Question about spoilers

[ibaflyer]

I was reading my new issue of Flying last night. They were talking about the "NEW" Citation Soverign (sp?). During the flight demo, they were talking about the use of spoilers and that they could be selected in settings to what you needed.

I always assumed that the spoilers were either stowed or they were extended. I did not realize that you could select a certin amount of spoiler deployment. Is this true for all jets that are equiped with spoilers?

Also, I was also told once that the spoilers automatically deployed upon touchdown and is this the lever that is typically located just to the left of the throttles?

BTW, the tail of the new Soverign, kind of reminds me of the old Lockheed Jetstar tail. For some reason, it just does not look like it fits right with the design of the jet.

Thanks for any help!

 

[Citationkid]

I think that jet looks neat. I love the 560XL my dad flies; I hope the owner gets one of these. I always thought that spoilers help turned the aiplane with aleroins. But those may be spoirleroins like on the MU 2. Any way I'm sure the different settings were for desending and slowing down. I'm pretty sure Speed Brakes only have two settings Up and Down, so maybe you got them confused.

 

[freightdogfred]

Spoilers is a catch- all term referring to flight spoilers, ground spoilers , and speedbrakes. They are the same panels on the inboard section of the wing that will deploy upwards, dependent on the control that actuated them. For example- "flight spoilers" will deploy on actuation of aileron wheel movement, in conjuction with the aileron, on one side only, to assist/increase roll capability. "Speedbrakes" (the handle left of the throttle) may be extended, incrementally, if desired, to increase descent rate without increasing airspeed. The amount the handle is pulled back corresponds to the extension of the panels, this time on both wings. "Ground spoilers" refers to the spoilers (Usually all the spoiler panels) that will extend fully when the handle is actuated on the ground. "Auto spoilers" refers to their auto-function, activated by anti-skid (wheel spin-up) or nose strut compression. The handle must be "armed" to enjoy this function. On some airplanes, not all the spoilers are flight spoilers, and these spoilers may not be used as speedbrakes. (there is no speedbrake handle) The DC-8 is an example of this.

 

[dsee8driver]

Your FLOWN description..

freightdogfred

Reading your "Flown" description....I had to laugh...So true!!

 

[logolight]

The CL-65 (CRJ) has 5 settings:

0: retracted
1/4: 8 degrees
1/2: 19 degrees
3/4: 33 degrees
Max: 50 degrees

These give you the opportunity to use only what you need without having too much or too little speed breaking.

The CRJ also uses spoilerons outboard of the speed breaks and are deflected in variation depending on the amount of aileron deflection. This helps to control adverse yaw.

Finaly, on landing, the CRJ automaticaly deploys the ground lift dumpers to take away any lift left on touch down to get the airplane's weight on it's wheels for directional control and for speed breaking. For the auto system to deploy. You need:
1. Weight on at least one wheel. (touch down)
2. Wheel speed of 16 knots.
3. Thrust levels at idle.

Hope this helps.


"Speed mode, heading, 1/2 bank."

 

[IAHERJ]

On some jets the spoilers/speedbrakes have only 2 positions (open and closed). The ERJ-145 is an example. In the air, you can move the handle for speedbrakes to open or leave it closed. It is all or nothing and kind of tricky to keep the retraction of them smooth without disconnecting the autopilot. On landing, it works like the CRJ in that they automatically deploy (both inboard and outboard spoilers). In the air, you only get the inboard spoilers as speedbrakes.

On the 717 I now fly, you don't have any settings in the air for speedbrakes. You can deploy them anywhere from fully closed to full speedbrake without any notches or stops in between. This is one change the 717 has from its predicessor, the DC-9. The spoilers will auto-deploy on the ground if the handle has been armed (pulled up) before landing. It is the first thing the non flying pilot checks when the wheels hit. If the handle does not move aft we have to call it out to the flying pilot asap. I've seen them not deploy in LGA once and we just lightly bounced about 800 feet until I manually deployed them at the captain's request.

 

[ibaflyer]

So, now that I some-what understand the concept, I assume that delpoying them in flight would then assist you with the so called SLAM-DUNK that some controllers may require of you.

Also, let's say the you have a decent rate of + 4000' per min (I do not know what is common in airliners), the speed breaks / spoilers are out and now you are about to intercept the Glide Slope on the ILS. Would you spool up the engines and stow the speed breaks at that point or keep them out and spool up the engines to overcome the extra drag to maintain the GS until touch down?

 

[Hawker rider]

In most jets that have spoilers, it's prohibited to select spoiler deployment together with flap deployment. i don't mean to say ALL aircraft, there will always be exceptions.

you don't neccesarily need to extend the spoilers for a "slam-dunk" descent. If you're normal on speed, power reduction and nose down will get you descending fast enough, but on the other hand if you've already slowed down pretty good, you won't descent beyond a few hundred feet per minute, and then it's necessary to extend speedbrake/spoilers.

M

 

[flx757]

In most jets that have spoilers, it's prohibited to select spoiler deployment together with flap deployment. i don't mean to say ALL aircraft, there will always be exceptions.

It's been my experience in jets that if there is any restriction to deploying spoilers and flaps together, it is usually something along the lines of "do not use speedbrakes when flaps are extended beyond xx degrees". The use of spoilers with an intermediate or approach flap setting is usually permitted.

Also, let's say the you have a decent rate of + 4000' per min (I do not know what is common in airliners), the speed breaks / spoilers are out and now you are about to intercept the Glide Slope on the ILS. Would you spool up the engines and stow the speed breaks at that point or keep them out and spool up the engines to overcome the extra drag to maintain the GS until touch down?

In this example, I think most pilots would stow the speedbrakes upon intercepting the GS.

 

[GCD]

On the B747 Classic, use of flight spoilers is prohibited with any flaps extended. On the B747-400, flight spoilers my be used until the flaps are extended past 10, then they are prohibited to be used.

The B747 Classic has six spoilers on each wing. In flight, the outboard five spoliers assist aileron (the outboard aileron is locked out with the flaps up). In flight the inboard four are used as speed brakes, to a maximum of about 40 degrees. On the ground, for a rejected takeoff, all 12 will deploy to 50 degrees with #2 OR #4 thrust reverse lever in reverse. On landing, with the gear out of tilt and with #1 AND #3 thrust lever in idle position, all 12 deploy to 50 degrees. If a go around is required, they will stow when #3 trust lever is in the takeoff range.

One thing to consider when using the speed brake function of the spoilers, is that roll control is more abrupt than when spoliers are stowed.