Helo EPs for FW Types

[ChunksJR]

Does the nose tuck?

How about with blade stall?

OH OH OH MY TURN MY TURN!

The nose may tuck, only because you've reduced collective resulting in less downwash on the Horizontal Stabilizer in aircraft without variable stabilizers (TH-57) and also depends on flight regime.

Blade stall on the MAIN ROTOR occurs at high airspeeds, T/R is completely independent of that.

If you're thinking about T/R Vortex Ring State (can maybe be confused with blade stall, unless you're a helo bubba), that happens as the air being driven through the tail rotor catches a Crosswind that pushes it back into the rotor (creating "dirty" air that doesn't have the same thrust characteristics as "clean" air...think "I'm caught in his jetwash" type dirty air).

This was the nice thing about the CH-46/47.

Wanna see what happens to an RPG in the T/R...watch/read "Blackhawk Down" Same shit. "Hey, you wanna get those PCLs?"...love Jeremy Piven.

~D

 

[ghost]

OH OH OH MY TURN MY TURN!

The nose may tuck, only because you've reduced collective resulting in less downwash on the Horizontal Stabilizer in aircraft without variable stabilizers (TH-57) and also depends on flight regime.

On the 60 I would think that the tail would initially drop. The T/R produces a small amount of lift, but it is at the end of a long arm. The sudden loss of this moment should cause a pitch up reaction. Once you lower the collective though, I am not 100% sure what would happen. Between control mixing, stab programing and whatever the AFCS decides to do, it would be really hard to predict.

 

[ChunksJR]

The T/R produces a small amount of lift, but it is at the end of a long arm.

That's right! I completely forgot about the 3% or so overall lift that does pull the tail up...Really significant on the S model (Blackhawk) because of the extra weight of the tail under the T/R...

Good call.

The last case I've heard of a T/R going bad was the 2 instructors (TH-57) back in 2003 or so...Both survived a crash landing on the beach, but it wasn't pretty. Tail delaminated in flight and at 2500 RPM, weight distribution quickly tore it apart...autoed to the beach, severe back injuries.

 

[lowflier03]

There have been a few more recent T/R failures in the 60. Also if you get blade stall in the 60 the nose will tend to pitch up and left. This is because the retreating blades (Left side of the helo) are the first to stall due to seeing less airflow than those on the right side, so the effect is felt on that side, as well as 90* forward of where they stall due to gyroscopic precession. ie over the tail. Lots of aero, etc involved, but thats the short version.

 

[Pags]

That's not speculation. That's a genuine helicopter question.
EDIT: Read it over again and I need to clarify what I am trying to ask. Do all helicopters share pretty common numbers in a H/V diagram or is it widely different depending on type? Like is it safer to hover in a -60, -53, -47, -46 at 200ft than a -57....

Besides, my buddies dad is in that Guard unit so I don't need to speculate.

I understand that it's a genuine question, perhaps deserving of it's own thread....not in a thread about a mishap with associated pictures.

 

[nittany03]

There's a Helo vs Fixed-Wing EPs thread spun off of this . . . I'm out the door to muster; will move the post when I get back.

Edit: done.

 

[MAKE VAPES]

I'll charge up my air-hog micro rc dealybopper and test all this crap out today...

 

[nittany03]

The last case I've heard of a T/R going bad was the 2 instructors (TH-57) back in 2003 or so...Both survived a crash landing on the beach, but it wasn't pretty. Tail delaminated in flight and at 2500 RPM, weight distribution quickly tore it apart...autoed to the beach, severe back injuries.

One of the pilots taught my API class Aero II; I remember him telling the story. Apparently he ended up med down, hard, from the back injuries. He was teaching at API while his redes package went through.

 

[Never_Fits]

SNA fresh outta helo aero class. Watch out, i know enough black magic to hurt someone. The Israeli 53 crash had to do with PIO or pilot induced oscillations. tail shook a little and the bouncing on the collective just kept getting worse and worse until he broke his tail off.

If the 57 loses its tail... first, bad day. second, there are eps for it, but they seem to be there just to make u feel better about defying gravity. if u lose tail rotor authority and still have the boom u can make it down if u keep sufficient speed (how i understand it).

There was one story our aero teacher told us about a forest ranger flyin the 57 who was making continual right turns and felt a shake in the petals, though it was something in the engine, did an auto, and when he landed found out that he was missing his entire tail rotor drive shaft. so, with God on your side, you can land without your TR drive shaft.

Plus if uve seen what the 57 can survive, SNAs are in pretty good hands in there.

 

[MIDNJAC]

Plus if uve seen what the 57 can survive, SNAs are in pretty good hands in there.

Knowing what the T-45 can't survive, maybe I should have gone helos

 

[KBayDog]

SNA fresh outta helo aero class. Watch out, i know enough black magic to hurt someone. The Israeli 53 crash had to do with PIO or pilot induced oscillations. tail shook a little and the bouncing on the collective just kept getting worse and worse until he broke his tail off.

If the 57 loses its tail... first, bad day. second, there are eps for it, but they seem to be there just to make u feel better about defying gravity. if u lose tail rotor authority and still have the boom u can make it down if u keep sufficient speed (how i understand it).

There was one story our aero teacher told us about a forest ranger flyin the 57 who was making continual right turns and felt a shake in the petals, though it was something in the engine, did an auto, and when he landed found out that he was missing his entire tail rotor drive shaft. so, with God on your side, you can land without your TR drive shaft.

Plus if uve seen what the 57 can survive, SNAs are in pretty good hands in there.

Just hitting the wave tops here:

1. Capitalize the first-person, singular personal pronoun "I".
2. Capitalize the beginning of sentences.
3. Spell "you." The extra two letters are your friends (and don't require that much extra effort).

In any event, enjoy your choppering. Remember the "power curve?" Don't get behind it, and you'll be fine. Best wishes for the HTs.

 

[Pags]

SNA fresh outta helo aero class. Watch out, i know enough black magic to hurt someone. The Israeli 53 crash had to do with PIO or pilot induced oscillations. tail shook a little and the bouncing on the collective just kept getting worse and worse until he broke his tail off.

If the 57 loses its tail... first, bad day. second, there are eps for it, but they seem to be there just to make u feel better about defying gravity. if u lose tail rotor authority and still have the boom u can make it down if u keep sufficient speed (how i understand it).

There was one story our aero teacher told us about a forest ranger flyin the 57 who was making continual right turns and felt a shake in the petals, though it was something in the engine, did an auto, and when he landed found out that he was missing his entire tail rotor drive shaft. so, with God on your side, you can land without your TR drive shaft.

Plus if uve seen what the 57 can survive, SNAs are in pretty good hands in there.

Flowers have petals. Helos have pedals. That's all I have the energy for now.

 

[Never_Fits]

Just hitting the wave tops here:

1. Capitalize the first-person, singular personal pronoun "I".
2. Capitalize the beginning of sentences.
3. Spell "you." The extra two letters are your friends (and don't require that much extra effort).

In any event, enjoy your choppering. Remember the "power curve?" Don't get behind it, and you'll be fine. Best wishes for the HTs.

Roger that, sir. At least I capitalized God. I was an engineering major, English is not my strong suit.

 

[Never_Fits]

Knowing what the T-45 can't survive, maybe I should have gone helos

I've had two instructors try and convince me that helo's are safer than fixed wing. I refuse to be convinced. The thing thats missing in the helo... the "Screw it" factor (I have a more colorful term, but you get the picture). If everything is going to hell, you can pull that little yellow and black handle and say "Screw it, I'm gone." Helo's don't have that luxury (at least TH-57's don't).

 

[KBayDog]

Roger that, sir. At least I capitalized God. I was an engineering major, English is not my strong suit.

Never fear:

I've had two instructors try and convince me that helo's are safer than fixed wing. I refuse to be convinced. The thing thats missing in the helo... the "Screw it" factor (I have a more colorful term, but you get the picture). If everything is going to hell, you can pull that little yellow and black handle and say "Screw it, I'm gone." Helo's don't have that luxury (at least TH-57's don't).

Helos don't have the luxury of an ejection seat, true, but look at it this way: When things go to hell in a helo, you don't have as far to fall. Therefore, helos are safer.