Forced Landings

[Chopper Reid]

It has been very interesting and informative watching the debate roll on over my comments on "My first Engine Out". Some of the comments were predictable and along party lines and oher's pretty scary. I dont like pointing someone out in particular but a lot of people could do well to go back and read what Tina said. I thought her comments showed a lot of respect, plain common sense and showed that she is a valuable member of the gyro world.


Okay, now assuming a gyro with an airspeed of 50 knots, a constant wind of 20 knots means a gyro flying WITH the wind has a groundspeed of 70 knots. Now, if the gyro is flying INTO the wind he will have a groundspeed of 30 knots.

Three gyros are flying along in the above scenario downwind, they all have an engine failure at the same time and at a height of mayby 300 feet or so.

Pilot A elects to land straight ahead, he maintains 50 knots all the way down, flares at the right time and executes a copybook landing.

Pilot B elects to do a quick, correctly executed 180 * and land into the wind successfully.

Pilot C looks down to where he might land and sees trees/, big gutters/ unfriendly terrain, a landing here will see him wreck his gyro, he is momentarily uncertain what to do. He has probably let the gyro sink below 50 knots airspeed and in fact it might well be back to 40 knots, he elects to do a 180 * turn back to a much better landing area. He doesnt get the turn done too well and has rushed it a bit but he had at the start of the turn a ground speed of 40 plus 20 wind = 60 knots. Now, as he turns into the wind, he will get a momentary kick of now facing into that 20 knot wind, not for long but it will be there as 60 knots groundspeed plus 20 knots wind speed = 80 knots.

Now, you and I know that he is not going to have a groundspeed of 80 knots, his groundspeed will be airspeed of 40 knots less 20 knots wind = 20 knots groundspeed. He had 80 knots going one way, now he has 20 knots the other way, thats a differential of 80 - 20 = 60. So it appears to me that 60 knots have vanished somewhere, where has it gone ???? and what effect has it had on anything ???????


By the way, pilot A had a groundspeed of 70 knots just before the flare, how far will his ground run be ??? It would be a great pity if there was an obstacle that he hit at that speed. I'm quessing here but I reckon he would still have around 50 knots groundspeed when he touched down, if he impacted something, he would hit it hard !!


Pilot B had a groundspeed of 50 - 20 wind = 30 knots groundspeed, he flared nicley and did a "Birdy" and has near enough to zero ground roll, if he did happen to have an obstacle in front of him, chances were that he missed it, why, because he was used to landing into the wind and felt very comfotable with his forced landing.

Pilot C made it down okay too as he too was a lot more comfortable with seeing the terrain going by at 40 -20 wind =20 knots, in fact he was probably patting himself on the back for doing such a great job !! and thanking his instructor.:hail:

[Chopper Reid]

Now. let the games begin !!:party: :welcome: :humble:

[GyroRon]

I will let the honorable Miss Tina answer this one for me since as you say....

her comments showed a lot of respect, plain common sense and showed that she is a valuable member of the gyro world.

I am just a dummy with a bad attitude that doesn't know how this stuff works.

[gyromike]

He doesnt get the turn done too well and has rushed it a bit but he had at the start of the turn a ground speed of 40 plus 20 wind = 60 knots. Now, as he turns into the wind, he will get a momentary kick of now facing into that 20 knot wind, not for long but it will be there as 60 knots groundspeed plus 20 knots wind speed = 80 knots.


Brian,

You can't add a tail wind and a headwind to your airspeed.

If the pilot had a 40kt airspeed plus a 20kt tailwind, he has a 60kt groundspeed.

If he maintains 40kts during his 180º turn, he now has a 40kt airspeed minus a 20kt headwind, for a 20kt groundspeed.

You won't see an increase in airspeed just from turning downwind to upwind.
Nor will you see a decrease turning from upwind to downwind.

But your groundspeed will change.

Now, you and I know that he is not going to have a groundspeed of 80 knots, his groundspeed will be airspeed of 40 knots less 20 knots wind = 20 knots groundspeed. He had 80 knots going one way, now he has 20 knots the other way, thats a differential of 80 - 20 = 60. So it appears to me that 60 knots have vanished somewhere, where has it gone ???? and what effect has it had on anything ???????

The speed differential depends on your frame of reference.

Someone on the ground would have observed him with a speed of 60kts downwind, and 20kts upwind.

Someone in a hot air balloon at the same altitude would have observed him at 40kts in either direction.

A gyro pilot flying alongside of him at the same speed would have observed him at 0kts while the two of them were traveling downwind at 40kts., and 80kts as he did his 180º turn.

So what speed was he really traveling?

[birdy]

Its all bout energy transfer.

[Aussie_Paul]

Its all bout energy transfer.

Birdy, I like to think of it as "energy management".

Aussie Paul. :)

[birdy]

Management is wot the pilot dose PB, the effects that Brian is talkn bout is wot happens AFTER the management has happened, and energy is be'n transfered.
If you crash, its coz of bad energy management. The energy was still transfered, only into the ground instead if the air.

[bones]

Very well written reply to that birdy, see listening to the likes of Doug,Chuck and Al is paying off :)

[dragonflyerthom]

Mark

Do you know Clinton Anderson the Ozzie horseman??

I watch a program called the best of horseman downunder.


Thom

[Chopper Reid]

Its all bout energy transfer.

You haved saved me a lot of time typing Birdy, thanks !!:whoo:

[Chopper Reid]

I am just a dummy with a bad attitude that doesn't know how this stuff works.[/QUOTE]

I did not say that Ron.

[groundhog]

yea; he shouldn't talk to himself like that,we might get the wrong idea:wacko:

[bones]

Its alright fellas Ol Rons just having a dummy spit, he find it again some time soon

[Chopper Reid]

Its alright fellas Ol Rons just having a dummy spit, he find it again some time soon


And it was quite a spit, took me by surprise. :drama: :confused:

I appreciate all those who have their say and listen carefully as everyone has something to offer.

Forced landings, specially when the engine fails down low, need to be managed right otherwise a gyro can get wrecked real quick.

One point to consider is that we are not taught as students to do forced landings downwind so when they try one, they only need to let indicated airspeed drop and a hard landing is quaranteed, panic a little and the gyro is going to hit very hard BUT, a turn back into the wind and most of us feel a lot more comfortable as its what we did when learning to fly.

[Aussie_Paul]

And it was quite a spit, took me by surprise. :drama: :confused:

I appreciate all those who have their say and listen carefully as everyone has something to offer.

Forced landings, specially when the engine fails down low, need to be managed right otherwise a gyro can get wrecked real quick.

One point to consider is that we are not taught as students to do forced landings downwind so when they try one, they only need to let indicated airspeed drop and a hard landing is quaranteed, panic a little and the gyro is going to hit very hard BUT, a turn back into the wind and most of us feel a lot more comfortable as its what we did when learning to fly.


Brian, recreational pilots should not get caught having to land downwind during a forced landing. If they do, they have already made their biggest mistake of the day!!!!:wave:

Aussie Paul. :)

[Chopper Reid]

"Miss Tina" as Ron quoted, was actually following the gyro when it had an engine out and saw from a backend view, what it looks like when a downwind forced landing wasnt handled exactly right so she would have had a good idea of how it all looked from a ground perspective and by the look of the photos and the pilots own posts, it was an interesting landing to say the least with a pretty big bounce occuring and the photos substantiated that.

Anyway Ron, good luck in finding that dummy !

[Chopper Reid]

Brian, recreational pilots should not get caught having to land downwind during a forced landing. If they do, they have already made their biggest mistake of the day!!!!:wave:

Aussie Paul. :)

True Paul, I agree with you !

Trouble is that there are a number of gyro pilots on this forum who were or are FW pilots before getting into gyro's and as you know Paul, the good book says in a FW engine out, "that under 500 feet a landing straight ahead is recommended".

Now, that is true of FW's as they [fw's] loose a lot of altitude doing a 180, unlike a gyro which only needs a good kick in the rudder to get it to do a 180 in a couple of gyro lengths and without much loss of altitude

[GyroRon]

Brian, I have wasted too much of my time in these wind threads and flying in general threads. In alot of cases were are on the same page, but were using different words to describe the same thing and it confuses the others in the discussion. I am trying to give input but I am loosing interest in being in every thread about it anymore....

As far as landing downwind, in a light wind it is not a big deal if you land carefully. In higher winds it is smarter to try to turn into the wind simply because of the slower ground speed that results in which reduces chances of tip over or other common landing problems.

The turn from downwind to upwind will load up the blades. If that turn is done low enough to the ground, the gyro will still have this excess rotor rpm as you are touching down, this makes the " upwind " feel like it HAS given you extra lift, but it is simply the turn itself that did that.

[Chopper Reid]

Brian, I have wasted too much of my time in these wind threads and flying in general threads. In alot of cases were are on the same page, but were using different words to describe the same thing and it confuses the others in the discussion. I am trying to give input but I am loosing interest in being in every thread about it anymore....

As far as landing downwind, in a light wind it is not a big deal if you land carefully. In higher winds it is smarter to try to turn into the wind simply because of the slower ground speed that results in which reduces chances of tip over or other common landing problems.

The turn from downwind to upwind will load up the blades. If that turn is done low enough to the ground, the gyro will still have this excess rotor rpm as you are touching down, this makes the " upwind " feel like it HAS given you extra lift, but it is simply the turn itself that did that.



Thanks Ron, what you say is right, there is a lot of time taken up with this sort of stuff but I posted this stuff as a result of our mate who had the forced landing and I didnt feel it had been explained sufficiently.

Yes, while the turn will load up the blades I have a sneaking suspicion that the transfering of the higher ground speed downwind to the lower groundspeed into wind [providing turn is done quickly] will also help load up the blades a fraction more and any increase in rotor revs is going to help immensly specially for the low hour pilot.

[Passin' Thru]

Thanks Ron, what you say is right, there is a lot of time taken up with this sort of stuff but I posted this stuff as a result of our mate who had the forced landing and I didnt feel it had been explained sufficiently.

Yes, while the turn will load up the blades I have a sneaking suspicion that the transfering of the higher ground speed downwind to the lower groundspeed into wind [providing turn is done quickly] will also help load up the blades a fraction more and any increase in rotor revs is going to help immensly specially for the low hour pilot.

Brian, I suspect you're correct! I wouldn't care to try to prove the point, I ain't smart enough, but I suspect that kinetic energy (mass X velocity) don't care which way the wind is blowing, ground speed is velocity.

Assuming the example of 40kts. IAS with a 40kts. tailwind = 80kts. ground speed, = 135 feet/second velocity. Assuming a gross weight of 500 lbs., that's 67,511 ft./lbs. of energy that goes "somewhere" during the 180^ turn. The only place I can see is into the rotor. Now that I'm over my head I'm going to have my morning coffee and wait for one of our more erudite contributers to elucidate. :help: :D

[Harry_S.]

I wouldn't recommend a low time pilot to practice this referenced 180* maneuver, solo. With additional experience...it would be advantageous to practice thiis.

Years ago, I made many a landing in this fashion, primarily for the practice. On one occasion, it wasn't practice, I did it after a Mac attack. No sweat.:)

I do believe Birdy performed this maneuver, around his hangar, in the Rob D. video.


Cheers :)

[Aussie_Paul]

The only time I like to be low and slow, (deadly in a fixed wing) in a gyro is in a 60 degree bank!!! A slight hint of sink, reduce the angle of bank and up you go. Energy management by the pilot.

The best energy management I have ever seen was Bob Hoover in his Shrike commander!!! WOW!!!

Aussie Paul. :)

ps. geez I had better get back to Firebird making :):):)

[birdy]

that's 67,511 ft./lbs. of energy that goes "somewhere" during the 180^ turn.
Pete, if the engine isnt feeding energy into the machine in the way of inertia, and the gyro lands without incident INTO the wind, after turning upwind, the energy you calculated is disspersed firstly into the rotors during the turn[ increased rrpm], then into the airstream,[ at the flare].
The energy accumilated in the form of altitude is fed into the rotors, and lost to drag in a steady poweroff decent. Its sacrificeing alt for rotor momentum, or hight for rotor propulsion.
The flare is the transfer of energy from rrpm to the air, the result be'n a gentle touch down.
If you time it perfectly, all excess energy in the rotors and the potential energy of hight are expelled into the airflow the moment the wheels touch.



Sorry, captain arrogance will go back under his rock now;)

[mceagle]

Assuming the example of 40kts. IAS with a 40kts. tailwind = 80kts. ground speed, = 135 feet/second velocity. Assuming a gross weight of 500 lbs., that's 67,511 ft./lbs. of energy that goes "somewhere" during the 180^ turn. You've lost me Pete. Is kinetic energy measured in ft/lbs. I will leave that one up to the experts. All the energy is not lost in a turn as the gyro still has airspeed at the end of it.
As Birdy pointed out the energy is finally transferred from forward speed to rotor speed when flaring for touchdown.
Your reference to groundspeed V's energy is only relevant if you crash into the ground, otherwise the "velocity" V's energy should refer to airspeed.

[Fencing Wire]

By the way, pilot A had a groundspeed of 70 knots just before the flare, how far will his ground run be ??? It would be a great pity if there was an obstacle that he hit at that speed. I'm quessing here but I reckon he would still have around 50 knots groundspeed when he touched down, if he impacted something, he would hit it hard !!


Pilot B had a groundspeed of 50 - 20 wind = 30 knots groundspeed, he flared nicley and did a "Birdy" and has near enough to zero ground roll, if he did happen to have an obstacle in front of him, chances were that he missed it, why, because he was used to landing into the wind and felt very comfotable with his forced landing.

G'day Brian,
If pilot B had zero ground roll with a 20 kn headwind, it would suggest a forward airspeed of 20 kn at touchdown.

If we apply the same set of criteria to pilot A, then ground speed at touchdown (flare) should be 20kn airspeed plus 20 kn groundspeed = 40 kn. Still hammering a bit, but nowhere near as bad as 70.

Mustering must be a bit quiet?

Cheers

[Chopper Reid]

[


]

G'day Brian,
If pilot B had zero ground roll with a 20 kn headwind, it would suggest a forward airspeed of 20 kn at touchdown.

If we apply the same set of criteria to pilot A, then ground speed at touchdown (flare) should be 20kn airspeed plus 20 kn groundspeed = 40 kn. Still hammering a bit, but nowhere near as bad as 70.

Mustering must be a bit quiet?

Cheers


Real quite this year :Cry: but hopefully got a couple of jobs next month to do but we havent been wasting the time, been hard at it here just fixing up and doing stuff that should have been done ages ago and enjoying been tucked up in bed when we had those- 5 C frosts ! !

Glad I wasnt up in the wind today, been gusting to 45 knots and its blowing harder tonight.

[1] I was looking where the excess energy disappered to in a turn and we have seen an explanation engine out and now I'm wondering what the equation looks like with power and would it make any diference if you had full power applied ?

[2]I realize there are a number of illusions that happen during flying and one of these has been [specially at low altitude] why when you seem to be struggling to keep out of the dirt while going downwind [sometimes, not all the time ] and you manage to get back around into the wind, the problem is solved instantly.

Fencing wire, you must be twitches brother :lol:

[Passin' Thru]

You've lost me Pete. Is kinetic energy measured in ft/lbs. I will leave that one up to the experts. All the energy is not lost in a turn as the gyro still has airspeed at the end of it.
As Birdy pointed out the energy is finally transferred from forward speed to rotor speed when flaring for touchdown.
Your reference to groundspeed V's energy is only relevant if you crash into the ground, otherwise the "velocity" V's energy should refer to airspeed.
.
Tim, you really surprise me.
Velocity is a measure of distance over time in energy equations
As for the ft./lbs., how would you express the results of a mass X velocity equation? Of course, you could use metric or some other unit of measure.
I realize that so called “V speeds” pertaining to aircraft performance, V-1, Vx, Vy, Vmc, ect. are specific to air speeds. But for energy calculations, time over distance is the measure. Somehow I suspect you already knew that.

I thought I made myself abundantly clear that this was an “off the top of my head” comment concerning Brian’s post, which I considered interesting in that “by-golly there really was a lot of energy being carried onto that 180^ turn!” And it applies to whatever media is used to arrest or divert it. Not just the ground!

No doubt there are several places in the “somewhere” as it is applied. I had hoped by leaving it open-ended, some interesting discussion could follow. But …

By the way birdy, that was a very good post! Except for a couple of questions I am still chewing on, I agree! :yo:

Brian; IMHO, you raised a very interesting point.

[mceagle]

.
Tim, you really surprise me.
Velocity is a measure of distance over time in energy equations
As for the ft./lbs., how would you express the results of a mass X velocity equation? Thats why I suggested that I would leave it up to the experts. I always thought that energy was measured in "Joules".
There are far too many variables in calculating kinetic energy transfer through a 180* turn than my head is capable of comprehending.

[Passin' Thru]

[QUOTE=mceagle;134849]Thats why I suggested that I would leave it up to the experts. I always thought that energy was measured in "Joules".
QUOTE]

Yes, it can be expressed in joules. Joules is a metric unit force or energy. It is equal to 1 Newton-metre, expressed as Nm.

1 Joule is also equal to 0.737562149277 ft·lb.

[Fencing Wire]

Brian said
Fencing wire, you must be twitches brother :lol[/B]:

Been a bit "twitchy" myself on occasions, Brian.

Mustering quiet because of the drought? Talking to my cousin in Wagga the other night. Reckons he has had only 5" rain this year. About to send his cows on the road.

Can't help you with understanding why they sink going downwind. Will probably remain one of the great mysteries of life, along with women.

Cheers
Fred

[birdy]

We'v only had 5" o rain since 2000:violin:

[Fencing Wire]

We'v only had 5" o rain since 2000:violin:

Must be the green house effect causing all that moisture:lol:

[Chopper Reid]

Its not too bad here, actually pretty good compared to a lot of places and the stock are in good condition but last year we were pretty good at this stage but no rain from October to June stuffed things.

Bet you still have fat cattle Birdy, amazing country up there.

[bones]

We'v only had 5" o rain since 2000:violin:

Be alot more if you take the tin off the top of the gauge,:whoo: :lalala: i'll be :phone: you soon mate