Can anybody give me some advice or information in regards to a 1978 Mini-nimbus B. When deploying the spoilers, and only the spoilers, the resistance, is very significant. From closed, but not locked to full deployment, is only about 2-3 inches. Which is not an issue as far as I can tell. but the resistance to opening and the force required to open them and to keep them open is very significant. If the least amount of pressure to hold them open is relaxed, they then slam closed. Obviously this is even greater at speeds above 50 knots. With approach speeds in the 45 knot range , the opening resistance is slightly less, but still way to difficult, they still slam closed if the handle is not held tightly. The logbook indicates that the gas strut has been replaced. Someone told me to check the rigging, but I can not find info on how to achieve that.
With "air brakes" i.e. flaps 8 plus full spoilers +the extra combination of both deflected to the full extent. It comes down at a very steep angle, which it is suposed to. 4.5 to 1. The spoilers deployed alone are very effective, just require a strong, constant hand on the handle.
any info would be appreciated.
Terry

Does your ship have the full trailing edge dive brake/flap
configuration? My first glider was a Mosquito which had that and it
seems to me that air flow assisted in opening and holding the brakes
open. Driving the flaps down required some effort, I don't recall how
much, but I wouldn't have called it "difficult". It's been a very long
time...

Dan
5J

On 11/15/23 17:57, Terry Buker wrote:
> Can anybody give me some advice or information in regards to a 1978 Mini-nimbus B. When deploying the spoilers, and only the spoilers, the resistance, is very significant. From closed, but not locked to full deployment, is only about 2-3 inches. Which is not an issue as far as I can tell. but the resistance to opening and the force required to open them and to keep them open is very significant. If the least amount of pressure to hold them open is relaxed, they then slam closed. Obviously this is even greater at speeds above 50 knots. With approach speeds in the 45 knot range , the opening resistance is slightly less, but still way to difficult, they still slam closed if the handle is not held tightly. The logbook indicates that the gas strut has been replaced. Someone told me to check the rigging, but I can not find info on how to achieve that.
> With "air brakes" i.e. flaps 8 plus full spoilers +the extra combination of both deflected to the full extent. It comes down at a very steep angle, which it is suposed to. 4.5 to 1. The spoilers deployed alone are very effective, just require a strong, constant hand on the handle.
> any info would be appreciated.
> Terry

On Thursday, November 16, 2023 at 8:31:10 AM UTC-5, Dan Marotta wrote:
> Does your ship have the full trailing edge dive brake/flap
> configuration? My first glider was a Mosquito which had that and it
> seems to me that air flow assisted in opening and holding the brakes
> open. Driving the flaps down required some effort, I don't recall how
> much, but I wouldn't have called it "difficult". It's been a very long
> time...
>
> Dan
> 5J
> On 11/15/23 17:57, Terry Buker wrote:
> > Can anybody give me some advice or information in regards to a 1978 Mini-nimbus B. When deploying the spoilers, and only the spoilers, the resistance, is very significant. From closed, but not locked to full deployment, is only about 2-3 inches. Which is not an issue as far as I can tell. but the resistance to opening and the force required to open them and to keep them open is very significant. If the least amount of pressure to hold them open is relaxed, they then slam closed. Obviously this is even greater at speeds above 50 knots. With approach speeds in the 45 knot range , the opening resistance is slightly less, but still way to difficult, they still slam closed if the handle is not held tightly. The logbook indicates that the gas strut has been replaced. Someone told me to check the rigging, but I can not find info on how to achieve that.
> > With "air brakes" i.e. flaps 8 plus full spoilers +the extra combination of both deflected to the full extent. It comes down at a very steep angle, which it is suposed to. 4.5 to 1. The spoilers deployed alone are very effective, just require a strong, constant hand on the handle.
> > any info would be appreciated.
> > Terry

Dan, Yes it has the full trailing edge dive brake system. I believe it is the same configuration at the Mosquito wing. And it seems that the airflow would assist in opening the spoilers. The flaps via the flap handle do not have any backpressure or resistance to selecting them in any position, and they are locked in the selected position by the flap handle detents. It is only the extension of the spoilers via the spoiler handle, ,,,prior to engaging the "air brakes", as the manual calls them, beyond the detent at the aft end of the spoiler handle"s travel. That detent is where the spoilers and flaps work in conjunction with each other. For what I call the barn door effect. Which is what makes her good for very short approaches and ground runs. In reviewing what I have of a maintenance manual, the only gas spring tolerances I saw, was that with flaps at -7, the gas strut had to hold the flaps at that position with a measured downforce at the root trailing edge of a specified amount of force. Just a thought, could it be that the gas strut is either the wrong one. Which I will check. I does not seem plausable that it would need to be broken in and excersised to soften the tension, as I would think if that were the case, then it would have to have some pressure released. Meaning a leak in the strut.
Still researching the info. Just thought I could tap into the experience of those who have been there bafore.
Terry
MG