Flying heavy

[sanships]

I have 20 hours on my 170 now. I flew at max gross yesterday and when on short final, tower could not accomodate a "land long" that I was expecting to get so had to modify my approach to reach the numbers. Of course I was a little high(300') and had to chop power and increased airspeed a bit. I thought I could get a wheel landing out of it but bounced. Then I changed it to a 3pt landing after powering up and fighting for alignment and center line. It was interesting to say the least.

The difference between flying heavy and light is like night and day! The power needed to recover from a bounce and the reaction of the aircraft all seems very sluggish. The sink rate that developed was also higher than expected making my timing for the roundout and flare a bit off which started me doubting myself. I think that it all started from not being decided if I was going to do a 3pt landing(which I am comfortable with) or a wheel landing(which I have made only when light). The only thought running through my mind was to fight for control all the way till it was stopped. Tower probably found my landing quite ammusing that they asked me what type of plane it was(I have the only 170 flying in the Philippines).

Are there tips for flying heavy? What speeds do you guys use for light versus heavy conditions when landing 3pt and wheelers?

[1SeventyZ]

I have discovered the same thing with similar "interesting" outcomes. I'd be interested too to hear any rules of thumb for target airspeed modifiers when at or near gross.

[Brad Brady]

Sanships,
Where as I'm no landing gurue....A land short, and wheel landing are oxymorins, Your landing the aircraft at flying speed when doing a wheel landing.....A little power and up elevator and your flying in ground effect.....After that your crashing unless you add real power. Speeds and power settings are on a airplane by airplane basis...No aircraft fly the same....You need to go out and experiment with what your aircraft will do......Brad

[Robert Eilers]

The Cessna 170, in my experience, is sensitive to total aircraft weight - assuming you are sitting behind a C-145. When the Cessna 170's total aircraft weight is 2000 lbs GW or less the airplane is quite nimble, i.e., short takeoff run, good climb rate and "flighty" in the landing flare. As the gross weight of the aircraft increases above 2000 lbs the performance and handling characteristics of the aircraft change. One thing in particular that changes is the location of the C.G. As the 170 is loaded toward Gross Weight the C.G. tends to move forward. The heavier C-170 handles differently in the flare that the lighter C170. The flare of the aircraft is shortened - the airplane tends to float less - and it generally requires more back pressure on the control wheel to achieve the three point attitude. The result, if you are accumstomed to landing a light C170, is the bounce. The other factor, based on your description, is probably the fact that you were unable to achieve and maintain a stabilized approach speed.

One suggestion to improve your gross weight three point landings is to carry a little more speed into the flare allowing you to better achieve the three point attitude. Best remedy is practice - at gross weight.

[Roesbery]

Don't forget that if you are high on short final you can do a slip. Loose a lot of altitude in a short distance without gaining airspeed

[GAHorn]

Don't forget that if you are high on short final you can do a slip. Loose a lot of altitude in a short distance without gaining airspeed

Sanships has a B-model. If he has full-flaps deployed ...HE MUST NOT ATTEMPT A SLIP.

It 's been my experience that as weight is added to the B-model that the CG shifts AFT...not forward. This presumes that the added weight is fuel and/or baggage, after passengers have been seated.

It has also been my experience that at light weights the B-models land better with less than full-flaps (I usually select 30-degrees). At heavy weights (more than 2,000 lbs) I find full flaps (40-degrees) to be better.

In ALL cases.... use a stabilized approach procedure. Also... MAKE UP YOUR MIND BEFORE SHORT FINAL as to what kind of landing you will attempt. This is especially important when the winds are high or gusty. Do NOT wait until short final to decide whether it will be a wheel-landing or a 3-point. Last minute choices are not decisions.

[voorheesh]

I believe that the wing will always stall at the same critical angle of attack but it will do so at a higher airspeed at heavier weights and forward CGs. (forward CGs result in higher download on the horizontal stabilizer resulting in higher stall speed). The problem with a taildragger is that the CG is behind the main landing gear and if the wing stalls at a slightly higher airspeed than you are expecting, the main wheels will contact the runway stopping the descent and the CG (behind the mains) will continue to descend (unless you stop it) increasing the angle of attack which produces more lift like right now. This combined with the bounce from the main wheels will get you airborne and you will find yourself with less airspeed and less control, a recipe for big problems. I don't want to get into the wheel vs 3point argument but if you are going to 3 point you want to get that tail down early rather than later. The AFM for the Husky recommends touching down tailwheel first which I find interesting. In a Supercub, it seems you get better landings if you feel the tailwheel brush a little before the mains touch down. I like a book called "the compleate" taildragger pilot. That is not a typo by the way. That writer has a lot of good things to say on these subjects. I would also like to say I have had the exact same experience as the guy who started this thread and it sure feels good when it rolls out straight after scaring the #@$%& out of you!

[GAHorn]

... (forward CGs result in higher download on the horizontal stabilizer resulting in higher stall speed). ...!

Another way of saying that a forward CG results in greater wing-load and therefore requires greater lift to maintain altitude. An aft CG results in the tail carrying more of the total weight of the aircraft and therefore relieves the wing of a portion of it's burden...therefore results in a lower stall speed. (but a more exciting stall when it actually occurs.)

[Hawkeyenfo]

A lot of data on landing heavy and CG issues but, never forget:
DO NOT LET THE TOWER TELL YOU HOW TO FLY THE AIRPLANE!!! If you are cleared to land, the runway is yours unless the Tower directs you to discontinue. Land it safely. Always remember, you are the pilot. If you are uncomfortable with what the tower tells you, ask for clarification. If you are uncomfortable with a rushed landing or landing beyond your comfort level for that moment.....PUSH the throttle forward and take it around. No one can fault you if you state your intentions and try it again.
We often forget that we are the PIC and, as such, have a responsiblilty to maintain Situational Awareness and conduct our flights in a manner which we can control. If you end up prnging the plane or hitting something on the ground, the guy in the tower will not be blamed.... you will.

Be predictable, maintain SA, state your intentions, follow checklists, decide what landing you will do prior to crossing the threshold, don;t be talked into a bad situation. Fly safe!!

[Bruce Fenstermacher]

As most know I fly helicopters for a living and as such I fly more approaches in a helicopter than an airplane. Helicopter approaches to a confined area or most hospital heliports are steep approaches. I therefor tend to find myself high on my approaches when in my Cub and 170. So I've become very familiar with loosing altitude quickly.

As George points out you DO NOT want to slip a B model with flaps deployed. It might not get you the first time but when you can least afford it, slipping with full flaps will blank out air over the elevator causing it to stall and you will be looking straight down.

What I have found though is it is not necessary to slip a B model. If you are high deploy full flaps and push the nose over and pick up an approach path to a point about 300 feet before your intended landing point. Yes you will gain some airspeed but not much. When you get just below the correct glide path for your point of touch down pull the nose up and adjust your path. The increase airspeed you pick up will bleed off as you float to touchdown. Obviously there is a point at which no approach can be saved and it is time to go around.

Flying heavy in any aircraft is different than flying light. The aircraft has more energy to stop in a flare and won't respond as quickly either. The hardest part about this is remembering to plan for it.

[1SeventyZ]

I can't remember the last time I used a forward slip to lose altitude. I used to do them frequently in other aircraft(152), but after some dual in Reno about 5 years ago in a 8KCAB (no flaps) with an instructor who was huge on pitch attitude flying, I've simply adopted a technique of reducing airspeed such that my decent rate increases. You can really get 'er to sink like a rock at any flap setting if you use between 60-65 mph. Of course, at max gross you'll be closer to stall speed and/or sink even faster at a given airspeed. If I roll out on final and I'm high, the first thing I do is pull back and bleed off some airspeed, even if it seems to arrest my descent momentarily. Once I'm back on normal glideslope I usually pitch back up to 68 or 70 mph. I'm also a pitch trim zealot, it seems to make stabilized approaches far easier...however I've lately come to prefer a lot of pitch down trim for wheel landings, and a lot of pitch up trim for 3-pointers. Trimmed somewhere in the middle creates kind of a dead feel in pitch response.

Since reading about tail blanking stories with 40 deg flaps in the 170B, I've taken it very seriously. The fellow who owned my aircraft before me told a tale of staring straight down at the ground on short final after slipping. My question is: Is the 30 deg setting OK to hard slip?

[jrenwick]

Quoting the owner's manual for a '56 170B:

The flaps on the 170 allow steep, well controlled approaches making slips unnecessary. Slips with full flaps are to be avoided because if the slip is extreme enough at a relatively high airspeed, the airflow is disrupted over the tail surface resulting in a sudden and steep, downward pitch of the nose.

John

[Roesbery]

Don't know about you folks, but at 300 agl I only have 20 degrees flap. I only pull full flaps when the landing is assured if the engine should quit. Slips like any other part of flying should be practiced untill you know how to handle them, heavy, light, in between. Same as practicing what to do if the engine quits "now", should be automatic, don't even have to think about it. You do always have a best spot picked from where you are, Right. As for full flap slips, yes, the nose will drop right quick at some point, as you enter the slip, but if you ease into it slowly and gently you can feel it start to break just before it does and you can recover with neutral controls in less than 50 feet when it does, and if you are really paying attention less than 20 feet. Now slamming one rudder to the floor might be real interesting, never been brave enough to do that. Not something to do in normal flying, but good to know what does and does not happen, just like knowing what happens in a spin entry or any of the stall entries