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Bell 206B3 performance check (off airport)


RagMan
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Looking for any info or advice on conducting in-flight performance checks for off airport landings, more specifically power available (not OGI or IGE stuff) for a Bell 206B3. I didn't think to ask my instructor after the flight or in-flight for that matter, but I wanted to see if any of you veterans have another procedure you follow, or can reference a procedure from a manual. I looked through "Cyclic and Collective" as well as the RFH but didn't see anything related to the matter.

 

What my instructor had me do during my flyover recon was slow the aircraft back to 50 knots while maintaining a constant altitude into the wind (roughly the same altitude as our intended landing area.) I would say we were probably pulling 45% torque with just the two of us plus 55gal of fuel. He then had me pull about 80-85% torque, while noting the climb rate and tachometers. The 80-85% torque gave us a indicated climb rate of about 500FPM, nose level at 50 knots. I'm guessing this was enough evident data that we were going to have plenty of power to make it in and out of the lz.

 

Any info is appreciated. I'm not saying the procedure my instructor had me do was wrong, just looking for a bit more advice into the matter. I will ask him later this week on our next flight about it, but in the meantime I want to see what you others have to say about in-flight power checks. Thanks!

 

- Marc

Edited by RagMan
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Looking for any info or advice on conducting in-flight performance checks for off airport landings, more specifically power available (not OGI or IGE stuff) for a Bell 206B3. I didn't think to ask my instructor after the flight or in-flight for that matter, but I wanted to see if any of you veterans have another procedure you follow, or can reference a procedure from a manual. I looked through "Cyclic and Collective" as well as the RFH but didn't see anything related to the matter.

 

What my instructor had me do during my flyover recon was slow the aircraft back to 50 knots while maintaining a constant altitude into the wind (roughly the same altitude as our intended landing area.) I would say we were probably pulling 45% torque with just the two of us plus 55gal of fuel. He then had me pull about 80-85% torque, while noting the climb rate and tachometers. The 80-85% torque gave us a indicated climb rate of about 500FPM, nose level at 50 knots. I'm guessing this was enough evident data that we were going to have plenty of power to make it in and out of the lz.

 

Any info is appreciated. I'm not saying the procedure my instructor had me do was wrong, just looking for a bit more advice into the matter. I will ask him later this week on our next flight about it, but in the meantime I want to see what you others have to say about in-flight power checks. Thanks!

 

- Marc

 

Marc, I have to ask a few questions?

What were you guys trying to do?

Going into a LZ to pick up passengers or loading cargo to take to another location, maybe both?

Just a confined area training flight in and out? No change in GW?

What was the OAT?

What was the DA?

What did the TOT & N1 indicate at the noted TQ parameters?

Why did you use 80-85%?

What did your instructor teach you during this?

 

You ask for Specifically, for determination of power available. Then use words like probably, about & guessing. I suggest that you review the factors that govern helicopter performance and consider all of them during every operation. Also understand and note the turbine engine instruments and which instrument will be your limit indicator for operational altitudes.

 

Ask your instructor to discuss all of the above with you.

 

If you need help after training more with your instructor, send me a PM and I will help.

 

Mike

Edited by Mikemv
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Looking for any info or advice on conducting in-flight performance checks for off airport landings, more specifically power available (not OGI or IGE stuff) for a Bell 206B3...

 

Here's the Performance section of the POH that they gave me when I did my turbine transition years ago. I don't know if its what you're looking for (or if it will attach ok?), but anyway...

:)

Chp D-1 Performance.doc

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Marc, I have to ask a few questions? What were you guys trying to do? Going into a LZ to pick up passengers or loading cargo to take to another location, maybe both?Just a confined area training flight in and out? No change in GW?What was the OAT?What was the DA?What did the TOT & N1 indicate at the noted TQ parameters?Why did you use 80-85%?What did your instructor teach you during this?You ask for Specifically, for determination of power available. Then use words like probably, about & guessing. I suggest that you review the factors that govern helicopter performance and consider all of them during every operation. Also understand and note the turbine engine instruments and which instrument will be your limit indicator for operational altitudes.Ask your instructor to discuss all of the above with you. If you need help after training more with your instructor, send me a PM and I will help.Mike

 

Off airport landing as part of a turbine transition training course. I'm asking about a power check procedure in flight prior to conducting an off airport landing, like you would do in an R22 as part of the PAWOTFEEL checklist; Slow to 50 knots, check for a 5-6 inch manifold spread from power applied to max power available (after you checked your PA and OAT considerations against the power placard in the aircraft.) But I'm asking specifically for the 206B3, and where that procedure comes from.

 

 

go to www.prune.com -> under rotorheads you will find a thread talking about the 206 which covers what you are asking for.

 

I'll have a look at that, thanks.

 

 

Here's the Performance section of the POH that they gave me when I did my turbine transition years ago. I don't know if its what you're looking for (or if it will attach ok?), but anyway... :)

 

The instructor agave us a whole heap of material as well, including those performance charts. Thanks though!

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Here's the Performance section of the POH that they gave me when I did my turbine transition years ago. I don't know if its what you're looking for (or if it will attach ok?), but anyway...

:)

 

I don't recall the requirement to turn the gen off? Bad things start to happen if you leave that switch off for an extended period of time, personally I can't imagine the gen robbing that much power to require turning it off.

 

Now I'm heading to my 206 docs to see if its in there......

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Yes, the "gen off" is there, and always has been. You're just checking to see if the engine will provide the power the performance chart says it should, and the generator does take some power. That power check is not for checking if you have enough power to make a landing or takeoff. You use the performance charts for that. Then there is the power trend check, which is done daily, to track engine performance. You don't need to turn off the generator for that, you just set the same parameters every day, and look to make sure the N1 and TOT are staying about the same, taking OAT into account. I don't know of any power check in the aircraft to see if there is power available for a contemplated maneuver. You should have checked the performance charts in advance, because that's the only legal way of checking.

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In confine,you need 10%tq more than your required Power at tako, to get in.

 

to get out, 20%tq more.

 

Settle the power when you security pass at translation speed, 60mph, than ad the numbers.

 

But first of all, check your out of ground effect hover in the chart and your max tako weight for that day, you prtty much have your anser there.

 

10%tq = 60kg at max pwr tako.

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www.prune.com

 

It's www.Pprune.com (Professional Pilot RUmour NEtwork) in case you didn't get there. Falko must be have been up late playing xbox and making typos again.... ;)

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In confine,you need 10%tq more than your required Power at tako, to get in.

 

to get out, 20%tq more.

 

Settle the power when you security pass at translation speed, 60mph, than ad the numbers.

 

But first of all, check your out of ground effect hover in the chart and your max tako weight for that day, you prtty much have your anser there.

 

10%tq = 60kg at max pwr tako.

 

hmmm

I've never like people saying x%tq=x amount of weight. 10%tq at sea level and 10,000DA are two totally different things.

 

Also the 10% more rule is more accurately said "if you are hovering IGE you should have 10% margin to make a confined takeoff."

 

Just pull into an OGE hover with a heading similar to your approach path. If you can hover you can get in, generally. Watch for wind barriers at the landing location. If you are hovering OGE right at max tq into the wind but are wanting to land right behind 100' tall trees it is not going to happen. There are no dead fast rules. Just look at the situation, judge your power (based upon either experience or OGE power check), and make a plan of action and decision. Leave yourself an out and spot on the approach to check available power while you are below ETL. After that point you should be either committed to the approach or to the go around.

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It's pprune.org, but you get a redirect.

 

Guess I was having the same issue as Falko!! Definitely deserved a negative mark for that one...... :rolleyes:

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It's pprune.org, but you get a redirect.

 

Guess I was having the same issue as Falko!! Definitely deserved a negative mark for that one...... :rolleyes:

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Looking for any info or advice on conducting in-flight performance checks for off airport landings, more specifically power available (not OGI or IGE stuff) for a Bell 206B3. I looked through "Cyclic and Collective" as well as the RFH but didn't see anything related to the matter.

 

- Marc

 

Check it again. The book "Cyclic and Collective" by Shawn Coyle, Page 256 and 257. Read under the headings "Whizz Wheels" and "Rules of Thumb".

 

Most of the Rules of Thumb look at N1/Ng or torque margins. You'll have to experiment before hand to see what works for your aircraft.

 

Military flight manuals include more of the performance data charts and tables you're looking for (i.e., torque/power available, torque/power required, fuel flow, etc.). Check the military OH-58 or TH-67 RFM.

 

TH67_B206 Supplement.pdf (flashing red arrow, download link)

 

This type of performance data is not found in the civilian RFM.

Edited by iChris
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Bell published a 53-page booklet in the late 80's titled "Flying Your Bell Model 206 Jet Ranger," on page 34 it had the following:

 

Bell 206 (Standard Skids)

Pilot's "Rules of Thumb"

1. Always keep feet on pedals, right hand on the cyclic, and left hand on or near the collective, whenever the rotors are turning.

 

2. For a given power setting, there is about 300 pounds difference in gross weight for IGE and OGE hovering.

 

3. At a given gross weight, approximately 10% more torque is required to hover OGE then IGE.

 

4. 1% of torque equals approximately 30 pounds of weight carrying ability.

 

5. 1% torque is lost with each 1.5ºC rise in temperature.

 

6. Approximately 3% torque is lost with each 1000 feet gain in altitude.

 

7. 1% torque equals about 4 shaft horsepower.

 

8. N1 is affected primarily by temperature.

 

9. Torque and TOT are functions of temperature, altitude, and humidity.

 

10. Fuel consumption at MCP will usually be 25-28 US Gallons per hour.

 

11. OGE hover is considered to be any altitude above IGE, but more specifically, above 1/2 rotor diameter in height, or about 17 feet above ground.

 

12. Use Anti-Ice air whenever the OAT is at or below +4.5ºC (+40ºF).

 

13. The helicopter should be level and close to the ground for an autorotative touchdown before the rotor rpm passes below 70 percent.

 

14. The autorotative glide ratio is approximately 4:1 at 69 KIAS (Max. glide distance).

 

15. Visual abrasion on trailing-edge outboard surface of the tail rotor blade(s) indicates track and balance problem.

 

16. A lean fuel control will cause slow starts in cold weather.

 

17. A rich fuel control will cause hot starts in hot weather.

 

18. If a low steady growl persists in the cockpit, check tail rotor for an out-of-balance condition.

 

19. The Bell 206 will land on a steeper slope with the right skid upslope than with the left skid upslope in a neutral, lateral CG cabin loading condition.

Edited by iChris
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