View Full Version : Houston Texas news helicopter accident
Helicopter crashes in Montgomery County - 10/13/08 - Houston News - abc13.com (http://abclocal.go.com/ktrk/story?section=news/local&id=6446793)
Matari
13th Oct 2008, 20:20
There's a bit more detail in this story:
Pilot, TV photographer die in Montgomery County crash | Houston & Texas News | Chron.com - Houston Chronicle (http://www.chron.com/disp/story.mpl/metropolitan/6055595.html)
Aircraft was a Bell 206L4 operated by Helicopters, Inc. in Houston.
Condolences to all.
Furia
14th Oct 2008, 06:46
Sad news indeed!
:(
My condolences to the families and friends.
Matari
1st Nov 2008, 01:57
Looks like it was loss of engine power, and autorotation into an unforgiving pine forest.
"Preliminary investigation revealed nut on PG line only finger tight."
CEN09FA012 (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20081013X24743&key=1)
Shawn Coyle
1st Nov 2008, 11:34
If it was the P3 line B-nut being loose, that's just another one in a very, very long line of this problem.
I wonder when something permanent will be done to fix the problem.
Matari
1st Nov 2008, 13:54
Shawn:
This problem has unfortunately been around for a while, and needs to be addressed. It isn't clear if this event happened after a governor or fuel control change, but somehow this B-nut problem continues to vex the industry.
We used to have trouble with overtorquing of the B-nuts, with a subsequent failure of the flare end, leading to line separation from the governor or fuel control. Another problem was bending of the lines to meet the fitting, instead of loosening the other end to relieve stress, then re-tightening. It took a lot of communication, visibility, and inspections to get the right maintenance practices in place.
For pilots doing preflights, it's always a good practice to run your fingers over the B-nuts, check for finger-tightness at least and look for any broken "torque-seal" indicators. Every little bit of extra diligence helps.
Shawn Coyle
1st Nov 2008, 23:26
Matari:
The problem has been around since I started flying helicopters in 19xx. Why has there not been a final solution to this?
Does the FAA not read the Service Difficulty Reports and Incident / Accident reports?
heliclint
14th Apr 2009, 17:05
Hey, can you guys help me understand what exactly the PG nut or b-nut is on the engine? Thanks.
clint
Matari
14th Apr 2009, 18:29
Heliclint:
There is some history and lore surrounding the term "B" nut, but generally the "B"-nut is a common term used for a female fastener (nut) at the end of a flared tube and sleeve combination, which connects with a beveled male-end fitting.
B-nut connections are usually used on tubes or lines with fuel, air, oil or other hydraulic systems.
B-nuts are also usually self-locking, by means of a small embedded wire, which when the B-Nut is torqued correctly, applies enough pressure to keep the nut from backing off. Many B-Nut connections are externally safety-wired, which is recommended especially where vibration, heat etc. can loosen a connection.
However, as this accident shows B-nuts are still prone to failure, through mis-installation or loosening. It is an area that demands more attention from engineers (mechanics) and pilots (on preflights) than it currently gets IMHO.
Oh, "PG, PC," varies but typically Pressure-Governor, Pressure-Compressor, etc.