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Short Field Landings

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Old 25th Feb 2003, 12:57
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Angel Short Field Landings

I am now the proud owner of a Piper Cherokee 6-300, which is a great aeroplane.

The manual lists the various techniques for "normal" takeoff, short field takeoff, soft strip takeoff, and standard landing techiques, but there is no mention of short field landing.

I am currently using full flap (so long as the wind isn't gusting) and an approach speed of 90 MPH, with 80 MPH over the hedge. This doesn't vary unless I need to go flapless.

Anyone know of a better technique for this type of short field landing? I have heard rumours of a so-called "helicopter" landing with a high nose attitude and more power leading me to think that this means operating on the back of the drag curve.
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Old 25th Feb 2003, 15:16
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The short field technique is the one given in manual to achieve the performance chart figures.

It sounds like you have heard about using a 'behind the power curve' method. All well and good - until you stuff it up & the insurer says you operated outside the manual specs.

There is less margin for error of judgement using this method, with a greater likelyhood of it resulting in a heavy landing or low level stall.
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Old 25th Feb 2003, 16:35
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I agree, steer well clear of the so called "helicopter" method. There are too many things that can go wrong.

1. Wind sheer and "dead air" will affect you more with a low speed/higher power configuration.

2. You are relying solely on one engine to stay the right side of that hedge. After a prolonged approach with low power settings we all know that some engines have a tendency to splutter now and again when you suddenly increase the power.

3. Your view is restricted with a higher niose attitude especially with that lovely long nose the Chezzer 6 has. If you are performing a short field landing I can only assume it is a grass/farm strip, therefore you need to be able to see exactly what you are about to touch down on etc.

4. In the event of a go around I would much rather have those few extra knots than be wallowing about on the edge of the performance envelope.

A good thing to try is to go up to a few thousand feet and really get to know how your a/c performs near the stall in all sorts of configurations and make a mental note of the different indicated stalling speeds. The actual stall may be a few knots above what it says in the POH, better to find out at 3000 than 3.

My A/C is based at a farm strip and I much prefer to approach at a sensible airspeed with low power and then bleed the speed on the final stages. A tiny amount of side slip is an excellent way of losing that extra 50ft on a short field landing approach without building up any unwanted speed.

Finally I would like to add that a short field landing with a good 15 to 20 knots down the runway with cool temperatures, 3 on board and half fuel can be quite a simple task to pull off.

On a calm and warm day when you're on your own it can be frightening how they can float and float and ffllooaatt.......
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Old 25th Feb 2003, 16:57
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Low speed / high power approaches aren't the way to do it. You have a bad view, make lots of noise, and expose yourself to risks of downdrafts or turbulence. If you're flying a flat, high-power approach at a lower than normal speed, you don't have much margin to modify your approach path; extra power isn't going to give you much of a climb, especially if you are heavy.

I have never flown a Cherokee 6, so my comments may not be applicable to you. I do quite a few short field landings though. My approach is:
  • The aircraft is going to touch down at essentially the same speed whether you fly a high power flat approach, or a normal approach. The important point is to touch down at the earliest possible point in the field.
  • Once you have identified where you want to touch down, you can determine an aiming point, which is where the aircraft would hit the ground if you didn't flare. The distance between the aiming point and the touchdown point depends on the wind, the speed at which you flew the approach, and the aircraft's characteristics. (Again, a reserve - in the aircraft I fly you can safely reduce power to idle well before touchdown, so the distance flown between aiming point and touchdown point is not affected by power setting.)
  • Once you've identified your aiming point, you fly a normal approach towards it, using flap and power settings that gives you the greatest flexibility. (In the planes I fly, that means full flap and usually 1500-1700 rpm. With that I can correct downwards by reducing power and sideslipping, and correct upwards by adding power). The speed should be whatever speed you've chosen that's going to take you from your aiming point to your touchdown point.
  • If your speed is too high on the approach, keep flying towards the aiming point, and reduce power a bit. If speed is too low, add some power. But don't stop focusing on the aiming point.
  • Once you start to flare, there's virtually nothing to stop you touching down at minimum speed right on your chosen touchdown point. It just takes a bit of experimenting to be able to choose the right aiming point.
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Old 25th Feb 2003, 17:43
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Aerobaticflyer.........can I be the first to say that was an excellently described "las stage of landing" description.
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Old 25th Feb 2003, 18:48
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Aidan

I've a few hours on the six and I agree that she is a good plane.

One of the few traps of this lovely lady is that she handles quite differently depending on the w&b and excess thrust varies depending on the load (I know this is a trusim, but it 'seems' lto have more effect in the six.)

If you fly the POH numbers and arrive accurately, you should be able to get into any reasonable field, so like the other posters I'd wouldn't try to be Chuck Yeager by imitating an egg beater!

Also, a useful tip that I got from a Dick Collins book was the 3000 rule for a six.

If you're over 3000lbs weight, or the runway is less than 3000ft or the density altitude is over 3000ft, then calculate performance carefully.

If none of those factors apply, still calculate, but you will find performance to be very good indeed!

Enjoy your lovely aeroplane.
 
Old 27th Feb 2003, 08:19
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In the Koliber's POH, in the section about short field landing, it contains the cryptic comment 'Maintain a high angle of attack'.

This would tend to imply that the approach is deliberately flown on the back edge of the drag curve.

Its a characteristic of the aircraft that she will sit quite happily power-off, nose high, wings level, flaps down, stick hard back and descending so maybe the technique is ideally suited to her.

I shall find a grown-up who knows about these things and try it.
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Old 27th Feb 2003, 10:26
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Koli

Whilst I haven't flown a Rallye/Koliber, I have observed that they have leading edge slats and large fowler flaps, which the 'six' doesn't.

Another example of why it is important to read the POH for each type flown.
 
Old 27th Feb 2003, 10:53
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I flew in a Rallye 180 quite a lot when I was a kid. I seem to remember the approach into short fields was power off, full flaps and stick hard back - it would come down like a .. er.. tin parachute.. then full throttle over the hedge to arrest the vast rate of descent right into the flare. I'd guess the landing roll was no more than 150m - impressive stuff!

Kingy
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Old 27th Feb 2003, 13:34
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The high AoA/High Power approach in Cherokee-type Pipers is a rather poor description of the typical POH-recommended Soft Field Approach. This mechanism helps to control the rate of descent on touchdown, and avoids premature digging in of the nose gear. It almost certainly doesn't apply to short field approach.

Although I have no Cherokee 6 book nearby, I would expect you to find that the approach should be flown in the normal approach configuration (full flaps), but at around 5 knots slower than the conventional approach.

On touchdown, which should be accurate and on the numbers, the flaps should be retracted in one smooth movement, and the brakes applied with the control column held fully back.

I would be surprised to find any significant variation of that technique in any checklist for the type. As others have written though, you should trust only the approved POH in matters like this.

Regards

Last edited by 2Donkeys; 27th Feb 2003 at 18:13.
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