Full Downs

[IFLY]

I flew with 2 different instructors doing full downs yesterday and today. Their technique were very different and I thought I would describe them and see what you all think. We used an R-22 @ 1330 to 1300 lbs entered a straight in full down auto at 500 agl and 75Kts, the glide was at a steady 65kts. Now for the difference.

 

CFI "A" at 40 feet agl with the rpm at the bottom or just below the green, start a gentle flair and control decent rate with collective - airspeed with cyclic and bring rpm up to redline as you reach maximum pitch. With the tails of the skids approx 3 feet up (my estimate not his) pitch forward to level the helicopter, allow it to settle (looks like steep approach at the end of a quick stop) and smoothly pull collective just before you touch down.

 

CFI "B" at 20 to 30 feet agl start your flair, pitch to bring the rpm to redline and hold it there slowly increasing pitch, control decent rate with collective, when the tails of the skids are approx 1 foot up (or less) and you have bled all the airspeed you can, pitch forward and as the helicopter becomes level you should touch down and be smoothly pulling collective to cushion landing.

 

For students what have you been taught and for instructors what do you teach?

[jehh]

I personally prefer "A", however there is more than one way to skin a cat...

 

I've always taught full downs as normal autos with a hover auto at the bottom. Not quite what happens, but pretty close. You just flare, level, and settle to the ground. It really isn't as complex as most people want to make it out to be.

[Mike Murphy]

I'm not a Robby pilot but my mantra is basically:

 

"Pull, pause, level, settle, cushion, cushion, cushion...."

 

The "pull, pause" before leveling the nose helps eliminate that last few knots of ground speed before leveling the ship.

[joker]

The first thing that caught my eye in the two scenarios were the altitudes.

 

A: 40 feet

B: 20-30 feet

 

And then you said what I was thinking in cenario B: "....the skids are approx 1 foot up (or less) and you have bled all the airspeed you can."

 

I was thinking, "How can you bleed airspeed with such a low flare?"

 

I am a big supporter of the flare starting early (50 feet even), and being applied progressively. You have so much more time with the disc in an aftwards pointing attitude, thus airspeed bleeding off.

 

With a low flare, you can barely bleed off speed, resulting in a long and ugly run on.

 

Given that the R22 is only 28 ft 8 in in length, starting a flare at 20' is WAY TOO LOW.

 

Just my opinion.

 

Joker

[joker]

The first thing that caught my eye in the two scenarios were the altitudes.

 

A: 40 feet

B: 20-30 feet

 

And then you said what I was thinking in cenario B: "....the skids are approx 1 foot up (or less) and you have bled all the airspeed you can."

 

I was thinking, "How can you bleed airspeed with such a low flare?"

 

I am a big supporter of the flare starting early (50 feet even), and being applied progressively. You have so much more time with the disc in an aftwards pointing attitude, thus airspeed bleeding off.

 

With a low flare, you can barely bleed off speed, resulting in a long and ugly run on.

 

Given that the R22 is only 28 ft 8 in in length, starting a flare at 20' is WAY TOO LOW.

 

Just my opinion.

 

Joker

[Mikemv]

IFE, I have read your posts a few times and I am still confused about your description of the maneuver? ??? You state that you have initiated a flare and then that you are controlling the rate of descent with the collective! ROD should be checked after initial entry and during a steady state when rotor RPM has stabilized! Also, ROD is determined by GW, DA, Rotor RPM, Airspeed, trim and pitch link settings. Rotor RPM is controlled by the collective. Please clarify about being in a flare and controlling ROD with collective?

 

Personally, I would always go with the 40' flare but have done flares in other aircraft(B407's) with different heights and aggression levels and the outcomes vary but are successful. For new CFI's and students, fly the maneuver as described in the R22 Factory Training/maneuvers guide!

 

I can see where the stated 20' flare would have to be more aggressive, build more rotor RPM, hurry to level and probably wack the tail before completion. 30' might work but still seems a little rushed to me unless there is a good headwind component! The amount of flare will vary so NO set flare (Pitch attitude) should be taught! Instructors should point out why the amount of flare for each Auto was correct or incorrect. Sometimes our height estimates are a little off (me included) and our descriptions vary but the maneuvers are close to the same within a few feet. (initial flare height)

 

Also, any remaining pitch pull/rotor inertia not used prior to touchdown is wasted. We all seem to have a little remaining so as not to be too early or run out. Fly safe, Mike

[FauxZ]

The way we did them at my school was to flare at 40' just like always, and hold the RPM at 110% as long as possible with aft cyclic while getting the collective to the floor. Of course don't over do it and stand the thing straight up on the tail. Once you've used up the flare, eyes outside, allow the aircraft to settle slightly, slight bump up on the collective, then level and cushion. The cushion will depend on your rate of descent and how long you wait to raise. I'm by no means a guru mind you, just have about 30 - 40 full downs 6 months ago.

[Goldy]

Reading these, I can recall being taught many different ways by different instructors/check pilots. In the late 80's it was a very aggressive flare starting about 40 feet and standing it on its tail until the last 10 knots or so.

 

I've had 3 CFI's and 2 Robinson test pilots demonstrate full downs in the last 3 years or so...all are a bit different but none have the aggressive flares from the earlier days. Of course, Robinson has been adding inertia in to the blades all along the way. The most recent experience with the most hours in R22...I think about 6,000 at the time( his name would sound very familiar to most of you!), was an easy flare starting about 30 feet and holding it right to 10 knots or so, level off with rotor at 110% and down she goes, cushion with collective of course. It seems we are less than 3 feet, maybe 2 when we are done leveling off, so yes, I am sure the tail is quite close, as always it is to Jokers point. Another reason not to have an aggressive flare, just a smooth pull back and level off at the end.

 

Howver to Jokers point, I have never done an auto where I start the flare at 50 feet, maybe in a B47 or a R44 sure, but not in the 22.

 

For students that may be reading this, be sure you have read this first. http://www.robinsonheli.com/srvclib/rhcsn38.pdf

 

Here's to hoping none of us ever have to do the real thing. Merry Christmas !

 

Goldy

Edited December 23, 2007 by Goldy

[IFLY]

I wanted to see what other people thought before I gave the rest of the story.

 

"B" I don't like because of the long ground run, lack of clearance for obstacles, rolling moment (forward) when you level and set down, and the precise timing it takes to get it right.

 

"A" makes for a much shorter ground run, is easier to control, and just seems safer after doing a dozen of each type. Now would be a good time to tell you that "A" is the southwestern area SSH instructor that does all of the full downs for all of the schools here. By having one experienced and CURRENT instructor (this is about all he does) the standard he holds you to is pretty high. While he was here we made a video of a series of full downs starting the flare at different heights to show how the ground runs vary. 40 foot entries seems to be the best with the shortest ground runs around 6 - 8 feet, under 20 foot entries having runs of over 60 feet.

 

For the R-22 what the book says seems to be the best way to do it, I guess Frank knew what he was doing.

 

Jerry

[IFLY]

IFE, I have read your posts a few times and I am still confused about your description of the maneuver? ??? You state that you have initiated a flare and then that you are controlling the rate of descent with the collective! ROD should be checked after initial entry and during a steady state when rotor RPM has stabilized! Also, ROD is determined by GW, DA, Rotor RPM, Airspeed, trim and pitch link settings. Rotor RPM is controlled by the collective. Please clarify about being in a flare and controlling ROD with collective?

 

Personally, I would always go with the 40' flare but have done flares in other aircraft(B407's) with different heights and aggression levels and the outcomes vary but are successful. For new CFI's and students, fly the maneuver as described in the R22 Factory Training/maneuvers guide!

 

I can see where the stated 20' flare would have to be more aggressive, build more rotor RPM, hurry to level and probably wack the tail before completion. 30' might work but still seems a little rushed to me unless there is a good headwind component! The amount of flare will vary so NO set flare (Pitch attitude) should be taught! Instructors should point out why the amount of flare for each Auto was correct or incorrect. Sometimes our height estimates are a little off (me included) and our descriptions vary but the maneuvers are close to the same within a few feet. (initial flare height)

 

Also, any remaining pitch pull/rotor inertia not used prior to touchdown is wasted. We all seem to have a little remaining so as not to be too early or run out. Fly safe, Mike

 

When you start the flare your at 40' and you still need to decend to 3' skid height. As you start pitching smoothly up you need to slowly lower the collective to continue the decent controlling the RPM with cyclic and to have more collective to pull at the bottom. I try to have the RPM at 108% as I arrive at my flare height and get the last 2 % just before I level, wait to settle, then pull enough collective to stop decending at about 1-2 inchs and finish with a nice gentle run-on from there.

 

Personally I want to have a ton of inertia to waste but not likely to happen in a R-22.

 

Jerry

[Mikemv]

When you start the flare your at 40' and you still need to decend to 3' skid height. As you start pitching smoothly up you need to slowly lower the collective to continue the decent controlling the RPM with cyclic and to have more collective to pull at the bottom. I try to have the RPM at 108% as I arrive at my flare height and get the last 2 % just before I level, wait to settle, then pull enough collective to stop decending at about 1-2 inchs and finish with a nice gentle run-on from there.

 

Personally I want to have a ton of inertia to waste but not likely to happen in a R-22.

 

Jerry

Dear Jerry, first, "Happy Holidays". I am sure that you know what you are doing and the autos work for you but your description confuses me as I try to picture/follow you within the description. You state that you start at 40' and descend to 3'skid ht. this is clear/obvious. You state that you have the RPM at 108% as you arrive at flare height(40')? Did you mean 3'skid ht? As you start pitching up you state you need to lower the collective, was it not full down during the glide? You are controlling rotor RPM with cyclic? As the first factory R22 CFI in R22's in Florida in 1981, I taught, enter the auto with collective full down, a/c in trim, adjust attitude rearward to 65kts, allow RPM to stabilize and adjust with collective, at 40' initiate the flare adjusting for the conditions, building RPM to top of the Green and checking there to prevent overspeed, a very slight pitch pull to further brake forward speed, level have near max RPM to cushion with minimum ground run! Tim Tucker demoed/taught me this procedure. It worked! Merry Christmas to All, Mike

[Goldy]

Tim Tucker demoed/taught me this procedure. It worked! Merry Christmas to All, Mike

 

And he is still out there teaching it..

 

Goldy

Edited December 26, 2007 by Goldy

[IFLY]

Dear Jerry, first, "Happy Holidays". I am sure that you know what you are doing and the autos work for you but your description confuses me as I try to picture/follow you within the description. You state that you start at 40' and descend to 3'skid ht. this is clear/obvious. You state that you have the RPM at 108% as you arrive at flare height(40')? Did you mean 3'skid ht? As you start pitching up you state you need to lower the collective, was it not full down during the glide? NO DAYou are controlling rotor RPM with cyclic? As the first factory R22 CFI in R22's in Florida in 1981, I taught, enter the auto with collective full down, a/c in trim, adjust attitude rearward to 65kts, allow RPM to stabilize and adjust with collective, at 40' initiate the flare adjusting for the conditions, building RPM to top of the Green and checking there to prevent overspeed, a very slight pitch pull to further brake forward speed, level have near max RPM to cushion with minimum ground run! Tim Tucker demoed/taught me this procedure. It worked! Merry Christmas to All, Mike

Ok, let me try this again. Our DA is a bit higher than yours, usually 4K to 6K, so yes you lower the collective full down, a/c in trim, level attitude so airspeed slowly comes back to 65kts, bump up collective to maintain RRPM in green, during the glide if you get the collective set correctly you don't need to move it again until slowly lowering it in the second half of the flare, at 40' initiate the flare adjusting for the conditions, control building RRPM to 108% with cyclic with how fast you pitch up while slowly lowering collective, at the 3' skid ht a very slight pitch pull to further brake forward speed and build to 110%, pitch level, wait to settle, then pull enough collective to stop decending at about 1-2 inchs and finish with a nice gentle run-on from there.

 

It sounds like we really are doing the same thing only the DA changes things slightly. We had a DA below 2K for the first time since I've been doing autos and I had the collective full down for most of the glide even in a 180 with a steep bank. Couldn't get the rpm to build very well at the bottom without pitching faster than normal, the instructor and I only weighed 300lbs together with half tanks or less, that should make any solo autos pretty interesting.

 

Jerry

[Mikemv]

Ok, let me try this again. Our DA is a bit higher than yours, usually 4K to 6K, so yes you lower the collective full down, a/c in trim, level attitude so airspeed slowly comes back to 65kts, bump up collective to maintain RRPM in green, during the glide if you get the collective set correctly you don't need to move it again until slowly lowering it in the second half of the flare, at 40' initiate the flare adjusting for the conditions, control building RRPM to 108% with cyclic with how fast you pitch up while slowly lowering collective, at the 3' skid ht a very slight pitch pull to further brake forward speed and build to 110%, pitch level, wait to settle, then pull enough collective to stop decending at about 1-2 inchs and finish with a nice gentle run-on from there.

 

It sounds like we really are doing the same thing only the DA changes things slightly. We had a DA below 2K for the first time since I've been doing autos and I had the collective full down for most of the glide even in a 180 with a steep bank. Couldn't get the rpm to build very well at the bottom without pitching faster than normal, the instructor and I only weighed 300lbs together with half tanks or less, that should make any solo autos pretty interesting.

 

Jerry

Dear Jerry, thanks for a much clearer explaination. Please forgive me for asking about your procedures as I am getting old (almost 61 any day now, with over 3,000 full downs & many pwr recov's) but I wanted things clear for all of the students/pilots here that draw info/techniques from our experiences and descriptions. I am sure that it is now clear to them also. Thank you for being patient with my post to draw it out of you clearly, I do apologize if I offended you. Soon to be older, Mike

[IFLY]

I am getting old (almost 61

I don't think your old, especially since I'm not that far behind you.

Jerry