Sport Pilot Talk

Hi guys,

I was an active member of this forum a couple years ago. Long story short, I'm now the proud owner of a Zenith 601 HDS, along with two friends. It's a nice experimental plane, rather similar to many LSAs with a Rotax 912 ULS engine. Here's the spec sheet for the kit: http://www.zenithair.com/zodiac/601-hds.html

Here's my question. The 601 HDS has what Zenith calls speed wings, short chubby wings without flaps. Since it doesn't have flaps, it stalls a bit fast at about 58 mph, and subsequently lands a bit fast too. My best final approach speed is 1.3 VS0, or 75 mph.

The 100hp engine is more than enough to make it a lively plane. However, at idle power, the plane has excessive descent speed of 800 fpm, maybe even 1000 fpm. As a result, I now keep about 3300-3500 RPM on the short final up to touch down, getting a nice 500 fpm rate of descent, and subsequently I get nice greaser landings.

But I have concern about the right technique to land it in an engine-out situation. What is the right procedure to land draggy planes that don't have flaps? When I cut the engine at pattern altitude, it drops like a stone, and I usually end up adding a touch of power to reduce the descent rate. Should I just have the fate that even a 1000 fpm descent can be stopped with the right amount of flare?

They somehow managed to land the space shuttle power off, so there’s undoubtedly a technique to accomplish it in your plane.

I’d suggest finding a CFI with experience in a wide variety of planes and figuring out the best way to land your plane from a glide. Regardless of your high rate of descent, the key will still be energy management and timing the roundout and flare to arrive in ground effect with the energy to hold it off and land at approximately stall speed.

Let us know how it goes - with video if possible!

You might even want to drop the nose on short final to pick up a little more airspeed before you level off and then flare. As Eddie said, get a good CFI to help you figure this out.

TimTaylor wrote:You might even want to drop the nose on short final to pick up a little more airspeed before you level off and then flare.

Original post deleted. My mistake, the "engine out" scenario is noted.
I concur with your post above, if a higher rate of descent is acceptable. It's a judgment call.

If you have engine failure you can't add power. Your only choice is to drop the nose to get the aircraft up to an acceptable airspeed. Nobody said drop the nose when 10 feet off the ground. Obviously, you need sufficient altitude. This is actually normal procedure for many ultralights.

TimTaylor wrote:If you have engine failure you can't add power. Your only choice is to drop the nose to get the aircraft up to an acceptable airspeed. Nobody said drop the nose when 10 feet off the ground. Obviously, you need sufficient altitude. This is actually normal procedure for many ultralights.

Concur . . . although, I have no experience with ultralights.

rezaf_2000 wrote:Hi guys,

I was an active member of this forum a couple years ago. Long story short, I'm now the proud owner of a Zenith 601 HDS, along with two friends. It's a nice experimental plane, rather similar to many LSAs with a Rotax 912 ULS engine.

My understanding is that the 601 HD is an LSA, but the 601 HDS is not, because it stalls too fast. The S indicates a short wing compared to the HD.

Right!

For it to be an LSA, Max stall speed is 51 mph or 45 kts CAS. The Zenith web page is a little vague about it... They list 48 and 54 but do not specify mph or kts... Nor do they state if it is CAS. These are for the HDS.

Another approach speed to consider is your Vy, best climb speed. It will be within a knot or two of your best glide speed.

MrMorden wrote:

rezaf_2000 wrote:Hi guys,

I was an active member of this forum a couple years ago. Long story short, I'm now the proud owner of a Zenith 601 HDS, along with two friends. It's a nice experimental plane, rather similar to many LSAs with a Rotax 912 ULS engine.

My understanding is that the 601 HD is an LSA, but the 601 HDS is not, because it stalls too fast. The S indicates a short wing compared to the HD.

I didn't get the impression that he was implying that it was a LSA.

This article by Jack Dueck describes how to determine your best glide speed for any airplane.

EAA Test Flight Card, Best Glide Speed
http://www.eaahighriver.org/sites/defau ... ngPt19.pdf

The Best Glide Speed can be described as the least altitude lost per distance traveled. If we lose power, and set up our best glide speed, it will give us the greatest horizontal distance that we can travel and hopefully our best chance of selecting an appropriate off-airport landing site should it become necessary.

We will work with three parameters time, distance, and indicated airspeed (KIAS), and determine the loss in altitude over a set distance in a set time period. The test is simple, and the reduction of the data involves several simple steps to provide a single useful airspeed for our best glide distance.

Jack's previous article about pitot static and IAS check is at http://www.eaahighriver.org/sites/defau ... ngPt18.pdf

My first CFI told me that the two most useless things to a pilot are runway behind you and altitude above you. Trim for best glide speed, and if you're too high when approaching for landing, you can always slip to lose altitude (even if you don't have flaps) once you know you're going to make it to the runway or off-airport landing area.

The third useless thing in aviation is fuel on the ground. Often, that is the cause leading to one of the other useless things (altitude above you).

drseti wrote:The third useless thing in aviation is fuel on the ground. Often, that is the cause leading to one of the other useless things (altitude above you).

Excellent point!

3Dreaming wrote: I didn't get the impression that he was implying that it was a LSA.

I assume that most folks on a board called "sportpilottalk" are either SPs or PPs flying under SP privileges. Not an absolute of course, but I think generally correct. Just pointing it out in case the owner thought the airplane is something it isn't.

...or Commercial or ATP's flying under Sport Pilot privileges.