PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Rotorheads (https://www.pprune.org/rotorheads-23/)
-   -   Skids on a Sikorsky (https://www.pprune.org/rotorheads/643363-skids-sikorsky.html)

Tickle 25th Oct 2021 05:51

Skids on a Sikorsky
 
I realised the other day that Sikorsky don't seem to do skids so I got curious and modified this S76 photo.

I'm no engineer so not sure if the struts are in the right places, but how do S76 drivers feel about it? Maybe it would mean less maintenance, less empty weight, less remembering, more fuel capacity.

Bell did it with the 222UT and Agusta with the A119.

https://www.uniquecarposters.com/media/S76-skids.jpg

heliduck 25th Oct 2021 05:57

It would make a terrible sound while taxiing. :ok:

ShyTorque 25th Oct 2021 10:57

No VIP/corporate aircraft should be on skids.

Sir Korsky 25th Oct 2021 11:16

you'd cause havoc at every airport with your downwash. At least you'd not have to remember to get the gear down when it's already down.

Dave B 25th Oct 2021 11:26

One of the most frightening incidents of my career was the collapse of the rear cross tube on a Bell 214 ST. Luckily nobody was underneath it at the time. I have also seen 212 rear tubes break on a couple of occasions.
The 214 was a contract maintenance job, When the first 214 demonstrate aircraft came to us, Allan Bristow took one look at it and said " anyone putting an aircraft that weight on skids wants their head testing".

Devil 49 25th Oct 2021 15:11

The struts on the landing gear also act as dampers against ground resonance.

albatross 25th Oct 2021 16:39

I could never understand why the 76 has retractable gear instead of fixed gear and fairings. Flew one with the gear bolted down for weeks. We lost about 2-3 knots in cruise and that’s with gear doors blowing in the wind.

212man 25th Oct 2021 17:43


Originally Posted by albatross (Post 11132113)
I could never understand why the 76 has retractable gear of fixed gear and fairings. Flew one with the gear bolted down for weeks. We lost about 2-3 knots in cruise and that’s with gear doors blowing in the wind.

surely you lost more than that? Vne is 130 kts gear down.

ShyTorque 25th Oct 2021 19:22

Maybe that’s why the doors were blowing in the wind? :}

[email protected] 25th Oct 2021 20:25


Maybe that’s why the doors were blowing in the wind?
Priceless:):ok:

Ascend Charlie 25th Oct 2021 21:09

"Less remembering"????

Umm.. time to land - gear down.
Fly away - gear up.
Not that difficult.

Nescafe 25th Oct 2021 21:22


Originally Posted by Ascend Charlie (Post 11132213)
"Less remembering"????

Umm.. time to land - gear down.
Fly away - gear up.
Not that difficult.

But not impossible, as the crash comics so often illustrate.

Nigel Osborn 25th Oct 2021 21:45

T he fixed under carriage system was not too popular, designed for military use originally. Where would you put the floats on the skids?

Nescafe 25th Oct 2021 22:38


Where would you put the floats on the skids?
Probably the same place that they go on all
other float equipped skidded helicopters, on the skids!

Brian Abraham 26th Oct 2021 05:36


But not impossible, as the crash comics so often illustrate
Bit hard to land a 76 gear up with the red "Landing Gear Up" caption front and centre and the head set tone, only heard of it being done once.

One chaps argument between the options.

https://kaypius.com/2016/08/14/wheel...kids-who-wins/

Wheels never caught on with the 412.


https://cimg7.ibsrv.net/gimg/pprune....28a250da1.jpeg

N707ZS 26th Oct 2021 08:06

That was supposed to be a photo of a 412ST mods please remove, thanks.

gulliBell 26th Oct 2021 08:46


Originally Posted by Tickle (Post 11131864)
...but how do S76 drivers feel about it?

Are there any skid equipped helicopters that can cruise at a Vne of 155 knots? I can't think of any. Run on landings at 40 knots in a 76 with skids would be interesting to say the least. As would arriving at the bottom after rejecting a vertical takeoff OEI from 50' up.

Boslandew 26th Oct 2021 10:37

From my army days, skid undercarriages were all about landing on rough or soft ground. For every time a 76 does that it will land 100 times on a runway/tarmac and have to taxi.

[email protected] 26th Oct 2021 11:17


Are there any skid equipped helicopters that can cruise at a Vne of 155 knots?
Lynx Mk 7 - and it goes quite a bit faster than that:ok:

Otterotor 26th Oct 2021 19:28

Vne or Vh?
 
The Vne for skid equipped AH-1Z Zulu Cobra is 200 kts but one does not cruise at Vne. Ott.

Tango and Cash 26th Oct 2021 19:34

I must say the S-76 on skids looks better than the 412 on wheels.... always thought the 412 on wheels looked like it had landed on top of a Cessna 172.

ShyTorque 26th Oct 2021 23:51

The S-76 looks even better with its landing gear retracted….

albatross 27th Oct 2021 11:35

212man
Well, long ago so excuse my memory, the 76A in the tropics 135 KTS cruise was what we flight planned and on a hot day we were happy to see that..
Just curious but I don’t recall the 130 VNE gear down limitations. Was it in Emergency Procedures? I don’t see it in limitations. Many moons since I flew one.
I recall the “Dance of Death” departing a low deck on a hot, no wind day. Not exactly a mighty leap into the air. Much fun.
Hope you are doing well in Nigeria. I miss the Miri / Anduki Daze.

gulliBell 27th Oct 2021 12:25

"Maximum airspeed with landing gear down or in transit is 130 KIAS"

It's been in the RFM Part 1 Section 1 Operating Limitations since day 1, and applies to all variants.

Phil Kemp 27th Oct 2021 13:02

Skids are for kids. Sikorsky preferred stumps!
https://cimg6.ibsrv.net/gimg/pprune....433e546103.png
World Speed Record holding H3/S61

albatross 27th Oct 2021 13:40


Originally Posted by gulliBell (Post 11133024)
"Maximum airspeed with landing gear down or in transit is 130 KIAS"

It's been in the RFM Part 1 Section 1 Operating Limitations since day 1, and applies to all variants.

Thanks very much for the info. Remembered the in transit limit but not the gear down and locked limit.

Winemaker 28th Oct 2021 00:08


Originally Posted by Brian Abraham (Post 11132332)
Bit hard to land a 76 gear up with the red "Landing Gear Up" caption front and centre and the head set tone, only heard of it being done once.

One chaps argument between the options.

https://kaypius.com/2016/08/14/wheel...kids-who-wins/

Wheels never caught on with the 412.


https://cimg7.ibsrv.net/gimg/pprune....28a250da1.jpeg

That looks like a tricycle tipping over accident just waiting to happen.......

megan 28th Oct 2021 10:24


Remembered the in transit limit but not the gear down and locked limit
Both the transit and gear down limit is 130.

gulliBell 28th Oct 2021 10:41

Yep, and you certainly hear the landing gear wheel well covers start to sing if they're left to dance in the breeze as you get close to 130.

chopper2004 28th Oct 2021 13:51

[QUOTE=Tango and Cash;11132702]I must say the S-76 on skids looks better than the 412 on wheels.... always thought the 412 on wheels looked like it had landed on top of a Cessna 172.[/QUOTE

Maybe they are mimicking Leonardo with the AW109 Trekker (my pic from recent Helitech)


https://cimg1.ibsrv.net/gimg/pprune....28931574e8.jpg

and AW169 well the UH-169 variant for their Guardia di Finanza and Air Cavalry.

https://helihub.com/2020/08/13/leona...69-with-skids/

What is the old addage if it looks right it flies right?

Cheers


All times are GMT. The time now is 09:36.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.