Advice for overshoot tendency?

[ayavner]

Hey all,

 

Just hoping for a bit of discussion on how to get over this tendency to level off rather than keeping the aim point in sight?

 

From turning base all the way through short final, my speed-aimpoint cycle is great, then for some reason right about 10 metres off the ground, i tend to slightly level off such that i start overshooting my aim point for no good reason. I still make it down ok, just 1/3 down the runway.

 

Its like I am still subconsciously afraid of ramming nose first into the ground, though I *know* there is no danger of this as my flare judgement is usually OK.

 

I have read about gradually shifting your focus away from the aim point once you are getting closer, so that the ground does not suddenly appear to be coming so quickly all of a sudden, could this be what is happening?

 

 

[XP503]

Keep practicing and you'll get it. Look at the end of the runway as you flare. You say your speed is correct but if you are floating down the runway then you're too fast. Not much of a problem on a nice big runway but when you have to land in a paddock you'll hit the trees at the end.

 

 

[ayavner]

Hi David, thanks!

 

OK, so once i do get down to flare height I seem ok with looking at the end of the runway and the actual landing... whatever this is seems to just be something that happens 10-15 mtr up, so really well before flare height. Then speed actually goes down, then by the time i get it sorted I am back on slope and speed but a bit farther down the run way. I've asked my CFI if we can do some STOL lessons, thinking that might help.

 

 

[motzartmerv]

What aircraft you flying?

 

 

[ayavner]

hi Motz, its the Jab 170

 

 

[motzartmerv]

Oh..Ok..Say no more.

 

What speed are you approaching at?

 

 

[Sapphire]

Like you said, you see the runway coming up fast, are scared of ramming into the ground and it takes one third runway to convince yourself otherwise. I've seen guys stall at 25 feet. That keeps me headed to the ground.

 

 

[ayavner]

hi Motz, 70 on final, 65 over the threshold. Normally full flaps unless its quite windy.

 

hi Sapph - yup you have nailed it! though, its not enough of a pull up to stall, more of a level off - would look great if done at the right spot lol. I figure it out pretty quickly, but as you say it chews up alot of runway even in that period of time. I'd like to be able to plant it right where i am aiming.

 

 

[facthunter]

I haven't gone into this.... Really unless people are directly involved with your instruction you are more likely to be confused than gain something near a solution on a forum. General comments maybe, but everyone is different. I don't think you can deal with a landing flare problem on line. Experienced pilots may even get it after years of flying, when they go on a new type. Nev

 

 

[XP503]

Nothing wrong with giving advice and having a discussion. Sometimes it helps to get a different perspective.

 

 

[motzartmerv]

Ok. I hate giving too much 'hands on' advice to students on here, your instructor is the dude who would have the answers for you. So I will tell you what I think is wrong, but dont take it to the bank..lol

 

70 kts is too fast. Way to fast. This is evidenced by the fact that you say you are ' raising the nose and slowing down' but still floating past your aiming point. For this to occur the initial speed MUST be too high. If it was spot on, and you slowed down, you would be working your way back along the drag curve and therefor SINK earlier and come up short of your aiming point. But the fact your reduced speed is causing floating means the initial speed is too high and the slower speed( after you raise the nose) is closer to best glide and your getting float.

 

The 170 is the worst of the Jab species for this problem. The 70kt appch speed is perfect for a 160, which has a much higher wing loading. Our strip is short and narrow, we dont have the luxury of floating 300 meters, so we have an appch speed of 65 on final down to 55-60 over the fence, full flap. It wont stall and flop on unless the stick is right back, and I mean right back. 55 + 5 minus nothing is our ref speed into the flair.

 

Its also advantageous to let it land as eraly as possible, ie, dont let it float too long as in gusty xwinds its a squirly little bugga and you quickly run out of control. So sit it down briskly.

 

 

[ayavner]

Yup that's it... my CFI and I will work it out, this is just a discussion, you know to get other people's thoughts and experiences. Believe it or not, I have learned TONS in just this way, sometimes someone will say something here that clicks in a way that it hadn't before when explained to me by the instructor. Then when I go back next time, he's happy to see i've finally gotten my head round it. Some of you guys might not realise how wise you are to someone such as myself to whom almost everything is new!

 

 

[facthunter]

I love having discussions. I am pointing out the "risks" of trying to sort these "difficult" things out on line. This should be done with the instructor in the loop. Ideally.. Nev

 

 

[motzartmerv]

Thats what we do, like I said, no going to the bank with the info...lol

 

 

[ayavner]

Yup, all good Nev. To be clear... my CFI and I have been and will continue to work this out. not really expecting to sort it here, but you'd be surprised when someone says "yeah that used to happen to me until I started thinking of it this way..." then it clicks. Sometimes your instructor is the one to say that, sometimes it just comes up in conversation here. I think of it the same as walking into the club house and saying, "gee i had a devil of a time with X today..." - don't think everyone there would just say "sort it with your instructor" and walk away.

 

 

[facthunter]

Everything YOU have said Motz is good advice and well explained. It doesn't always happen as you have done it and sometimes the result isn't good. A new pilot is very inclined to "take -up" good tips or well intentioned solutions that work for one person but not another.. General principles are fine. Ie If you are floating a long way and the throttle is closed you are too hot over the fence etc.

 

We have excess speed and some difficulty with height of flare commencement and rate of backstick movement. Needs an instructor to address that in the plane. (AS you said) Nev

 

 

[facthunter]

I don't just say "sort it out with your instructor", but in this case you do need to. It's that important.

 

I once overheard a discussion between an instructor and an instructor to be. The way it was discussed and explained did not come out right as it seemed to me but I didn't say anything. It was none of my business .

 

The result was the 2nd pilot took a plane up ( the type in question) and ended up crashing it. No-one died, but the confusion caused that prang, directly because of the technique used, incorrectly. Nev

 

 

[motzartmerv]

Really? he/ she get it too slow?

 

 

[ayavner]

Well.. that's fair enough. I'd still like to hear opinions and thoughts, and I promise I am only looking at this as mental exercise, not a substitute for doing the hard yards with my instructor.

 

He did recommend a bit of Flight Sim time to help program that tendency out, so think i'll get onto that tonight!

 

 

[fly_tornado]

remember landing is 1% of flying and 39% of accidents...

 

 

[cherk]

Really? he/ she get it too slow?

reminds one of the PIC commanding (on missed approach- go round)....."TAKE OFF POWER" and the Co Pilot did EXACTLY that!

 

the fence and ravine came up really quick after that!

 

 

[cscotthendry]

Well.. that's fair enough. I'd still like to hear opinions and thoughts, and I promise I am only looking at this as mental exercise, not a substitute for doing the hard yards with my instructor.He did recommend a bit of Flight Sim time to help program that tendency out, so think i'll get onto that tonight!

Ayavner:

I have a friend that used to get what we called "ground rush" He didn't solo until he had around 50 hours up because of it. In the end the solution for him was powered (rather than gliding) landings with a flatter approach angle. That got his confidence up in the controllability of the aircraft near the ground. Then he went on to develop his confidence with gliding approaches. His ground rush was particularly severe as he was flying an open frame trike and he could well and truly see the ground rushing up under his feet. But as others have said, when you get over the end of the runway, you need to be watching the far end to get your peripheral vision measuring the height for you through the perspective angle made by the edges of the runway.

 

Try this little exercise: Stand in a long hallway in a building and slowly squat down while focussing your attention on the far end of the hallway. But as you squat down, pay particular attention to your peripheral vision of the lines where the walls meet the floor and see how you can judge your elevation by the apparent angle of those lines. It's something we do automatically when we're on our feet. When we're in the air, there's a tendency to look down at the ground rather than at the end of the runway.

 

Something else you could try with your instructor on board is: From a safe height of say 3,000' AGL or more, set up a glide like you do for landing. When the aircraft is established at the best glide speed with power off, pull back on the stick with varying degrees of rapidity to see how the airplane responds. Make some mental notes of the following: How long does it take before the aircraft stalls? What happens to your height and airspeed when you pull back on the stick slowly or quickly? What does it feel like just before it stalls? Hopefully this should give you a good idea of how much vertical control you have at approach speed and what the aircraft feels like when it's about to stall.

 

I could be wrong with this point, but I think that recreational aircraft are required to have a stall speed of not much more than 40kts. If you're coming over the fence with 65-70kts, you've got a 25-30kt buffer between you and stall. Now given that you have to get the wing to stop lifting and it does that around 40kts, that's how much speed you've got to bleed off before you are going to get the airplane to stop flying, but more importantly, that's some little energy in the bank that you can use to slow the descent by pulling back on the stick. Your experiments up higher should give you a feel for how far and fast you can push that without getting into danger.

 

Finally, I'd like to say that with more time in the saddle, you'll learn how much control you have of the airplane and you'll start to be able to control it reflexively rather than having to consciously think about all the numbers etc. Then you'll build your confidence with controlling the plane closer to the ground. It's just a matter of time. But don't compare your progress to anyone else's. We're all different.

 

I have to add that I am not a flying instructor, but I am a pilot and I was an instructor in another discipline for 15 years. So take what I've said here and run it past your flying instructor if you feel any of it is of interest.

 

One of my instructors used to say: "In all the history of flying, no one has ever got stuck up there. They all had to come down eventually." meaning Takeoff is optional, landing is mandatory.

 

 

[aro]

I'd like to be able to plant it right where i am aiming.

You will always fly past your aim point. Your aim point is only for the purposes of the approach, then you level out and flare, and you will always fly past it - how far depends on your speed. In a short field landing you will be slower, and won't fly as far past, but you will still fly past (unless you have a very abrupt arrival!) If you need to touch down exactly at a particular spot, you will adjust the aim point to a point before the actual touchdown spot.

It does sound like you are a little too fast. If you are too fast the aircraft will be more sensitive to your back pressure, and more likely to climb again, which both mean it is easy to end up too high in the flare. The J170 manual online at the Jabiru site recommends 65KIAS for the approach speed, so that is the speed I would be aiming for (check your aircraft POH), preferably stable on speed by 200 feet. Trying to slow from 70 to 65 "over the fence" will also make you high - speed and height are both energy, so you will just trade one for the other.

 

As for looking down the runway, the best advice I have heard is when the runway looks like a highway, look down the runway like you are driving a car. It's probably more like 3-400 metres ahead rather than the very end of the runway, but the important think is not looking right in front of the aircraft. It sounds like you have the idea there anyway.

 

I would not recommend using the flight simulator for this, the last 20 feet is probably the time when the flight simulator is least helpful in showing what you need to look at and feel. There is no substitute for practice in the aircraft.

 

 

[ayavner]

Thanks aro, yeah probably stated that poorly... i didn't exactly mean "land on my aim point" but more "land where i should land for the aim point I chose". Great advice though thanks!

 

and cscott - exactly what I am looking for, your "hallway exercise"... great mental exercise that doesn't cost $200 an hour!

 

Next lesson is saturday, i'll definitely report back here on how i go!

 

 

[Keenaviator]

It's interesting that 65 knots is being used for the approach speed. I would have thought that you would be aiming for 1.3 times stall speed for any given configuration. Therefore with a full flap stall speed of 40 knots the approach speed should be stabilised on 50 knots. This buffer should be enough to provide the required energy for the round out/ flare and then there will be minimal float before landing.