Slow retraction of speed brakes in cold weather

[RobertE]

I’ve got the pneumatic speed brakes from Precise Flight.  In normal weather they operate fine but when it gets to near freezing they extend a bit slowly but sufficiently (say 5 seconds from full down to full up) but retract very, very slowly (30-60 seconds).  Anyone experience something similar or have an opinion as to root cause?

Thanks.

 

[BorealOne]

Sorry - just noticed that yours are pneumatic, so reposting. My electric ones function very well in -20. Can't speak to pneumatics, but Boyle's Law applies. 

 

Edited March 6, 2018 by BorealOne

[Nomad Pilot]

What is the pneumatics services with? If it’s shop air you might have a small icing condition. Try purging the system and try servicing it with nitrogen.


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[kortopates]

I’ve got the pneumatic speed brakes from Precise Flight.  In normal weather they operate fine but when it gets to near freezing they extend a bit slowly but sufficiently (say 5 seconds from full down to full up) but retract very, very slowly (30-60 seconds).  Anyone experience something similar or have an opinion as to root cause?
Thanks.
 

Pretty common actually with these older brakes. It could be moisture at the bearings but more likely the conduit cables may be in very poor shape and need replacing. They're stiffer in the cold so I'd look there first. Look up in the wheel wells for any cracking.



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[Piloto]

Avoid extending them during icing conditions because they may not retract. Try lubricating them with WD-40. 

José

Edited March 6, 2018 by Piloto

[jetdriven]

WD40 for everything.

WD40 is not a lubricant and has no place on an aircraft. 

https://www.popularmechanics.com/cars/how-to/a6064/wd-40-vs-the-world-of-lubricants/

[N201MKTurbo]

13 minutes ago, jetdriven said:

WD40 for everything.

WD40 is not a lubricant and has no place on an aircraft. 

https://www.popularmechanics.com/cars/how-to/a6064/wd-40-vs-the-world-of-lubricants/

It's not like it's useless. It's good for degreasing your landing gear. I use it for spraying down my screws before I put them back in. It makes them easier to get out the next time. I use it for stuck screws, which I havnt had in a long time. I use it on the hangar door.

[jetdriven]

So is Mineral Spirits. not a lubricant either, but a solvent.

Edited March 7, 2018 by jetdriven

[Piloto]

Check this: https://www.wd40.com/ and this: https://en.wikipedia.org/wiki/WD-40

José

 

Edited March 7, 2018 by Piloto

[jetdriven]

yeah, the only use for "aircraft" was "keeps model aircraft hinges from sticking."  And your point is?

[Piloto]

30 minutes ago, jetdriven said:

yeah, the only use for "aircraft" was "keeps model aircraft hinges from sticking."  And your point is?

By 1965 it was being used by airlines including Delta and United; United, for example, was using it on fixed and movable joints of their DC-8 and Boeing 720s in maintenance and overhaul.

José

[Andy95W]

And the A&P mechanics in 1965 would wash their hands in MEK.  Thank God we've progressed a bit since then.

[Tony Starke]

11 hours ago, jetdriven said:

WD40 for everything.

WD40 is not a lubricant and has no place on an aircraft. 

https://www.popularmechanics.com/cars/how-to/a6064/wd-40-vs-the-world-of-lubricants/

The long-term active ingredient is a non-volatile viscous oil which remains on the surface to which it is applied, giving lubrication and protection from moisture.

-wikipedia

 

seems it is a lubricant 

[Oldguy]

Use the lubricant/solvent of your choice to clean your cables if they appear to be in good condition. I had one sticking on retraction, and a good cleaning/lubing took care of it. If they are cracked or in poor condition as @kortopates describes above, they need replacing. Unfortunately, if there is anything else of a somewhat major issue, it is likely you are out of luck as Precise no longer supports them.