View Full Version : Bell 206 - Common errors, performance, handling & C of G characteristics...
For the benefit of people who are 206 rated with low hours on type, or interested in becoming rated.....
Could those of you with vast hours experience on type suggest common things to watch out for that could catch a less experienced pilot out? with regards to the start, loading & C of G, any handing characteristics (VRS, limited power checks, loss of TRE, Blade sailing etc... ).
One example that I recently read is that if you were to accidentally do the throttle full and free travel check with the fuel pumps & batt on, then the residual fuel in the chamber on start would be sufficient to lead to a hot start. Or that the time that might catch you out with a hot start is the second spike on the TOT as opposed to the primary run up... And ensuring before start that the batter power is sufficient to keep the starter motoring until approx 60% N1 (is there a way or if in doubt use a GPU). I vaguely remember somebody telling me that the governor can behave in slightly unexpected ways in a peddle turn, and that if your not careful it may close the throttle in a right hand peddle turn to maintain rpm relative to the fuselage, then droop the rpm when stopping the turn as the turbine is slow to spool up again (unlike the piston ships)....
Anything tips, or instructional points that over the years you has helped you to fly the aircraft safely and without incident, that are not necessarily stated in the manual or checklists :ok:
Much appreciated, Aucky
helonorth
5th Feb 2011, 16:53
I don't have a lot of time in the 206, but at one time (not anymore) I would double check that the throttle was closed (by opening it) before starting with the battery on. I rarely started it with boost pumps on. I never had a problem, but I have heard it could light off when you hit the starter. I (knock on wood) have never hot started, but been around plenty. The only time I saw damage was when it was started with the throttle open. You can save it if you're quick, but mess up and you'll have some big bills coming! You will notice a weak battery right away as it winds up slowly and the igniters don't make their rapid clicking sound. If in doubt, get a cart. Be careful with pedal inputs at high power settings. It's easy to overtorque if you're not careful.
I rarely started it with boost pumps on.
How do you manage that? The latest I heard from Bell was to not pull the CB's on shutdown----on the L4 we use the fuel valve to disconnect the boost pump from the battery......ergo, with the fuel valve open---the boost pumps will be running.
I ALWAYS do a full throttle check with battery, fuel valve on etc---never hjad a problem with hot starting.
Ascend Charlie
5th Feb 2011, 22:18
You can do whatever you like with the throttle, boost pumps, fuel valve etc BEFORE hitting the starter button, and it won't matter a rat's. All the boost pumps do is provide pressure up to the engine-driven pump. Nothing gets past that pump until it is running.
When you hit the starter and the N1 turns and the engine-driven fuel pump starts to push fuel into the engine, that is when your ducks should be in line.
Ensure the throttle is OFF when you hit the starter - no airflow through the engine would mean an awfully hot and expensive start if the throttle is open from the first rotation.
At 12-15% depending on temperature, open throttle to IDLE, it should light off.
It is possible to take the throttle all the way open at this stage, the N1 FCU is only concerned with getting the engine to idle RPM of 58% self-sustaining, but if it then sees that the throttle is anywhere but at idle, it will pour the fuel in and away goes the temperature. So, keep it at idle until it settles at 61%.
Of course you can start without the boost pumps on. You only need them above 6000'pa to push the fuel to the engine, because the atmospheric pressure is too low for the engine to suck hard enough.
The governor doesn't "close the throttle" as such, and it would need to be a rapid pedal turn to get such a result. There is less torque required to yaw right than to yaw left, and it is possible, if you are near your torque limits, to get a spike when stopping a right pedal turn, as the torque demands increase quickly.
CG in a B206? Very hard to get out of cg, unless you have 2 real porkers in the front seat and nothing else.
The 206L is another story, having a longer arm to play with, and movable fuel cg as it burns down. Devise yourself a simple Excel prog to sort this, or download an app.
An excellent start thanks guys, all useful info :ok:
helonorth
6th Feb 2011, 00:44
Almost every 206 I get into has the boost pump breakers pulled when I get in it. Old habits die hard, I guess. And every checklist I've seen checks the throttle before the battery is turned on, but often a big red placard on the panel saying:CHECK THROTTLE CLOSED BEFORE ENGAGING STARTER. I've had my hand slapped for checking the throttle one last time by opening it with battery and boost pumps on. Not following the checklist!:= I prefer the old way because if you leave the boost pump breakers in with the fuel valve on: dead battery if you leave it too long. The left boost pump will run with the fuel valve on and the battery off.
Here is a link to an Allison Service Letter previously posted on the 206 thread which provides lots of useful on starting a 250-C20:
http://fireheli.com/Files/allisonstart.pdf
handbag
6th Feb 2011, 01:54
watch your VNE, especially if you have air con installed. VNE goes to S*** over 3000 lbs and it doesn't take too much to get it there.
rotorrookie
6th Feb 2011, 02:52
Could those of you with vast hours experience on type suggest common things to watch out for that could catch a less experienced pilot out? with regards to the start, loading & C of G, any handing characteristics (VRS, limited power checks, loss of TRE, Blade sailing etc... ).
just to mention few.
becoming a 206 pilot you will also become a 100% guy ( meaning you will spend lot of time with TQ near the red line).
if the **** hits the fan, the 206 is not bad place to be in compaired to some other types, the high inertia rotor is very forgiving.
dont try extreme aerobatics, like rolling or loop :E
If you need to start in high wind it is safer to point the nose so wind is at 30° right of nose rather than having blade/tailboom kissing each other (those blades love to sail)
For 206 L3 if hot and high you can easily get out left pedal before other pwr limits
For L types load the rear seats always before mid seats, with full load ist often front heavy, to front heavy means your autoflare will be more interesting than normaly, put the fat guys in the rear seats.
If heavy for a confind area and mountain landing, a good pratice (at least while you are getting more familiar with its perfomance) do high hover pwr check, to see how much T/Q you need to hover, if dose not hover near full blast then you might consider some alternatives.
and for heavy, hovering and take-offs be patient and give the rotor a little time cath up rpm at 100%TQ.
and well tracked and balanced (Long Rangers especially) should be very smooth in the air, if not in might need some tracking of the rotor
have fun, fly safe
pitot212
6th Feb 2011, 07:53
Before going anywhere near to starting make sure you know which fuel system you have….Bendix or CECO.
I have personally only ever flown aircraft with the 'Crack and back' bendix system, is that more common than the alternative with manual fuel flow modulation?
edit: for anyone who is unsure of the differences they are explained in this thread http://www.pprune.org/rotorheads/154796-cracking-throttle.html
The CECO is way too expensive to maintain these days, so the Bendix is more common
Phil
Lets see if we can confuse Aucky even more! I have been taught to start a C20W (Enstrom 480) with Bendix by opening the throttle (at 12- 15% N1) just to light off (not to or past the idle stop) and then just a tiny bit more to avoid flame out (still not to or past the idle stop). The reason I was given for this is to allow the fuel to be shut off instantly without releasing the idle stop button if the need should arise. Done it this way for years with no problems. Depending on the way the throttle is rigged, one might need to go past the idle stop to get light off, but in the 4-5 480's I have flown this was never the case. Dont know if this might apply to the 206 as I have no 206 time. :bored:
pitot212
6th Feb 2011, 12:38
EN48 your description is spot on. I've always taught students to adopt this technique.. that way you are always on the safer side whatever the fuel system.
FH1100 Pilot
6th Feb 2011, 14:25
There are a million different techniques for starting 206's, depending on so many things (location of starter button, stiffness of throttle, etc.). You'll quickly learn which technique works for you. Yes, Bell says that c.b.'s are not to be used as switches, and therefore should always be in, but many, many, many pilots start a 206 with the Caution and boost pump breakers out. Reality: IT DOES NOT MATTER. But do it by the book anyway ;)
On the other hand, do not sit there for 20 minutes with the battery on, the boost pumps pumping, the strobe light strobing, and the gyros humming while you go through the million-item pre-start checklist. The battery is way up in the nose, and the cables that go back to the starter are loooooooong. Can you say voltage drop? I knew you could. 206's do not have voltmeters, so you cannot predict how good your battery is before hitting the button.
When you roll it up to 100% for takeoff, *ALWAYS* hit the Caution Light Test button before pulling pitch. This will alert you to the fact that you forgot to push the Caution and boost pump circuit breakers in after starting the engine with them out. Trust me on this.
206B's hover a little nose-high when it's just you inside. 206L's hover a *LOT* nose high when it's just you, especially if you're a 170 pound skinny kid. With two people in the front seats a B-model will hover fairly level. (All models also hover a little left-skid low all the time.)
With two people onboard, be careful when hovering downwind. The cyclic will be back in your gut. And the bigger your gut, the further aft the cyclic will be. When air gets under that horizontal stab, it wants to lift the tail big time. Don't say I didn't warn you.
Do an actual c.g. calculation and see how much you can carry in the baggage compartment when you're solo. Your "most-aft c.g." does not include having passengers onboard. Some day you WILL find yourself in a situation where someone wants you to carry a big, heavy, oily something and you don't want it on the back seats or on the floor. They'll ask if they can put it the baggage and you'll go, "Derrrrrr..." Easy solution: Find out now.
Finally, use some friggin' cyclic friction! The 206 pre-takeoff checklist only calls for the friction to be "set as desired." Many pilots take it completely off, which in most 206's give you an extremely sloppy cyclic. Put just enough friction on to give the cyclic some "drag." Otherwise you'll be making all kinds of extraneous and unnecessary inputs as the fuselage gets jostled around in the wind. (The fuselage will react to a smaller gust of wind than will that big, heavy rotor. And if the rotor doesn't move, the fuselage *will* come back without you having to make it.) Even *tiny* cyclic movements impart a "roughness" to the ride that is noticeable to the passengers even if it is not noticeable to you. Every 206 pilot thinks *he* is the smoothest guy to ever strap on a 206 since 1966. Trust me on this. Think about it: If you move the cyclic even 1/8th of an inch when it doesn't need to be moved, the swashplate *will* move a proportionate amount. If the swashplate moves, the rotor *will* move. Now you've just introduced a little PIO. And no matter what you think (or what you've been told), you CANNOT hold the cyclic steady enough with zero friction. Bottom line: Use a little cyclic friction. You'll look like a better pilot than you actually are - unless the air is glass-smooth.
DO NOT PARK DOWNWIND!!! As soon as a passenger pops the door open (and they will, even if you told them not to), they will lose their grip on it and the door will come around and slap a) the front door, or b) the bubble. Breaking any of the "glass" on a 206 is an inconvenient, expensive proposition. Those wimpy straps and/or little hydraulic struts are not guaranteed to keep the door from coming around. For loading and unloading, don't set down downwind. Don't say I didn't warn you.
Finally, leave the anti-collision light switch on ALL THE TIME. This way, when you shut down and you're in the FBO enjoying a nice cup of coffee, you can look admiringly out at your JetRanger and go, "Damn, I left the battery on. Again." Don't say I didn't warn you.
many, many, many pilots start a 206 with the Caution and boost pump breakers out. Reality: IT DOES NOT MATTER
Well ... maybe it does matter - not with respect to the operation of the acft, but because CB's are not designed for frequent operation such as a switch might see. May compromise the functionality of the CB in time. :( You can do it but its not a great idea.
heliski22
6th Feb 2011, 20:19
Ditto on the anti-coll, FH1100, though I've applied the practice to every type I've flown!
An old hand once told me the most important thing about a 206 is to know how far you can f**k it up and still save it.....! :E
22
pitot212
6th Feb 2011, 20:26
When your in a brand new aircraft then I agree with the statement regarding cbs are not switches, but in the real world of old jetboxes with batteries and turbines that have seen better days, conserving battery power is essential. I also think it comes from the training and students sitting in the aircraft running down the battery for 20 minuets before hitting the start button, so instructors would pull the cbs and therefor the newbie pilots would continue to do this for ever more...but that's just my opinion for what it's worth.
students sitting in the aircraft running down the battery for 20 minuets before hitting the start button, so instructors would pull the cbs
I see what you mean. But using the CB's as switches involves a tradeoff. Doesnt the 206 have switches for the boost/xfer pumps? I am flying a 407 which has these switches and just assumed the 206 was similar.
SASless
7th Feb 2011, 00:08
FH knows of what he speaks! Definitely take note of those comments followed by "Trust Me on this!"
I would add never....never....never...never hit the starter button until you can see both blade tips and have your grubby mitt on the blade tie down. Trust me on this!
Also....if the aircraft is heavy....torque, Temp, or N-1....or any combination of the three are at max.....don't be stomping any pedals. Be as light and steady on yer toes as you can be.....else you shall have need to chat with the Engineers and perhaps the Boss Fellah.
Also....never carry yer fat wallet in your hindend pockets....it will give you a crook roll attitude and lumbago. Jet Ranger seats are a crime against Humanity. If you are required to fly them for extended periods of time...say...anything over about five minutes....invest in some Oregon Aero seat cushions or retain a first class Chiropracter.
dodgy1
7th Feb 2011, 01:12
F.B.I.T
I use the above when starting any 206. You shouldnt have any problems if you follow all below.
F
Fuel Switch - Ensure On
Fuel Cap - Ensure Secure and On
Fuel Pressure - CB's in / Test seperately to ensure operation of both
Fuel Quantity - Ensure enough for the job
B
Blades - Level and Untied
I
Instruments - Static check of all but most importantly TOT <150 degrees
T
Throttle - Ensure completely closed
Timer - Have clock ready to start timer for start
I think if you cover all of these, you will never have a drama starting the Jetbox's
D1
Gomer Pylot
7th Feb 2011, 01:17
No, the 206, regardless of model, does not have switches for the boost pumps. The only way to disable them is with the circuit breakers. In the L, the left boost pump is almost always pulled on the ground, because if the fuel valve is on, the boost pump is running, even with the battery off. That gives you two switches that will kill the battery if they are left on. Most experienced pilots pull the left boost pump breaker, just in case, because there are those who have, and those who will, in addition to those who both have and will.
I agree about the cyclic friction also, for two reasons. I can't stand the lack of feel, and I don't want the cyclic to fall all the way over if I happen to let go of it. I don't often do that in flight, but it's easy to do on the ground, when looking for paperwork or yelling at the pax to try to keep them alive when they get out or try to get in. It seems to me that most 206 pilots fly with zero friction, for reasons that escape me, but I always put friction on both the cyclic and collective. I don't want them to move unless I do the moving.
IMO the secret to flying a 206 is having very steady hands and very busy feet. You don't want the rotor moving around, but you don't want the fuselage to yaw at all, either. A 206 is severely limited in yaw control, and you never, ever want to let the thing start yawing. Come in hot and heavy, with a left crosswind, and you can get LTE before you can blink. The kinetic energy that has to be bled off is proportional to the mass, but to the square of the velocity. Come in fast and you have to pull a lot of collective, thus lots of left pedal, and the rotor vortex will hit the nearly stalled tailrotor and away you go. Slow approaches will save your butt. The 206 weathervanes strongly, and you're always better with the nose into the wind, even if that causes you to go over more obstacles. With a 20 knot wind or so, I've gone from flat pitch to OGE hover and back, repeatedly, with my feet flat on the floor. Any crosswind requires much more power, and the more crosswind, the more power required.
Bell_Flyer
7th Feb 2011, 10:20
Compressor rinses are very important if you fly coastal. The pineapple looking part of the compressor corrodes faster than a rat up a drain pipe and is terribly expensive.
Pardon the silly question (I prefer to ask and look inexperienced than not ask and look stupid ;)), but by 'Light out' do you mean 'Engine off' light out? i.e. N1 > 55%? I have only started the 206 10/11 times and not heard that expression mentioned before... nor does the manual mention 'Light out' anywhere in the start checks, and in the engine start video's shown on youtube, many don't have any light's 'on' - to go out during the start (perhaps they've pulled the caution light breaker for start if no audio mute button installed, to prevent constant beep on start?)
EN48 - If you are starting using your method, and for some reason you do get a flame out, I assume the safe procedure would be to cool her down, rest it for 1 min and go again? (as opposed to keeping her motoring until TOT<150 and open up the fuel again?). I guess the 40sec Batt / 25sec GPU starter limitation, as well as a recommendation of introducing fuel at 12-15% N1 and not above, would indicate that it's necessary to rest her, and start again..
Gomer - In the L, the left boost pump is almost always pulled on the ground, because if the fuel valve is on, the boost pump is running, even with the battery off
I know you are referring to the L models as opposed to the A/B but out of interest why in that case only pull the Left Boost Pump breaker? Is the Right boost pump turned off with the battery? Also is the logic here that in an electrical fire etc where you would turn the battery off, some fuel boost pressure would remain?
206 jock
7th Feb 2011, 11:30
#1
Whatever else you do, don't ignore the strange knocking noise coming from the back. It's where your passengers who departed rotors running left the seatbelts outside of the aircraft and the buckle is now beating hell out your paintwork....a quick glance at the paintwork behind the rear door of a few Jetties will demonstrate that I am not alone in having fallen into this little trap!
#2
Always use a checklist on start. Even if you have started them a gazillion times before, you'll regret not doing it one day. I learned this when jumping into another machine (not my own), went to start all went well, until after a few seconds the turbine wound down. Turned out that the fuel valve was turned off. I know you should, but do we all? No
Question for other pilots of 206's: external fuel drain under the belly. Do you do this check/water drain on every flights, every day or every so often? I only ask as on my last Jettie, the drain had a tendency not to seal properly after each check, so I would do it 'occasionally'. That habit has transferred to my current machine. The walkround checklist lists it as a daily check...
BH06L3
7th Feb 2011, 12:10
You can do whatever you like with the throttle, boost pumps, fuel valve etc BEFORE hitting the starter button, and it won't matter a rat's. All the boost pumps do is provide pressure up to the engine-driven pump. Nothing gets past that pump until it is running.
I would not agree with the statement above as I have flooded the engine can doing a A/F fuel filter drain. Throttle was left full open and when boost pumps and Battery where turned on fuel started spewing out the engine drain valve......
As mentioned before when hot and high keep on those pedals. If you let the yaw get away on you it will take more power to stop it especially in the L and you may not have the power and over torque. Sometimes it is actually easier to reduce collective rather than use lots of left pedal which may also require more collective. So if you find yourself running out of left pedal reduce the collective if possible. Don't forget to do a regular scan after any power change or at least every couple of minutes in flight and in the L check the forward fuel tanks regularly because if you got 300lbs of fuel and 150lbs in the FWD tank then you have a problem. I got caught once low fuel light flickered hit the caution panel to see what light was flickering looked like low fuel check the forward tank and it was still full. only had about 60lbs of usable fuel if I remember correct.
As for starting the 206 learn a flow start and once you learn a way that works for you don't let anyone change it or that will just screw you up and you will probably miss some checks. Was teaching a new pilot to start the 206 with the 2 finger method one on the starter and one presses the detent once it pops for a quicker shutoff. The guy pressed the detent and let go of the starter. luckily my hand was close by and caught the starter.........That was the last time I tried to change a guys system that worked for him as long as he didn't miss anything. Although learning the 2 finger start or as mentioned earlier just cracking the throttle and not going past the detent allows a quicker shut off and may just save you from a hot start one day.
EN48 - this guy seems to follow the technique you mention, cracking it past the detente at around 30% N1 once the secondary start/acceleration spike has stabilised (he may have done it slightly before, but sounds similar)
iwgKMRGeI-M
FH1100 Pilot
7th Feb 2011, 13:44
BH06L3:I would not agree with the statement above as I have flooded the engine can doing a A/F fuel filter drain. Throttle was left full open and when boost pumps and Battery where turned on fuel started spewing out the engine drain valve......
BH06L3 is a little confused. In a RR-250, the engine-driven fuel pump is what they call a "positive displacement pump." That is, if it stops, the boost pumps *cannot* push fuel through it. If the engine-driven pump stops (shaft shears, say), the engine WILL quit from fuel starvation.
Conversely, with the engine shut down there is no way that fuel can make it past the engine-driven fuel pump to the fuel control and then to the nozzle screwed into the burner can.
The drain valve on the airframe fuel filter on the engine deck is *before* fuel gets to the engine-driven fuel pump and fuel control. In the case BH06L3 cites, the result would have been the same whether the "throttle" was opened or closed. If the battery is on and the A/F fuel filter drain is left open, boost pump pressure will cause fuel to spew out if the fuel shut-off is open. But no fuel will go through the engine.
You cannot "flood" a turbine engine if it is not running. Fuel will not get past a non-rotating engine-driven fuel pump.
"Question for other pilots of 206's: external fuel drain under the belly. Do you do this check/water drain on every flights, every day or every so often? I only ask as on my last Jettie, the drain had a tendency not to seal properly after each check, so I would do it 'occasionally'. That habit has transferred to my current machine. The walkround checklist lists it as a daily check..."
Should be every day - you can't rely that much on the suppliers to do their jobs properly. Sounds like it needs fixing. The Twin Squirrl has that problem as well.
Phil
BH06L3
7th Feb 2011, 14:40
Conversely, with the engine shut down there is no way that fuel can make it past the engine-driven fuel pump to the fuel control and then to the nozzle screwed into the burner can.
FH1100
Well I can tell you that I have filled the burner can full of fuel on a jetranger when attempting to drain the A/F fuel filter ( boost pumps on, Battery on, Throttle left in full open position). The Owner & DOM of the company I worked for interrupted me in the process and after talking for a moment we all heard fuel spilling all over the hanger floor which was draining out of the burner can. So we had to wheel it outside pulled the IGN breaker and motored the starter a couple times waited a bit then perfect start.
I am not saying you are wrong and I am no AME just a pilot, but I do know the difference between the A/F fuel filter and burner can. And no, definately not confused.
Another thing for new pilots to watch out for is when draining the fuel from the A/F fuel filter be careful that the boost pumps are on and that the drain valve is closed after draining If the boost pumps are off and drain valve locks open and not noticed when you start the aircraft you will have fuel draining out of the helicopter and I have heard of pilots taking off with the drain valve still open.
Back to the boost pump CB question.....on the L's the left boost pump is connected direct to the battery. That way, if one has complete electrical failure, you will still have the left boost pump operating.
The only way to turn it off is to either pull the left boost CB----OR turn off the fuel valve (which is the Bell recommended procedure. This is taken directly from the flight manual shutdown checklist for the L4.
NOTE
Left fuel boost pump will continue to
operate until FUEL VALVE switch is
positioned to OFF. This pump
operates directly from battery and
will not be deactivated when BAT
switch is OFF. Battery power will be
depleted if FUEL VALVE switch
remains on.
17. FUEL VALVE switch — OFF.
There is NO mention of pulling any CB's. From a legal standpoint, (and you all know how I love to argue this....), by pulling the CB, you will be in a bad position should something go wrong---especially in a litigious society that we all now find ourselves in.
Onto some helpful numbers:
I fly in the mountains most of the time and was taught these by the former chief pilot of Rocky Mountain Helicopters...
These numbers assume the following approach procedure:
1. Set up for a steep approach to be 100 feet above the obstacle in front of you....for the sake of explanation we will call this the "decision point". You would aim to arrive at the decision point in a deceleration to little to no airspeed and less than 300fpm descent and almost hover power.
2. Just as you reach the decision point, assuming you have made the approach smoothly, you will push the nose over slightly to stop the deceleration and you will feel a little drop..raise the collective a tad to stop the drop and note your pedal position, N1 and TOT.
3. From those numbers you need the following to hover IGE:
a. An extra ONE inch of left pedal
b. An extra 10% N1
c. An extra 35 degrees TOT
4. From those numbers you need the following to hover OGE.
a. An extra one and half inch of left pedal
b. An extra 15% N1
c. An extra 50 degrees of TOT
Therefore if when you add the extra pedal you are at the stop, or if when you add the extra N1 or TOT to what you have already and it puts you in the red....you are in a position right now to pull power gently and nose over slowly to regain airspeed and fly away. I have used these numbers in the Jetranger, the L4 and a 407 and they all work.
I will agree with everyone else that the Bells work really well as long as you take your time and do not rush.
When operating hot and high, with heavy loads, you need to let the aircraft "catch its breath" on lift off......by this what I mean is take it slow---I will start to lift the bucket out of the water and once I start to take the strain, will pause for a few seconds without moving the collective....the aircraft will "catch its breath" and start lifting all by itself.....
I am lucky that I work the same helicopter, (LaFawnduh..) year round. It sounds weird and I expect to be teased by this---but learn to become one with your helicopter...... treat her with respect...... give her a name, (just like the aircraft in the world wars), and others will treat her with respect too, they will no longer see it as just a machine...... Most of all...have fun.... some of us have the best job in the world, and the rest reading this have the best hobby in the world....enjoy.
If you are starting using your method, and for some reason you do get a flame out,
So far I have never had a flame out using this method. If I did, I would close the throttle, continue holding the starter engaged until TOT below 150 (its not actually likely to get above 150 before a flame out occurs since you open the throttle a bit more to prevent a flame out), rest for a minute, and repeat the start process. I would not open the throttle to or beyond the idle stop until both temp peaks have occured and N1 is stable at around 58% - after all, this method is intended to help deal with hot starts and these are most likely to occur in the part of the start where the temp is peaking. Then I open the throttle to about 70% N1 to assure that I am past the idle stop, and then roll it back to the stop. Let me be quick to add that this is all in reference to the C20W in an E480 - things may be different on the 206.
Gomer Pylot
8th Feb 2011, 00:36
Gordy, I'm not saying that the circuit breaker should be pulled, just that it is almost always pulled when I preflight the aircraft. Pulling circuit breakers in flight is, IMO, not quite the same as pulling them while the engine is not running. I don't often do it, but it does seem to be common practice.
@Aucky: Gordy pretty well covered your question. The right boost pump is off if the battery is off, but the left is wired differently. Rube Goldberg obviously worked very closely with Bell, especially with the fuel system designers, and most especially with those who designed the one on the 412. I suspect Rube himself did that job.
uniformkilo
8th Feb 2011, 21:13
In the cruise on a jolly for the neighbours, when the rear passenger door popped open in flight. Screams from the passengers. Landed to sort it out.
1968 vintage AB206 lesson: If the ladies in the back are together wider than the back seat, put one of them in the front. The door latches are lame.
I know, I know, the slim pretty one was in the front. :E
that chinese fella
8th Feb 2011, 23:33
on the L's the left boost pump is connected direct to the battery. That way, if one has complete electrical failure, you will still have the left boost pump operating.
Close, but not quite correct - depends on what you mean by complete electrical failure I guess - but more specifically a failure of the battery relay will be the ultimate reason for the left hand pump being directly wired to the battery. Not sure it has been mentioned but the reason for this is so that without any boost pumps, fuel from the forward tanks will not be transferred to the main tank and hence becomes an unusable quantity.
Something not often realised is that the fuel pump warning lights in the 206L series actually sense flow and not pressure. Only by cross referencing the fuel pressure gauge will you be able to determine if you have had a pump failure or just a venturi blockage within the poorly named 'transfer pump system'
Bell_Flyer
9th Feb 2011, 04:37
1. Don't paint the tail cone white - it'll stain and go grey from exhaust fumes
2. Carry some oil with you on long flights - All 206's leak - even the brand new ones from the factory
3. Install low skids if you want less drag to go faster
4. Replace your expensive NiCads with very cheap Odysseys.
FH1100 Pilot
9th Feb 2011, 12:59
The question often comes up: Where do you put the second passenger?
The first, obviously, goes in the "copilot" seat. But what if there are two pax?
Some pilots want the second passenger right behind them, i.e. in the right-rear seat. This makes the ship hover a little more skids-level.
Me...and I know you're going to think I'm crazy...but I prefer to have the second pax on the left-hand side. This way, the ship hovers a little more left-side low. For me, it's easier to land if I can feel for that left-rear skid to touch. Put that on the ground, then ease the rest of the landing gear down. Otherwise, my landings are sometimes akin to what happens when you drop a silver dollar on a table.
One side benefit to having both people on the left is that they'll both get out on the left-hand side. If someone is sitting behind you, no matter what you've told them previously, it is GUARANTEED that as soon as the skids touch he'll pop the door, hop out and then walk under the tail boom to the baggage compartment before you can get the rotor down to idle. Sometimes I wish the 206 didn't even have a left-rear door - just the pop-out window. Sometimes I wish helicopters had those child-proof doors like cars have. (Not really, but you know...)
Landing with pax onboard is like herding cats. And the more they've flown, the more they think they know, the more dangerous they are.
Savoia
10th Feb 2011, 09:21
.
206 Jock said: " .. the drain had a tendency not to seal properly after each check .."
As PACO mentioned, this should be a daily check but, 206's (both regular and L's) are susceptible to 'sticking' fuel drains and I have come to the rescue of more than one 206 driver who, standing beside his trusty steed, was scratching his head wondering when his beast would stop peeing!
The solution is to tap the end of the fuel drain outlet (anything solid will do) and which usually abates the leak. Thereafter one should inform maintenance to get it fixed.
Gordy said: "It sounds weird and I expect to be teased by this but learn to become one with your helicopter, to treat her with respect, give her a name .."
My godfather named just about every aircraft he flew. He formed emotional attachments with them, would tell stories about them and would talk to them. It was not however something I was able to replicate during my own career but, I get what you are saying.
Re: Treating the aircraft with respect, this (to me) naturally flows from an emotional attachment. As I was unable to form strong emotional attachments with the aircraft I flew this 'respect' was manifest through developing an awareness of the aircraft's and my own limitations.
Re: Circuit breakers, in my view the fuel pumps and caution warning should have been switches. The pumps are so loud that simply by selecting them one by one you can establish whether they are functioning (corroborated of course by the corresponding pressure indication). Like many I would rarely leave the pumps running without the engine in order to conserve battery power. As for the caution warning I simply couldn't tollerate that shrill bleeping sound and so the confouded thing was decidedly off until N1 was properly established and off again just prior shut down! (It was also easier to confirm the operation of the igniters with the caution off).
Re: Controls. I always maintained slight friction on the collective and which was usually applied post take off but would operate the cyclic friction free. I would very much like to have sampled Ferranti's auto-stabilisation system for the 206 but, alas, never had the opportunity. Rumours were that it made the 206 a dream to fly!
While I prefer flying aircraft with more than two main blades the 206 has (despite what I have written above) earned a place of nostalgic affection with me. As with the R22 she pretty much transformed the industry and I struggle to think of an application in which she has not been used. She is as reliable as ever - the Labrador of helicopters.
https://lh3.googleusercontent.com/__dRpfF8qlVM/TPAjWHaW5KI/AAAAAAAAAQ4/FlpKIcteWtU/s720/Croatian%20Police%20B205%20III%209A-HBZ%20Zagreb%20Aug%2009.jpg
S.
47guy's
10th Feb 2011, 14:47
G'day to All
Re'f BELL 206 performance computer and cruise data guide
I know a wizz weel computer exist for the OH-58A kiowa.
Wonder if we have a equivalent for the civil 206b,b2,b3,l,l1,l3,l4.
GUY
handbag
20th Feb 2011, 12:46
I'll be moving over to an L3 soon and would appreciate some info on the transition. What can I expect to do differently from the trusty old B3?
Thanks guys.
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
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
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
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
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
Cheers Charlie. Much as I suspected...
206L Fuel System.
Looks pretty much like this post http://www.pprune.org/rotorheads/196414-bell-206-jetranger-longranger-2.html#post204309] (http://www.pprune.org/rotorheads/196414-bell-206-jetranger-longranger-2.html#post204309) of nearly 10 years ago!