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30 and 40 degree landings


Ed Cesnalis

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We just learned that 30 degree landings in a CT are a 'mess'. My first reaction is 'What does that mean?' as I stated in the other thread 30 degree full stall landings in a CTSW are a beautiful thing. By that I mean a few things, first the round-out / flare are like a golf swing, a few interlinking phases that must coordinate. It beautiful because it is dramatic. First you have an unusual nose down pitch attitude that has to be ridden almost to the runway if your throttle is closed. The round-out / flare is both dramatic and abbreviated. Once you know that you are behind the power curve you can gradually pull the stick to the stop and thats when I see the AOA ( looking at wing tip ) increase a lot and the main gear seem to reach out like a bird doing a spot landing. Sweet.

 

My last ride was an 180hp skyhawk and to land with 15 or zero takes the skills of a skyhawk driver. To do it with an extra 10kts requires no energy management ( though it might require some runway ) To land with 30 or 40 takes the skills I learned as an ultra light pilot, its all about energy management. 30 degrees is the sweet spot, I save 40 for practice or actual short fields. I know that with 30 I won't get any quirky behaviour, with 40 I'm more alert so I can avoid stalling and dropping a wing prior to contact.

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When flying other airplanes, I almost always used "full flaps" except for strong crosswinds. With the CTSW, I typically use 30°, sometimes 40° and if it is gusty crosswind I use 15°.

This subject will get going pretty hot soon and I'm not going to get involved. I fly per the POH/AOI and AFH and that is all I'll have to say on the subject.

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We just learned that 30 degree landings in a CT are a 'mess'.

 

I'm still kind of amazed that any single person can be so consistently wrong about so many things.

 

No experience with the CT, but conditions permitting, my goal with virtually every plane I've flown has been to land power off with full flaps.

 

Works for me!

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Nothing wrong with 30 or 40 flaps in the CT as long as you follow the AOI and only do them in light winds. They are a blast, require practice as does perfecting any skill. We teach our students them once they have mastered the 15 flap approaches and landings. 15 flaps are our normal landing setting still, which is plenty slow for most runways longer then a 1000ft. 0 flaps as the crosswinds increase beyond 10kts.

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I pretty much mirror what Eric (Coppercity) does.

 

I landed today with a direct cross wind from the right at 19 gusting 25 and a heavy aircraft. I approached at zero and 65 and kept 2900 rpm right to touch. Nice and smooth. Enough rpm prop wash for full control authority and good escape route/plan if need be. Could have handled another 10 knts. Some things just make life easier verses hard.

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Well its April and crosswinds gusting to 40kts are typical in Mammoth. Left quartering crosswind 15-39kts seems pretty typical and surprisingly it can be pretty landable in a CTSW. I use 15 as opposed to zero or less because the limitation that I am likely to fight is sink. The gusts will have cycles and with local terrain the vertical component of the gusts can be the biggest challenge and I feel as though I need 15 for the climb performance.

 

For me 30 is normal up to 15kts of crosswind.

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You can really squeak em on at 50kts and 0 degrees

 

For both my students and myself, I'm looking for these two things (among others) on touchdown:

 

1) SLOW - wind permitting, full flaps and as close to the stall as physically possible, and,

 

2) SMOOTH - needs no explanation.

 

But I stress that of the two, the first is more important.

 

Much like a tennis serve, where it's easier to work on accuracy first, and then power, I think it's easier to nail speed first and then work towards smoothness.

 

I think lots of pilots end up going for smooth above all else. My next post, a re-post, will outline why I think a smooth landing with extra speed and/or power is more dangerous than a slow landing dropped in from a few inches with a thump.

 

I think the striving for smoothness has two sources:

 

1) It impresses non-pilot passenger, and,

 

2) It is way, way easier than a full stall landing - just fly the plane on.

 

On to the re-post...

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This post is from July of last year to the Sport Pilot Talk forum and pretty much sums up my take on the matter:

 

 

I've visited this before, but its worth revisiting.

 

First, a caveat: I have never flown a CT*.

 

That said, how about this for a thought experiment:

 

If you knew that on your next landing your right axle would fail, what would you want your speed to be at touchdown?

 

Slow as possible, right?

 

Now, how do you know for certain that on your next landing that axle will NOT fail? Or that a deer will run into your path, or that the brakes will fail, or that your nose wheel tire is flat, or whatever...

 

So, slow as possible, right?

 

With that in mind, I virtually always try to land at a full stall, power off, in my Sky Arrow, with full flaps. That should result in touching down at 39k, minus any headwind component. It may seem trivial, but the difference between 39k and 49k (let's say) could be the difference between grinding to a halt on the runway and cartwheeling in a ball of fire.

 

I will occasionally do a no-flap landing for practice, and may use less than full flaps or no flaps if its really gusty, but that's rare.

 

As an exercise, go to Wolfram Alpha, either via the web or the free app. Ask it for the kinetic energy of your plane at full flap stall speed and 1,320 lbs. Add 5k and do it again. Add 10k and do it again. Note the percentage change in inertia with each increment.

 

The key is that kinetic energy increases as the square of an increase in velocity, and when things go wrong kinetic energy is the enemy - an enemy that must be dissipated somehow. Yes, you may go an entire flying career landing "a bit" fast and never come to grief. Yet there's always a chance that at least once you'll find yourself in a position where your really, really wished you had been going slower when things got ugly.

 

 

*I'd still really love to correct this deficit in my flying experience, and would be willing to travel a couple hundred miles from my N GA home to get together with a CT owner and swap rides. Let me know!

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Hi Eddie and Ed,

 

You guys listed the pros of why you like full stall landings, but there is a different side of the coin.

I would like to hear what problems may arise out of a full stall landings. You can't say there aren't any because no one makes perfect landings 100% of the time or it wouldn't have been the leading cause in damaged LSA aircraft since 2005 especially in CT's.

Why not list the cons because there is the other side of the too slow stall coin.

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It sounds like you are blaming all landing incidents on full stall landing technique but most CT pilots don't use it so maybe a lot of those incidents since 2005 were never intended to be full stall landings? also wouldn't that be true in all of general aviation? ( the leading cause of damage is landing incidents)

 

You don't have to make perfect landings 100% of the time. In order to do full stall landings safely in a CT you have a good sense of where the ground is and maintain adequate energy until you get close enough to stall. If you first get behind the power ( already close to the ground ) then you can pull the stick back and adjust the rate of settling so that the stall happens at contact.

 

Sorry Roger, I don't see the other side of that coin. I do see a coin where heads = fast = less safe and tails = slow = more safe.

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Sorry Roger, I don't see the other side of that coin. I do see a coin where heads = fast = less safe and tails = slow = more safe.

 

Ditto that.

 

It's important to bear in mind that the kind of accident that happens when a full stall landing drops in hard is far less likely to cause injury than the sort that can follow a porpoising incident or a high speed swerve off the runway.

 

Later I'll try to dig out a list of Cirrus landing accidents - virtually all of them resulted from too much speed - not too little.

 

Part of the argument seems to be that full stall landings are more difficult. I guess I'd stipulate to that, since flying the plane on at 10+ knots over stall takes very little skill. But the ability to land in a full stall consistently and safely is a valuable tool to have at your disposal, especially for an off-airport emergency landing - there's a world of difference between hitting a ditch at 39k vs. 49k.

 

Again, any pilot who's uncomfortable with full stall landings just needs some targeted instruction. It's simply not all THAT hard.

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"It sounds like you are blaming all landing incidents on full stall landing technique". I'm not blaming the technique just the pilot's. It's a slow speed maneuver that does get some in trouble. Just as Eddie said, it takes more experience and diligence on landing. Very few ever get injured because they were 5 knots over stall and veered off a runway, but many many pilots have smashed gear which is undeniable with the NTSB reports. Too slow has always got more people in trouble than little fast.

 

"Cirrus", is not a low weight, low energy or low speed aircraft that our LSA are. Different critters.

Different planes different techniques.

 

 

Hi Eddie,

 

True:

"Part of the argument seems to be that full stall landings are more difficult. I guess I'd stipulate to that, since flying the plane on at 10+ knots over stall takes very little skill. But the ability to land in a full stall consistently and safely is a valuable tool to have at your disposal, especially for an off-airport emergency landing ".

 

 

True:

"10+ knots over stall takes very little skill."

Correct it makes consistent landings easier.

 

True:

"Is a valuable tool to have at your disposal".

But not needed for the everyday every pilot scenario.

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Like I said in the other thread I like to land on the mains with the nose wheel in the air. I din't try to get to a full stall, but I would guess that I'm somewhere close. I for sure don't like the idea of landing on all three wheels at the same time.

Making 30° or full flap landings is fine if the conditions are right, but if they are not it can lead to trouble. On our airplanes we have flaperons. With full flaps and aileron input you have two very different angles of attack on the wing tips. As you approach stall speed one wing tip is going to stall before the other, and having the stall at the tip is not a good thing. I have had a CTSW drop a wing on me hard in a stall twice. Once in rough air the other with a pilot who applied aileron to try and keep the wings level. Both of these happened with 40° flaps, power at idle, and one aileron input was a factor. I for sure wouldn't want this to happen while I was close to the ground. I know that some of the landing accidents were caused by this happening. One was at Sebring a few years ago with 2 instructors in the demo airplane.

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"It has everything to do with "energy management."

 

I fully agree, but way too many are poor at it and inconsistent enough to cause problems. Large heavy aircraft are easier to manage with more energy. Too slow (full stall type landings), poor energy management and full flaps has been the number one cause of CT under carriage damage along with other LSA. A person may be very good at full flap landings and or full stall landings, but not everyone is and some will never be and that's okay so long as each knows their limitations and don't subject themselves to the extra risk. Light aircraft in a cross wind and or full flaps is a different animal. Very little energy in most LSA so it goes away before the pilot has time to compensate or realize he is even in trouble.

 

 

I'm not against full stall landings and or full flaps by any means, but there is a time and place. I practice them all, but don't always use them for a normal everyday landing and wouldn't teach them to newer students until certain other aspects of the aircraft are more proficient. My mental landing technique toolbox stays full, but it doesn't allow me to get into a mental rut using the same tool on every job. I land different most of the time so I never get used to just one way and don't even need the panel to land.

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Correct Roger. The lighter more slippery carbon fiber planes like the Samba and the FD CT need speed to cut thru a crosswind. Flaps over 15 is like trying to land either of these planes with a parachute open. The glide slope gets steep, and the landings risk stall and bounce. Thats why the schools in the know are teaching students to land with 15 degree or less, and cross the runway at 62kts to keep the plane moving in any cross wind, and in case of engine failure or power loss. Its not only safer, its also far easier to 'feel' the plane in ground effect and make the flair without dropping the last few feet in a stall and damaging the carriage or wheels or worse.

 

That's quite a post! Perhaps you could get your CT to fly in the relative wind and eliminate the need to cut thru the crosswind? ;)

 

Landings don't risk 'stall or bounce' due to being configured with more than 15 degrees of flaps. You risk a stall by flirting with the critical angle of attack and you risk bouncing by not controlling your vertical speed. Its the pilot not the flap setting.

 

Crosswinds won't prevent your from moving they will cause you to drift from the center-line if you don't correct with a side slip or a crab. 62kts as a target to cross the runway won't have any real effect in case of a lost engine.

 

Simply saying its safer isn't persuasive. 'dropping the last few feet' is once again a vertical speed control issue. If you run out of energy and the sink becomes rapid you can counter it by advancing the throttle or increasing the aoa or both. 62kts won't save you from bouncing in fact it will encourage it.

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I disagree that the Cirrus is fundamentally different in the landing than an LSA. Any given wind has more effect, of course, and controls may be lighter, but the control inputs and desired result are basically the same.

 

Someone over on the COPA site compiled some recent landing accidents:

 

 

#1 - ON AUGUST 17, 2012, AT 1213 PM, N855CD, A CIRRUS SR 20 OPERATING PART 91 VFR, LANDED ON RUNWAY 23 AT MYRTLE BEACH, SC, AT THE GRAND STRAND (CRE) AIRPORT. THE AIRCRAFT LANDED AND BEGAN TO PORPOISE AS IT SLOWED TO EXIT THE RUNWAY CAUSING A PROPELLER STRIKE TO ALL THREE BLADES. THERE WAS ONE SOUL ON BOARD WITH NO INJURIES. THE DAMAGE TO THE AIRCRAFT IS MINOR. THE STUDENT PILOT WAS ON HIS SECOND LEG OF HIS SOLO LONG CROSS COUNTRY. HIS ROUTE WAS KJQF-KFLO-KCRE-KJQF. HE TOOK OFF FROM KFLO GOING TO KCRE AFTER COMPLETING HIS FIRST LEG. HE CAME INTO KCRE AND HAD VISUAL CONTACT WITH THE FIELD. HE MADE A 45 DEGREE ENTRY INTO THE RIGHT DOWNWIND FOR RUNWAY 23 AS PER INSTRUCTIONS. HE MADE A NORMAL APPROACH TO LANDING AND AS HE CAME CLOSE TO TOUCHDOWN THE NOSE ABRUPTLY DROPPED AND MADE CONTACT. THIS CAUSED THE AIRCRAFT TO PORPOISE...

 

#2 - MONROE COUNTY AIRPORT TWR RECORDED AN AIRCRAFT DAMAGED DURING LANDING AT 1504L ON 2/1/2013. THE AIRCRAFT WAS N586PU, A CIRRUS SR20 THAT WAS ATTEMPTING TO LAND ON RUNWAY 24 RESULTING IN A HARD LANDING AND DAMAGE TO THE NOSE GEAR AND A PROP STRIKE. THE ONE PERSON ON BOARD WAS A STUDENT PILOT ON A VFR SOLO CROSS COUNTRY FLIGHT AND WAS UNINJURED. THE AIRCRAFT WAS TOWED TO THE RAMP OF THE LOCAL FBO.

 

#3 - DURING FINAL APPROACH TO LANDING THE NOSE WHEEL CONTACTED THE RUNWAY FIRST CAUSING THE AIRCRAFT TO START PORPOISING. ON THE THIRD BOUNCE THE NOSE WHEEL BROKE OFF AND THE PROPELLER CONTACTED THE RUNWAY. AIRCRAFT CAME TO REST IN GRASS OFF THE SIDE OF THE RUNWAY MIDFIELD.

 

#4 - AIRCRAFT BOUNCED/PORPOISED UPON LANDING. DAMAGE TO RIGHT FLAP AND ALL PROPELLER BLADES.

 

#5 - AFTER A BOUNCED LANDING ON RUNWAY 31 AT KHIO, THE PILOT IN COMMAND ATTEMPTED A REJECTED LANDING OF HIS CIRRUS SR22. THE RESULT WAS THAT THE AIRPLANE DRIFTED OVER THE INFIELD, IMPACTED THE GROUND, AND SHEARED OFF ITS LEFT AND RIGHT MAIN LANDING GEAR. THE CIRRUS SR22 CAME TO REST SOUTH OF TAXIWAY A APPROXIMATELY 2,500 FEET FROM THE INITIAL CONTACT POINT ON RUNWAY 31.

 

All except maybe the second one involved extra kinetic energy on landing. A PLANE LANDED IN A FULL STALL CANNOT BOUNCE".*

Land with the stick all the way back in a full stall as the plane either smoothly touches down or "plotzes" on the runway, and it will NOT bounce.

I will probably have another post concerning "A Tale Of Two Landing Accidents" to follow.

 

*Barring a sudden gust lifting you up, but full stalls are not indicated on gusty days anyway.

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I thought the reason for not using 30 or 40 degree flaps in a crosswind was the limited aileron deflection with full stick deflection due to the design of the control system. If I recall, most of the CT crashes on landing were from limited roll authority and the aircraft was blown off the runway. I have not seen that mentioned very often.

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Just my 3 cents on cross winds in the CTSW. I only have 620 hrs in mine but have flown down to Jamaica (both ends) Cayman Islands (all 3) Cozumel and all over Mexico, 20+ of the Bahaman Islands. I state only these destinations because each one of the island's requires a crosswind landing. Since the real estate on islands is a premium the airport approach/departure thresholds are right next the beach/water & never seem to aligned with the prevailing winds. Sure you can "get the wx" for your destination but after 5+ hrs it is what it is and always a cross wind. 0 degrees minimum is all I use, normally -6. Have fun with that one :)

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Glenn,

 

Eric (Coppercity) mentioned this just the other day. Same thing with the Robertson conversions on Cessnas, especially the 180/185. Even without the ailerons which deflect with the flaps, you would not typically use flaps 30/40 in cross winds because you want a little extra speed for better controllability and less drift.

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Absolutely zero in high cross wind landings. I don't use -6 for landings as a rule, but have practiced them. No different than zero really. The difference between 30 & 40 is fairly negligible too. They're both high drag slow landings and not much changes between the two. When the winds are 20+ I'm at zero and power right to the ground. With that method I can land in 30 mph winds without breaking a sweat. Okay maybe a little sweat. ;) Under 20 is a walk in the park. My normal is 15 and sometimes 30 and once in a while 40 for fun.

See I believe in all ways to land because they all have a purpose at sometime and some place.

Train for everything and hope you only need one thing. Landing only one way all the time usually puts people at a severe disadvantage when circumstances turn bad and aren't in your normal train of thought or normal pattern type landings. It has saved my butt more times than I can count over the last 33 years. Getting stagnant in one style of landing or pattern work makes emergency actions tougher to deal with mentally and physically and all the numbers you memorized for the pattern may be out the window and then what do you do if you haven't trained. That's why firemen train so much, to train under all conditions and options to solve a problem and not get locked into textbook problems because real life isn't always spelled out in the textbook and real problems don't usually follow and didn't read the textbook.

 

If you haven't trained with a -6 landings what would happen if the ailerons locked in at -6? It has happened.

 

 

Like the Boy Scouts motto says. "To be prepared" and you can't do that with always thinking and training in the box. You need to look and train outside the box so the emergency then becomes routine. Train for the worst and be happy with the routine.

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