quick question: is inflight spoiler extension not recommended with flaps at a certain degree

[victorlima01 4]

Hi guys. 

 

I am currently unable to access my manuals and I just landed from a flight from Miami to Rio on a B772. The STARs that link to the most commonly used approach to RWY15 are rather steep and usually present an unusual challange to crews in terms of energy management. Today I was seating right at the trailing edge of the right wing and noticed that the crew had the spoilers up to pretty much flight detent all the way from around 9000' to gear down, flaps 20 (somewhere around 1500-2000'). I remember from the 737NG manuals that spoilers should not bet used with flaps setting greater than 5 (or 1 - can't recall exactly). 

 

Does anyone know off the top of their heads if there is such a recommendation for the 777? Obvisouly if the PF decided to opt for this maneuver I'm imagining it might not be explicitly written in the flight manual that it's forbidden or even "not recommended". But it might be frowned upon. Anyway, he proceeded to get us down quite smoothly after the spoilers  went down. Thanks in advance for your input.  

[PMDG777 231]

Hi there,

 

First of all, please familiarise yourself with this topic: http://forum.avsim.net/topic/447430-blunt-warning-sign-your-posts-or/

 

If the approach is steep and idle isn't enough to maintain speed/slow down then I would imagine there would be no other option, other than landing blazingly fast. There's probably regulations on not using spoilers below a certain altitude/speed etc more for safety.

[scandinavian13 5,192]

 

 

There's probably regulations on not using spoilers below a certain altitude/speed etc more for safety.

 

More likely SOPs or FCOM guidelines/requirements. The FAA can get into some detailed stuff, but they usually leave a lot up to pilot discretion. Regulating spoiler use is, to be honest, a bit asinine (not that a government entity is immune to acting in an asinine fashion  ).

[PMDG777 231]

More likely SOPs or FCOM guidelines/requirements. The FAA can get into some detailed stuff, but they usually leave a lot up to pilot discretion. Regulating spoiler use is, to be honest, a bit asinine (not that a government entity is immune to acting in an asinine fashion  ).

Sorry when I said regulation I was meaning airline regulation as in SOP not FAA regulation Definitely should have worded my post better!!

[Ocean2b 0]

On the 777 spoilers are a flight control, use them as much as you like! I've never seen an approach without the use of them. They are especially handy at high weights as opposed to dropping the gear for drag as it gives you more flexibly to reduce drag quickly if needed. For my company spoilers are not to be used whenever gear down is selected on approach as to not achieve an unstable high rate of decent.

 

Alex Dority

[Artur Munteanu 1]

"While VNAV is accurately modeled and "rugged" like the real thing, it isn't a miracle worker: if you get messages like DRAG REQUIRED, etc., it usually means the conditions outside (winds) or FMC programming (restrictions) or both are not in agreement on what the airplane can do without extra assistance from the pilot. (Use flight spoilers, manual speed intervention or drop the gear if you really have to!)"

Introduction manual pg.54
 

[skelsey 765]

I may be imagining it (because, typically, I can't now find the reference!) but I'm sure I've read in the past that using speedbrake with lots of flap extended can, on certain types, cause damage to the flap assembly (presumably because of the change in airflow).

 

Certainly the 747 will give you a >SPEEDBRAKES EXT EICAS caution and associated bleeper if you try to use speedbrake with flap >20.

 

That said, I agree with those above who point out that the speedbrake is a flight control and should in essence be used when required. Most aircraft have a configuration that will give best gradient of descent; from memory in the NG flap 2, gear down, speedbrake out will see you dropping like the proverbial rock.

 

In practical terms, company restrictions notwithstanding you need to have the speedbrake in by 1000ft AGL in order to comply with stabilised approach criteria.

[victorlima01 4]

Hi there,

 

First of all, please familiarise yourself with this topic: http://forum.avsim.net/topic/447430-blunt-warning-sign-your-posts-or/

 

If the approach is steep and idle isn't enough to maintain speed/slow down then I would imagine there would be no other option, other than landing blazingly fast. There's probably regulations on not using spoilers below a certain altitude/speed etc more for safety.

 

Hi Chris, Thanks for the quick reply. Is my signature not showing? It's supposed to say "Cheers, Victor". That's my name. And as luck would have it, my last name actually is Lima. No, my dad isn't in ATC. Just one of these bizarre coincidences of the universe where the guy who loves aviation gets to have a first and last name from the NATO phonetic alphabet! So I'm not blaming you for reminding me to sign my posts with my real name... but it sure gets a little old after 10+ years of hanging around these forums!

 

And thanks to all for the replies as well. Informative thread. I kow of the universal "spoilers down and stable approach by 1000 AGL". I was just really wondering about possible structural damage as Simon pointed out. 

 

A Brazilian Airliner's SOP actually recommends NG drivers to drop the gear as high as 8000' to help maintain the vertical profile of some of hese STARs. Rio presents some challenging terrain, but in my honest opinion some of the procedures were very badly planned out. And a lot of controllers and pilots seem to think the same. 

[serviceceiling 135]

In the 777 you can use the spoilers as much as you want. If for some reason your wind prediction is way off then sure, you might use them somewhere intill the final appraoch, after the gear is down. However, it is not a good idea (aerodynamically speaking) to use lift-enhancing devices (flaps) in conjunction with lift-decreasing devices (spoilers).

 

On the Embraer E190 for instance, the fly-by-wire system prevents the pilot from deploying the spoilers once the flaps go past a certain setting...this may be both a good and a bad thing. Some pilots I spoke to dislike this logic. 

[777simmer 117]

Yes, on the 737 extended spoilers with flaps more than 5 was suspected to be the cause of flap damage/wear.

Probably due to the turbulent airflow the spoilers cause.

So we had the recommendation in our SOPs to not use spoilers with more than flaps 5.......it was not a limit though as far as I remember, so if required you could still do it.

 

To avoid buffeting, the 777 has the same recommendation in Chaptor 4 of the FCTM!

Also mentioned there is a  recommendation to avoid throwing the gear down above 200kt for pax comfort and gear door life (even though the limit is 270kt/M.82).

But these are recommendations.....not limits.

[scandinavian13 5,192]

 

 

So I'm not blaming you for reminding me to sign my posts with my real name... but it sure gets a little old after 10+ years of hanging around these forums!

 

To be honest, I'd assumed it was Victor Rio. While I now know that your full name is your username, the requirement is to have the full name in your posts. It's a little specific, but it does help us out a whole bunch as mods to have it all, fully, in the same place. I think that's what he was getting at.

 

 

 

Some pilots I spoke to dislike this logic. 

 

Personally, I don't like the thought of automation taking me out of the loop, but if there's some sort of evidence that it's safer that way (and not the notional "safety" that is rife in the aviation world), then I guess I'd be more okay with it. So, the thought bothers me, but I haven't done research to make a formed opinion either way.