Jump to content

407 Manual


Recommended Posts

Ok, I have absolutely no need to download that, but I did anyways. So I'm going through the EPs and notice that for an engine failure in flight, it doesn't specify an approx height to begin a flare. To me, higher ROD at the entry of the flare will directly affect what height you should begin said flare. With that in mind, heavier ships should have a higher ROD, all other things being equal. So when am I supposed to flare in the 407 then?

 

I'm going out on a limb here and saying that 40' is a bit too low...

Link to comment
Share on other sites

Ok, I have absolutely no need to download that, but I did anyways. So I'm going through the EPs and notice that for an engine failure in flight, it doesn't specify an approx height to begin a flare. To me, higher ROD at the entry of the flare will directly affect what height you should begin said flare. With that in mind, heavier ships should have a higher ROD, all other things being equal. So when am I supposed to flare in the 407 then?

 

I'm going out on a limb here and saying that 40' is a bit too low...

I can see why your thinking the way you are but that's not really the way it is. Lets compare a 206B or even an L model. Those things just flat out float. It's been about 5 years since I've flown a R-44 but a jetranger will have a lower rate of descent when light compared to a 44. Also the more blades you have the higher ROD you will have. A 407 drops like a rock compared to a 206L. Plenty of inertia just a higher ROD. Also the reason they don't give you an exact height to flare is every situation is different. It's something you will learn with practice and experience.

Link to comment
Share on other sites

More blades = more lift. How does that equate to a higher ROD? If I were to slap two more blades on a 22, a higher ROD is the last thing I would expect...

 

 

 

EDIT: I also just looked at how much it would cost me to buy an RFM from Bell... $265!!! Do they print these things on gold or something?!?!

 

http://www.bellhelicopter.net/media/orderform.pdf

 

Pick a model... any model...

Link to comment
Share on other sites

Ok, I have absolutely no need to download that, but I did anyways. So I'm going through the EPs and notice that for an engine failure in flight, it doesn't specify an approx height to begin a flare. To me, higher ROD at the entry of the flare will directly affect what height you should begin said flare. With that in mind, heavier ships should have a higher ROD, all other things being equal. So when am I supposed to flare in the 407 then?

 

I'm going out on a limb here and saying that 40' is a bit too low...

There's a vid YouTube where Bell's Chief Pilot was teaching a 50 ft decel. I believe our company teaches 50-75 ft.

 

As far as weight and ROD. Ever read aerodynamicist Ray Prouty's theory on that? He states that ROD actually decreases with increase in gross weight. I'm no aerodynamicist but in a UH-60 I actually observed this first hand. I've done hundreds of autos in 14,500 lb 60s and a bunch in 16,500 lb 60s. The lighter one comes down at 2,300 FPM and the heavier one at 2,000 FPM. Makes no sense whatsoever and it's contrary to the -10 but that's what I got. I've read at some point the weight increase will start again an increase in ROD but I imagine it's somewhere around max gross.

  • Like 1
Link to comment
Share on other sites

More blades = more lift. How does that equate to a higher ROD? If I were to slap two more blades on a 22, a higher ROD is the last thing I would expect...

 

 

 

EDIT: I also just looked at how much it would cost me to buy an RFM from Bell... $265!!! Do they print these things on gold or something?!?!

 

http://www.bellhelicopter.net/media/orderform.pdf

 

Pick a model... any model...

Like I said I can see your thought process i use to think the same way, but that's not how it is. Talk to somebody who has flown a 300... They will tell you it autos like a brick. Any multi bladed helicopter is the same way. I've auto'd Robbie's, 206's, 407's, astars, Ec-130's and 500's. the Robbie's and 206's float like a feather compared to the rest.

 

On the price from Bell, think of all the hassle, time, lawyers it took to make up the flight manual and to get it FAA approved. If you know somebody with a Bell ask them if you can have the serial number to get a flight manual. Other than that pony up up if you want one. Nothing is free especially in aviation ;)

Link to comment
Share on other sites

Also the more blades you have the higher ROD you will have. A 407 drops like a rock compared to a 206L. Plenty of inertia just a higher ROD.

 

Also the reason they don't give you an exact height to flare is every situation is different. It's something you will learn with practice and experience.

 

Most things being equal, Disc Load influences the rate of descent. The advantage of low Disc Loading is lower rates of descent in autorotation.

Disc load = Max gross wt./ (disk area ft2)

R44 - 2.2

B206B3 – 3.6

B206L4 – 4.1

B407 - 5.1

AS350B2 - 5.1

 

 

As far as weight and ROD. Ever read aerodynamicist Ray Prouty's theory on that? He states that ROD actually decreases with increase in gross weight. I'm no aerodynamicist but in a UH-60 I actually observed this first hand. I've done hundreds of autos in 14,500 lb 60s and a bunch in 16,500 lb 60s. The lighter one comes down at 2,300 FPM and the heavier one at 2,000 FPM. Makes no sense whatsoever

 

For each given aircraft the rate of descent will decrease, to a degree, as the weight increases because the potential energy goes up faster than the power-required increase. Another way to say it is, the power-required is less than proportional to the increase in gross weight.

 

However, at increasingly higher gross weights the trend reverses; otherwise, it could be said at infinite weight the helicopter would stay up forever.

 

The chart show power vs. airspeed from which rate of descent in feet per minute can be approximated by multiplying the required power (hp) by 33,000 and then dividing the result by the gross weight. You can see how the rate of descent (@60kts) changes from gross weights of 4,000, 6,000, and 8,000.

 

4,000 lbs. (175hp x 33,000)/4,000 = 1443 ft./min

6,000 lbs. (220hp x 33,000)/6,000 = 1210 ft./min

8,000 lbs. (350hp x 33,000)/8,000 = 1443 ft./min

 

PRvsAirspeed22_zps8f6a68b5.jpg

Edited by iChris
  • Like 1
Link to comment
Share on other sites

Like I said I can see your thought process i use to think the same way, but that's not how it is. Talk to somebody who has flown a 300... They will tell you it autos like a brick. Any multi bladed helicopter is the same way. I've auto'd Robbie's, 206's, 407's, astars, Ec-130's and 500's. the Robbie's and 206's float like a feather compared to the rest.

 

On the price from Bell, think of all the hassle, time, lawyers it took to make up the flight manual and to get it FAA approved. If you know somebody with a Bell ask them if you can have the serial number to get a flight manual. Other than that pony up up if you want one. Nothing is free especially in aviation ;)

 

Huh... Your experience coupled with iChris' response puts it all in perspective. Still weird though...

 

I tried signing up on their website with serial numbers of "0000" so I could try to at least check out the digital versions. I don't think it's going to work though. Hopefully I didn't screw myself by doing that...

Link to comment
Share on other sites

  • 7 years later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...