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So, how do you land?

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So, how do you land?

Old 12-13-2020, 09:21 AM
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JSF-TC
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Default So, how do you land?

We were at the field yesterday to assess a new member for his turbine waiver flight sign-off. I had performed the first flight of his model, set it up to my preferences and coached him through the buddy-box phase over the last few weeks.

It was a challenging day as there was zero wind, making good circuit planning essential to achieve a neat landing. After the first waiver flight, we spent a flight just shooting approaches with verbal coaching for the appropriate positioning etc. before final successful 'solo' to achieve his waiver.

Afterwards, we discussed the various landing methods that we tend to use, so I thought I'd open it up to the wider community.

For all my models I use 3 Flight Modes; Flaps Up, Take Off Flap and Landing Flap, with the model fully trimmed in each Flight Mode.

After a mid (take-off) flap, gear down gear pass for a gear check, I select Landing Flap about mid-way along downwind, and control any transient ballooning with elevator to keep a level flight path. I let the speed bleed off and then select a power setting to maintain level flight for the rest of downwind. Once this trimmed 'hands-off' condition is set, the model is trimmed at the nominal final approach speed, and I fly the rest of the pattern to the flare at this speed with minimal elevator inputs.

I use the base and/ or finals turn to initiate the descent to intercept the final approach path and then use power to maintain the correct glide-slope, essentially hands-off the elevator the entire time apart from any major 'gross' adjustments to the flight path, which are immediately followed up by a power correction. At the appropriate time, power is then pulled back and the elevator used to initiate the flare to touchdown.

Other pilots commented that they prefer to hold elevator (up or down, not sure) to 'feel' the model on approach, but I find that tends to result in a very variable approach speed.

Just like full-size, given that elevator controls Angle of Attack and hence speed, and power setting controls flight path you can end up with a very consistent approach speed by flying a correctly trimmed approach. If you are sinking, don't use elevator to flatten the approach, just add a few clicks of power until you re-intercept the correct flight path.

On a windy day, just add more power on finals to compensate for the slower ground speed. Also add a few clicks of down trim to increase the trimmed speed to account for wind gradient and gusts if necessary.


So, how do you land???


Paul
Old 12-13-2020, 11:36 AM
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David Gladwin
 
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Originally Posted by JSF-TC View Post
We were at the field yesterday to assess a new member for his turbine waiver flight sign-off. I had performed the first flight of his model, set it up to my preferences and coached him through the buddy-box phase over the last few weeks.

It was a challenging day as there was zero wind, making good circuit planning essential to achieve a neat landing. After the first waiver flight, we spent a flight just shooting approaches with verbal coaching for the appropriate positioning etc. before final successful 'solo' to achieve his waiver.

Afterwards, we discussed the various landing methods that we tend to use, so I thought I'd open it up to the wider community.

For all my models I use 3 Flight Modes; Flaps Up, Take Off Flap and Landing Flap, with the model fully trimmed in each Flight Mode.

After a mid (take-off) flap, gear down gear pass for a gear check, I select Landing Flap about mid-way along downwind, and control any transient ballooning with elevator to keep a level flight path. I let the speed bleed off and then select a power setting to maintain level flight for the rest of downwind. Once this trimmed 'hands-off' condition is set, the model is trimmed at the nominal final approach speed, and I fly the rest of the pattern to the flare at this speed with minimal elevator inputs.

I use the base and/ or finals turn to initiate the descent to intercept the final approach path and then use power to maintain the correct glide-slope, essentially hands-off the elevator the entire time apart from any major 'gross' adjustments to the flight path, which are immediately followed up by a power correction. At the appropriate time, power is then pulled back and the elevator used to initiate the flare to touchdown.

Other pilots commented that they prefer to hold elevator (up or down, not sure) to 'feel' the model on approach, but I find that tends to result in a very variable approach speed.

Just like full-size, given that elevator controls Angle of Attack and hence speed, and power setting controls flight path you can end up with a very consistent approach speed by flying a correctly trimmed approach. If you are sinking, don't use elevator to flatten the approach, just add a few clicks of power until you re-intercept the correct flight path.

On a windy day, just add more power on finals to compensate for the slower ground speed. Also add a few clicks of down trim to increase the trimmed speed to account for wind gradient and gusts if necessary.


So, how do you land???


Paul
Pretty much like you suggest. works on everything from a BobCat, by BVM, to a 767 by Boeing !

However , that said, increasing power to reduce ROD, or vice versa, means you have to raise, or lower the nose slightly to correct the glideslope and ROD. The. need is to coordinate the control inputs to achieve the required result.
Simply adding or reducing power if you are going low or high simply takes you down a steep glidepath faster or slower and vice versa.

Trim, trim and trim again to achieve a stable flight path.

Last edited by David Gladwin; 12-13-2020 at 12:00 PM.
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Old 12-13-2020, 12:22 PM
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I always teach people to be descending from that opposite down wind point, it reduces the chance of losing speed, but for sure it’s important to set a speed before you turn in on the last leg. Once it’s facing you judging the speed is much more difficult. Knowing you are varying speed takes feel through the sticks and that only comes with experience.
I always trim at full flap to slightly descend but just a tiny bit, this reduces the need to control the pitch. If you are a little faster when applying full flap it will descend and not balloon, which is when people get into trouble.

Aircraft with large inlets, big flaps (or low wing loading) are easier to manage as you can carry more speed on the approach and lose it quickly to land where you need to. The guys who start jets at our local club grass field turn out to be good pilots, if you miss the strip damage occurs so it focuses the mind!

Dave
Old 12-13-2020, 12:23 PM
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Originally Posted by JSF-TC View Post

On a windy day, just add more power on finals to compensate for the slower ground speed. Also add a few clicks of down trim to increase the trimmed speed to account for wind gradient and gusts if necessary.

Paul
Agree with everything but this. if it is windy, I turn closer. But adding more power to maintain groundspeed means higher airspeed and risk of ballooning on flare. Same with flaps. I always land on the same flaps/speedbrake configuration, since all we see is sink rate and AOA, not airspeed. If it is windy, land closer, judge and correct based on angle of attack and sink rate.

But that is what works for me, I guess everyone has their own technique

Good conversation

Old 12-13-2020, 12:30 PM
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What he said.
Having enough drag helps big time, I've experienced the need of more drag in my jets, my Boomerang XL would glide on final and it was hard to land on the same spot every time, after I added more flaps down to increase the drag it became very predictable on final approaches, one other thing I moved away from the long approaches, with the added drag I can turn it to the final approach closer than before and I know that it will slow down.

Last edited by CARS II; 12-14-2020 at 07:40 AM.
Old 12-13-2020, 01:50 PM
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Thumbs up Jack Diaz - the master!!

Originally Posted by JackD View Post
Agree with everything I always land on the same flaps/speedbrake configuration, since all we see is sink rate and AOA, not airspeed.

Good conversation
Jack,

Your Dad showed me how to land properly in 1997 at Wroughton in the UK. He is the master and I will never forget the following advice he offered:

- Always remember, 1st position flap is for lift and full flap is for drag.
- Get your wheels down check done then setup1st position flap on early down wind and get the plane flying level, stable and slowed down.
- Try to maintain a side-on view of your plane for as long as possible. So pick your touch down spot and then super impose that on to the downwind leg.
- When reaching "that" point on down wind start your turn towards landing. This is a wide, gentle 180degree turn all the way to touch down. It is a constant decending turn and you will have a side-on view of your plane for the maximum length of time. During this turn you will deploy full flaps and manipulate throttle (for height) and flaps (I use a slider for flaps and can therefore manipulate the drag) for speed. Assisted by the usual aileron, rudder and elevator for a smooth landing.
- If you are constantly decending, you will never stall and with a constant rate of turn, you will never have the dreaded final turn spin. Neither will you have to judge the approach speed in a head-on approach.

Finally, touching down is flying 150mm (6 inches) of the ground, slowing down (throttle back) and adding more and more elevator until the plane will no longer fly and gently settles down - like a butterfly with sore feet.....LOL

BUT.... like you said, we all do what works best, I just found what your Dad advised, works best for me.

Cheers,

JanR
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Old 12-13-2020, 04:00 PM
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I like to keep things simple. One switch for flaps / slats and moving the rudders in for extra drag and pitch. Like others said donít do to long of an approach. Here is one of my F22 landings.

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Old 12-13-2020, 05:05 PM
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Its the setup that makes the landing successful. I teach getting the airplane trimmed with gear down full flaps and SBs if used and fly it around in that configuration (level flight). It must be trimmed hands off at about 1/2 throttle or higher based on how draggy the airframe is. If properly trimmed a slight power reduction will result in a descent at the same airspeed as trim is based on airspeed. The airplane will descend to maintain that speed. (Conversely if trimmed hands off like this and you add power the airplane will climb) When you bank to start the turn some lift is lost (change in lift vector)and the nose will drop to maintain the speed the jet is trimmed to and will result in a descending turn. (Glide slope or descent rate is then controlled by throttle). Generally when you roll out on final a slight power increase is required to reduce the descent rate. This is all done with aileron and throttle only. Elevator controls airspeed.
Old 12-13-2020, 06:12 PM
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Originally Posted by tp777fo View Post
Its the setup that makes the landing successful.
Ditto what he said.
Old 12-13-2020, 06:29 PM
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Originally Posted by Springbok Flyer View Post
Jack,

Your Dad showed me how to land properly in 1997 at Wroughton in the UK. He is the master and I will never forget the following advice he offered:



JanR
Guess who taught me too

Good to hear from you Jan, hope your are ok and being able to fly during these crazy times

later
Jack G
Old 12-13-2020, 06:52 PM
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Speaking of landing...Jack your info on the Fouga makes landings great. Flew it today at home field which is the shortest one yet. Used 1/2 of the 600' runway. Im still tweeking full flap trim and getting real close. I really expect it will be almost hands off on final. What a great jet!
Old 12-14-2020, 03:44 AM
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How about a stall warning device ?
Most fullsize aircraft have such a device. On airliners its a stick shaker driven by angle of attack sensors.

We can emulate that with modern electronics.

CB Elektronics makes a very sensitive asi, calibrated against Winter instruments ( Winter make fullsize glider instruments) and I have recently been trialling this in a PST Reaction. It works very well and now we have repetitive warnings available on tge PB Core, so we can set up a stall warning easily.

I have not been able to air test this setup yet due CV but this is the plan:

Stall the aircraft at height in the landing configuration, note speed.

Assign warning on the Core at ,say, Vs plus 10 announcing SPEED and vibration when airspeed falls to this value. emulating the stick shaker.

At Vs plus, say, 5 set the alarm to announce “STALL STALL” and vibration.

Viola ! A stall warning device with a weight penalty of less than one ounce and so simple to install.

I will test this as soon as CV allows.
Old 12-14-2020, 04:54 AM
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Another tip is to not bring the engine back to idle until you made the runway. Even if you have the throttle cracked just a touch it will throttle up much faster then it would from idle incase you need a go around.

I see many mess up their landings by poor throttle management. Many beginners simply fly to fast then go to idle and try to land. If your landing speed is letís say 15knots then you will only be at that speed for a split second while slowing down.
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Old 12-14-2020, 05:25 AM
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Great point Gunradd. I tell my guys " if you are ever at idle thrust you had better ask yourself WHY" every one of my landing accidents through my jet years was missing the WHY question. My last "big wreck" happened when I hit a windshear during the final turn....just didnt recognize it and kept pulling power. Stalled in the turn with a ton of groundspeed but no airspeed. Recovered it just above the ground but then it flew out of sight below a small hill...RIP Dolphin L.

Last edited by tp777fo; 12-14-2020 at 05:32 AM.
Old 12-14-2020, 06:16 AM
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Yes and no

Our field you have to fly a steeper glide slope, essentially down a hill or tree line then flare and bleed off speed because of our layout so if you're not at idle you overshoot and the far fence can come up fast.
Old 12-14-2020, 07:45 AM
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Originally Posted by gunradd View Post
Another tip is to not bring the engine back to idle until you made the runway. Even if you have the throttle cracked just a touch it will throttle up much faster then it would from idle incase you need a go around.

I see many mess up their landings by poor throttle management. Many beginners simply fly to fast then go to idle and try to land. If your landing speed is letís say 15knots then you will only be at that speed for a split second while slowing down.
This, very strong on that.
Old 12-14-2020, 08:13 AM
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Originally Posted by BarracudaHockey View Post
Yes and no

Our field you have to fly a steeper glide slope, essentially down a hill or tree line then flare and bleed off speed because of our layout so if you're not at idle you overshoot and the far fence can come up fast.
Hance the need for more drag, I think 🤔
Old 12-14-2020, 08:24 AM
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Yea, you don't land a jet at our field without a buncha flap.
Old 12-14-2020, 09:13 AM
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Originally Posted by gunradd View Post
Another tip is to not bring the engine back to idle until you made the runway. Even if you have the throttle cracked just a touch it will throttle up much faster then it would from idle incase you need a go around.

I see many mess up their landings by poor throttle management. Many beginners simply fly to fast then go to idle and try to land. If your landing speed is letís say 15knots then you will only be at that speed for a split second while slowing down.
I agree with Kris, when I throttle down I bounce it off the bottom and add/come up a couple clicks until I make the runway. Works great.
Old 12-14-2020, 09:14 AM
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Originally Posted by Springbok Flyer View Post
Jack,

Your Dad showed me how to land properly in 1997 at Wroughton in the UK. He is the master and I will never forget the following advice he offered:

- Always remember, 1st position flap is for lift and full flap is for drag.
- Get your wheels down check done then setup1st position flap on early down wind and get the plane flying level, stable and slowed down.
- Try to maintain a side-on view of your plane for as long as possible. So pick your touch down spot and then super impose that on to the downwind leg.
- When reaching "that" point on down wind start your turn towards landing. This is a wide, gentle 180degree turn all the way to touch down. It is a constant decending turn and you will have a side-on view of your plane for the maximum length of time. During this turn you will deploy full flaps and manipulate throttle (for height) and flaps (I use a slider for flaps and can therefore manipulate the drag) for speed. Assisted by the usual aileron, rudder and elevator for a smooth landing.
- If you are constantly decending, you will never stall and with a constant rate of turn, you will never have the dreaded final turn spin. Neither will you have to judge the approach speed in a head-on approach.

Finally, touching down is flying 150mm (6 inches) of the ground, slowing down (throttle back) and adding more and more elevator until the plane will no longer fly and gently settles down - like a butterfly with sore feet.....LOL

BUT.... like you said, we all do what works best, I just found what your Dad advised, works best for me.

Cheers,

JanR
Jan, one thing we do differently than what you describe is flaps on a slider. We use flaps on a 3 position switch. No fiddling with flaps. As I mentioned earlier, always land on the same configuration, that way you can judge your AOA and sink rate, independently of ground speed as that is variable based on wind speed. We even slave airbrakes to full flaps. Always land with the same configuration.

I guess things change after 20 years

Later
Jack G
Old 12-14-2020, 10:17 AM
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Landing is actually an energy balance. Energy is what makes the airplane stay in the air … controlled reduction of energy makes it land. The game is to manage those energies.

There are three “sources” of energy available:
- Air speed
- Engine thrust
- Rate of descend (trade of potential energy … i.e. change of altitude)

There is a “user” of energy:
- Drag. Drag is controlled with the angle of attack, flaps, and some kind of speed brakes.



To land, we need to reduce the air speed as much as feasible. (High speed landings are the main cause of bad landings. They will either end up in uncontrollable bounces …. or the airplane dropping hard once the speed is bleed off over the runway. Diving into the runway is a no no ! ).
Nonetheless, reducing the speed (by setting the appropriate angle of attack) will reduce the available energy; thus, it has to be compensated by the other two sources: rate of descent and power.

This may sound too simple, but making a mental image of these energy changes while landing is of great help (for me at least !).

A great way to acquire the feeling of that balance is by practicing dirty fly by (full flaps, gear down, speed brakes out); gradually reducing the speed of the dirty fly by during the approach.

Another useful tip: you should never see the top of the wing on final.

Jack
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