Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

slips

Matronics Email Lists Forum Index -> Kolb-List

View previous topic :: View next topic

Author Message

russ(at)rkiphoto.com
Guest

Posted: Thu Apr 23, 2009 5:41 am Post subject: slips

In  re slips & descents -- my 170 was placarded against slips with full flaps. But I never could get it to do more than a slight wobble, and that maybe once in  50 times or so. I slipped it a lot, with no trouble.We did have to berate the jump-plane pilots into doing slips, instead of a closed-throttle screaming spiral down  -- which shock-cooled the engine & tended to break rings. 

OK, that was lots more fun, but treat the engine kindly, fellas!

Russ K

do not archive

 [quote][b]

lucien

Joined: 03 Jun 2007
Posts: 721
Location: santa fe, NM

Posted: Thu Apr 23, 2009 6:10 am Post subject: Re: slips

[quote="russ(at)rkiphoto.com"]In ï¿½re slips & descents -- my 170 was placarded against slips with full flaps. But I never could get it to do more than a slight wobble, and that maybe once in ï¿½50 times or so. I slipped it a lot, with no trouble.We did have to berate the jump-plane pilots into doing slips, instead of a closed-throttle screaming spiral down ï¿½-- which shock-cooled the engine & tended to break rings.ï¿½

OK, that was lots more fun, but treat the engine kindly, fellas!

Russ K

do not archive

  	  Quote: 	
		  [b] 	




Uh oh. Not the shock-cooling thread again . I'll only state my side and then quietly get out of the way.



FYI....



It's not the shock _cooling_ that's the problem, it's the shock _heating_ of hammering the cooled engine again to wide open once you're back on the ground.



You can take a red hot motor, pull it back to idle and go all the way down to the ground like that with no problems BUT.... be sure and do a warmup again once down before you put the coals to it again. For aircooled folks, if those CHT's get back down to 200F again apply the throttle sloooowly or do a full stop/taxi back. 



I havn't seen my 912 CHT's drop precipitously in a descent and the oil temps tend to remain up too, but I still always apply power slowly when doing TnG's (I never hammer to wide open unless it's a priority situation).



Lets be careful out there with those throttle arms!



do not archive



LS

_________________
LS
Titan II SS

Ralph B

Joined: 14 Apr 2007
Posts: 367
Location: Mound Minnesota

Posted: Thu Apr 23, 2009 6:12 am Post subject: Re: slips

I have slipped the Kolbra with full flaperons and taken off with full flaperons. I did this just yesterday with my heavy son onboard. I'm still debating whether full flaps makes for a shorter takeoff. There is a lot more drag and slows it down, although full flaperons on the Kolbra are like one notch on regular aircraft. I need to experiment more. I took my neighbor for a ride and he is a good 230 lbs. The Kolbra took awhile to get airborne, but it did climb ok on 80 hp.



Ralph

_________________
Ralph B

Kolb Kolbra 912uls
N20386
550 hours

russ(at)rkiphoto.com
Guest

Posted: Thu Apr 23, 2009 8:46 am Post subject: slips

Lucien

I was only parroting what our mech said. The landing  & taxi-out was  

basically at idle power, then  the plane would sit a little while  

before launching again. The mech said it was shock-cooling, sounded  

logical, and I believed him. (Air-blast cooled the cylinders quickly,  

but not the pistons & rings)

But your advice is good & I'll keep it in mind.

Russ, quietly out of the way

do not archive



On Apr 23, 2009, at 10:10 AM, lucien wrote:



 	  Quote: 	
		   



 [quote="russ(at)rkiphoto.com"]In ï¿½re slips & descents -- my 170  

 was placarded against slips with full flaps. But I never could get  

 it to do more than a slight wobble, and that maybe once in ï¿½50  

 times or so. I slipped it a lot, with no trouble.We did have to  

 berate the jump-plane pilots into doing slips, instead of a closed- 

 throttle screaming spiral down ï¿½-- which shock-cooled the engine  

 & tended to break rings.ï¿½

 OK, that was lots more fun, but treat the engine kindly, fellas!

 Russ K

 do not archive



> [b]

 Uh oh. Not the shock-cooling thread again . I'll only state my  

 side and then quietly get out of the way.



 FYI....



 It's not the shock _cooling_ that's the problem, it's the shock  

 _heating_ of hammering the cooled engine again to wide open once  

 you're back on the ground.



 You can take a red hot motor, pull it back to idle and go all the  

 way down to the ground like that with no problems BUT.... be sure  

 and do a warmup again once down before you put the coals to it  

 again. For aircooled folks, if those CHT's get back down to 200F  

 again apply the throttle sloooowly or do a full stop/taxi back.



 I havn't seen my 912 CHT's drop precipitously in a descent and the  

 oil temps tend to remain up too, but I still always apply power  

 slowly when doing TnG's (I never hammer to wide open unless it's a  

 priority situation).



 Lets be careful out there with those throttle arms!



 do not archive



 LS



 --------

 LS

 Titan II SS





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p 40901#240901

JetPilot

Joined: 10 Jan 2006
Posts: 1246

Posted: Thu Apr 23, 2009 9:49 am Post subject: Re: slips

 	  Ralph B wrote: 	
		  

 I need to experiment more. I took my neighbor for a ride and he is a good 230 lbs. The Kolbra took awhile to get airborne, but it did climb ok on 80 hp.



Ralph 	




How much do you weigh Ralph ?  Do you put the passenger in the back seat ?  That is a very good load for 80 HP.  My Kolb can lift heavy weights just fine, me and a heavy passenger.  For me the biggest problem with a heavy passenger is the nose down trim I get from it, my limit is running out of up elevator long before the weight itself becomes an issue.   I guess in your Kolb the passenger is closer to the CG, do you get much of a trim change ?



Mike

_________________
"NO FEAR" - If you have no fear you did not go as fast as you could have !!!

Kolb MK-III Xtra, 912-S

Thom Riddle

Joined: 10 Jan 2006
Posts: 1597
Location: Buffalo, NY, USA (9G0)

Posted: Fri Apr 24, 2009 3:35 am Post subject: wing & power loading

Thread was SLIPS



Ralph's comment about carrying a heavy passenger prompts me to ask about the size (sq. ft) of the standard MKIII and Kolbra wings. The reason I ask is that I've flown our RANS S6-S (155.25 sq ft wing) at MTOW of 1200 lb with a 280 lb passenger and light fuel. I weight about 215, so there is a lot of human carcass aboard in this configuration. This comes to a wing loading of 7.73 lb/sqft wing loading and 15 lb/hp for my 80hp 912.



At our low elevation and generally cool climate the performance at MTOW is adequate. Not enough power for that weight in the Rockies. Most of the time I fly solo with more fuel at about 950 lbs TOW which comes to only 6.12 lb/sqft and 11.88 lb/hp. with great performance. 



Just curious about MkIII and Kolbra wings for comparison.

_________________
Thom Riddle
Buffalo, NY (9G0)

Don't worry about old age... it doesn't last very long.
- Anonymous

Ralph B

Joined: 14 Apr 2007
Posts: 367
Location: Mound Minnesota

Posted: Fri Apr 24, 2009 3:57 am Post subject: Re: slips

 	  JetPilot wrote: 	
		   	  Ralph B wrote: 	
		  

 I need to experiment more. I took my neighbor for a ride and he is a good 230 lbs. The Kolbra took awhile to get airborne, but it did climb ok on 80 hp.



Ralph 	




How much do you weigh Ralph ?  Do you put the passenger in the back seat ?  That is a very good load for 80 HP. My Kolb can lift heavy weights just fine, me and a heavy passenger. For me the biggest problem with a heavy passenger is the nose down trim I get from it, my limit is running out of up elevator long before the weight itself becomes an issue.  I guess in your Kolb the passenger is closer to the CG, do you get much of a trim change ?



Mike 	




Mike, I weigh 200 lbs and the passenger is in the back seat. I have an manual adjustable trim on the elevator and a motorized adjustable bungee on the stick, but I didn't adjust the manual trim for this heavy passenger and held a little "back stick" as I ran out of trim adjustment on the bungee trim. I didn't have a problem on landing as there was plenty of "up elevator". It happened to be a turbulent day and the extra weight smoothed things out. I commented to the passenger that if I had been flying the Firestar, I would be all over the sky. The rear passenger space is limited, so anyone over 230 lbs may not be able to get back there.



Ralph

_________________
Ralph B

Kolb Kolbra 912uls
N20386
550 hours

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Sat Apr 25, 2009 2:22 pm Post subject: slips

> I havn't seen my 912 CHT's drop precipitously in a descent and the oil 

temps tend to remain up too, but I still always apply power slowly when 

doing TnG's (I never hammer to wide open unless it's a priority situation).

 	  Quote: 	
		  

 > LS
	


Do you have to be careful for shock cooling with a 912?



Mine doesn't have a cast iron liner.



john h

mkIII

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

lucien

Joined: 03 Jun 2007
Posts: 721
Location: santa fe, NM

Posted: Sat Apr 25, 2009 4:53 pm Post subject: Re: slips

 	  John Hauck wrote: 	
		  



Do you have to be careful for shock cooling with a 912?



Mine doesn't have a cast iron liner.



john h

mkIII 	




I don't worry about it myself on any engine I have, I"ve never had any problems that I could trace to rapid cooling.



OTOH, I'm extremely careful about proper warmup before putting an engine to work. Especially my 2-strokes that all had steel liners, if I did a long descent say in a practice engine-out, I'd usually do a full-stop taxi back with a quick warmup. Even doing TnG's under the 912 I apply power on the go slooowly....



LS

_________________
LS
Titan II SS

Ralph B

Joined: 14 Apr 2007
Posts: 367
Location: Mound Minnesota

Posted: Sun Apr 26, 2009 6:09 am Post subject: Re: wing & power loading

 	  Thom Riddle wrote: 	
		  Thread was SLIPS



Ralph's comment about carrying a heavy passenger prompts me to ask about the size (sq. ft) of the standard MKIII and Kolbra wings. The reason I ask is that I've flown our RANS S6-S (155.25 sq ft wing) at MTOW of 1200 lb with a 280 lb passenger and light fuel. I weight about 215, so there is a lot of human carcass aboard in this configuration. This comes to a wing loading of 7.73 lb/sqft wing loading and 15 lb/hp for my 80hp 912.



At our low elevation and generally cool climate the performance at MTOW is adequate. Not enough power for that weight in the Rockies. Most of the time I fly solo with more fuel at about 950 lbs TOW which comes to only 6.12 lb/sqft and 11.88 lb/hp. with great performance. 



Just curious about MkIII and Kolbra wings for comparison. 	




Tom, I forgot to answer your questions about the wing loading on the Kolbra. I believe the Kolbra has the same wing at the Mark III with 153 sq ft. The maximum gross weight is 1150 lbs and can carry a passenger up to 250 lbs, but the question is whether someone of that size would fit  in the rear seat. The 80 hp 912 is struggling with a heavy passenger, but the climb is probably better than most small GA aircraft with heavier passengers. I know some of them cannot carry a full load of fuel with a heavy passenger. The Kolbra has a 13 gallon tank which is 81 lbs full, but on the opposite side of the cg which helps balance things out.



Ralph

_________________
Ralph B

Kolb Kolbra 912uls
N20386
550 hours

Display posts from previous:

	Matronics Email Lists Forum Index -> Kolb-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum