What is the proper procedure for deploying spoilers on the descent phase of flight? I fly on business alot and I notice that pilots seem to deploy them toward the latter part of the descent for maybe a couple of minutes just prior to lowering flaps. I realize they are trying to slow the aircraft to below the max V speeds for flaps and gear but is there a proper time these should be deployed or is it left to pilot judgement? Also is he deploying them when in autopilot with the autothrottle engaged?In MSFS when the spoilers engage the decrease in speed is dramatic, dropping from about 350 to 220IAS in a few seconds - not for the length of time it seems the spoilers are deployed on the real aircraft. Also, in MSFS when in autothrottle with the autopilot controlling the descent, the engines spool up and the plane noses up when the spoilers are deployed. I don't notice this on the real thing but I can't tell if the plane is being hand flown at this point either.On my next business trip I will sit over the wing and time how long they are up. There's one thing that I wish MSFS would simulate and that's the satisfying deep vibration an aircraft makes either when the spoilers are up or the flaps are down. You can really feel the braking power behind those control surfaces. In MSFS the vibration noise should be easy to simulate, but the braking forces are left to your imagination.

I really don't know for sure, but from my add-on aircraft manuals, the speedbrakes can be deployed in autopilot with autothrottle since idle throttle wouldn't slow the plane much on a descent. I believe they can only be deployed below 300 KIAS however, depending on the jet. I'm sure there are many other restictions as well. Edited to add- Here's a really nice Boeing 737 site that has some great technical information:http://www.b737.org.uk/

Hi there,the flight models of the default jets aren't very realistic, but if you try a plane like the PMDG 737 or 767 PIC, you'll notice exactly the behaviour you described (including the noise). As to the use of spoilers - ideally, pilots would like to avoid using them, but traffic may dictate otherwise (very late descent, short turn to final at 240KIAS etc. ) Generally, spoilers are not used in combination with flaps, i.e. spoilers are retracted as soon as flaps are extended. Otherwise, it's up to you - whatever is necessary to comply with speed/altitude restrictions... :).Cheers,Gosta.http://hifi.avsim.net/activesky/images/wxrebeta.jpg

Heard a good story a while back about the use of speedbrakes - A large passenger aircraft (type unknown) was being vectored for an approach to an airfield and the radar controller was exceptionally busy. The controller asked the subject aircraft to slow down and expedite descent to which the captain agreed. Obviously it wasn't quick enough so the controller asked the captain if he had spoilers and could he please deploy them to which the captain replied that yes, he had spoilers, but they were for his mistakes, not the controllers!KFD

I also noticed pilots use them on finals even with flaps down.One thing when use in FS is that you don't want to use the spoilets key "/" it deployes the 100% and that is not realistic in flight only after touch down if you have a joystick like chFlightsim yoke I have three levers one for Thrust, one for Reverse Thrust and one for spoilers when set up correctly via FSUIPC or maybe even works without it the spoilers will deploy only gradually as the travel of the lever it can also be done using mouse and draging it on the panel (it means lever for spoilers) but that's hard and inconvinient so I use my Yoke to control them and when deployed only little bit they will not have big impact on aircraft speed but the effect is there.Hope it helpsAndyPS> not a real pilot

Thats an excelent idea Andy, I never thought of it. I will try to configure my CH Yoke tonight with that setup!

Sometimes military aircraft deploy spoilers during the approach. I've noticed this on aircraft near my house, where they will even fly circuits with the spoilers partially open. Also, at airshows I've seen aircraft landing like this.- Martin

Could it be perhaps that landing with spoilers allows them to have the engines running at higher RPMs thus if they need to initiate a go around they don't have to wait for the engines to spool as much? I imagine retracting the spoilers would be quicker than waiting for the engines to spool from idle speed.Just a wild guess :)

For the sake of terminology, speed brakes are drag-only devices such as a cone-shaped or clamshell divice on the rear of a fuselage. Spoilers are lift spoil devices that also induce drag.Not familiar with the model in question but I do not think the terms are alsways exchangable. And then we have ground spoilers on deployed on ground contact for braking and prevent any lift after touchdown roll-out where the power/thrust lever must be at idle.

I think you have to look at the flight man for each model you are concerned with. On the 727, there are flight spoilers and ground spoilers. Also on the 727, the flight spoilers work in conjunction with the flaps and ailerons. Some models have an auto-deploy feature for the ground spoilers, and FS provides for auto-spoiler arm. Once the aircraft is on the ground the ground spoilers are deployed to kill the lift. Once airspeed and flaps are in approach configuration, I don't believe flight spoilers are used (although, you might see them when the yoke is ordering aileron movement).------------------------SPOILER/SPEED BRAKESThe flight spoilers are powered by hydraulic system A and B and operate automatically in conjunction with the aileron control wheel to assist in roll control. When banking the aircraft, the flight spoilers on the wing with the