Not so simple retractable gear

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

Fireflyer228

Member
Lifetime Supporter
Joined
Aug 17, 2020
Messages
24
Location
Oregon, USA
Hey all,
I didn't want to hijack the Simple Retract thread. Are any of you familiar with the Infinity main retract gear kits sold for canards?

The Infinity system is a hydaulic system with 3 ways to get the gear down. Any experience with these kits? I like the idea of hydraulic system even though it adds some weight compared to electric actuated gear. Cranking down the gear in a Bonanza or Baron is just over 50 less than fun cranks with a small handle behind the front seats. Awkward position and it wears you out, but at least it can be done.

Any other companies that have canard main gear kits? Have any members thought through designing a system?

thanks,
Kenneth
 

Voidhawk9

Well-Known Member
HBA Supporter
Joined
Mar 26, 2012
Messages
490
Location
Timaru, NZ
I have the Infinity installation manual, but not the gear itself. It's out of production and only available used (sometimes a set comes up, never installed).
I have talked about the gear with a couple of owners / builders. They really like it.
If you ask the wider canard community, you'll get a lot of negative feedback, mostly from people who have never installed it.
 

Marc Zeitlin

Exalted Grand Poobah
Joined
Dec 11, 2015
Messages
866
Location
Tehachapi, CA
I have talked about the gear with a couple of owners / builders. They really like it.
If you ask the wider canard community, you'll get a lot of negative feedback, mostly from people who have never installed it.
So a couple of people like it. As with all reports, negative reports are far more useful than positive ones.

Here's what John McAvoy (Waiter) said about his retrofit (so he had an A:B comparison) regarding the installation of the Infinity landing gear on his Long-EZ:

CONCLUSION
Regarding the "fixed-to-retractable" main gear retrofit, the big question in everyone’s mind; "Was it worth it"?​
YES/NO​

YES - I like the full retract, there is an improvement in speed, I like the looks of the plane, and I like the complexity. I like the ground handling characteristics. There seems to be a slightly better response in roll rate. Take off and climb performance is improved, once the gear gets in the well. Landing performance is good,​
NO - The 10 kts was not worth the effort that went into the "Retrofit" HOWEVER, If this were a new build, I would say that its acceptable. I do most of my travel at higher altitudes, At FL180, At this altitude, I only seen a 2 kt improvement, but lost about 5 gallons of fuel and about 100 lbs of useful load.​

This, to me, is hardly a ringing endorsement of an expensive modification (or install). The full discussion is available here:


but to me, the fact that he picked up 9 KTAS at SL is meaningless, since no-one cruises a canard at SL. If we assume that at 9K ft, he'd pick up 1/2 the difference between 9 KTAS and 2 KTAS, that would be a 5.5 KTAS increase. Up higher - less. Obviously, these things are personal preference, but given the cost, maintenance needs, complexity and weight differential, this is not a modification to EZ type aircraft that I recommend to my customers. Put on a good set of wheel pants and a well shaped gear leg fairings, and you're only slightly worse off from a speed standpoint (which means little on 500 NM block flights - cruising at 175 KTAS vs. 180.5 KTAS costs you 5 minutes and 13 seconds on a 2 hour and 51 minute flight ).

My $0.02.
 

Voidhawk9

Well-Known Member
HBA Supporter
Joined
Mar 26, 2012
Messages
490
Location
Timaru, NZ
Thanks for the data, Marc. Unfortunately I cannot get Waiter's site to load, gives me a 403.
Given the differences reported, I assume this is directly correlated to IAS - the higher the IAS, the greater the effect of the drag reduction. Makes sense. What speeds was he doing?
 

Marc Zeitlin

Exalted Grand Poobah
Joined
Dec 11, 2015
Messages
866
Location
Tehachapi, CA
Thanks for the data, Marc. Unfortunately I cannot get Waiter's site to load, gives me a 403.
Yeah, it's an http rather than an https site, so some browsers won't let it through.

Given the differences reported, I assume this is directly correlated to IAS - the higher the IAS, the greater the effect of the drag reduction. Makes sense. What speeds was he doing?
Here's what he says for the SL run:

BEFORE
SPEED : 158kts (2300rpm, Full throttle Sea level)
WEIGHT : 1060lbs
SPEED : FUEL CAPACITY : 44 gal
AFTER
SPEED : 167kts (2300rpm, Full throttle Sea level)
WEIGHT : 1150lbs
SPEED : FUEL CAPACITY : 39 gal

So, not very fast. 167 KTAS/KIAS (SL, remember) is kind of slow, but he was running an MT electric C/S prop at only 2300 RPM, which in my experience with one on a COZY MKIV is a POS from a performance standpoint. He doesn't say anything about 2700 RPM runs, or speeds/RPM's at anything other than SL. There are no real flight reports or sequences of reports of testing, either before or after the retrofit. So the data is pretty thin.

I just remember reading his postings on the mailing lists or newsgroups (don't remember which) when he first started flying with the new gear, and he seemed pretty disappointed in the performance, for all the $$$ and time he spent on it.

Also note that an 1150 lb. Long-EZ is ridiculously heavy, and a fuel capacity of 39 gallons is ridiculously low - standard LE's carry 52 gallons, and an O-320 LE normally weighs between 875 - 975 lb. (although there's one for sale on Barnstormers, I think, that claims that it weighs 710 lb. empty, which I don't believe for a second).
 

Voidhawk9

Well-Known Member
HBA Supporter
Joined
Mar 26, 2012
Messages
490
Location
Timaru, NZ
Thanks, Marc. Seems like the retracts make more sense at 180+. Super Cozies and the like.
 
Top