Welcome Guest
HeliTorque
  
User Control Panel

Security Code: : Security Code
Type Security Code Here: :
 
Register Here
Lost Password?

Online Stats:
Visitors: 52
Members: 0
Total: 52

Membership:
New Today: 0
New Yesterday: 0
Registering: 0
Members: 6662
Latest: chrisw

Most Ever Online
Visitors: 447
Members: 10
Total: 457


HeliTorque :: View topic - UH-1H
Forum FAQ
Forum FAQ
Search
Search
Memberlist
Memberlist
Usergroups
Usergroups
Profile
Profile
Contact Manager
Contact Manager
Log in
Log in
Log in to check your private messages
Log in to check your private messages
HeliTorque Forum Index » Flight Dynamics

Post new topic   Reply to topic All times are GMT
UH-1H
View previous topic :: View next topic  
Author Message
kulttt
Shy 'Torquer
Shy 'Torquer


Offline
Joined: Feb 02, 2008
Posts: 2



PostPosted: Sat Feb 02, 2008 12:39 am    Post subject: UH-1H Reply with quote

Hello,
I have Q about UH-1 autorotation. Manual says in chapter 9;" Should the Eng malfuction during a left bank maneuver, right cyclic input to level the helicopter must be made simultaneously with collective pitch adjustment. If the collective pitch is decrezsed without a corresponding right cyclic input, the helicopter will pitch down and the roll rate will increase rapidly, resulting in a significant loss of altitude"
So, what is the point that aircraft will roll left and nose down unless pilot roll it to right while lowering collective in this autorotation case?
If that rule does make sense (leveling helicopter as soon as engine stops during left bank maneuver) is it valid for all counter-clockwise rotating helicopters?
Back to top
View user's profile Send private message
Ascend_Charlie
H Addict
H Addict


Offline
Joined: Aug 23, 2005
Posts: 266
Location: On a course.... golf course


australia.gif

PostPosted: Sat Feb 02, 2008 3:59 am    Post subject: Reply with quote

I don't recall seeing this entry in the Huey manual, but it would be due to left yaw.

In flight, you are using some left pedal, depending on cruise speed, weight etc (though sometimes you might have 1" of right, due to the fin unloading the T/R) so when the engine torque stops, this pedal input will cause the nose to yaw left. You might also have some left pedal applied as you roll into the left turn, to help things along a bit. The combination of a left turn, left yaw, and the complicating aspect of a high-set tail rotor can result in a nose-down attitude. The high-set T/R would cause adverse yaw, wanting to roll you out of it, so it is hard to say how it would affect things.

Dumping the collective would also cause a left yaw if no corrective pedal was applied, though if there was no torque this would be minimal.

Would this apply to all helicopters? Remember that the Huey design dates from the 50s, so a newer design might not be so liable to yaw and roll, particularly if it didn't have a high-set tail rotor.
Back to top
View user's profile Send private message
kulttt
Shy 'Torquer
Shy 'Torquer


Offline
Joined: Feb 02, 2008
Posts: 2



PostPosted: Mon Feb 04, 2008 7:02 pm    Post subject: Reply with quote

Thank you Ascend_Charlie, it is a confusing autorotation case, I have not been sufficiently able to figure out Why Huey is pitching down an d rolling left ? Is this described in an aerodynamics book, have you ever seen?
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    HeliTorque Forum Index » Flight Dynamics All times are GMT

 
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Sponsors


Billund Air Center

Visit HeliTorque!