There are few ( if any types ) where you are permitted by the manufacturer to deploy spoliers once configured on finals. The 146 above has speed brake deployed but at no point spoliers. Energy management is a large part of descent planning and rather than aim to throw out the anchor on final aim to apply power to keep your speed up for the last 5 miles , ideally power will manage your descent rate and if commenced by glideslope capture your power will only need fine adjustments in order to keep a constant speed / descent rate. Some types like the A318 do have a " steep approach " function to ammend law, certain spoiler panels are deployed for a portion of the descent but must be fullly retracted once on short final or below 2500feet QFE ( above runway threshold).

The other misconception is that reversers reverse the flow of thrust to stop the aircraft.Reversers are basically engine cowls that open and allow the air (thrust) to dissipate instead of being funneled backwards toward the second (N2) fan. Thus, no thrust = no forward, or slowed momentum.The same is true of reverse buckets. They are diverting the flow of air, so it doesn't get concentrated out the back and maintain thrust / forward inertia.

This isnt quite true, the thrust is increased on purpose once reversed and a solid ( in thermodynamic terms ) wall of air is created which acts as a physical barrier to the air passing over the engine and surrounding wing area , essentially you can imagine it as a big parachute being opened. The surface area of this reversed ( or diflected ) collum of thrust is quite large and hence drag is substantially increased thus slowing the aircraft down. In some reverse systems e.g the 737- 200 a portion of the deflected thrust is " pushed " forwards also.

On most modern airliners, spoiler deployment is not possible when in the air and flaps are out of up. So, during approach, when flaps are set, you simply cannot deploy spoilers to decrease speed since the systems inhibit spoiler deployment in such situations.Some planes like the Fokker 70/100 series or BAe 146 can deploy speed brakes during approach which are different from spoilers.The flaps of modern airliners introduce a great amount of drag, so spoilers aren't needed. Spoilers deployment on approach would be a high risk maneuver because of the possibility of a stall in a very critical flight phase, that's why you shouldn't even think of deploying spoilers on approach.Proper planning and energy management are crucial for airliner handling in general. If you come in too high or too fast, all that's "allowed" is a go around. Practise is key.Andreas

A quick FYI:-http://www.boeing.com/commercial/aeromagaz...ly/sy02txt.html

I've been on a flight that used spoilers AND landing gear (we were up way too high for normal gear drop). I asked the pilot he said "ATC kept us high".Here's a thought experiment:If a plane is on autopilot descending on the vertical profile at idle thrust (most efficient, gliding) what happens if an unforecast tailwind pushes it ahead of the profile? How does the plane get back on profile?

I've been on a flight that used spoilers AND landing gear (we were up way too high for normal gear drop). I asked the pilot he said "ATC kept us high".Here's a thought experiment:If a plane is on autopilot descending on the vertical profile at idle thrust (most efficient, gliding) what happens if an unforecast tailwind pushes it ahead of the profile? How does the plane get back on profile?

It is not unheard of to lower gear higher than normal to slow down , this however is not the same as being " configured for final " i,e landing flap and then deploying spoilers. In regards to your question the response should be " go around " when you dont bad things can happen , such as happened the Iberia Airbus in Quito.

Do pilots of jetliners ever deploy spoilers prior to touching down? Sometimes when im on final in FSX with an airliner, and a little too high and fast, rather than abort, Ill deploy the spoilers for a few secs and bleed off airspeed and be able to salvage the approach. I can't recall seeing this while as a passenger in real life. I don't want to do it, if its not something that would happen in the real world. Sorry if this is a dum question, but Ive always wondered if Im doing something very wrong.Rob

First I think you're thinking of speed brakes and not spoilers. Speed brakes allow you to increase your rate of descent without having to even reduce power or having to use your landing gear for extra drag. Speed brakes will also slow you down if you pull back on the power. Spoilers, on the other hand, dumps lift dramatically from the airfoil as is used on landing. Modern airliners use a single lever for spoilers and speed brakes and a detent and lock prevents you from deploying spoilers in flight but will let you deploy speed brakes. But make sure you realize that spoilers and speebrakes are not the same. If my old brain remembers correctly you could deploy spoilers in flight on the old 737-100 / 200 (which may have been retrofitted at some point during service to prevent it) and a captain told me that it would make for "a wild ride" if deployed in flight. (someone may want to verify my recollection)That said, continually having to use speed brakes on approach is a sign of extremely poor approach technique in both speed and altitude management. On the other hand, having to use speed brakes on approach is sometimes a necessity.Case in point, many times flying into major airports we can be sequenced to a short final transition in front of another aircraft. Often in such cases we weren't prepared ATCs little surprise of short final so speeds and altitudes and planning are going to be off. This is especially the case where sequencing is ahead of a heavy aircraft with faster approach speeds than us so we are instructed to "keep the speed up" all the way until the middle marker. In this case we can fly the aircraft dirty with the boards popped to get her down until we're pretty sure we can bleed off for Vref without out them when coming over the fence even if at a steeper than 3 degree descent rate. Another case is when flying into terminal airspace where there are multiple large airports, like NYC and you don't always get cleared to the altitudes on the charts because you are crossing the paths of other aircraft below you. Most times you are close enough to the airport where you can deploy the gear and use that for drag to get down to where you need to be to capture the glideslope or where you want to be to properly capture your approach speed and flap schedule. If not, you can hit a notch of brakes to the top of your flap schedule and you're good to go from there.Most airlines don't want you to use speedbrakes unnecessarily because the disruption of the laminar airflow over the wing causes vibration into the cabin. It has nothing to do with fuel economy, but rather passenger comfort. But you gotta do what you gotta do! I was on a COA flight about 3 mos ago and they had speed brakes deployed down to about 200 or 300 feet all the while deploying flaps to full. It wasn't until a few seconds before we crossed the fence that he pulled the boards in for a soft touchdown right in the TDZ. Again, ya gotta do what ya gotta do. The FO on the flight was a friend of a friend and I asked her what was up with that to which she rolled her eyes and said "don't ask!" :-)Another time I was picking up a COA 757-200 first officer buddy of mine coming into KEWR and on the way down the NJTP to pick him up I noticed noticed a COA 757-200 coming in with gear down but no flaps from way up by the George Washington Bridge where KEWR traffic inbound is usually still clean. I got to the airport late and it turns out that was my friend who had to literally dive to get down to the given altitude but still had a speed restriction of 200 kts so instead of deploy speed brakes he dropped the gear. But this is all to say, you gotta know my friend, an ex 727-200 second officer forced into the right seat on the Mad Dog and unwittingly forced into the the right seat 757 when COA got rid of both the 727 and MD-80s so he is still trying to figure out the plane anyway. You should have been there for his first flight in the MD-80, I swear I was 6'1 but I'm now 5'11" after he compressed my spine during has first landing, so he may not be the best example to use :( Final point. ITRW, you'd better have a real reason for a go-around. ATC will not be happy because now they have to sequence you back in the pattern. Flight Ops will not be happy because you will arrive late. And the chief pilot won't be happy because he'll question your ability to properly land an aircraft. Passengers also get scared by such things and what do you tell them over the PA? "Ladies and gentlemen, I botched the approach again, we had to go around, let's see if we can make it next time around!". If the aircraft ahead of you landed, I would highly advise you land too. Coming in high and fast is NOT a reason for a go around unless you are dangerously high and fast in which case you'd let ATC know that you can't make the airport and pull yourself out of the pattern long before you come over the fence.I would highly advise that you work on your approach technique because any pilot will tell you, the secret of good consistent landings is found in a good approach!HTH.

Thanks for all the great info everyone. Ill have to work on my approaches a lot. I fly mostly small planes in FSX, but once in a while get the desire for a big jetliner. My skills in the large planes needs a lot of work, but Ill follow the advice of others in this thread and see what develops.Rob

Ooops. I'm a dumb dumb. I somehow missed the "on finals" part.Although I'll add that one problem with extended spoilers would be forgetting they're out in case of a go around. Also I've never seen Vref take into account "spoilers extended".Was that better? :(

To my surprise I just flew a few nights ago on an AA flight from Dallas to Miami in a 738, then changed planes and flew in a 763 from Miami to Rio de Janeiro and much to my surprise on both flights the speedbrakes were deployed during the decents. It looked like they only had them extended a touch and not fully, maybe 1/2 way. I dont fly commercially that often, maybe 4 or 5 times a year, but I dont ever recall seeing the airbrakes used in flight except when the wheels hit the ground.