Landing HooDoo - Operations at or close to MTOW

[.Evan.]

Things have been going well. Lots of milestones and such, but there is still so much more to learn.

 

What I am finding now that I'm flying with different people (i.e. different weights), is that the aircraft seems to react very differently when landing at or close to MTOW. My instructor is not very heavy at all, and I'm only a medium build. The flying school has fuel in the hangar, so generally we'd only have a light fuel load meaning that the J160 was usually operating fairly low in it's weight range during my training.

 

I have been able to get fairly consistent greaser-ish landings when practising by myself, but I am finding that once the weight is up (bigger Pax, more fuel, etc), it is a very different ball game. During the hold-off, instead of continuing to fly until the speed bleeds off and then it settles on to the runway, it seems to hold-off normally and then suddenly 'plop' on the deck from that last half a foot or so. Not entirely unsafe, but not so comfortable for my Pax (or me!). I think it is due to the already high wing loading on the 160 - add some extra weight and it decides not to fly so very much earlier.

 

Has anyone else found this too? How do you guys cope with this change?

 

I can think of two things:

 

1. Keep a trickle of power on through the flare and hold-off and pull steadily to idle once the mains are on the ground.

 

2. Raise the approach speed by 5 knots or so, bringing more potential energy into the flare/hold-off scenario.

 

Or, am I barking up the wrong tree entirely?

 

 

[fly_tornado]

You need to adjust for the extra weight with more lift ie go faster.

 

 

[Guernsey]

You need to adjust for the extra weight with more lift ie go faster.

Or hold off just one centimetre above the runway to lessen the ' plop '. :thumb_up:

Alan.

 

 

[.Evan.]

You need to adjust for the extra weight with more lift ie go faster.

Thanks FT, will try that.

 

Or hold off just one centimetre above the runway to lessen the ' plop '. :thumb_up:Alan.

Hehe yep G, I wish I could judge that perfectly every time!

 

 

[.Evan.]

... Your approach speed in ultralight types is normally given as the correct speed for MTOW, so increasing your approach speed will not resolve your issue. You just need to understand that the hold off will be a shorter duration with higher weights and allow for it to settle quicker. Practice will make perfect.

Thanks David, that thought was lurking in the back of my mind.

 

A solid 'plop' is not a bad landing, a firm sit on the runway always means she is stalled and will not be going anywhere other than on the runway. A solid sit is always preferable to skipping along a runway with flying speed; 'skipping' is a very bad technique and will get you into trouble one day.David

I feel much better now! Practice will certainly make it much better. I've already booked a session of dual with my instructor (and a full load of fuel!) to work through the different feel of MTOW operations.

 

 

[poteroo]

Because of your higher weight - stall speed is higher than you are used to. Carrying perhaps idle + 200-300 RPM will bring that stall speed back to what you are used to. If you want to make a glide approach - then be prepared to speedup your elevator inputs in the later part of the holdoff.

 

happy days,

 

 

[Neil_S]

Hi Evan,

 

I found the same, so now when I have 2 up I add a small touch of power just to arrest that final bit of descent and the landing is smoother (no flaps in the Gazelle). Close it right down when the mains have touched.

 

Cheers

 

Neil

 

 

[Mazda]

Yes, heavier means faster approach, and conversely lighter means a slower approach, and it is obvious on some types when solo, the 'normal' dual spee feels too fast.

 

If you do feel like the 'plop' is coming, do add a trickle of power to cushion it.

 

Also be aware of the effect of weight on take off and landing distance.

 

 

[drifter45]

I got quite a shock the first time I carried a 110kg pax in the drifter. I've found adding a good 5kts is easier on the gear.

 

cheers John

 

 

[.Evan.]

Thanks all. :thumb_up: I'm going to raise the approach speed a tad and see what happens.

 

I'll also give the ThrottleTweak® method a bit more of a try.

 

 

[kaz3g]

Thanks all. :thumb_up: I'm going to raise the approach speed a tad and see what happens.I'll also give the ThrottleTweak® method a bit more of a try.

Hi Evan

 

Perhaps stick to the book approach speed figure for the flap setting (if relevant) but add that trickle of power so you have a little more control to play with as you hold off?

 

Remember to keep the nosewheel raised so you land on the mains... try to keep the yoke/stick coming back as your speed drops just above the rwy until it gently stalls and touches.

 

Look forward to your horizon but use your peripheral vision to help you estimate height AGL and lateral placement on the rwy.

 

And practice :-)

 

kaz

 

 

[ParkesFlyer]

Hey Evan,

 

Thanks for asking the question, I've noticed the same thing! I'd tried a little power in the flare (it works with models!) but haven't mastered it, - will keep practicing!

 

-PF.

 

 

[naremman]

Learning to fly in a two seater with an instructor is onboard usually means that MTOW in not too far away.

 

Remember when the instructor jumped out and all of a sudden you were in charge of a far more lively performer?

 

In the GA environment pilots learning in a C172 or Warrior with half tanks will invariably get a hell of a surprise when they try a Full Load check. Yes, it is the same aircraft that you trained in.

 

There is no better demonstration of the effect of weight than in formation flight. Many moons ago I trained for my formation endorsement at Northam with a friend who had a Jodel DR 1050 Sky King. My Victa Airtourer 100 and the Jodel were well matched at the same load, but a variation of as little as 50lbs gave the lighter aircraft a noticeable advantage. Before we went for a training run we used to scout through the aero club trying to con onboard the most likely person that would even our weight out!!

 

On this site you oft see quoted: "Don't take an aeroplane anywhere that you mind did not visit five minutes ago". Rolling onto final all the variables for the landing should already be factored in. Reacting to surprises on final does not always produce sound results!!

 

 

[.Evan.]

Landing Hoodoo... ABOLISHED!

 

Went up with my instructor this morning, carrying an almost full load of fuel and went through several CCTs using a couple of techniques. He also briefed me extensively on the mathematics and the concepts behind everything that is going on during the various phases of landing (taking my understanding to a new level).

 

Result: Much more consistent and controlled touchdowns (not necessarily all greasers, but much more consistent).

 

On this site you oft see quoted: "Don't take an aeroplane anywhere that you mind did not visit five minutes ago".

Now that I've experienced it in a safe and supportive environment, I now know what to expect and what to do. My mind can be five minutes ahead.

 

Thanks everyone for your help and support!

 

P.s. more details, as usual at my blog. If you wanna.