B747 use of ground spoilers
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B747 use of ground spoilers
As flight crew, it was always my understanding (or rather, assumption) that ground spoilers were used on all aircraft on all landings whether or not you were "limited" by landing distance available.
Although the other day, on an apparently ops normal B744, we landed and rolled out with no use of ground spoilers. They were used in the air, so I assumed they were still serviceable a few minutes later.
Is it an option to use them, or mandatory on the 744? If you forget to arm the ground spoilers, will the aircraft alert you to the fact, like Airbus aircraft?
Although the other day, on an apparently ops normal B744, we landed and rolled out with no use of ground spoilers. They were used in the air, so I assumed they were still serviceable a few minutes later.
Is it an option to use them, or mandatory on the 744? If you forget to arm the ground spoilers, will the aircraft alert you to the fact, like Airbus aircraft?
Speedbrakes are armed prior to landing on all 747's. This is confirmed as part of the Landing Checklist. Once the weight on microswitch system detects an 'on ground' condition, the spoilers should automatically deploy. This is normally confirmed by the non flying pilot. If they do not deploy, they can be manually selected by pulling the lever aft ( much easier for the Captain). If they do not deploy and the lever is NOT pulled back, you have no ground spoilers and your landing roll will be longer. You do not deliberately land a 747 without deploying the ground spoilers one way or the other.
Therefore, by definition, they were either unserviceable ( very unusual) or somebody owes somebody a beer!
Therefore, by definition, they were either unserviceable ( very unusual) or somebody owes somebody a beer!
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I was under the impression that even if the speedbrakes are not aremed(deploy upon main gear touchdown), the will deploy automatically anyways upon nosegear touchdown and reverse idle selected on 1 and 3(or is it 2 and 4). That is why the lever is held forward on landing with loss of hydraulic system 4, to prevent a rapid pitchup/potential tailstrike due to the rest of the spoilers that are still powered automatically extending.
Last edited by JammedStab; 25th Oct 2012 at 12:47.
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What airline?
If the reverses were deployed and the spoilers didn't deploy it must have been a unserviceable speed brake actuator.
The crew then failed to deploy them.
The only reason not to deploy them is with a sys 4 hydraulic failure as stated to prevent a pitch up on landing.
Some people don't use them to pull off the smoothest of landings on long runways
If the reverses were deployed and the spoilers didn't deploy it must have been a unserviceable speed brake actuator.
The crew then failed to deploy them.
The only reason not to deploy them is with a sys 4 hydraulic failure as stated to prevent a pitch up on landing.
Some people don't use them to pull off the smoothest of landings on long runways
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It was BA.
I have no way of knowing whether reverse was deployed; it didn't sound like it but then I have no idea what idle reverse sounds like in an overwing seat on a 744.
Since they were used considerably in descent (through flap extension) until just before gear down, I'm assuming they were serviceable a few minutes later.
I thought at the time that perhaps given their late use the crew were distracted and didn't arm them. Given the long runway (4000m) with a RET taken at about 2500m it certainly didn't get exciting.
Just curious, really.
I have no way of knowing whether reverse was deployed; it didn't sound like it but then I have no idea what idle reverse sounds like in an overwing seat on a 744.
Since they were used considerably in descent (through flap extension) until just before gear down, I'm assuming they were serviceable a few minutes later.
I thought at the time that perhaps given their late use the crew were distracted and didn't arm them. Given the long runway (4000m) with a RET taken at about 2500m it certainly didn't get exciting.
Just curious, really.
