No flare at 60 kts....

...and full flaps.

Made an approach to short runway over trees and forgot the previous established procedure to that runway - add a bit of power going into flare out of a steep 60 knot descent.

Wow, what a sinking feeling as there was insufficient energy to stop the descent, hit pretty hard on all three and bounced.

Power was on quick after that and flew out of there, went around and tried it like in the past and squeaked it on.

Live and learn, my old brain needs more flying....no damage to trusty RV 8...just my ego for letting it happen.

Something's not right. You should have plenty of energy to flare at 60 kts.

Mel said:

Something's not right. You should have plenty of energy to flare at 60 kts.

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That may also depend on the approach angle.

Mel said:

Something's not right. You should have plenty of energy to flare at 60 kts.

Click to expand...

The approach angle was very steep Mel. Granted, I did not hit aft elevator stop but the nose was quite high when runway connect was made.

No intent to start an aerodynamics dissertation here, just making the point a little power going into flare out of such an approach makes it work out much better.

David, glad to hear you made it through your "teachable moment".

On a steep approach, over trees, to a short grass runway, at 60 KTS, the dissent rate can be sufficiently high that ground effect will not provide enough cushion for a comfortable flare (assuming not flying behind the power curve).

I have these exact conditions and find I need a few extra knots or a small burst of propeller to help "mush" into ground effect.

It sounds like we have similar behaving airplanes.

Your teachable moment is my teachable moment.

Setup at 60 kts, steep approach, full flaps, mine comes down as David and Glen described. If your not careful the ground will come up and smack you. A little power right near the end helps to arrest that decent. But you two are landing on short runways (- 1500 feet)? Challenging.

I envy you guys that get to fly off grass, drop it in over trees and get her stopped. Nothing like that around here to practice on.

David, was that a wheelie or a 3 pt?

This is consistent with the behavior of my non-RV. Below a certain speed, I can change the deck angle but not seriously change the trajectory.

Dave

My RV-8 at 60 knots solo with power off and full flaps will not quite arrest the descent. But it will at 65 and float a short distance.

Also beware of the accelerated stall with aggressive flare out of a steep descent. You will get no warning. Just immediate loss of lift.

Chkaharyer99 said:

Your teachable moment is my teachable moment.

Setup at 60 kts, steep approach, full flaps, mine comes down as David and Glen described. If your not careful the ground will come up and smack you. A little power right near the end helps to arrest that decent. But you two are landing on short runways (- 1500 feet)? Challenging.

I envy you guys that get to fly off grass, drop it in over trees and get her stopped. Nothing like that around here to practice on.

David, was that a wheelie or a 3 pt?

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It touched down 3 point....and bounced, It would have been impossible to arrest the descent from bounce, full poser saved the day.

A little power helps break the sink, and when it touches a little forward stick makes it stay there.

Two other possible contributing issues.

With trees around some of the headwind component may have been lost near the ground.

Airspeed may have dropped below your desired 60 kts as the natural reaction is to slightly pull back on the stick when the ground is rushing up. Not easy to notice this as the eyes are on the landing strip rather than the ASI when near the ground - good argument for an AoA with audio.

Fin
9A

Practice

I landed in Gadabout Gaddis in ME one day in my 3. The approach
Was over a mountain with tall trees and had to get down fast to the threshold. My power management was not good and came in hot ,landing after one go around, half way down the runway and almost ended up in the river at the opposite end. Bad experience, had the grass been wet I would have been swimming. I later found out this is an infamous runway for wet airplanes.

I spoke to my transition trainor, he asked my stalling speed full flaps;52mph.
He suggested practicing slow speed at altitude. Flying at 60 mph, I was able to arrest my decent to 0 with 2400rpm. However, I've learned 60 mph over the trees is to slow with little margin for error. The plane sinks like a stone and to easy to get behind the power curve. Not to mention very difficult to determine an accurate glide slope to clear the trees as the high nose pitch makes it difficult to see over the nose.

In sum, 70mph is a better number adding power in ground effect to soften the landing. The practice was invaluable for short field obstacle approaches. Better visibility over the nose to actually see the trees. This was also great practice for an emergency landing or an ice landing. How much power do you need to maintain 0 decent at slow speed? Fully loaded?

Good call to go around after the big bounce. Trying to re-flare with so little airspeed could have gotten ugly!

I have power lines 200' off the North end of my 1800' grass runway. What makes matters worse is the strip declines slightly to the South. I am still trying to find the best method of landing. 75 mph approach will bring me in steep enough but I have to goose it just before the flair. If your coming in with a 15 mph headwind at 75 mph and the wind lays down just before that flair it can ruin your day!

Flare at 60 nauts

My 8 although in the CG parameter is nose heavy. It is all but impossible to 3 point. It will decend right through ground effect at slower speeds. Of course as you speed up it will no longer 3 point. Have not flown since taking 23# off prop and 8# off starter and have not measured CG yet. I'm thinking it will be much happier landing.

At 60 knots and the resulting high angle of attack the induced drag is very high and the flair at the bottom results in a spike of increased induced drag which adds to the sink rate with little vertical lift component...

Power boost

A shot of power in the flare, not only compensates for the induced drag spike, but puts higher velocity air over the inboard wings and flaps (faster air over the lift producing surfaces) Done correctly, neither the IAS or groundspeed should increase. In military parlance, this is "blown lift".

Cheers, David
RV-6A

Mel said:

Something's not right. You should have plenty of energy to flare at 60 kts.

Click to expand...

60 kts on approach in one aircraft may not be the same as 60 kt on another, for several reasons:

• ASI instrument errors can be 5 kts, or more on each aircraft,
• static system position errors can differ between the two aircraft, leading to differences in indicated airspeed,
• one aircraft may have a leak in a pitot or static system, leading to erroneous airspeed indications,
• gross weights may differ between the two aircraft, leading to one aircraft being closer to the stall than the other,
• CGs may differ between the two aircraft. At the same gross weight, forward CG requires the tail to create more down force than at aft CG. The tail down force must be compensated by increased lift from the wing, so the total force = the gross weight. Thus the wing must create more lift at forward CG than at aft CG,
• Different props have different amounts of discing drag. Some props have enough discing drag at idle to disrupt the airflow over the inboard part of the wing.

Bottom line: while an approach indicated air speed of XX may be perfect in one aircraft, it may be completely wrong in a different aircraft.

MikeyDale said:

I have power lines 200' off the North end of my 1800' grass runway. What makes matters worse is the strip declines slightly to the South. I am still trying to find the best method of landing. 75 mph approach will bring me in steep enough but I have to goose it just before the flair. If your coming in with a 15 mph headwind at 75 mph and the wind lays down just before that flair it can ruin your day!

Click to expand...

We have similar situation at our airpark due to tree's that also continue a few hundred feet down one side of the runway. It has "ruined" more than one persons day, including one of my buddies who was a little late on the throttle - bent gear, prop strike, etc... when the "bottom" dropped out on his RV7.

I have had a bit of this discussion before, but pulling back to arrest a sink is the absolute worst thing you can do. I hadn't hear the term "blown lift" before for a quick burst of power, but that is extremely effective. In those conditions, I also insure that I am not at full idle, just a touch of throttle seems to allow me to get off the post quicker. If the bottom drops out, I am on the throttle and pushing the nose down. You want airspeed, not more drag.
If you have an extremely short field, the "long props and big rocks" guys routinely drag them in under pretty high power. Watch the Valdez videos. I just don't like to be hanging off the prop near stall.

We all have had, and will continue to have, hard landings. More than once I have gotten out of the RV6 and fully expected to see some horrific evidence of damage to the gear. RV's are pretty darn tough....

I notice a 9-10 knot speed loss from the round out.
I try to make closed throttle landings to keep my skills up. I notice when gliding down final with full flaps that the pull to run parallel to the surface slows the plane down that much. I have come down final too slow and that roundout pull has mushed thru and put me on the runway earlier than I had planned. Any less airspeed would have been an accelerated stall with an unpleasant arrival.
Jim Triggs, our EAA Chapter 326 Safety Guru has an excellent presentation on Low Aspect Ratio wings and RVs.
This condition applies to Thorp T-18s also.
This is probably where the advocates of Reserve Lift Indicators begin commenting...