Zenith 601...2 questions

[Aaron H]

I'm in the market to buy a plane and the 601 is one that would fit my mission.

Question 1: would the 601 hold up on tie downs the same as a Cessna or Piper?
(No hangars available in the area at this time)

Question 2: has any wings follen off since the "b" has been installed?
(From the reasearch I did online, seems like they never found out why and the b mod was there best guess to solve the problem)

Any input would be appreciated
Thanks!

 

[bflynn]

No idea about 1. On question 2, from what I have read, no. The problems came from over stress situations in the first place and the reengineered wings are good. There was a weakness in the original 601 design, which was fixed long before the B model. You can think of 4 iterations - 601, 601 with wing fix, 650, and 650b. Don’t pull 9Gs and they will be fine.

 

[Aaron H]

Thx bflynn,

U said the wing was fixed before the b mod, is there a model year that they changed the design and what was the change?

Thanks

 

[Kenny Phillips]

I did research into this plane, as a friend wanted to build one with Corvair power. The "best guess" as to what was occurring was overspeed (either intentional, or due to poorly installed instrumentation), resulting in wing or control surface flutter (cause unknown, perhaps due to structure flex) and the bad things that happen because of that. There are several article on the subject, and an FAA report.
I'd certainly want to verify that the wing met or exceeded the current version! Zenith is likely the best source for comparison material.
https://www.flyingmag.com/technique/accidents/aftermath-pattern-failure
https://www.faa.gov/aircraft/gen_av/light_sport/media/Zodiac.pdf

 

[Lndwarrior]

1. Zenith 601 uses 6061 T6 aluminum. Most Cessnas use 2024 T3. General consensus is 6061 T6 i more corrosion resistant than 2024 T3.
2. No. The B upgrade required on all 601s includes a very strong I beam that is probably over-kill.

 

[Aaron H]

Thx Ken,
I read the first but no the second link.
Will read it later.

Thx lndwarrior,
Good info on the metal differences.
In your opinion, since I don't have a hangar now and don't know when one would open, should I cross the 601 off my list of possible aircraft?

 

[Stan Cooper]

Thx Ken,
I read the first but no the second link.
Will read it later.

Thx lndwarrior,
Good info on the metal differences.
In your opinion, since I don't have a hangar now and don't know when one would open, should I cross the 601 off my list of possible aircraft?

Aaron, I'll let Gary (Lndwarrior) speak for himself, but the CH601XL-B (and I'm referring specifically to the XL with the B modifications) should be just as suitable as a Cessna 172, Piper PA-28, or any other aluminum airframe GA airplane for outside tiedown.

I've looked over the NTSB reports since the B modifications were introduced in 2010, and have found no unexplained mid-air breakups. If you're considering a homebuilt 601XL-B, you should take the workmanship of the builder into consideration and have a very thorough pre-purchase inspection performed. I purchased a 2008 AMD factory built 601XL-B SLSA and converted it to ELSA using a DAR (Rainbow Aviation Services in Corning, CA).

 

[Kenny Phillips]

I will note that Zenith states that their aircraft are suitable for outdoor tie down.

 

[Stan Cooper]

It is also worth noting that as a result of the in-flight breakups, the CH601XL is probably the most thoroughly scrutinized LSA design since the ASTM standards were developed and the Light Sport rule adopted in 2004. Zenith, the FAA, NTSB, LAA, and a number of independent consultants participated in the design review and provided input for the "B" modifications. The modifications include a number of structural upgrades as well as aileron mass balance weights to prevent aileron flutter.

A copy of the FAA's Zodiac CH601XL Special Review Team Report - January 2010 may be downloaded at this link:
https://www.faa.gov/aircraft/gen_av/light_sport/media/Zodiac.pdf
https://www.faa.gov/aircraft/gen_av/light_sport/media/Zodiac.pdf
The appendices to the report is here:
https://www.faa.gov/aircraft/gen_av/light_sport/media/Zodiac_Appendix.pdf

 

[RyanB]

Just make sure that you have a proper latch and secure the canopy correctly before flight. There was an incident here a few years back where a man flew out of his 601 after it went into a negative-g dive during a training lesson with a local CFI.

They found out that his seatbelt wasn’t fully secured, as he believed it to be and the canopy had an improper lock and seal.

 

[Stan Cooper]

Just make sure that you have a proper latch and secure the canopy correctly before flight. There was an incident here a few years back where a man flew out of his 601 after it went into a negative-g dive during a training lesson with a local CFI.

They found out that his seatbelt wasn’t fully secured, as he believed it to be and the canopy had an improper lock and seal.

Ryan, the 601XL and 650LS canopy latching system was redesigned in 2007 using a centrally located lever between the two seats that operates a torque tube to the over-center cam latches on both sides. The original cable operated system did require extra visual scrutiny to confirm both side latches were securely engaged. The Zodiac XL POH instructs pilots who have the canopy come unlatched during flight to decrease airspeed to 60 KIAS, ignore the wind and noise, and the canopy will "float" open a few inches but will not depart the airplane. Once slowed, land at the earliest opportunity without flaps. Too many pilots panic when the canopy opens during flight instead of concentrating on flying the airplane.

The new torque tube latching system is far superior to the cable latching system, but the pilot should always visually check both side latches to ensure they are properly engaged.

http://api.ning.com/files/P5YXEJcAp...C2Xs3f1hqaGu*jSIMt/ch650canopylatch5B15D1.pdf

 

[RyanB]

Ryan, the 601XL and 650LS canopy latching system was redesigned in 2007 using a centrally located lever between the two seats that operates a torque tube to the over-center cam latches on both sides. The original cable operated system did require extra visual scrutiny to confirm both side latches were securely engaged. The Zodiac XL POH instructs pilots who have the canopy come unlatched during flight to decrease airspeed to 60 KIAS, ignore the wind and noise, and the canopy will "float" open a few inches but will not depart the airplane. Once slowed, land at the earliest opportunity without flaps. Too many pilots panic when the canopy opens during flight instead of concentrating on flying the airplane.

The new torque tube latching system is far superior to the cable latching system, but the pilot should always visually check both side latches to ensure they are properly engaged.

http://api.ning.com/files/P5YXEJcAp...C2Xs3f1hqaGu*jSIMt/ch650canopylatch5B15D1.pdf

Well in this case, the man receiving dual instruction had just purchased the airplane and he hired a local CFI who was also unfamiliar with the aircraft type. The CFI took it around the patch a few times beforehand to familiarize himself. Once he got back, the individual climbed into the airplane and believed that he had secured he seatbelt, but it was not fully latched. Once in the air while maneuvering, the CFI reported that he could see daylight through the canopy and also hear wind blowing through it, as though it was not latched. The airplane experienced an in-flight upset and negative-g dive followed by the owner departing the airplane mid-flight. It was an odd series of events. They ended up finding the body of the individual a few miles from the airport.

 

[Aaron H]

I will note that Zenith states that their aircraft are suitable for outdoor tie down.

I read that on there website, but wanted to check with people that are familiar or owners to see if it was true for any weather. I was suspicious kind of the same suspicions I have about the cruise speed and takeoff distances in the poh alot of times.

Tied downed outside in Arizona weather vs here in Pennsylvania (Frost belt) can be yes for one and no for the other. Both are better than Florida for corrosion anyway.

 

[Lndwarrior]

Thx Ken,
I read the first but no the second link.
Will read it later.

Thx lndwarrior,
Good info on the metal differences.

In your opinion, since I don't have a hangar now and don't know when one would open, should I cross the 601 off my list of possible aircraft?

I think you mis-read my post. The 6061 T6 metal used in the 601 is MORE corrosion RESISTANT than that used in most Cessnas. So the 601 is a good choice for parking outdoors.

 

[Aaron H]

Aaron, I'll let Gary (Lndwarrior) speak for himself, but the CH601XL-B (and I'm referring specifically to the XL with the B modifications) should be just as suitable as a Cessna 172, Piper PA-28, or any other aluminum airframe GA airplane for outside tiedown.

I've looked over the NTSB reports since the B modifications were introduced in 2010, and have found no unexplained mid-air breakups. If you're considering a homebuilt 601XL-B, you should take the workmanship of the builder into consideration and have a very thorough pre-purchase inspection performed. I purchased a 2008 AMD factory built 601XL-B SLSA and converted it to ELSA using a DAR (Rainbow Aviation Services in Corning, CA).

Thanks Stan,
Good to know the 601 xlb should be as good if not better holding up to corrosion than a Cessna or Piper.
I am finding out that most wings and fuselage are made from 2024 alluminum because it's stronger (have no clue by how much?) Than the 6061 that the 601 is made from. I am reading that the 2024 is not as corrosion resistant as the 6061.

Good to know about the latch also.
Will make sure the one I'm looking at has that upgrade.
So many changes over the years, hard to keep track and to know which model with which upgrade to look out for.

For me, the plane I buy must have the b upgrade and nice to have the latch upgrade.
Anything else you recommend to look for?

 

[Aaron H]

I think you mis-read my post. The 6061 T6 metal used in the 601 is MORE corrosion RESISTANT than that used in most Cessnas. So the 601 is a good choice for parking outdoors.

Haha, I was just going to post that I did misread that. Thanks for clarifying. Been working alot of hours lately.

If I were to purchase a 601, would I need to purchase anything other than a canopy cover to leave it outside?
Would the opening for the elevator get rain or moisture in it?
Any spot on the wings that would need covering?

Thanks

 

[Kenny Phillips]

Haha, I was just going to post that I did misread that. Thanks for clarifying. Been working alot of hours lately.

If I were to purchase a 601, would I need to purchase anything other than a canopy cover to leave it outside?
Would the opening for the elevator get rain or moisture in it?
Any spot on the wings that would need covering?

Thanks

I would get in touch with Zenith directly; I've found them responsive (but then again, I may buy a kit from them!)

 

[Stan Cooper]

Yeah, I read the NTSB report about the incident a while ago; NTSB Accident No. ERA13LA183, N999NA. Tragic. Like most LSAs, the pitch input is pretty sensitive, so it's likely that the buyer-owner accidentally pushed the stick forward enough to cause the negative Gs, and with the seat belt not secured he departed the airplane.

Here's the final report:
https://app.ntsb.gov/pdfgenerator/R...ID=20130330X85743&AKey=1&RType=Final&IType=LA

 

[RyanB]

Yeah, I read the NTSB report about the incident a while ago; NTSB Accident No. ERA13LA183, N999NA. Tragic. Like most LSAs, the pitch input is pretty sensitive, so it's likely that the buyer-owner accidentally pushed the stick forward enough to cause the negative Gs, and with the seat belt not secured he departed the airplane.

Here's the final report:
https://app.ntsb.gov/pdfgenerator/R...ID=20130330X85743&AKey=1&RType=Final&IType=LA

Yup, that’s the one. I know the CFI personally. Goes to my church and I’ve flown with him many times. Very very competent pilot who I would trust with anyone’s life.

 

[Stan Cooper]

Haha, I was just going to post that I did misread that. Thanks for clarifying. Been working alot of hours lately.

If I were to purchase a 601, would I need to purchase anything other than a canopy cover to leave it outside?
Would the opening for the elevator get rain or moisture in it?
Any spot on the wings that would need covering?

Thanks

Gust lock, wheel chocks, cowl plugs.

Zenith doesn't offer gust locks to my knowledge, but I bought mine off of ebay. I have the dual stick option, so a gust lock for the center "Y" stick would be different.

 

[Aaron H]

Gust lock, wheel chocks, cowl plugs.

Zenith doesn't offer gust locks to my knowledge, but I bought mine off of ebay. I have the dual stick option, so a gust lock for the center "Y" stick would be different.

Gust locks, cowl plugs, chocks added to the list.
Imoron paint, wing lockers, and vgs added also.

Nice interior Stan!

 

[Aaron H]

Yeah, I read the NTSB report about the incident a while ago; NTSB Accident No. ERA13LA183, N999NA. Tragic. Like most LSAs, the pitch input is pretty sensitive, so it's likely that the buyer-owner accidentally pushed the stick forward enough to cause the negative Gs, and with the seat belt not secured he departed the airplane.

Here's the final report:
https://app.ntsb.gov/pdfgenerator/R...ID=20130330X85743&AKey=1&RType=Final&IType=LA

Very tragic.
I've read that's the trickiest part transitioning from ga to LSA, about how much more sensitive they are.
I've flown 2 lsas that weren't to bad as far as sensitivity. Is the 601 alot more sensitive?

 

[Stan Cooper]

Thanks Stan,
Good to know the 601 xlb should be as good if not better holding up to corrosion than a Cessna or Piper.
I am finding out that most wings and fuselage are made from 2024 alluminum because it's stronger (have no clue by how much?) Than the 6061 that the 601 is made from. I am reading that the 2024 is not as corrosion resistant as the 6061.

Good to know about the latch also.
Will make sure the one I'm looking at has that upgrade.
So many changes over the years, hard to keep track and to know which model with which upgrade to look out for.

For me, the plane I buy must have the b upgrade and nice to have the latch upgrade.
Anything else you recommend to look for?

Personally, I like the dual stick option instead of the standard "Y" control stick, although some like the "Y" because it leaves the floor area clear. Also, personally I prefer certificated direct drive engines from Lycoming and Continental (I have a Continental O-200-A in my Zodiac). Rotax, Jabiru, and UL Power are lighter, which gives you more useful load, but that's a trade-off I'm happy with.

 

[Stan Cooper]

Very tragic.
I've read that's the trickiest part transitioning from ga to LSA, about how much more sensitive they are.
I've flown 2 lsas that weren't to bad as far as sensitivity. Is the 601 alot more sensitive?

No, not in my opinion. Compared to Cessnas and Pipers, most LSAs have lighter control inputs. It took me four landings and takeoffs during my transition training with a CFI to nail it.

 

[Stan Cooper]

Gust locks, cowl plugs, chocks added to the list.
Imoron paint, wing lockers, and vgs added also.

Nice interior Stan!

Thanks. That's the AMD factory paint and interior.

My plane doesn't have wing lockers, and I think I'd be tempted to load the plane over gross if I had them. I've also heard several complaints that they leak in the rain, so if you're going to tie it down outside that's a consideration. Most of these planes, especially those with heavier engines, have an empty weight between around 800 and 850 pounds, so you have to be careful with the fuel and passenger/baggage tradeoff.

 

[Aaron H]

Thanks. That's the AMD factory paint and interior.

My plane doesn't have wing lockers, and I think I'd be tempted to load the plane over gross if I had them. I've also heard several complaints that they leak in the rain, so if you're going to tie it down outside that's a consideration. Most of these planes, especially those with heavier engines, have an empty weight between around 800 and 850 pounds, so you have to be careful with the fuel and passenger/baggage tradeoff.

Some more good info...I haven't heard that the wing lockers leak. If that's true, wings without locker will be a must have.

The 1 airport by me is expanding and plan on having new hangars in 2 years (I'm guessing double with anything airport related). The other aiport, someone would have to sell and I don't know of anyone selling yet.

 

[Aaron H]

I wanted to ask about the hingeless ailerons.
Any comments take on them?
Idiotic or brilliant?

Thanks

 

[Stan Cooper]

I wanted to ask about the hingeless ailerons.
Any comments take on them?
Idiotic or brilliant?

Thanks

I decided against them when I bought a 601XL quick build kit. Although I never heard anything negative about them, one significant physical property of aluminum is that it has no fatigue limit. Every time the ailerons deflect, no matter how small the deflection, the bending location is stressed and fatigues, and that fatigue is cumulative so that eventually it breaks at the bend. I opted for the hinged option because of that concern.

https://en.wikipedia.org/wiki/Fatigue_limit

 

[bflynn]

Thx bflynn,

U said the wing was fixed before the b mod, is there a model year that they changed the design and what was the change?

Thanks

2009 is when this was all going on. You can find a video of Zenith upgrading their aircraft - http://www.zenith.aero/profiles/blogs/installing-the-upgrade-package. My understanding is that it was all about insufficient structure in the spars. They added some doublers, beefed up some other areas and everyone that knows about the engineering of these things is happy. As was mentioned above, this is one of the most scrutinized aircraft in the LSA fleet.

 

[X3 Skier]

Even though the B mod is probably overkill, I would not have the wing lockers. Cutting into the structural skin just gives me the willies.

Cheers

 

[Stan Cooper]

The Zenith drawings for the B mod structural upgrades (6-ZU-1, 6-ZU-2, 6-ZU-3, and 6-ZU-4) were dated 25 January, 2010, and made available to builders soon after. Those drawings plus the detailed British Light Aircraft Association drawings of the Aileron Mass Balance (LAA/MOD/162B/004) made up the B mod package.

 

[mscard88]

One landed here the other day. A student and myself were in the pattern doing touch and wents on runway 16, light crosswind from the east. The goober in the Zenth kept asking why we were using 16 and something about the wind favoring 34. He asked 2-3 times, and he was inbound from the north. I just ignored him but finally the FBO transmitted wind was calm and a plane (us) was doing T&Gs on 16. Cool looking plane though. Oh, we were in the chocks by the time he landed, so he could have used whatever end of the runway he wanted to.

 

[Stan Cooper]

Some folks just like to hear themselves talk, I guess. Maybe a nervous newbie.

 

[Capt. Geoffrey Thorpe]

see if it was true for any weather.

Large hail will eff up purd near any airplane - Cessna, Piper, Zenith, it don't matter. And, no, the dents don't work like the dimples on a golf ball. Some parts of the country, U b skrewt. Other parts of the country, probably get away with it.
Ya pays yer money and ya takes yer chance.

6061 vs Alclad 2023 - If that makes an actual difference, you are right on the ragged edge of destroying an airplane no matter which it is made of - perhaps you took it for a dip in saltwater?

 

[Stan Cooper]

Hail is the biggest single reason to keep aluminum and tube & fabric airplanes in hangars in geographic areas where there is a significant risk of weather events with hail. Other reasons are sun damage to paint and fabric over longer periods of time and theft and vandalism.

 

[Kenny Phillips]

Hail is the biggest single reason to keep aluminum and tube & fabric airplanes in hangars in geographic areas where there is a significant risk of weather events with hail. Other reasons are sun damage to paint and fabric over longer periods of time and theft and vandalism.

Yeah, hail did $13K worth of damage to our Skyhawk (long waiting list for hangar, got one two months after the incident!) We actually left the dents, put on new wing/tail plastic tips.
I will never tie down outside if it can be helped.

 

[tinerj]

It's interesting that under very specialized hail size, a fabric plane will survive without damage. The hail bounces off of both, but leaves dimples on the aluninum.

 

[Stan Cooper]

It's interesting that under very specialized hail size, a fabric plane will survive without damage. The hail bounces off of both, but leaves dimples on the aluminum.

I could be mistaken, but wouldn't it depend to some extent on the condition of the fabric?

For example, the fabric might pass a punch test and be considered airworthy, but still be sufficiently deteriorated that hail could damage it enough to be non-airworthy.

 

[Kenny Phillips]

It's interesting that under very specialized hail size, a fabric plane will survive without damage. The hail bounces off of both, but leaves dimples on the aluninum.

It is interesting to me that of the fifty or so planes that were outside during the storm that damaged our plane, only five or so had any real damage.

 

[David Hempy]

How can you visually confirm the the wing modifications have been made? I'm considering a very old 601 and don't know what to look for. I asked the owner, who "found it in a barn" a year ago and has never flown it. He said he had not heard about the wing problem.