Landing

Why can't I ever land on the two rear wheels. I seems as though I always land on one of the rear two wheels? Am I going too fast or too slow (160 knots)?

Try to slow it down to about 140, or even 130, and keep wings level (may not be possible in cross wind)

Approach with 21 units aoa, 3deg glideslope. Flare when in ground rush.

See if this helps, study it carefully:

Why can't I ever land on the two rear wheels. I seems as though I always land on one of the rear two wheels? Am I going too fast or too slow (160 knots)?

Most of the time you're not going to be landing heavy, you'll be either out of weapons, or have few left, and you'll have used a fair amount of fuel, in that vid it's at nearly full internal fuel, so the approach is naturally a bit faster than most cases.

That video is rather old ... it used to be a lot easier to land the F-15, now, apart from the Spit, its the toughest to keep on the runway!

Really? I just roll out and it goes straight by itself ... except when crosswinds. I have a pretty hefty rudder curve though.

The video is appropriate. The difference between heavy and light in this case is the timing of the flare. The speed is irrelevant because you'll be keeping 21 uAoA on approach, which will set the speed 'by itself'.

Most of the time you're not going to be landing heavy' date=' you'll be either out of weapons, or have few left, and you'll have used a fair amount of fuel, in that vid it's at nearly full internal fuel, so the approach is naturally a bit faster than most cases.[/quote']

To keep the descent rate and therefore the glide slope the same while lighter you will end up flying slower.

If you weigh less you can fly slower and maintain the same ROD, and therefore the same glide slope, you're forgetting that weight is a factor, less weight means you only have to generate less lift, and you can do that by either flying slower, or lowering your AOA.

Maintain the 21uAoA on 3 deg glideslope, speed adjusts to what it needs to be for the given weight. That's the basic eagle landing technique, right by-the-IRL-book.

The only calculation you have to make now wrt weight is to ensure you've got enough runway.

So, you're right about the effects, but effects are not technique.

I'm not forgetting anything. What you are writing is simply physically impossible. If the glideslope is fixed at e.g. 3deg, a lower airspeed means a lower ROD.

The only thing that remains constant is the AoA.

 

3deg GP = groundspeed /2 x10. e.g. 160kts /2 x 10 = 800fpm

3deg GP = groundspeed /2 x10. e.g. 120kts /2 x 10 = 600fpm

No, if you're not forgetting it, then you're ignoring it, the weight of the aircraft is an issue, since it affects stall speed, personally I don't care about AoA, if I'm landing light, I fly the approach slower, if I'm landing heavy I fly it faster, simple as that.

Showing a video of a heavy landing is not really helpful if the most common case is that you're not going to land heavy, but light on fuel and weapons.

If you don't care about AoA you are apparently lacking basic aerodynamic understanding.

HAHA, no.

What I mean is I will adjust it as needed.

First you were talking about the glideslope and now about approach speed.

Nope, I've been talking about all the factors involved, glideslope, and airspeed and weight, and you know that.

On a related note, this is worth a look at.....

https://uk.mathworks.com/help/aerotbx/examples/calculating-best-glide-quantities.html?s_tid=gn_loc_drop

Note the 2W in the TASbg formula....

Weight is a factor on a glide, there is no getting around that.

As GGTharos said..... "you're right about the effects, but effects are not technique."

The technique is up to you.

Ok, you're right about that, that the horizontal component does affect that, but you can still maintain the same glideslope by flying slower, personally I would consider the glideslope and airspeed more important, and if we're going to offer advice to someone asking for help landing, then the number one thing is to slow it down, it makes things easier to manage, and it acts like giving them more runway to play with.

We're trying to help someone who's having basic problems getting the thing on the ground, and the best advice for that IMO is to slow things down, and learn the more advanced methods later, think about the OP question.

"A professional pilot always knows the actual weight"

Not true, if you can have the ASI and or the AoA sensor giving incorrect data, then you can also have the fuel quantity be incorrect either by faulty sensors, guages, or incorrectly input quantity in the flight computer, and that means an inaccurate weight, throwing all those factors off.

You're missing the point....

"If everything is working you have the ability to do cross checks to verify the indications."

That's basically what I said, if everything is working, and that's sometimes not the case, such as the fuel quantity, and this not working has caused real life crashes, so don't rely on it, you said it yourself, when you said this....

"Otherwise you will not be able to detect if e.g. the ASI and/or AoA are showing wrong data."

"Especially someone like you, who doesn't care about that AoA, needs to know the weight, otherwise the approach speed would be wrong."

Which you can understand from flying the aircraft and looking at what the approach should look like, using visual cues, if you know your plane, and have flown the approach hundreds of times you shouldn't need to be looking at instruments at all, it should be instinct at that point, if you need to be looking at them then that suggests to me that you need to spend some time in a plane that is a bit more basic for a while and just concentrate on flying instead of managing, and again, that is more helpful to someone asking for basic advice like the OP.

Always trusting your instruments over what you can see out the window is the worst advice ever, and has got pilots killed.

The first rule in flying is fly the plane.

WTF?

Of course you could fly in instrument conditions, you'd have to fly by instruments in that case, I am saying that if you are flying in VFR conditions then all you need to do is look out the window, and again considering what the OP is asking, they're going to be flying VFR, so instead of worrying about whether they have the exact right AOA they should be looking out the damn window.

You need to get off your high horse and deal with the fact that aviation is as much to do with experience as it is to do with reading a damned dial, congrats on totally derailing this thread.

@ williehayesjr, do what you have to do to get it down and then go from there, if that means ignoring the IRL technique, then do so, you can watch the dials later.

...If you fly slower and you keep the ROD, the glide slope will be steeper...

Not if you hold the same AoA. The AoA (holding 21 units) will adjust the airspeed for your landing weight and your rate of descent will be the same.

Thank you.

No! That's physically (and mathematically) impossible!

A 3deg glideslope is fixed at 3deg. If you maintain the same glideslope at different speeds (and the same AoA) the vertical speed will change as well.

 

Otherwise the groundspeed /2 x 10 formula wouldn't work.

:) OK. At this point all that I can suggest is that you make some ILS approaches holding 21 units all the way down the slope. Do it extremely heavy and do it extremely light. Take note of your airspeed. And keep an eye on the accelerometer.

That isn't the issue, the issue is that if you're maintaining the glideslope, and you're light you will do so either by flying slower or by flying at a lower AoA to generate less lift, and if you're heavy then you'll maintain that slope by either flying faster or at a higher AoA to generate more lift.

How are you helping the OP by making it more difficult than it has to be?

Anyway I thought you was "Out".

For OP: