RC India

General Topics => Chatter Zone => Topic started by: anwar on May 04, 2011, 12:23:05 PM

Title: Stealth heli crashed
Post by: anwar on May 04, 2011, 12:23:05 PM
http://www.huffingtonpost.com/2011/05/03/osama-bin-laden-unarmed-during-raid_n_857257.html

Why did the heli crash ?

With officials at the CIA and the White House watching on television monitors, tensions increased when one of the two Black Hawk helicopters lowered into the compound and, beneath a moonless sky, fell heavily to the ground. Officials believe that was due to higher-than-expected air temperature that interfered with the chopper's ability to hover – an aeronautical condition known as "hot and high."

So what exactly is "hot and high" ?
Title: Re: Stealth heli crashed
Post by: vinay on May 04, 2011, 12:26:26 PM
Quote from: anwar on May 04, 2011, 12:23:05 PM
So what exactly is "hot and high" ?

probably air pressure reduces and hence heli comes down. Just wondering how does real helis move up and down? pitch variations or rpm variations.
Title: Re: Stealth heli crashed
Post by: asinghatiya on May 04, 2011, 12:37:39 PM
Quote from: anwar on May 04, 2011, 12:23:05 PM
So what exactly is "hot and high" ?

Anwar bhai, this is reported by a news channel, please dont expect anything from them that they understand aeronotics....most of the times when they dont have an appropriate word to explan a situation they invent  ;D.....it......


Title: Re: Stealth heli crashed
Post by: VC on May 04, 2011, 12:39:23 PM
There you go:

http://en.wikipedia.org/wiki/Hot_and_high
Title: Re: Stealth heli crashed
Post by: anwar on May 04, 2011, 12:39:45 PM
Don't care about the term itself.  What exactly happened aeronautically, was the point/question.
Title: Re: Stealth heli crashed
Post by: asinghatiya on May 04, 2011, 12:43:48 PM
well some news reports say that noting happened ...there was a technical failure so ...and Heli could'nt  took off hence just to avoid its miss use, they burnt it.  :headscratch:.....
Title: Re: Stealth heli crashed
Post by: VC on May 04, 2011, 12:44:20 PM
If I am not mistaken, a F 16 of the Thunderbirds Team had crashed while completing a loop. There are some graphic videos of this event. Here is a link:

http://www.f-16.net/news_article968.html

Though I am not sure if this crash has anything to do with 'hot and high', would request Gusty to comment on this.
Title: Re: Stealth heli crashed
Post by: VC on May 04, 2011, 12:45:41 PM
Quote from: anwar on May 04, 2011, 12:39:45 PM
Don't care about the term itself.  What exactly happened aeronautically, was the point/question.

"Air density decreases with increasing temperature and altitude. Lower air density reduces the amount of lift generated by the wings of an airplane or the rotors of a helicopter, which may hamper an aircraft's performance, or in some cases, prevent it from becoming airborne at all."

That should answer it.
Title: Re: Stealth heli crashed
Post by: anwar on May 04, 2011, 12:46:03 PM
Interesting notes about the heli itself.

http://cencio4.wordpress.com/2011/05/03/mysterious-helicopter/

http://www.aviationweek.com (http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=27ec4a53-dcc8-42d0-bd3a-01329aef79a7&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a275902dd-e7a2-40fd-ab78-d46e3bf922b1&plckScript=blogScript&plckElementId=blogDest)

It is a stealthy variety... that is why it was destroyed :headscratch:

Judging by how the tail landed on the wall, seems like a pretty nasty crash.  Wonder how the commandos/seals were affected, or was this after they had roped out, and only the pilot was inside when it went down.
Title: Re: Stealth heli crashed
Post by: SunLikeStar on May 04, 2011, 12:51:50 PM
These helies have been falling in Afghanistan like dead leaf because of the same reason. They have even made some modification to fix this but it has not proved helpful.
Title: Re: Stealth heli crashed
Post by: asinghatiya on May 04, 2011, 12:53:31 PM
 {:)} {:)}...good one, really appreciate that knowledge piece.
Title: Re: Stealth heli crashed
Post by: rcpilotacro on May 04, 2011, 07:28:34 PM
here it is
http://www.rcindia.org/rc-general-topics/basic-aerodynamics-for-rc-flying/msg60603/#msg60603
Title: Re: Stealth heli crashed
Post by: anwar on May 05, 2011, 05:33:28 PM
Better pictures of the crashed heli here :

http://www.reuters.com/subjects/bin-laden-compound
Title: Re: Stealth heli crashed
Post by: anwar on May 05, 2011, 05:35:37 PM
http://www.reuters.com/article/2011/05/04/us-binladen-pakistan-photos-idUSTRE7437KK20110504

Also says the helicopter is previously unknown and "stealthy".
Title: Re: Stealth heli crashed
Post by: SunLikeStar on May 05, 2011, 05:44:52 PM
Quote from: anwar on May 05, 2011, 05:33:28 PM
Better pictures of the crashed heli here
:o now way.. thats not a black hawk
Title: Re: Stealth heli crashed
Post by: SunLikeStar on May 05, 2011, 05:55:03 PM
Found this, its in Russian but looks they are getting somewhere with this:
http://www.avsimrus.com/forum/topic/116416-padenie-vertolyota-2-maya-2011-v-pakistane/
Title: Re: Stealth heli crashed
Post by: anwar on May 06, 2011, 12:37:13 AM
http://english.aljazeera.net/video/americas/2011/05/20115515014654164.html
Title: Re: Stealth heli crashed
Post by: anwar on May 07, 2011, 11:28:34 AM
http://edition.cnn.com/2011/US/05/06/bin.laden.helicopter/index.html?hpt=T2
Title: Re: Stealth heli crashed
Post by: anwar on May 11, 2011, 10:48:11 PM
Interesting article... towards the last part.  Are helis fragile in general ?

http://translogic.aolautos.com/2011/05/10/bin-laden-caught-but-another-black-hawk-down-on-critical-missio/
Title: Re: Stealth heli crashed
Post by: iamahuman on May 11, 2011, 11:10:59 PM
Quote from: anwar on May 11, 2011, 10:48:11 PM
Are helis fragile in general ?

I would think so.Since weight is a limitation,they can't be heavily armored(especially attack helicopters) and the heavily armored ones are slow.Not exactly ideal for insertion and extraction missions.

I would like to see Augustine sir's point on this.
Title: Re: Stealth heli crashed
Post by: SunLikeStar on May 11, 2011, 11:19:14 PM
Of-course they are fragile, try throwing a small stone on your friends heli when its revving up ;D
Title: Re: Stealth heli crashed
Post by: anwar on May 11, 2011, 11:25:22 PM
Quote from: iamahuman on May 11, 2011, 11:10:59 PM
I would think so.Since weight is a limitation,they can't be heavily armored(especially attack helicopters) and the heavily armored ones are slow.Not exactly ideal for insertion and extraction missions.

I was trying to point out the "large number of moving parts" aspect.  Applies to RC helis too... and I have seen many people give up heli flying, some after one session, and others after years :)
Title: Re: Stealth heli crashed
Post by: iamahuman on May 11, 2011, 11:29:19 PM
But any reason why it hasn't been simplified?Or is it as simple as it gets?
Title: Re: Stealth heli crashed
Post by: Ajay JM on May 12, 2011, 09:58:09 AM
Quote"large number of moving parts" aspect.Applies to RC helis too... and I have seen many people give up heli flying, some after one session, and others after years

Well, that is one reason I stick on to heli flying alone. The challenges are more  :)