fspilot747
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Landing With A Little Power In 152's/172's

Thu Jan 16, 2003 8:00 am

Many times, to keep a landing smooth, I add a bit of power right before touch down. Do a lot of you guys do this, or do most of you idle it coming in over the threshold and keep it that way? Is there anything wrong with keeping a little power in on touchdown?

Just wondering,
FSP
 
Olympic A-340
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RE: Landing With A Little Power In 152's/172's

Thu Jan 16, 2003 8:21 am

Sometimes if I am sinking a bit too much I do indeed add a little more power. Also that gives you the added benefit of more air travelling over the elevators, so you have a bit more control in that axis of flight. Usually, you add about 300 RPM on soft field landings to transfer the weight from the wings to the wheels at the slowest speed in landing.
 
Mr Spaceman
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RE: Landing With A Little Power In 152's/172's

Thu Jan 16, 2003 8:57 am

Hi guys.

I was trained to reduce power to 1500 RPMs and dump 20 degrees of flaps while turning onto base. Then trim the C-152 for 60 knots. Once on final, I'll put down 30 degrees of flaps, re-trim for 60 and keep the power at 1500 RPMs untill I reach the threshold. That's when I pull the power to idle as I flare over the numbers.

As mentioned by Olympic A-340, you need to add power (1800 RPMs or so), if you're at your target speed and are sinking below your glidepath.

I'll usually hold my power at 1800 RPMs if I'm landing into a stiff headwind (so that I can get there), and I'll reduce my throttle to idle at a "much slower rate" when flaring, so that I actually land with a bit of power still on (about 850 RPM's).

That's one of my techniques.

Chris  Smile
"Just a minute while I re-invent myself"
 
Guest

RE: Landing With A Little Power In 152's/172's

Thu Jan 16, 2003 11:01 am

When I'm flying the 152, I usually add a little bit of power when I flare, as when you pull the throttle to idle in a 152, you can sink like a rock when you're slow with flaps down. Just helps to cushion the settling.
 
XFSUgimpLB41X
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RE: Landing With A Little Power In 152's/172's

Thu Jan 16, 2003 12:10 pm

You've just described a soft field landing, haha. That's fine and dandy, but touching down with power is just not good technique and means that you are not flaring enough. You start the flare with a bit of back pressure and steadily increase it to hold that airplane off as long as possible (I cannot emphasize this enough... hold it off the runway longer than you think you can), by the time your mains have settled onto the runway you should be at full back pressure on the yoke. Keep the back pressure in and "fly" your nose wheel down to the ground...which isnt very far.

The only reason power should be added is if you started the intial part of the flare too high and are dropping fast with a nose up attitude. Use the power just enough to arrest your descent and bring it back to full idle again.
Chicks dig winglets.
 
SkyGuy11
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RE: Landing With A Little Power In 152's/172's

Thu Jan 16, 2003 4:34 pm

I always land at idle in smaller airplanes such as the 152 / 172. Usually if I need power it means I was sinking too fast and hence did not perform a good approach (unless I am practicing softs).
.
 
Illini_152
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RE: Landing With A Little Power In 152's/172's

Thu Jan 16, 2003 5:12 pm

I'll second what XFSUGimp stated. In an airplane with as light a wing loading as a 152 or 172 there is no reason to have to add power in the flare to cushon a landing. If you need to do this you are either not flaring enough as he said, or if re too slow and don't have enough energy to arrest the rate of descent.

Not to confuse you, but some airplanes MAY be able to be landed shorter with power, but that is because final is flown just a few knots above stall speed, and the power is then used to flare, instead of airspeed. But even then, you'll have the power out as the mains touch down.

Read Rick Durden has a very good column on Avweb about this and many other of aviation's "old wive's tales", I'll post a link if I can find it; they seem to have redone their archives  Sad

- Mike
Happy contrails - I support B747Skipper and Jetguy
 
SSTjumbo
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RE: Landing With A Little Power In 152's/172's

Fri Jan 17, 2003 2:14 am

Usually in a 152 when I turn left base I decrease the power to 1500 RPM then use flaps and minimal power changes to control my descent whilst maintaining 70 kts until I cross the threshold. I usually then power idle to get down to 60 kts before I reach significant ground effect (try getting into ground effect when you let your speed creep up to 90 kts  Big grin). I've never had to use power to make a smooth landing (or at least one that's not rough  Laugh out loud) using that technique. I personally want to be concentrating on landing the aircraft when I'm landing the aircraft and not changing up on power if needed. That's just my personal preference though. Do what your CFI tells you first and foremost.

Cheers
-Mike
I don't know, so this is my signature.
 
SophieMaltese
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RE: Landing With A Little Power In 152's/172's

Fri Jan 17, 2003 1:56 pm

If I'm sinking too fast I'll add a little power.
 
Kay
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RE: Landing With A Little Power In 152's/172's

Fri Jan 17, 2003 5:31 pm

flaring is cruicial

you'll be surprised how long a 152/172 can stay in the air at flare. and if it does, it means it has to. the technique is: don't let it sink, do everything, flare more and more. and before it wants to sink again, flare some more to keep it in the air. and before you know it, you'll hear "iiiiiiiiiiiiiiiii" of the tires smoothly scratching on the surface of the runway.

kay
 
ExpressJet_ERJ
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RE: Landing With A Little Power In 152's/172's

Sat Jan 18, 2003 12:43 am

Usually I just idle all the way in. On final I try to stay around 1000-1200RPM. I only add power if my speed is decresing, if im sinking, or too low. But not very often.
ETOPS...Engines Turn Or People Swim
 
KAUSpilot
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RE: Landing With A Little Power In 152's/172's

Sat Jan 18, 2003 4:14 am

On final, I do whatever it takes to maintain about 65 knots in the 172 while keeping the sink rate somewhere between 500-800 fpm, usually with 30 degrees of flaps. However, once I'm over the threshold I pull the power to idle, gradually increasing back pressure and trimming as I go. If you can think about it, try trimming a lot during the flare. It really helped me smooth out my landings because I don't need to pull quite so hard for a good flare. I only add power if I'm making a "soft field landing". I suppose it is "OK" to add power all the time if you really want to, but it really isn't necessary on hard surface runways.


I was originally taught to pull the power on the downwind when you pass the approach end of the runway, then execute the rest of the traffic pattern with the power off. This method also works, but the pattern has to be a little tighter since you have no power to work with. In addition, this is good practice for making emergency power off landings.
 
XFSUgimpLB41X
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RE: Landing With A Little Power In 152's/172's

Sat Jan 18, 2003 7:30 am

From the operating procedures that I give my students:


Traffic Pattern-

- Do assigned takeoff procedure.
- Use standard callouts as prescribed by SOPA at an uncontrolled field.
- Climb at Vy using any necessary crosswind correction down extended runway centerline to 400-500
AGL.
- Turn right or left as assigned (or specified on an uncontrolled field) onto crosswind leg while maintaining
Vy and bank angle not to exceed 30 degrees.
- Climb on crosswind at continued full throttle until Vy to 900 AGL or pattern altitude-200 feet.
- Turn onto downwind, level off and establish normal cruise with crab angle as necessary to maintain the
proper distance from the field.
- Do Landing Flow..
- When abeam the numbers of the runway- Carb heat- ON, Reduce power to 1500, pitch to maintain
altitude, Flaps 10 when below 110 KIAS.
- When airspeed reaches 80- pitch to maintain and follow 80 KIAS down on the descent.
- When just past a 45-degree angle from the runway (approximately 900 AGL), turn base leg.
- When established on base leg- Flaps 20, pitch for 70 KIAS.
- Turn on final while accounting for wind- Don’t overshoot!
- When established on final- Flaps 30, pitch for 60 KIAS
- Pitch to maintain airspeed, Power to maintain desired glideslope.
- Apply proper crosswind crab angle to track down extended centerline of the runway.
- Add half of the gust factor to final approach speed in gusty conditions.
- Reference 1500 RPM as a stabilized descent power setting.
- Do landing technique as necessary- Modify pattern and descent as necessary by ATC instructions or
traffic conditions.




Normal Landing-

- Establish on stabilized final with crosswind crab angle as per traffic pattern procedure so as no abnormal
maneuvering is necessary for landing.
- When runway landing is assured, smoothly bring power back to idle and maintain 60 knots.
- Begin rounding descent out 15-20 feet above runway to burn off airspeed.
- Apply crosswind correction (aileron into wind to maintain airplane tracking down centerline.. opposite
rudder to point airplane straight down the runway).
- Hold the airplane off the runway for as long as possible approximately 2-3 feet in the air and let the main
wheels settle on the runway.
- Maintain backpressure as long as possible and let nose wheel settle onto runway.
- Use rudder to maintain directional control and apply brakes if coming to a full stop.
- If doing a touch and go- retract flaps and smoothly apply full throttle.
- When at a safe exit speed, turn off the runway.
-Execute a go-around if approach becomes unsafe/unstabilized at anytime.
-Maintain 60 KIAS +10/-5 KIAS

For maximum crosswind component landing-
-Fly final approach with appropriate crab angle.
-Reduce flaps setting to 20 degrees and increase speed 5-10 knots if so desired.
- On landing flare add crosswind correction:
-Lower upwind wing to keep yourself tracking down runway centerline
-Use rudder to keep yourself pointed down the runway
-Don’t let the airplane fly you- FLY THE AIRPLANE
- In gusty situations- be prepared for a windshear! Go around if approach becomes unsafe or a windshear becomes evident as shown through rapid airspeed and altitude loss.
Chicks dig winglets.
 
fspilot747
Posts: 3455
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RE: Landing With A Little Power In 152's/172's

Sat Jan 18, 2003 10:54 am

Hey guys..Thanks for your input.

I don't land with power the time, actually I rarely do it. I just had to do it a lot the last time I flew because it was pretty windy and my airspeed would drop, and I was just for some reason flaring a bit to much at once causing me to balloon a bit.. I just wanted to know if there was anything significantly wrong with doing that every now and then...

thanks again.
FSP
 
flightsimfreak
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RE: Landing With A Little Power In 152's/172's

Sat Jan 18, 2003 11:21 am

I was reading an above post, and someone mentioned that they put the flaps out while turning base on a 152... I just finished the transition to the 172, and if I'm correct, they have similar flap settings. I was explicitly told not to do anything with the flaps while turning, because that flap system has the possibility of a split flap... that's bad when you are turning because it is harder to diagnose. I would recomend that you wait until you are on that leg of the pattern, or before you do the turn to put the flaps down.
 
Notar520AC
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RE: Landing With A Little Power In 152's/172's

Sun Jan 19, 2003 3:10 am

I've pretty much tought myself to land "airliner style," approaching with a nose-up attitude and power. My instructor hates this, because if we had to go around, we wouldn't have the same power boost as if I was idling the engine. He wants me to trim like I'm going to nose right into the threshold and then when I get into ground effect idle the throttle and flare off the airspeed. I was surprised just at how much the Skyhawk can float when he had me try this a few months ago- I mean, I knew it could float, but just not at like 40 knots! He said it was okay to keep power until I get into ground effect, but to prevent excessive wear/tear on the tires, I need to land as slow as possible.

BMW - The Ultimate Driving Machine
 
fspilot747
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RE: Landing With A Little Power In 152's/172's

Sun Jan 19, 2003 5:59 am

Flightsimfreak: Are you sure about this turning while putting flaps down?

Can anyone else please confirm this? Many times, I set the flaps to 20 while turning base, and sometimes 30 while turning final...I haven't flown with my instructor for a while so next time I do I'll ask him, but in the meantime, can someone please confirm?

Thanks
FSP
 
XFSUgimpLB41X
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RE: Landing With A Little Power In 152's/172's

Sun Jan 19, 2003 6:13 am

Flightsimfreak.. thats incorrect. It's amazing how we instructors teach things that have just been passed down and haven't been confirmed. I am just as guilty as the next on some things, but i have put alot of effort in trying to dispell things that are just "handed down" and that i am just repeated from what i have been taught.

You will know it if you get a split flap in the turn. The correction is simple.... match the flap that is working to the one that is stuck. Generally I dont have students do their flaps in the turn just for workload issues and to keep their head up while making the turn. If we are keeping things tight though, it's perfectly fine with me to keep things flowing smoothly and get flaps in the turn.

As far as the airliner style approach... a Cessna or CRJ for that matter will not be in a nose up attitude on approach for one simple reason- no slats. Slats are what give airliners such a nose high attitude on approach. IF you are pitching to maintain the airspeed in your Cessna that is presribed for the approach, you will have maybe a nose level attitude, but typically a little bit below the horizon for 60 knots.
Chicks dig winglets.
 
flyf15
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RE: Landing With A Little Power In 152's/172's

Sun Jan 19, 2003 6:21 am

Notar, just to add in what XFSU said. What you've described leads me to believe you've very nicely put yourself on the back end of the power curve. Not always the best place to be, especially if you have to do a go-around.
 
Kay
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RE: Landing With A Little Power In 152's/172's

Mon Jan 20, 2003 8:02 pm

Me too, I had my checkride with a 747 captain and he said not to put flaps down while turning because one flap gets stuck and you're dead. maybe he does it I don't know, but he tought me not to.

kay
 
flightsimfreak
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RE: Landing With A Little Power In 152's/172's

Mon Jan 20, 2003 8:24 pm

From the 1978 172N POH:
Regarding landing with power, from Section 4 "Normal procedures" Page 4-19, Normal Landing
"...Actual touchdown should be made with power-off and on the main wheels first to reduce the landing speed and subsequent need for braking the landing roll... This procedure is especially important in rough or soft field landings"

 
ThirtyEcho
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RE: Landing With A Little Power In 152's/172's

Tue Jan 21, 2003 4:00 pm

Ahhhh, the delightful days of yesteryear and flying 152s. Great training airplane and if you don't have speed nailed at the flare it will give you a little lesson and float like it was full of helium or splat on the runway and bounce like a basketball. Yes, especially in gusty conditions, it is OK to use a burst of power to straighten out the airplane or prepare for the second landing after a bounce. I wouldn't carry power into the flare as a routine matter, however. The first problem is that the airplane just isn't going to ever touch down if you have power on and the longer you sit there floating above the runway the more gust problems you'll have. Have you done much slow-flight practice in the 152? If you have, you'll remember that, with even a notch of power in, you can walk the rudder and spend all day tooling around at what seems like 0kts. Thats the situation you are putting yourself in if you keep power on into the flare.

In the old-timey days, when there were a lot of ex-military instructors around, you were expected to pull carb heat as you passed the runway threshold on downwind, cut the power, and fly your pattern so that you arrived over the end of the runway at the proper altitude and speed. The only time that you'd touch the throttle was to "clear" the engine on final and, otherwise, no power was allowed.

I'm not saying you have to fly like that; the point is that a stabilized approach will get you where you need to be to make a good landing without using power as a crutch. Good landings come out of good approaches.
 
ThirtyEcho
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RE: Landing With A Little Power In 152's/172's

Tue Jan 21, 2003 4:30 pm

A couple of more things and then I'll shut up. As for the flaps in a turn, the "split flaps" situation doesn't seem to crop up very often in light singles; I do think its smart, if one is trying to get a student to make coordinated turns, to not introduce the pitch change associated with flap travel into the mix. I have heard a lot of old timers insisting on not deploying flaps in a turn, however.

I'm as lazy as the next person about trimming out back pressure but don't overdo it. First of all, if you have to go around, that sudden application of power is going to make the nose go way up like the Space Shuttle and nose-up trim isn't going to help matters. Secondly, when you move on to instrument training, you'll probably want a more neutral trim when flying the glideslope, anyway.
 
Jason McDowell
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Joined: Tue Apr 10, 2001 4:40 am

RE: Landing With A Little Power In 152's/172's

Wed Jan 22, 2003 3:38 am



You know, if you add power while flaring in a 150/152/172, and the conditions are even a little windy or gusty, the likelyhood of getting a tailstrike goes up significantly. I've actually witnessed quite a few tailstrikes, and almost every one was a direct result of adding power in the flare.




 
Mr Spaceman
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RE: Landing With A Little Power In 152's/172's

Wed Jan 22, 2003 5:02 am

Hi guys.

> Kay, the technique you were explaining about how to arrest your sink rate while over a runway, and then arrest it again, and again untill your main gear tires contact the pavement (just above stalling speed) was called "checking back" by a former CFI of mine.

> FlightSimFreak, I'm the one who first mentioned that I was trained to dump 20 degress of flaps while starting my turn onto base leg. I've flown with over ten CFI's in Cessna 150/152's (some got hired by an airline and disapeared, some were onboard for checkrides, and some I fired), and not one of them ever told me to NOT extend my flaps while turning onto base. I was trained to quickly look at my flaps while they were extending though, to make sure they were working correctly.

I believe that if it makes you feel better to wait untill you're established on base leg with your wings level before extending your flaps...then by all means fly that way.

The most important thing is to watch your AIRSPEED and FLY the airplane.

Chris  Smile
"Just a minute while I re-invent myself"

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