SMALL - Telemetry SMALL - Radio
Thread Tools
Old Aug 19, 2015, 09:22 PM
Daemon is online now
Find More Posts by Daemon
Registered User
Daemon's Avatar
Lakewood, Colorado
Joined Aug 2002
30,717 Posts
Quote:
Originally Posted by timbuck View Post
I remember a story on here from a guy who used to fly them. It about getting chased buy a missile and the pilot out smarted and out run it.
I'm not sure who wrote it but I'll have a go at finding it.

Tim
Ya, it's told about 39 minutes into this documentary.
SR-71 Blackbird : Documentary on The Fastest Aircraft Ever Built (44 min 22 sec)

They detected missiles launched at em before they got to their surveillance target, and
they had to decide whether to turn away immediately, or just go for it, overflying the target
first. They throttled up, and went for it and then ran away (the ground based missiles
are faster, but just can't make up the head start).

One of the books talks about an exercise they did out over the Pacific west of California.
The assertion had been made by some (pushing for the retirement of the SR-71)
that modern fighters had gotten good enough to find it and lock onto it in time to
launch a missile inbound (only way an air to air missile had a chance of catching it
before it ran out of fuel), so they decided to test the theory. To make it even easier the
SR-71 pilots told the fighter pilots where they'd be and when. No lock. Not even close.
By the time they detected it, it was already gone. It was still a viable platform the day
it was retired, and probably still is today. Just too expensive, and the people who knew
how to work on it, have all retired.

BTW, it was *beast* to fly. It had an analog computer that controlled the position of the inlet spikes
and sometimes it would miscalculate a bit, and one engine would "unstart"
at Mach 2+, causing anything up to a full flameout of the engine and afterburner, which
caused a violent yaw, sometimes enough to cause the other engine to unstart.
https://books.google.com/books?id=ZH...ameout&f=false
Scroll up to middle of page 26, and read for a while.
Daemon is online now Find More Posts by Daemon
Last edited by Daemon; Aug 19, 2015 at 09:35 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 19, 2015, 09:30 PM
Aerogance is online now
Find More Posts by Aerogance
High on speed!
Aerogance's Avatar
United States, CA, Ventura County
Joined Sep 2008
3,408 Posts
It is possible it isn't fully retired. But it is a shame to see such amazing planes on display like stuffed animals at air museums around the country.
Aerogance is online now Find More Posts by Aerogance
Reply With Quote
Old Aug 20, 2015, 03:15 PM
primitivebow is offline
Find More Posts by primitivebow
Registered User
Spain, AL, Marbella
Joined Nov 2013
8 Posts
I managed to get my second flight with the K2M today, wind was not strong, between 15-19mph.
I got to the slope nice and early to see the low clouds right on the ridge showing the sheer line. It is nice to see it for a change.

Here is a question from a novice; when the wind gets stronger, would the sheer line move higher at all, or will it just stay at the same height?

Kinetic 2M DP - Dynamic Soaring - Getares 2015 (5 min 39 sec)
primitivebow is offline Find More Posts by primitivebow
Reply With Quote
Old Aug 20, 2015, 04:00 PM
Aerogance is online now
Find More Posts by Aerogance
High on speed!
Aerogance's Avatar
United States, CA, Ventura County
Joined Sep 2008
3,408 Posts
The position of the shear is related to wind speed and angle to the slope. The stability of the shear is greatly affected by the variation in wind gust and changes in wind direction. Ideal confusions would have a steady wind speed with a steady wind direction.
Aerogance is online now Find More Posts by Aerogance
Reply With Quote
Old Aug 20, 2015, 07:42 PM
Jim.Thompson is offline
Find More Posts by Jim.Thompson
Entropy is happening!
Jim.Thompson's Avatar
Australia, NSW, Bellingen
Joined Aug 2008
8,039 Posts
I like those "ideal confusions". I have my share of them!
Jim.Thompson is offline Find More Posts by Jim.Thompson
Reply With Quote
Old Aug 20, 2015, 09:11 PM
Soaring Junkie is offline
Find More Posts by Soaring Junkie
Addicted to carbon and speed
Soaring Junkie's Avatar
Australia, QLD, Tingalpa
Joined Jul 2013
250 Posts
So many factors can impact the quality and positioning of the shear layer. As Aaron said the wind speed and strength and the variation between average and gusts can have a big impact. The shape of the hill is important but we find here at our local sites the land forms in front of the hill can play a major part in determining the quality of the shear. At Larrikin we have a big solitary hill disturbing the airflow when the wind is west or W/SW and as the wind speed increases the shear layer on the ridge can do strange things.

At Cactus Ridge, the area in front is mostly open and clear, but as the wind speed increases the shear layer tends to roll over the hill more onto the backside, meaning we need to fly a lower line to stay under it for the bottom turn. Wind angles seem to be a major contributor to the degree of turbulence, too. There won't be a general rule for all sites. Every hill that supports DS will have its own particularities and observation and trying it out in a range of conditions, wind speeds and wind angles will demonstrate what works and what doesn't. Listening to the plane cross the shear is a good indication of the quality. When it's good it will punch through with a clear, crisp sound, and when it is separating it will sound all fluffy and fluttery and soft.

Enjoying your videos. Keep at it, you are flying that K2m really well!
Soaring Junkie is offline Find More Posts by Soaring Junkie
Reply With Quote
Old Aug 21, 2015, 01:25 AM
primitivebow is offline
Find More Posts by primitivebow
Registered User
Spain, AL, Marbella
Joined Nov 2013
8 Posts
Thanks Aaron, for you reply.
Thanks Brent for the explanation, it all makes sense. I guess Im going to have to wait for the big winds to kick in before knowing if that slope is going to work well. At the moment is seems shallow at the bottom end, I have scraped the bush several times now.
primitivebow is offline Find More Posts by primitivebow
Last edited by primitivebow; Aug 21, 2015 at 08:23 AM.
Reply With Quote
Old Aug 21, 2015, 04:45 AM
bjoernohlau is offline
Find More Posts by bjoernohlau
Registered User
Joined Aug 2007
8 Posts
Hi Karim,

nice flying again.

Just my 2 cents:
From what I see at our spots in Germany, mostly smaller sites. The angle hill wind is really important, specially when it moves more and more from 90 degrees. You will get much more turbulences. So we always start slowly in a new day, then you will find out from your first laps where the shear layer is. What special turbulence you find today. I lost my first Pace VX on a windy day in a tubulence at the bottom turn. It turned to the inside of the circle and I should have pushed down but pulled and only heard the impact sound. The bad thing about this was that I had more or less the same turbulence twice that day before, which I could recover from. So sometimes when the conditions are not so good it can be a good idea to wait for the next good day.
And once you feel everything is fine you can fly lower in the back and check for the max you can reach.

Greetings Bjoern
bjoernohlau is offline Find More Posts by bjoernohlau
Reply With Quote
Old Aug 21, 2015, 09:32 AM
Aerogance is online now
Find More Posts by Aerogance
High on speed!
Aerogance's Avatar
United States, CA, Ventura County
Joined Sep 2008
3,408 Posts
You can test conditions with a less exotic plane before risking the more expensive plane.
Aerogance is online now Find More Posts by Aerogance
Reply With Quote
Old Aug 21, 2015, 11:36 AM
primitivebow is offline
Find More Posts by primitivebow
Registered User
Spain, AL, Marbella
Joined Nov 2013
8 Posts
Hi Bjoern, thanks for the advice. I keep getting the same thing, there is a black hole at the bottom turn, if I go slightly lower then it wants to suck the plane to the ground.
These are light winds for this hill, I could not launch with less wind by myself anyway. Next month the winds will get strong again and this is the only hill I have.

Aaron, I always fly my 2m Pace Desire before the K2M. I have a couple of foam wings, but I am not entirely happy with DSing them. They end up landing in places I don't want and its all prickle bushes here, so a pain to get your plane every time.
primitivebow is offline Find More Posts by primitivebow
Reply With Quote


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Complaint its in the chit chat area Manta1 Moderation Appeals 9 Jan 18, 2012 10:14 AM
Cool My new toy! cool video! speedster Dynamic Soaring 6 Jan 03, 2009 02:54 AM
Bug Can't nuke posts in new Chit Chat forum ElectRick Site Suggestions / Complaints 3 Jul 17, 2007 12:26 AM