I know its used after landing to slow down but what are some other proper or common uses of the speed brake in a flight?

To slow down ...haha

I don't actually know what the real operating procedures are for speedbrake use during flight, but here is where I use it:

 

Descending at cruise speeds

When you command the autopilot to fly at a lower altitude, it will typically choose a descent rate that adds about 10kts to your target airspeed. Before initiating the descent, set the target speed down 10kts and then use a little speed brake to bleed off that 10kts before retracting the speed brake and descending. If you aren't in a rush, then don't use the speed brake, maintain level flight until the speed has dropped off. If you are controlling the descent manually you control your airspeed with pitch changes and can fly a lot smoother.

 

Descending to Approach/VFR airspace

ATC will give you altitude changes that require you to descend at a much faster rate (giving 20-30kts extra airspeed) and you will need to comply quickly. You may not have time for the engines to reduce thrust and even at idle you may still increase airspeed in the descent. Initiate the descent as before but this time don't retract the speed brake, continually monitor airspeed and change the brake setting if necessary. When leveling out, retract the speed brake. In VFR airspace you will need to fly below 250kts, and even slower if you are maneuvering for approach, you will need to slow down during your descent. In this case, modulate the speed brake during the descent to slow down gradually as you descend.

 

Approach and Landing

First check that the speed brake is retracted. Don't apply the speed brake in level flight at approach speeds. Arm the speed brake to deploy on touchdown ( shift + / ). Visually check that it is armed (One of the displays may announce it and the lever will move to 25%). On final, check that it is still armed. On landing check that the speed brake deploys and retracts automatically, intervene if necessary.

 

Emergency Situations

The only emergency situation I can think of is if you are overspeeding at very high altitude. Normally an overspeed can be corrected with a reduce in thrust and nose high pitch. However, jet engines react slowly and at high altitude pitching up is at a greater risk to stall. I'd use the speed brake in such a case.

 

Use of the speed brake should be a proactive affair. When you have planned to use it, you have far better control and understanding of the craft. If you have to re-actively use it, then you can expect things to not go so smoothly.

To wake up light sleepers with a gentle buffeting.

There's a difference between speed brakes, and spoilers.

 

The primary function of spoilers, is to increase down force upon landing, to enhance braking efficiency. There was a nasty accident a few years ago, on a wet runway, because the pilot forgot to arm the spoilers. The secondary function is to add drag in flight, in order to decelerate or descend quicker, very handy with large slippery airliners with lots of inertia.

 

Speed brakes are designed to add drag for rapid deceleration.

 

 If you want to see both examples in operation, watch the 146/Avro landing. Speed brakes on the tail are deployed between 100 feet and 20 feet, and large wing spoilers automatically deploy upon touchdown to increase down force and thus braking efficiency. The 146/Avro has no need for reverse thrust, due to the huge spoilers on the wing, and the large speed brakes on the tail make speed control on the steep approach at EGLC a piece of cake.

I have been trying to get out of the habit of using my spoilers to maintain a safe speed on descent. I was told by a pilot that proper planning is a must to start the descent early enough that there's no need to drop out of the sky at 2400 FPM. I've been working hard at that planning thingy. It seems to be working and I have not touched my spoilers while airborne since.

There's a difference between speed brakes, and spoilers.

 If you want to see both examples in operation, watch the 146/Avro landing.

 

Point noted, thanks.

 

Like this?

I have been trying to get out of the habit of using my spoilers to maintain a safe speed on descent. I was told by a pilot that proper planning is a must to start the descent early enough that there's no need to drop out of the sky at 2400 FPM. I've been working hard at that planning thingy. It seems to be working and I have not touched my spoilers while airborne since.

 

Some of my airline pilot friends call it the 'poor planning lever'.

Some of my airline pilot friends call it the 'poor planning lever'.

Never heard of that one before. Sometimes not much you can do. I was on a United 757 once on descent into SFO and we had a speed restriction of I believe 290 knots. When we switched over to Norcal Approach, the first officer asked if we still had a speed restriction. He told him we didn't, out came the speed brakes.

Never heard of that one before. Sometimes not much you can do. I was on a United 757 once on descent into SFO and we had a speed restriction of I believe 290 knots. When we switched over to Norcal Approach, the first officer asked if we still had a speed restriction. He told him we didn't, out came the speed brakes.

 

It's just a little tounge-in-cheek humor, is all.

 

In this case, it wouldn't be a case of poor planning since it was an ATC assigned speed. Not much the flight crew can do about that.

 

The poor planning part comes more from when you get a pilot's discretion descent and then hang it up when you should be going down. I've had airplanes that get PD descents come into my airspace up in the flight levels, and then get vectored all over the sky on the great Anchorage tour while they get down.

Some quotes from 727-100 procedures:

 

Speed brakes may be used in the event a high rate of descent or a speed reduction is necessary.

 

EMERGENCY DESCENT
Any situation in the loss of cabin pressure requires an emergency descent to a lower altitude. Prior to beginning the descent, the immediate and secondary action checklist items for the decompression should be accomplished. It should then be determined if control of the cabin is possible. If not, check for factors which main affect the descent maneuver.
While still on autopilot, close the throttles and extend the speed brakes. Then disconnect the autopilot and smoothly initiate a 30O bank turn, letting the nose of the aircraft fall to an approximate 10O nose-low pitch attitude.

 

SPEED BRAKES
When landing in adverse weather conditions, rapid lowering of nose after touchdown and immediate application of speed brakes, reverse thrust, and brakes will result in minimum landing roll. During normal weather conditions, the speed brakes can be fully raised after touchdown while the nose wheel is being lowered to the runway with no adverse pitch effects.
The Captain will normally apply the speed brakes. The pilot flying, upon application of speed brakes, call for flaps 25O. If an aileron control deflection exists at this time, the double action from partially raised speed brakes will only be transitory and have a negligible effect on lateral control. The speed brakes spoil the lift over the wing and apply a downward force, which places the airplane weight on the main landing gear, providing excellent brake effectiveness.
Unless speed brakes are raised after touchdown, very little weight will be on the wheels and any brake application may cause rapid anti-skid cycling. Braking will be ineffective and landing distances will be considerable increased.