Bell 206: JetRanger and LongRanger
Join Date: Jul 2001
Location: Australia
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Before you start pulling the engine down, check you have the right graph. If you have a particle separator fitted, there is another graph in the applicable RFM supplement.
Join Date: Feb 2002
Location: N20,W99
Age: 53
Posts: 1,119
Likes: 0
Received 0 Likes
on
0 Posts
How are you performing the Power Check, are you at an OGE hover, or 52 knots? You are supposed to reach a limit first (TOT, TQ, N1) and then take readings, if you don't reach a limit you can't be sure how the engine will behave when you really need the power. Make sure you use the appropriate chart, Particle Separator or not.
BP is quite correct. You MUST reach a limit to access the engine correctly. Usually 100%TQ. Make sure the heater and anti-ice are off as well and set 29.92 on the altimetre.
Remember, when you read the chart you are looking for the torque percentile that the engine should AT LEAST produce.
If you are pulling 100% TQ and the chart plots out at 85% TQ, then the engine is actually producing MORE power than spec.
Therefore a +15 engine.
Remember, when you read the chart you are looking for the torque percentile that the engine should AT LEAST produce.
If you are pulling 100% TQ and the chart plots out at 85% TQ, then the engine is actually producing MORE power than spec.
Therefore a +15 engine.
Join Date: Nov 2002
Location: AUS
Posts: 331
Likes: 0
Received 0 Likes
on
0 Posts
Just putting the technical stuff aside for a minute. From a practical point of view I've never flown a 206 with the N1 & TOT so high at 77% Tque. For the conditions you describe generally the N1 would be 90-91 % and you certainly shouldn't be up on max continuous TOT.
Mr S,
I'd certainly follow all the good advice here, but if a power assurance comes in negative, carry out instrument checks first before you start (expensive) work on the engine. Dead-weight test on the torque indicator, Barfield check on the ToT indication, calibration on the Ng gauge: even a pressure test on the altimeter could be worth the effort if the engine is actually healthy, and the instruments are wrong. Has this engine always given these figures, or has there been a noticeable deterioration over a period of time?
Mind you, it can sometimes work the wrong way: some time back we had an S76A with a negative engine. After a Barfield calibration, Chief Engineer decreed that all 6 ToT indicators were to be ignored for both engines, and revised manually by some 20C. Needless to say, the Barfield was out of whack, and we still had an engine change
I'd certainly follow all the good advice here, but if a power assurance comes in negative, carry out instrument checks first before you start (expensive) work on the engine. Dead-weight test on the torque indicator, Barfield check on the ToT indication, calibration on the Ng gauge: even a pressure test on the altimeter could be worth the effort if the engine is actually healthy, and the instruments are wrong. Has this engine always given these figures, or has there been a noticeable deterioration over a period of time?
Mind you, it can sometimes work the wrong way: some time back we had an S76A with a negative engine. After a Barfield calibration, Chief Engineer decreed that all 6 ToT indicators were to be ignored for both engines, and revised manually by some 20C. Needless to say, the Barfield was out of whack, and we still had an engine change
Chief Engineer decreed that all 6 ToT indicators were to be ignored for both engines
Are you talking about the thermocouples?Regards.
Aser
Aser,
Two analogue, 2 digital and 2 sets of LED's = 6 indicators for two engines.
Alas, we simple pilots spent some days convincing management that we couldn't quite understand how they could all have the same error
Two analogue, 2 digital and 2 sets of LED's = 6 indicators for two engines.
Alas, we simple pilots spent some days convincing management that we couldn't quite understand how they could all have the same error
Join Date: Apr 2003
Location: USA
Age: 75
Posts: 3,012
Likes: 0
Received 0 Likes
on
0 Posts
As a rough rule of thumb, the power loss below spec can still allow "airworthiness" if the cause is known (ie, a dirty engine or one with a worn compressor and not one with internal cracks) and if the power loss is reasonable.
Some maintenance procedures for military turbines allow one that fails power assurance (HIT check) by -10% torque to be flown (Black Hawk for example) , some even allow -15%.
Is a low power engine more likely to quit? Probably not, if the cause of the power loss is not an internal mechanical failure.
Is a low power engine less trustworthy? Not necessarily, but a dirty engine or a worn one is more likely to stall, and more likely to accelerate more slowly when called on for power.
Some maintenance procedures for military turbines allow one that fails power assurance (HIT check) by -10% torque to be flown (Black Hawk for example) , some even allow -15%.
Is a low power engine more likely to quit? Probably not, if the cause of the power loss is not an internal mechanical failure.
Is a low power engine less trustworthy? Not necessarily, but a dirty engine or a worn one is more likely to stall, and more likely to accelerate more slowly when called on for power.
One thing you must remember is that all the performance charts are based on a "SPEC" engine.
Therefore if you have an engine that is failing the power assurance check the durned thang ain't going to perform as advertised.
Not a big problen going from A to B at the same altitude but you could have a problem going to a higher altitude or in such things as OGE hover.
I have seen the result of a compressor stall on short final and it was not pretty - the 206 was definitely not serviceable afterwards! It was even less serviceable after it was dropped from 2000 ft by the 205 slinging it out of the bush!
I think it would have been cheaper to replace the engine after it failed the power check.
Therefore if you have an engine that is failing the power assurance check the durned thang ain't going to perform as advertised.
Not a big problen going from A to B at the same altitude but you could have a problem going to a higher altitude or in such things as OGE hover.
I have seen the result of a compressor stall on short final and it was not pretty - the 206 was definitely not serviceable afterwards! It was even less serviceable after it was dropped from 2000 ft by the 205 slinging it out of the bush!
I think it would have been cheaper to replace the engine after it failed the power check.
Join Date: Sep 2004
Location: Australia
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Bell 206 Checklist needed.
G'day all,
Nothing overly exciting, but currently OS and in need of a standard (well layed out if possible) Bell 206 Checklist.
If anybody can assist please PM me.
Much appreciated in advance.
Regards
Loachboy
Nothing overly exciting, but currently OS and in need of a standard (well layed out if possible) Bell 206 Checklist.
If anybody can assist please PM me.
Much appreciated in advance.
Regards
Loachboy
Join Date: Sep 2004
Location: GIRT, BY SEA
Posts: 132
Likes: 0
Received 0 Likes
on
0 Posts
Arrange all the switches in a pleasing and eye-catching manner, and start the engine.
Start at the top overhead panel, go front to back, top to bottom, left to right. Look at every switch or button, determine whether it needs to be on or off. For a JetBanger, you need Batt ON, Gen START, boost pumps ON, fuel valve ON, throttle OFF. Everything else is as desired.
After start, turn on what you need. Test the controls and hydraulics and fail-safe.
Pre-take off VAs are the same for most helos, works for everything from an R22 to an S76, and are borrowed from the venerable Huey:
Hatches
Harness
Heaters
Electrics
Fuel - quantity, pressure, selection
Instruments in limits
Lights out
Audio
Auto (autopilot and/or/auto governors)
Full throttle
Top of green
Blast off.
Start at the top overhead panel, go front to back, top to bottom, left to right. Look at every switch or button, determine whether it needs to be on or off. For a JetBanger, you need Batt ON, Gen START, boost pumps ON, fuel valve ON, throttle OFF. Everything else is as desired.
After start, turn on what you need. Test the controls and hydraulics and fail-safe.
Pre-take off VAs are the same for most helos, works for everything from an R22 to an S76, and are borrowed from the venerable Huey:
Hatches
Harness
Heaters
Electrics
Fuel - quantity, pressure, selection
Instruments in limits
Lights out
Audio
Auto (autopilot and/or/auto governors)
Full throttle
Top of green
Blast off.
I notice that in the checklist John Eacott posted that the prestart has "HYDRAULIC SYSTEM (Control boost ): off" and the engine shut down has
"CYCLIC & COLLECTIVE FRICTION: hydraulic switch off
BOOST PUMPS SWITCHES: off
TOT: stabilize for 2 minutes
CAUTION SWITCH: off
THROTTLE: close
TOT and N1: decreasing
FUEL VALVE: off
Not taking John to task at all for posting the site. It is, after all, not his checklist.
I have a few hours in 206s and I do not agree with starting / stopping with the hydraulics off. In fact I would say that except for testing the hydraulics should be on if the blades are turning.
Also why turn off the boost pumps before shutdown? Remember that the engine driven fuel pump is lubricated by fuel.
Have things changed since I flew 206s? It has been a while! I fly 212s and we start and stop with Hydraulics and boost pumps on.
Just curious.
"CYCLIC & COLLECTIVE FRICTION: hydraulic switch off
BOOST PUMPS SWITCHES: off
TOT: stabilize for 2 minutes
CAUTION SWITCH: off
THROTTLE: close
TOT and N1: decreasing
FUEL VALVE: off
Not taking John to task at all for posting the site. It is, after all, not his checklist.
I have a few hours in 206s and I do not agree with starting / stopping with the hydraulics off. In fact I would say that except for testing the hydraulics should be on if the blades are turning.
Also why turn off the boost pumps before shutdown? Remember that the engine driven fuel pump is lubricated by fuel.
Have things changed since I flew 206s? It has been a while! I fly 212s and we start and stop with Hydraulics and boost pumps on.
Just curious.