Full flap/specialty landings - 172

[Chuck Ellsworth]

I will do that on a long final....but at a mile....the speed comes right off.

To me, its the controllers job...to sequence the traffic properly...not to browbeat a 172 into a 100 knot short final...

Look at it from a controllers viewpoint, for that last mile you now have increased the closure speed on you of any following jets to at least 80 knots faster than you are going.

You may have four people in your 172 but the following jet may have 400 people on board.

[Beefitarian]

Easy .. I think a mile is a little early. If I ever get to fly a 172 again I'll have to discuss this with the guy that makes sure I'm not doing crazy things or getting lazy with the controls while I taxi and stuff.

[Old Dog Flying]

Rookie...I've done that many times going into YYZ when I needed spares from the north end. The most memorable..orbitting Terminal Two at 500' waiting for R32..."Whiskey Blue..Cleared to land 32 ..keep the speed up ..land long, B707 0n final to follow". The American came back "yur cuttin' it close aren't you tower?" Towers reply "We know his capability but we don't know yours" Big laughter from multiple sources.

The thing here is to be able to use all of your abilities to get the job done and that only comes with good training and practice and knowing your aircraft limitations.

Barney

[Rookie50]

I agree...to dawdle down a 7 mile final at 65, at a busy airport is not cool at all....its the repeated demands to keep it up when approaching a mile....that I thought a bit much. Very rare though....most controllers do a great job mixing all kinds of traffic! Tough job too.

[Rookie50]

Rookie...I've done that many times going into YYZ when I needed spares from the north end. The most memorable..orbitting Terminal Two at 500' waiting for R32..."Whiskey Blue..Cleared to land 32 ..keep the speed up ..land long, B707 0n final to follow". The American came back "yur cuttin' it close aren't you tower?" Towers reply "We know his capability but we don't know yours" Big laughter from multiple sources.

The thing here is to be able to use all of your abilities to get the job done and that only comes with good training and practice and knowing your aircraft limitations.

Barney

Never happened here, in the US...but I think at least they let us little guys into these big places...., so not really complaining....tons of runway of course. Man indianapolis is a LARGE airport when one needs to taxi to the other side!

[photofly]

I agree with Rookie, give or take.

There's an interesting article online somewhere about testing the minimum time, altitude and distance taken to slow from cruise speed to a sensible threshold speed while flying an ILS in a light single. It's not very much.

I found that, in a 182, starting at 120 kts at 400 (300?) agl and maybe a mile-ish final it wasn't much challenge to slow, land, and turn off in 1500 feet. If I can do it, I'm sure most people could.

Look at it from a controllers viewpoint, for that last mile you now have increased the closure speed on you of any following jets to at least 80 knots faster than you are going.

Scenario 1: you fly over the threshold at 120 knots and spend 30 seconds slowing to touchdown speed and turn off at the far end. The airliner is still gaining on you all that time.

Scenario 2: you maintain 120 knots until 20 seconds before threshold; bleeding off the speed in the air where you have more drag. You fly over the threshold at 65 knots, touchdown, and exit 2000' from the threshold. You're out of the way of the airliner much earlier than scenario 1.

[Shiny Side Up]

Would you have a student slip ? Reduce power ? Nose up ? Everything ???

None of the above. Recognize the learning opportunity for what it is - you botched the approach, recognize that, go around, and get it better next time, 'cause now you know what bad looks like.

Bingo. The flaps shouldn't be going in because you are trying to correct a screw up, they should be going down because you planned to put them down. The approach should already be under control. In lots of cases when I see this done, they're high, they're fast and still attempt to push a bad approach into a landing until the very end. Usually you have to remind them to go around, we're not doing anything so important to do or die in a Cessna after all. What's troublesome though is when some pilots just don't seem to learn from previous mistakes. Something about doing the same thing expecting different results comes to mind, people are sometimes depressingly unimaginative in their problem solving technique.

Though in a 172 you have lots of capacity in the forgiving design to fix a horrible approach, there are many types where you will not be able to fix the approach - the plane is just not capable. A fixably high approach in a 172,m is not fixable when flown the same way in a Cub, or Moth, or other light types. Similarly, a low and slow approach can be fixed in the 172, but would be a disaster in a twin, if you mixed it in with a failed engine.

Very correct. You can slip like a stone with a 172, its got a reasonable enough ammount of power to respond to any misjudgements to be able to go around at almost any segment of the whole thing. Not only is it student friendly, but instructor friendly in how far it can be pushed and still be able to easily enough be brought back into something more reasonable. Just because the airplane can be flown so terrribly though, doesn't mean one should accept that, set the bar a bit higher.

[Chuck Ellsworth]

Scenario 1: you fly over the threshold at 120 knots and spend 30 seconds slowing to touchdown speed and turn off at the far end. The airliner is still gaining on you all that time.

Scenario 2: you maintain 120 knots until 20 seconds before threshold; bleeding off the speed in the air where you have more drag. You fly over the threshold at 65 knots, touchdown, and exit 2000' from the threshold. You're out of the way of the airliner much earlier than scenario 1.

How dumb of me not to have considered the above.

Especially in a thread where people are over stressed with the complexity and challenge involved in landing a 172 with full flaps.

I never learn.

[Rookie50]

I agree with Rookie, give or take.

There's an interesting article online somewhere about testing the minimum time, altitude and distance taken to slow from cruise speed to a sensible threshold speed while flying an ILS in a light single. It's not very much.

I found that, in a 182, starting at 120 kts at 400 (300?) agl and maybe a mile-ish final it wasn't much challenge to slow, land, and turn off in 1500 feet. If I can do it, I'm sure most people could.

Look at it from a controllers viewpoint, for that last mile you now have increased the closure speed on you of any following jets to at least 80 knots faster than you are going.

Scenario 1: you fly over the threshold at 120 knots and spend 30 seconds slowing to touchdown speed and turn off at the far end. The airliner is still gaining on you all that time.


Scenario 2: you maintain 120 knots until 20 seconds before threshold; bleeding off the speed in the air where you have more drag. You fly over the threshold at 65 knots, touchdown, and exit 2000' from the threshold. You're out of the way of the airliner much earlier than scenario 1.

Exactly my thought photo. Bit of a thread drift.

On another note...any school not comfortable with teaching full flap usage at the outset...not sure I get that. I learned on a short, 40 ft wide runway...kind of glad I did.

I wonder if it's a lack of comfort with the student, in slow flight controllability. The student is drilled, properly, that stalling low in the pattern is fatal perhaps. Then, its easy to form the habit -- I had this for a bit and trained out of it -- of carrying way too much energy on final for the aircraft. Got to be common -- with all the overruns you hear of. It is a bit of an art, takes practice, to carry exactly the right amount of energy into the flare, and not a bit too much. Amazing how little runway you need when done right.

[LousyFisherman]

snip......
landing a Twin Otter on a 15,500 long runway in Africa, my Captain (who was right seat to me that day) looked over to me and said "Land long". Yes, I had figured that out!

Huh, at Springbank, I always land long (between 5000 and 7000 feet) on their 10,000 footer. 100% of the time, as I pass the 2000 foot mark ATC pops up with "BZX, are you planning a go around?"



LF

[iflyforpie]

Photofly, in your first scenario you've got to remember that if it was a heavy jet landing in front of another heavy jet, that the first jet would also have to slow from 120 knots at touchdown before exiting at the end of the runway... so really, sequencing shouldn't be any different.

For me, I have absolutely no problem screaming in on final to cut power and dump flaps at the last second to get off at the first exit. In a 182, 206, 172, 152... you set trim for cruise (as it should be), then it is simply gradually increasing pitch attitude as you cut power to bleed off speed, quickly reducing pitch attitude as you lower the flaps, then increasing pitch as you come to a normal approach speed.

If your plane is rigged right, it will fly hands off at approach speed with an approach power setting (1500RPM or 13-15" MP) without messing with the trim wheel. Most of the slowing down happens in the last few seconds... so you just have to be patient as it seems like you are going like a speed demon still at half a mile out.

[photofly]

Photofly, in your first scenario you've got to remember that if it was a heavy jet landing in front of another heavy jet, that the first jet would also have to slow from 120 knots at touchdown before exiting at the end of the runway... so really, sequencing shouldn't be any different.

Let's say you're in a 172 and your goal is to achieve the maximum separation between you and a jet on approach behind you until the time when you exit the runway.

There are essentially two things you can adjust: the speed profile (for a given distance from the chosen turnoff point) and the chosen turnoff point itself.

In terms of your speed profile you want always to fly as fast as possible, then as close to the turnoff point as possible use the maximum deceleration to safely exit the runway at the fastest speed possible. That may mean no flaps etc., depending on how much extra drag the flaps give you.

Now note that at all times you're flying slower than the aircraft behind, so the distance between you is continually decreasing. That means the minimum separation occurs at the moment you exit the runway.

You should therefore fly an approach that exits the runway as early (in time) as possible using an approach that keeps the speed as high as possible until then. That means using the first (in distance) turnoff, not the one at the far end.

Considering it in reverse: you can spend another thirty seconds flying down 6000ft of runway at 120kts before closing the throttle and landing, but in that thirty seconds the following aircraft which is closing on you at 20 or 30 knots has decreased the distance by 1000 or 1500 feet. Of course it closes the distance even more as you slow to land, but it does that in any case. By planning to touchdown at the end of the runway you just threw away an extra 1000 feet of separation.

If the aircraft behind is approaching at the same speed as you it doesn't matter where you choose to turnoff - the separation is the same. And if the aircraft behind you is flying more slowly then a longer landing gives you a bigger separation.

It's possible that ATC's goal isn't just to maintain maximum separation; maybe they have a good reason to ask you to land long. Or it might amount to the same thing. For instance, the first turnoff might be well past the midpoint, in which case the first possible turnoff is a long landing.

[Ref Plus 10]

Huh, at Springbank, I always land long (between 5000 and 7000 feet) on their 10,000 footer. 100% of the time, as I pass the 2000 foot mark ATC pops up with "BZX, are you planning a go around?"

Now, would that be the 5000' or 3400' 10,000 footer? I can certainly understand Tower's need for clarification..given that 5-7000 feet would put you roughly in my backyard...

While I realize that flap settings are somewhat PFM to some, in my opinion, the flap setting that gives you the best (read slowest) controllable landing scenario would be the obvious choice. On the airplane I currently fly, there is a 20 knot gap between ref speed at gross, and ref speed at empty weight, while the speed for any given weight changes a grand total of 2 knots for flapless to full flap landings. That being said, I will normally land with all the flap the wonderful designers at Douglas saw fit to grant me, as it reduces the speed at touch down, thus reducing the length of runway I need, and the amount of brake required, making the company happy. In the flight training world, I realize that this has little to no impact on flap settings, which is fine, but bear in mind the conditions of the crosswind limitations in your POH, I believe they are found with full flap extended.

Back to the original post, it's all about your landing attitude. Go sit in a small tail dragger for a bit, et voila! you've found the landing attitude (barring the endless discussions as to which is better, wheel or three-point). The Twin Otter full flap landing is something a little awe-inspiring the first time you're at the controls, and it's hard to overcome the feeling of over-rotation as you pull the nose from -10 degrees to around +5...the patient people I flew with can attest to my reluctance...

Ref