I had a chance to go on a breakfast run yesterday in a buddy's 601 XL/Jabiru 3.3 liter. I came away from the experience a little puzzled and possibly concerned... and I'm wondering if the issue is pilot or if it's just that airplane.  I was not handling the controls for this experience, but I was hanging on to whatever I could. 

For starters, the takeoff was nothing like my 650 demo ride with Roger at the factory. No flaps, screaming down the runway to 75 mph and then literally leaping into the air in an immediate climb... I thought it would/should have been a much less forceful liftoff and then go into a good steady climb.  

Landing was even more "exciting" - no flaps were used, approach speed was again around 75-80 mph.  Nose was always high, basically flew it right into the runway with little to no flare. The second landing (coming back from breakfast) got crabbed around 30 degrees, 25' off the deck, the plane came down and the gear straightened it out, but bounced back up around 25' and came down, again I thought it was hard - but the airplane seemed to handle it ok.  I looked at the gear when I got out.  

Kudos to Zenith for designing such a strong airplane!

My questions are,

1. Is the elevator authority in the 601/650 so sensitive that it's hard to make a nice gentle departure or use ground effect on takeoff?

2. Is it normal for 601XL's to fly nose high?  It seemed like it was typically difficult to see over the panel. Trying to trim the plane to lower the nose just made it lose altitude.  If that is true of the XL, can I expect my 650 to be different?

3. Is it normal to not use flaps? I suspected that some of the approach nose-high attitude and high landing speed was because they were not used.  The PIC didn't use them because he has no position indicator, and was uncertain of "how long to hold the switch" for any % of  extension/retraction.

4. Am I lucky I survived?

Thanks

Brian M.

   

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Hi Brian,

I don't own a 601/650/XL plane so I won't comment on #2 but for #1, I don't think that it is HARD to make a nice/gentle departure and stay in ground effect... You have to dose the input to the elevator and you can pretty much stay in ground effect forever...unless it is crazy WINDY with lots of turbulence ! Then, you want ot grab altitude ASAP and clear the ground!

On #3, I would say it is the pilot choice and weather to use flaps or not. If you do use them, you lower the nose and the speed at which you can land... Makes for a smoother touch down every time. If you don't know the plane or are not used to the flying envelop in which you're flying, then coming in faster keeps you further from the stall and that alone keeps you safe. I don't have an incidence meter for the flaps, you can always LOOK OUTSIDE to ascertain how far down they're deployed... After all, these aren't BIG planes !

On #4, Not really... I don't think you were in any real danger...The pilot made sure he had plenty of speed on takeoff not to stall the plane ... And he kept Lots of power with no flaps coming down. SPEED = SAFETY remember that !

I would suspect that either this is a low time pilot, a new plane for this pilot or the pilot didn't fly this plane with full gas and 2 on board very often (unknown configuration near gross weight). 

Near FULL GROSS, planes behave differently; they are slower, heavier and require more power to sustain flight and let's face it, it is not that often that we fly with a copilot (heavy ???). Also, WEATHER and especially gusty conditions would make me refrain to use flaps....You get tossed around more with the flaps down...

It's not always easy to be the PIC but sometimes it ain't easy being a knowledgeable passenger !

Regrads,

Norm

CH701 C-GFEU

PA28-160 

 

I should have mentioned that departure conditions were 8:00 am, dead calm, and the pic was relatively new to the type, with about 20 hours. My intention is not to demean him or his skills - but more to learn about any idiosyncracies of the airplane.
And also, that was my first-ever experience being in an a/c crabbed 30 with the ground 25' below... I'm glad my bladder was empty.

Brian,

 

I have always said the 601XL is pitch sensitive.   Obviously that can exascerbate itself close to the ground. Has the pilot ever gotten any real training in a 601XL?  An instructor familiar with the authoratative elevator could certainly help him master both the takeoff's and landings.  Even with a good transition instructor, my first few solos were probably not too unlike what you experienced.  But with practice and adherence to what my instructor showed me, my 601XL was easily tamed in short time.  Dare I say that my airplane (and its low wing ground effect) makes me look like a good pilot as I grease the landings most of the time. Compare that to my C-150 training when any greaser suprised both me and my instructor.

 

#1: No.  Gentle departures, and landings, are easily possible despite the authoratative elevator.

 

#2: My Jabiru powered 601XL has a Dynon D180, where I can download pitch information.  It shows that I cruise at around 1-1.5 degrees nose-up.  I do not find that a problem.  But with different circumstances, others have complained about the pitch angle. I had a slightly higher anlge of attack early on before I re-pitched my horizontal stabilizer nose-down to take out excess trim tab angle.  I think the 650, and the different wing incidence angle, was meant to improve the view over the nose.

 

#3: I do not use flaps unless going into or out of a grass strip, and I use about half.  It is easy to see the flap indication by looking over your shoulder at the flap.  I have half and full flap indications drawn on my aileron inner wall, so with neutral ailerons, I can get a quick indication of approximate flap travel.  I recall I am ~4 seconds for full flap travel either way.

 

My no-flap takeoff technique is after application of power and air over the elevator, is pull the stick back to where it feels neutral.  While accelerating through 50mph I pull the stick back approx. 1".  This unsticks the airplane with a gentle pitch angle.  I eventually settle into a 75mph climb, which is my Vy.

 

On landing with no flaps, my approach is around the 75-80 MPH as you experienced, but I slow it to around 70-75 over the fence and I am flaring around 60-65mph or so.

 

There are many videos of 601XL's taking off and landing on this Zenith site and I suggest you view them to get a better baseline that shows what Roger demonstrated to you is routinely attained by us normal people. Here are a few of mine that are quite typical for me.  They are not nearly as 'exciting' as you described:

 

No flap landing on pavement:

http://www.zenith.aero/video/oshkosh2010arrival-1

No flap takeoff from pavement:

http://www.zenith.aero/video/departoshkosh2010-1

Half flap takeoff from grass:

http://www.zenith.aero/video/waco91810-1

 

Good luck,

 

Dave

Thanks, Dave!

Definitely looked smooth.

Brian M

Hi Brian,

What you describe has not been my experience at all.  I can make smooth takeoffs and landings without difficulty.  Yes, the 601 has a responsive elevator, but it is not so overly sensitive that it makes precise or smooth maneuvering impossible or difficult.  You just can't ham-fist like a Cherokee or a 182. 

Early in my phase 1 testing I discovered that I was waiting too long and built up too much speed for lift off.  I used to rotate at 65 MPH and the 601 would rocket off the runway.  I started applying gentle back-pressure around 50 to 55 MPH and my takeoffs were much smoother and consumed much less runway.  At gross weight I'm always off the ground in less than 1000 feet, even on a 90 degree day.

I find that my 601 does fly slightly nose up, but not to the point where visibility was compromised.  Hard climbs do produce a steeper angle and visibility over the nose is somewhat diminished.  If I recall correctly, one of the changes in the 650 is the incidence of wing which brought the nose down in level flight.

I've taken off and landed with 5,10,15,20, and 25 degrees of flap extension.  My conclusion is you don't really need them.  5 to 10 degrees help with shortening the takeoff run and improves climb somewhat.  Full flaps let you fly slow and descend steeply.  I only see that necessary for extremely short runways.  In general I don't use flaps for landing or takeoff.  By the way, the flaps induce a healthy nose down condition so up trim and back pressure are a must.

No offense to your friend, but it sounds like he can use a little more practice exploring the low end of the 601's speed spectrum.  Another thing I've noticed makes a difference is landing gear.  I have the Grove gear which sit a bit taller than stock.  My nose is pointed down with my gear compared to the nose pointing up on my friend Roger's stock gear 601.  My plane will not lift off on its own no matter how fast you go.  It is glued to the ground until you apply back pressure.  I found this to be a nice feature upon landing in high winds, especially cross winds.  Once my plane's nose wheel touches down it is stuck to the runway.

I've included a link below to a short youtube video I compiled for you to get an idea of typical takeoffs and landings in my plane.  I believe only one of the landings and takeoffs were in calm winds.  The rest were in pretty windy conditions. 

https://www.youtube.com/watch?v=D3cbH_k5TMc

Good Luck,

Ken Pavlou

Awesome video, Ken!

I'm sure my pal would admit that he could use more time, and he's averaging about 4 hours per week.  He told me that he was sorry I had to witness "the worst landing I ever made" - my only care was that we were in one piece, and secondly, that his plane took it without any apparent issues and was OK.  

I'm sure that the bounce we took was exacerbated by the "hot speed" coming in, we were above 75 mph when the plane got crabbed (an unexpected gust I think) and it kind of side-slipped from that crab very quickly to the pavement.  The airframe was immediately jerked back toward on-center, and then went airborne again.

This XL is pretty "light" based on what I've heard - it weighs around 780 lbs.  We had around 13 gallons of gas and the total human weight was around 460 lbs. - so we were right at gross of 1320.  

I came away from this with an absolute determination to get some high-quality training in type, like maybe going to Arizona or Tennessee to one of the guys who does 601/650 transition training. I will also hire someone with high Zenith experience to do the initial test flights of my 650.

Really appreciate all of the responses, 

THANKS!!

Brian M

I know I am late coming into this discussion, but I had a similar problem on my first few flights. The main landing gear hoop was installed backwards. This causes the main gear to be several inches too far aft, and it takes a LOT more aerodynamic force to get the nose in the air.

Bottom line.....push down on the tail, it shouldn't take more than 25-30lbs of weight to lift the nose wheel.

This will show up when you scale the airplane too. I think I remember about 180lbs on the nose scale.

Wes
N650WP
601XLB KGSO

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