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-   -   Bell 206 - Common errors, performance, handling & C of G characteristics... (https://www.pprune.org/rotorheads/441825-bell-206-common-errors-performance-handling-c-g-characteristics.html)

OvertHawk 20th Feb 2011 14:34

If you are doing ground-runs or air-tests after work has been done on the engine or FCU - check that the throttle position indicator on the FCU (the arm in the green / amber / red arc) is actually in the closed position when the throttle lever is closed.

I had an incident where the throttle was mis-rigged so that when the throttle on the collective was fully closed - the FCU was still slightly open - It lit off at about 7%N1 (before i had opened the throttle lever) and i had to use the shut off valve to cut the fuel. Not pretty!

OH

spb 7th May 2011 04:06

B206 78 kt limit.
 
Can anyone please tell me why a B206 with an increased max internal gross (1519 kg) is limited to 78 kt above 1451.5 kg? ie blade stress, transmission limit etc.

Thanks.

Heli-Jock 7th May 2011 13:11

Longranger Fuel fact
 
Hi Guys, i need to share this one with you. I once read in a book about a fuel gauge problem in the Longranger which has stuck in my brain since reading and goes as follows:
If you are ever in a situation in the LR, where your "Fuel Low" light comes on in flight, but you have 270Lbs or so showing on gauge,,,,"Land Immediately"!

If theres one thing all you guys remember about the Long Ranger, there are two other fuel tanks below each seat, at the back of the drivers and front pax seat. The tube that feeds the main tank from both these tanks can become blocked by the smallest of particles,,,,In this instance the tube was indeed blocked by something as little as a grain of sand. Thus allowing the fuel gauge to be reading up to 270LBS of fuel in the tanks,,,however, if the 270Lbs or so cannot be transferred to main tank,,,,the main tanks low fuel mechanism will be activated when main tank gets low on fuel,,,,as in "Low Fuel" warning light on CWP!

HJ :eek:

Ascend Charlie 8th May 2011 00:33

SPB:

Prior to getting upgraded to the higher weight, anything above 3200lb / 1451kg had to be carried on the hook, as the skids weren't rated to cope with that, and in an auto, that excess weight could be pickled off.

Now that you can carry it internally, you will be pulling lots of power and you are in a similar situation as with pulling over 85%Tq, limited in speed to 80kt. This is largely due to the bending stresses on the driveshaft between the engine (fixed to the fuselage) and the transmission (able to tilt slightly forward) and also on the mast (mostly fixed to the vertical position) and the rotor head (trying to pull the mast forward).

You want your machine to survive to the next overhaul, treat it gently.:eek:

topendtorque 8th May 2011 02:28


as the skids weren't rated to cope with that, and in an auto, that excess weight could be pickled off.
A.C.
Is this the same reason that we could carry an extra 150 lbs on the '47 G3B2A as long as it was external?
I never could work it out, nor found anyone to know, especially when the hook we had on that model was the four point lower mainframe instead of the old style swinging bar mounted on the Lord mounts.

The aircraft was identical in blades and xmon to the 3B2 except for the engine which was the wet sump instead of the dry sump, but I cannot remember the upper MAP limits on the 3B2A model separate from the 3B2 which was, from a foggy memory, .6" higher than the 3B1 with the 600 series xmon.
tet

bob2s 8th May 2011 06:49

206l fuel system
 
The L FUEL SYSTEM has the l/h pump wired direct battery,this is due to the a/c being built with ni cad batteries,a requirement of which is if a batt hot light comes on, then you are supposed to turn off the batt switch.This stops the batt from further over heating,but also turns off the r/h boost pump ,there fore if both pumps were wired to the bus bar as per the r/h pump, then there is no way of getting the fuel from the foreward tanks to the reartank as the boost pumps also operate ejector pumps in the fwd tanks These ejector pumps have a very small opening for the fuel to flow thru to draw fuel from the tanks to the rear tank and are subject to blockage from contamination, which causes NO fuel transfer from the fwd tanks to the rear.The fuel pump caution lights are operated by FLOW SWITCHES and not pressure switches as per 206A/B So if pump caution light is on then NO fuel is being pumped from that tank as there is no flow
This is why it is possible to have an engine failure due fuel starvation even though the fwd tanks show plenty of fuel remaining SO LOW FUEL LIGHT ON MEANS EXACTLY THAT ,lowfuel despite what gauge indicates
Lesson over!

vfr440 8th May 2011 07:17

206L fuel system
 
B2S
Very well put :D

Also worth noting that to rectify this problem is a POTFO (Pain Of The First Order). The plumbing form Front to Rear goes through the box section on the centreline of the rear cabin. That has to come out, + the front seats, trim etc, and if contam in the main tank all that has to be investigated. Smelly job, nice trim and carpets at risk etc etc. Takes time and is a POTFO of consequence. :sad: - VFR

spb 8th May 2011 07:50

Cheers Charlie. Much as I suspected...

RVDT 8th May 2011 09:14

206L Fuel System.

Looks pretty much like this post http://www.pprune.org/rotorheads/196414-bell-206-jetranger-longranger-2.html#post204309] of nearly 10 years ago!


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