Go Back  PPRuNe Forums > Aircrew Forums > Rotorheads
Reload this Page >

Unknown Equipment, please identify

Rotorheads A haven for helicopter professionals to discuss the things that affect them

Unknown Equipment, please identify

Old 12th Dec 2015, 14:01
  #1 (permalink)  
Thread Starter
 
Join Date: Mar 2012
Location: unsteady
Posts: 351
Unknown Equipment, please identify

Hello everyone,
Browsing through an article about presidential helicopters I found this picture (I believe showing a UH34)... Wondering what that interesting accessory on the landing gear is? Can't come up with a reasonable explanation.

whoknows idont is online now  
Old 12th Dec 2015, 14:04
  #2 (permalink)  
 
Join Date: Jan 2015
Location: Europe
Posts: 112
Floats.

Inflated below


Last edited by Never Fretter; 12th Dec 2015 at 14:22.
Never Fretter is offline  
Old 12th Dec 2015, 14:14
  #3 (permalink)  
Thread Starter
 
Join Date: Mar 2012
Location: unsteady
Posts: 351
Thank you! Very interesting. What is the function of the metal hemispheres?
Also, how effective was this type of floats? They seem a bit small for that a/c.
whoknows idont is online now  
Old 12th Dec 2015, 14:22
  #4 (permalink)  
 
Join Date: Jan 2015
Location: Europe
Posts: 112
They seem to have pipes leading to them. Not sure if they are some sort of plenum to mix ambient air with high pressure gas.

IIRC the tail boom was filled with foam (at least on the Wessex) to be the third point of contact.

Probably good enough to ditch in an ornamental pond.

Wonder why Marine One needed a winch.
Never Fretter is offline  
Old 12th Dec 2015, 16:44
  #5 (permalink)  
 
Join Date: Apr 2000
Location: EGDC
Posts: 8,469
Pressurised with Nitrogen - the same idea has been used on many helos - you push a button or make a switch in the cockpit and the floats inflate almost instantly. The aircraft will still turn turtle and float upside down though.
crab@SAAvn.co.uk is offline  
Old 12th Dec 2015, 17:13
  #6 (permalink)  
 
Join Date: Aug 2007
Location: mobile
Posts: 242
For landing on snow or mud like bear paws. Floats on H34 types like the Wessex and S58 had gas generators and pop out floats supporting through the axle of the main U/C.
mtoroshanga is offline  
Old 12th Dec 2015, 18:19
  #7 (permalink)  
 
Join Date: Feb 2002
Location: Escaped from ABZ...
Posts: 294
Usually Helium as the gas flows much more quickly than Nitrogen to the floats due (in part) to it's smaller atom size compared to the much larger molecule of N2. Only problem is that over a period of time Helium leaks out of the bottle (again due to the small atomic size) and it's much more expensive.
detgnome is offline  
Old 12th Dec 2015, 19:48
  #8 (permalink)  
Thread Starter
 
Join Date: Mar 2012
Location: unsteady
Posts: 351
Originally Posted by Never Fretter View Post
Not sure if they are some sort of plenum to mix ambient air with high pressure gas.
You mean like a nitrogen/air jet pump? Interesting concept... Although it seems a bit counterintuitive that the nitrogen would go into floats as opposed to finding it's way out.
whoknows idont is online now  
Old 12th Dec 2015, 20:21
  #9 (permalink)  
 
Join Date: Apr 2008
Location: Forres
Age: 77
Posts: 126
Sorry Crab but after we ditched Wessex Foxtrot in the South China Sea off Hong Kong in a Typhoon the flot gear worked as advertised, she remained upright, and not a drop of water entered the cabin. Even as we were recovered, by other Wessex from the squadron, Foxtrot was still afloat and heading for mainland China!
Oldsarbouy is offline  
Old 13th Dec 2015, 01:35
  #10 (permalink)  
 
Join Date: May 2002
Location: "Deplorable but happy as a drunken Monkey!
Age: 72
Posts: 16,612
The account I heard about a Sikorsky S-58T Ditching was a bit amusing.

You hit the switch to arm the floats and Salt Water Immersion switches did the dirty work for you. The interesting bit is it takes a bit of time for the Saltwater and Switches to shake hands and then it takes a bit of time for the Floats to inflate.

My Chum said all went well following a decent arrival into the water....he heard something akin to the Alka Selzter sounds....Pop Pop....Fizz Fizz....and as the water began to go up over the wind screen he took a very...very deep breath thinking he was going to need as much as he could hold.....when out of the deep up she rises....wallowed back and forth and soon settled down very nicely all cozy and dry.
SASless is offline  
Old 13th Dec 2015, 01:44
  #11 (permalink)  
 
Join Date: Mar 2005
Location: N/A
Posts: 3,783
Comparison of the Presidential and Wessex


Foxtrot was still afloat and heading for mainland China
Ahhh, you forgot the last item on the ditching check list - slash float with survival knife. SOP from those that flew the thing (31B).
megan is offline  
Old 13th Dec 2015, 02:14
  #12 (permalink)  
 
Join Date: May 2002
Location: "Deplorable but happy as a drunken Monkey!
Age: 72
Posts: 16,612
Upon ensuring the Tech Log was inside the aircraft.
SASless is offline  
Old 13th Dec 2015, 02:44
  #13 (permalink)  
 
Join Date: Mar 2005
Location: N/A
Posts: 3,783
I guess all militaries would have been the same SAS, whenever an aircraft was lost you wouldn't believe the amount of stuff that got written off, must have been in the thousands of tons.
megan is offline  
Old 13th Dec 2015, 09:35
  #14 (permalink)  
 
Join Date: Oct 2006
Location: UK
Posts: 5,120
When XD183, a Whirlwind, crashed in 1970 during the rundown of RAF Changi in Singapore the shortages on the Hercules, Shackleton and both Whirwind Squadrons were written off. They included 2 (two) Griffon engines and a Hercules nosewheel assembly.

I know that because I was 183's inventory holder and I had to sign all the disposal chits.

Strangely enough, even though I was not flying it, all my V&A flying clothing went with it too.
Fareastdriver is offline  
Old 13th Dec 2015, 09:38
  #15 (permalink)  
 
Join Date: Jun 2009
Location: France
Age: 77
Posts: 6,365
How many officers' swords were lost when Brampton HQ burned down in the 80s!
Wander00 is offline  
Old 13th Dec 2015, 12:36
  #16 (permalink)  
 
Join Date: Feb 2006
Location: PLANET ZOG
Posts: 309
Wessex had a an inflated flot bag in the tail cone, at least the ones I worked on did! Very comfortable as well.
3D
3D CAM is offline  
Old 13th Dec 2015, 12:48
  #17 (permalink)  
 
Join Date: May 2002
Location: "Deplorable but happy as a drunken Monkey!
Age: 72
Posts: 16,612
The Float Bag determined the Max Height the aircraft could fly as it expanded as you climbed to altitude. First indication you had gone too high was the Tail Rotor Pedals would not move as the bag swelled against the cables.

One could use that method as a way of creating Pedal Stops and footrests on long transits. So the Big Boys always told me anyway!

I loved the old Sikorsky's I got to fly....lovely old Girls!
SASless is offline  
Old 14th Dec 2015, 08:16
  #18 (permalink)  
 
Join Date: Apr 2008
Location: Out of Africa
Age: 67
Posts: 229
845 Wessex Squadron had stores packed in chacons (Chatham Containers) about 8 feet by 8 feet by 10 feet tall lashed to the side of the flight deck in HMS "happy" HERMES as we searched for a missing Hull trawler ( the Gaul) in horrific winter storms off Bear Island in 1973.

Several chacons including the one belonging to 845 were washed overboard in spite of being secured well above the waterline.

Some months later we were berthed in Kalkara Creek Malta when a man from MOD procurement pitched up and insisted that a protesting 845 Squadron AEO bring out an extensive array of spares from stores including several Gnome engines and blade folding poles about 20 feet long making an enormous stack on the hangar floor. He then requested an empty chacon and instructed the AEO to place all the items in the chacon.

The AEO protested that there was no way even a small fraction would fit in the chacon.

"But that is what you wrote off in the chacon you lost! Was the MOD chaps reply.
Troglodita is offline  
Old 14th Dec 2015, 11:45
  #19 (permalink)  
 
Join Date: May 2002
Location: "Deplorable but happy as a drunken Monkey!
Age: 72
Posts: 16,612
Was that MOD Chappie introduced to the ages old tradition of the" Plank"?
SASless is offline  
Old 14th Dec 2015, 14:08
  #20 (permalink)  
 
Join Date: Apr 2008
Location: Out of Africa
Age: 67
Posts: 229
Planks had all left several years earlier - just rotary by then!

Sorry SAS just being obtuse!

I suspect he just fancied an all expenses paid holiday in the sun - can't remember any flak or Courts Martial following his visit - I think he just had a few pints of "nerve gas" and headed for the beach.

Trog
Troglodita is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.