has consequences, and these consequences are augmented by special sounds and vibrations. It can be horrible - I mean great. Thanks to A2A for adding more realism to the sim!

After a lot of practice, I can make decent landings with the C172 - ok, most of the time, anyway. Now, when I make a decent landing, I appreciate it a lot, considering the consequences of a screwup. And the C172 is definitely NOT boring! :)

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Re: Pitch during touchdown

Post by DHenriques_ »

computerflyer wrote:I've often heard that the Cessna C172 is, in real and in simulated life, a "boring" airplane. So I was quite surprised that, after having mastered landing all of the A2A WWII fighters, I was having difficulty landing the C172. I expected the lowly C172 to be very easy. I'm glad that no one was watching, seeing me bouncing down the runway, stalling out 5 feet off the ground, etc. :oops:

But I have always felt that simulated planes in general have let me get away with too much when landing. I could screw up and often not much bad would happen. Not so with the C172. Any mistake has consequences, and these consequences are augmented by special sounds and vibrations. It can be horrible - I mean great. Thanks to A2A for adding more realism to the sim!

After a lot of practice, I can make decent landings with the C172 - ok, most of the time, anyway. Now, when I make a decent landing, I appreciate it a lot, considering the consequences of a screw up. And the C172 is definitely NOT boring! :)
Accusim IS amazing !
Once through an initial learning curve and the realization sets in that an Accusimmed airplane isn't just another add on the real learning and fun begins. Where it was easy to deal with other add ons that don't task you as much to do it right, when you DO do it right with an Accusimmed airplane you know you actually HAVE done it right.
The wonderful thing about Accusim is that it's not a stationary or static program. It's constantly evolving and getting better all the time and as it does the improvements are factored into the Accusim fleet. What this means to you as an A2A pilot is that if you own an Accusim aircraft from A2A, long after you have purchased that aircraft, A2A could be working on a completely new and different airplane and while doing so discover something that will add to the Accusim experience......and you guessed it......it comes to you in an update and your already great Accusim aircraft becomes an even better airplane for you to enjoy.

About your comment on the 172; as an instructor I had many an occasion during my tenure to check out ATP rated pilots in the venerable old 172. I can't count the times where these highly experienced pilots having flown the heavies needed serious remedial instruction to be safe in the lighter and easier to fly 172.
In many of these cases a large part of their problem was complacency. They "assumed" the little old 172 would be a piece of cake to handle. Their wake up calls as we flew together were sometimes quite amusing :-)
No airplane is boring really. Each has it's own individual personality and requires constant attention to the basics. The old 172 was and is no exception.

I think it was Max Stanley out at Northrop Flight Test who opined one day when talking about getting checked out in a Cub,
"The J3 Cub is the safest airplane in the world; it can just barely kill you." :-))
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Great Ozzie
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Re: Pitch during touchdown

Post by Great Ozzie »

DHenriquesA2A wrote:The Oz is giving you "Wizard" advice.
I appreciate you saying that, Dudley. Thanks sir.

Liked that Cub quote btw. :D
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DHenriques_
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Re: Pitch during touchdown

Post by DHenriques_ »

Great Ozzie wrote:
DHenriquesA2A wrote:The Oz is giving you "Wizard" advice.
I appreciate you saying that, Dudley. Thanks sir.

Liked that Cub quote btw. :D
Nice having your input here Oz. You're a welcome addition to the A2A forums.
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Re: Pitch during touchdown

Post by aprewett »

+1 and thanks
Allan

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Re: Pitch during touchdown

Post by L.A. »

Oh...............the power off landing scenario. I should have logged on earlier.

This is one of my preferred aviation subjects. I remember when learning to fly the Cessna 172's and Piper Warrior and Archer, that it was mostly power off, over the threshold. It's a judgement call, as mentioned. When getting instruction in the Piper Arrow, with it's heavier landing gear and constant speed prop.................it was use a bit a power to keep the nose up. Then I built my Van's RV6 with a constant speed prop. The prop acts like an airbrake. It works amazingly well for managing airspeed in the pattern, as I could dump a lot of airspeed fast. With this airplane, I started keeping more of an eye on airspeed down to the flare. If it dropped below 60 kias, the plane would just fall through any ground effect, and hit hard on the landing gear.

My options, were to now use a power off landing, with a steep approach, that could scare passengers, or use power on. The power off, requires a flare at the precise moment..........or, it was back to smashing into the runway. Being a frequent airport bum, since I had a hangar there, I'd often question other pilots, since there was such a variety of high performance airplanes, that were not floaters, as well as back country pilots. I shared a hangar with two Pitts M-12 owners. This plane is a larger style Pitts, with a Russian radial of about 400 HP. It also has a large three blade constant speed prop. This plane is definately power on all the time. It needs to keep the approach speed up, because of the enourmous amount of bi-wing & flying wire drag, then level out above the runway.

The back country pilots also become proficient at power on, because they have to essentially drag the airplane to some of those remote landing strips, and then chop power at the precise moment, to set the wheels on the ground. There is an old saying, that goes something like........."treat every landing as a power out, in case the engine fails." My response to that...........is don't fly the airplane then. If you can't trust the engine, why would you want too?

P.S..... I'm no longer a full size airplane pilot, and have reverted back to R/C. With a lot of todays RC airplanes being powered by high powered electric outrunner motors instead of fuel, some get quite draggy from the prop while landing. More than not, it's again a case of using a bit of power.

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Re: Pitch during touchdown

Post by Oracle427 »

I did some tests while flying yesterday and unfortunately did not notice that my camera battery died so none of the figures I thought where being recorded are here to review. I am not sure what VSI was reading on average as a result.

Conditions at 12N were A30.26 and temp around 15C and dead calm winds.

The descent rate of a 172N with 2 passengers, 30 gallons of fuel, full flaps and around 45-55 KIAS at idle power in a level attitude is actually much slower than I expected and *feels* very much in line with the "floaty slow descent" of the A2A 172. I was practicing short fields yesterday and with the calm winds I felt comfortable lowering the approach airspeed by 15%.

The aircraft weighed about 2100 lbs at that time.

I estimate the descent was around 300-400 FPM. If I pitched up a tiny bit more until the airspeed reached the very bottom of the green arc, then I saw an increase in sink rate. However, I wasn't watching the VSI or airspeed closely so I really can't be more specific. I was hoping the video would get that! Doh!

In all the A2A 172 once again appears to perform very close to reality in this respect.
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Re: Pitch during touchdown

Post by AKar »

Oracle427 wrote:If I pitched up a tiny bit more until the airspeed reached the very bottom of the green arc, then I saw an increase in sink rate.
That's expected as you get below your minimum drag speed - the drag and therefore the sink rate increases with decreasing airspeed. I understand that it takes some rather precise flying in most SEP airplanes to measure the fall of the polar curve on the low end, good job there. Hopefully you'll get some video stuff uploaded! Would be interested! :)

-Esa

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Re: Pitch during touchdown

Post by Oracle427 »

Yes it totally makes sense as I begin to trade lift for more drag (!!!!). I was curious to see at which point that began to occur as I normally do not come in that slow in a 172 on final, but I got lucky with super nice flying weather yesterday.

I had seen a number of posts crop up again about the 172 floating too much and unrealistically and I wanted to see how short I could land anyway, so I figured I'll kill too birds with one stone. :)

I didn't really lay into the brakes, but I'm pretty sure I could have stopped in the first 500-600 feet of runway if I needed to thanks to coming in at that low speed. I definitely turned off the runway within 700-800 feet.
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Re: Pitch during touchdown

Post by taildraggin68 »

Oracle427 wrote:Yes it totally makes sense as I begin to trade lift for more drag (!!!!). I was curious to see at which point that began to occur as I normally do not come in that slow in a 172 on final, but I got lucky with super nice flying weather yesterday.

I had seen a number of posts crop up again about the 172 floating too much and unrealistically and I wanted to see how short I could land anyway, so I figured I'll kill too birds with one stone. :)

I didn't really lay into the brakes, but I'm pretty sure I could have stopped in the first 500-600 feet of runway if I needed to thanks to coming in at that low speed. I definitely turned off the runway within 700-800 feet.
The 172 will handle just fine at 50 knots and land quite short.....it's really a matter of understanding the airplane, where your power falls off, and trusting the glide.....elevator mode is what I call it lol, learned a long time ago, due to neighborhood restrictions and steep approaches required as well as short field landings in the North Georgia mountains.....set her up right and you get a nice slow, easy approach at idle power, ease back through the round out and she usually touches about the same time as the stall chirp starts.

Granted it has been a long time since the real one, but I can still make the A2A 172 do the same...it feels "floaty" due to the high wing configuration. Of course my instructor had me fly circuits at 70 knots to learn the slow flight handling....lots of fun that was 8)

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