Chinook Autorotation?

Moving in and around an area of operations. Helicopters, Bikes, RSOVs, Zodiac's, etc...
Post Reply
User avatar
prouddad
Embryo
Posts: 22
Joined: March 6th, 2006, 9:24 am

Chinook Autorotation?

Post by prouddad »

A friend and I having a debate that needs to be settled. He's saying a CH-47 can't autorotate.

I'm saying it can (I don't see why it couldn't), and I've read detailed accounts of Takur Ghar, where Razor 03 autorotated to the base of the mountain after getting shot up.

He's saying the nature of a dual rotor system make it impossible to autorotate--or at least not able to autorotate in the same manner as a single rotor system like a Blackhawk. So, a dual rotor system inherently is not as safe as a single rotor system.

Has anyone out there actually autorotated a Chinook? Whether I'm right or wrong, I'd like to hear knowlegable comments.

Rock Island Ranger
Ranger
Posts: 10935
Joined: February 8th, 2004, 10:00 pm
Location: Occupied Mexico
Contact:

Re: Chinook Autorotation?

Post by Rock Island Ranger »

prouddad wrote:Has anyone out there actually autorotated a Chinook? Whether I'm right or wrong, I'd like to hear knowlegable comments.

Not and live to speak of it.
RS Class # 7-76

I'm not the way I am because I was a Ranger - I was a Ranger because of the way I am.

¿Querría usted el primer redondo en la rodilla o la cara?

The road goes on forever and the party never ends.

User avatar
The Holmchicken
Ranger
Posts: 3943
Joined: July 29th, 2003, 3:17 pm

Post by The Holmchicken »

Um...those are the big birds with the two thingys on top, right?
2/75 97-00

It's not that I'm lazy........it's that I don't care


75th RRA

Rock Island Ranger
Ranger
Posts: 10935
Joined: February 8th, 2004, 10:00 pm
Location: Occupied Mexico
Contact:

Post by Rock Island Ranger »

The Holmchicken wrote:Um...those are the big birds with the two thingys on top, right?
No, think they are on the bottom. :?
RS Class # 7-76

I'm not the way I am because I was a Ranger - I was a Ranger because of the way I am.

¿Querría usted el primer redondo en la rodilla o la cara?

The road goes on forever and the party never ends.

User avatar
Looon
Ranger
Posts: 9486
Joined: March 30th, 2003, 7:27 pm

Post by Looon »

I auto rotated my ass outta the door and fucked up my rope attempt, and proceeded to fall 60 ft onto assfault. :x

As far the bird, I have no fucking clue. :lol: :lol: :lol:
B Co 3/75
1989-1990
Just Cause Airlando Commando

Rock Island Ranger
Ranger
Posts: 10935
Joined: February 8th, 2004, 10:00 pm
Location: Occupied Mexico
Contact:

Post by Rock Island Ranger »

IN fairness to the asker of said question, I believe there are Auto Rotate properties to the newer (modified) Chinooks....ie, as you read on Roberts Ridge. Not sure the finite details. One of the Rotor Heads will come along soon enough and answer.
RS Class # 7-76

I'm not the way I am because I was a Ranger - I was a Ranger because of the way I am.

¿Querría usted el primer redondo en la rodilla o la cara?

The road goes on forever and the party never ends.

User avatar
DoorGunner
CrewChief/Ranger Parent/Rest In Peace, Brother
Posts: 2726
Joined: April 24th, 2004, 5:27 am
Location: Boston, MA

Post by DoorGunner »

Done a million in a Huey, well maybe not a million, probably 10 tops, but let's say I did a million just for the sake of it. You need fall, yes that's right drop, for the air passing by the rotors, to get them to spin which in fact creates lift with forward motion. Better have some attitude I mean altitude................... I think it has somethin to do with phsycic errrrr physics Somezin like that.
Height verses velocity curve better known as the dead man's curve.

Are ya with me on this. Good cuz I really don't know the answer. I was never in a "shit hook". I do believe if you had enough height it could be done. The issue maybe the Shit Hook rotor blades turn into each other, rotate in the opposite direction. That's why twin main rotors don't need a tail rotor. If the pitch on the rotor blades was enough, and you had enough height, I don't know why you couldn't auto.

That's an awfulllllllllllll big sum of a biatch to be pullin a stunt like that.

Just my opinion, not to be cofused with fact It's been many a year.
A Veteran is someone, who at one point in their life, wrote a blank check made payable to "The United States of America," for the amount of, "Up to and including my Life." This is Honor, and there are way to many people in this country that no longer understand it!

RVN 72-73
UH1H/U-21 1st Aviation Brgd.
Crewchief

User avatar
Tater Nuts
Ranger/Moderator
Posts: 4367
Joined: September 24th, 2003, 6:05 am
Location: East Tennessee

Post by Tater Nuts »

I don't know if it was an autorotation or not, but 1st Batt. did a FTX at Dahlonega in 80-81 time frame and were traveling back to HAAF on Chinooks. The bird I was on (wpns plt.) started doing an impression of an unbalanced washing machine full of pea gravel and was squrting hot hydraulic fluid everywhere. We went down pretty fast and hard, collapsed the nose wheel thingie in a field in the middle of nowhere. I do remember that there was not the usual slow shutdown proceedure when we landed, kinda like an Oh Shit, thump and silence (except for the high pitched squeeking of unclenching sphincters). Had to do the rucksack flop for 5-6 hours waiting on duece and a halfs to come and get us for the all night drive back to Hunter.
A Co. 1/75 79-81
RIP 4-79 (Honor Grad)
class 4-80 (white thread)

User avatar
prouddad
Embryo
Posts: 22
Joined: March 6th, 2006, 9:24 am

Post by prouddad »

Well, after a little googling, it looks like the Chinook certainly does something called autorotation. See these excerpts from the following sites. Still, any Chinook pilots out there to make the definitive call?

http://www.chinook-helicopter.com/maint ... miner.html
Download a self extracting Word document designed to enhance your Autorotation check and TEAC MOI skills

http://www.helicopterpage.com/html/unique.html
In a Chinook, the rear wheel locks are electrically operated. During autorotation, If the rotor RPM decreases below a certain value, the generators will fall off line, and the wheel locks will disengage. If this happens, the aircraft will most likely land aft wheels first, and without swivel locks engaged on the rear wheels, it could make for a very interesting ride.

http://www.gruntonline.com/TheWar/chalee_3b.htm
Today aircraft transitions like into the heavy Chinooks and Black Hawks do not get any practice autorotaions. Fact it was not even covered in the second transition course I attended in the mid 1990s. Even the instructors had never shot a practiced autorotation in the aircraft. I held the distinction of being the only one in the qualification class to ever have shut the engines down and landed a Chinook, and then the reserve unit, I think may only have had one, maybe two pilots who had performed an engine off autorotation in Hueys or Chinooks. (More later on Chinook Autorotations). [my note: never could find his 'more later' story]

http://www.theyworkforyou.com/wrans/?id ... 7a.65739.h
Autorotation is defined as the unpowered rotation of helicopter rotor blades that may occur during engine failure, thereby allowing the aircraft to effectively 'glide' to a safe landing. The minimum height at which autorotation is considered safe for a Chinook HC2 is 100 ft above ground level. Weight has no significant impact on autorotation flight performance. However, practice autorotations for Chinooks are not allowed to be carried out above the regulatory maximum weight of 20,000 kg.
[my note: the HC2 is what the Brits call a CH-47]

User avatar
avidwanderer
USAF Vet/US Army Chopper Pilot
Posts: 95
Joined: July 29th, 2004, 2:00 pm
Location: Unkown

Post by avidwanderer »

Thanks guys, making me do my homework:

Yes Chinooks can autorotate, and power on autorotations (in a TH 67) are practiced in flight school. I am not sure if 47s practice.

I am not sure if there is a helicopter that cannot autorotate, provided the pilot is familiar with the autorotational airspeeds and emergency procedures for that aircraft.

If you really want to understand how autorotation works you can look it up in FM 1-203, page 6-53.

I'm sure there are some other helo drivers in here that could explain autorotation better than I, maybe they will be around shortly...

Cheers,
Avid
Nov 2001--March 2006 52 SFS, 49 OSS
as active duty air force security forces
--crossed to army--
March 2006-May 2006 WOCS Class 06-07
May 2006-Nov 2007 B Co. 1/145th
Nov 2007-In a US army CAB
Oct 2008--Oct 2009 Camp Speicher B. 3-10 AVN
Oct 2010--Present JAF Task Force Six Shooters (Calvary)
AIR CAV!!!!

KW Driver
Ranger/Moderator
Posts: 6568
Joined: December 8th, 2004, 2:20 pm

Post by KW Driver »

since you responded to a very old post, I'll add some more to it. Army multi-engine aircraft until very recently never practiced autos, or simulated engine failures w/ a termination with power. I've never seen a shit hook do one.

they used to do engine out roll on landings routinely (one engine failure), and still do.

autos are however, practiced in the simulator to the best of my knowledge.
A Co & HHC 3/75 '93-'98.
RS 10-94.


200 meters of green shit next to a river in the desert does not qualify as a "Crescent of Fertility" -me

"The meek shall inherit the earth, one meter wide and two meters long" -Lazarus Long

Post Reply

Return to “Ranger Transportation”