View Full Version : B737 Winshield wiper operating limits.
HAWK21M
23rd Jul 2001, 09:14
Whats the Speed beyond Windshield wipers will not operate.If there is Any.
Normally Wipers will be used during Takeoffs & Landings.
But If used at Cruise will they function with the Airloads.
regds
HAWK.
Skyjob
23rd Jul 2001, 14:42
In our technical manuals there i no reference to any speed at which not to use the wipers any more.
Just curious why you would need to use them in the cruise? At the speed at which you're flying, the windshield will be dried by the air rushing around it anyway....
HAWK21M
23rd Jul 2001, 15:39
The reason was I wanted to know Will the motor convertor unit operate against greater Airloads.
regds
HAWK.
FlapsOne
23rd Jul 2001, 19:26
Judging by how bl00dy useless they are on finals and take off I can't think why anyone would want to use hem anyway!!
Mr Porsche and Mr Ferrari have sorted out hi speed wipers but Mr Boeing has a lot yet to learn.
static
24th Jul 2001, 01:01
Boeing has improved them on the next generation aircraft. They even have an interval position on the switch and they are virtually silent.
CaptainSandL
24th Jul 2001, 01:37
Hi Hawk,
We never really need the wipers above about 210 kts (clean speed) because at higher speeds the rain is blown away. Also above 210 you are not usually at a critical phase of flight for looking out of the windows, ie near decision height or below. If it is raining then you are generally heads in flying on your instruments. I have tried to park them at higher speeds to stow them a bit lower down, but they usually end up worse perhaps because of the increased aerodynamic load. BTW they are so incredibly noisy and distracting most people prefer to leave them off unless the view is really impaired. Great pity they are withdrawing the rain repellent, that worked a treat and was silent.
S & L
HAWK21M
24th Jul 2001, 08:23
The Rain repellant has been replaced by a Hydrophobic coating on the #1L & #1R windows on the B737s.
It operates as if the repellant has been sprayed.
regds
HAWK.
Checkboard
24th Jul 2001, 09:06
BWahahaha :D
Sorry, obviously you haven't used rain repellant, or the "Hydrophobic" stickers on our windscreens are just that - stickers only!
Rain repellant is ten times better than hydrophobic screens!
Diablo
27th Jul 2001, 16:53
One point to watch out for, the motors on the 2/3/4/500 have overheat switches in them, if they are used for extended periods on dry(ish) windscreens they can get too hot and cut out. They do self reset after a cooling down period. About the time we get called out to "Operational check carried out, No Fault Found" Doh!
spannerhead
28th Jul 2001, 10:33
I'm glad to see the back of rain repellant!!
Typical top sheet..."Windscreens require cleaning"
You try to get boeshield off :mad:
Coke don't work no more :(
Hudson
30th Jul 2001, 16:08
Spannerhead. You were probably using Diet Coke. Much weaker solution...
stab trim
21st Jan 2003, 11:22
Oh yes, we’ve had some trouble with the 737NG wiper. Modified units are doing better. Out of curiosity, anyone know if any airplane (possibly smaller airplanes) use compressed air directed towards the windshield, instead of wind-shield wipers? I would guess in combination with rain repellant.
I’m not aware of any myself, but a colleague indicated some airplane did, without being able to confirm which type of airplane.
English Electric (BAC) Lightning interceptor used HP compressor air via a fish tail onto the base of the windscreen. Most effective unless you were the poor QFI in the right hand seat of a trainer when the student bottled out in a strong crosswind and rain 'cos the R/H screen did not have it!
I know..............:eek:
Stab Trim,
If I recall, the DC8 used air instead of wipers.
comxtek
23rd Jan 2003, 06:49
The Next Gen wiper motors have overheat switches in them as well. There was a modification done on them a couple of years back. The mod wasn't to the motors (at least ours wasn't), but thw iring associated was modified.
WhiskeyNovember
11th Feb 2003, 00:13
Is Boeshield really used as rain repellent? I'm an avid cyclist (mountain and road), and Boeshield T-9 lube is the best there is. I use it to lube the chain and cables as well as a frame polish/protectant.
-WN
decimal86
16th Feb 2003, 10:38
from taxi to V ref plus 20 kts maximum? i agree with the other post...why would you want to put it on at CRZ?
just curios you understand? not meaning to start anything here.
swish266
17th Feb 2003, 18:59
F-----g MEL says can go with either low/high speed inop. But if on high and hardly moves than what?! Only way line up and if u feel dey dont do d job just take d bird back to d guy who send u off...:)
G-SPOTs Lost
17th Feb 2003, 19:44
Citation Bravo uses Windscreen Bleed Air!
av8boy
18th Feb 2003, 06:16
C-141 used ducted air instead of wipers as well, if I recall correctly...
Dave
swish266
19th Feb 2003, 04:09
Most MiGs after MiG-19, and Suhois after Su-17 as well...
BaByJet
20th May 2003, 17:39
Hi,
I have not found any speed limits on the wipers, but there is a termal switch that protects the motor from overheating. This switch is set at 266 deg F. When the switch cools, it resets automatically.
bbj
TopBunk
20th May 2003, 20:27
While knocking the 737 wipers, the Airbus A319/20 wipers are just as noisy and clear a smaller amount of the windscreen. Now the 747-400 wipers are much better (quieter).
Sonny Hammond
22nd May 2003, 14:46
I have seen wipers used on a 737-400 at around 280 IAS and they went OK, but as someone else has said generally they make lots of noise but thats about it....
eng123
23rd May 2003, 06:11
Forgive my ignorance,being a humble ground engineer,surely there would never be a need to use windscreen wipers in the cruise.What is the highest altitude you have ever encountered rain?
CaptainSandL
28th Mar 2005, 20:07
"The highest altitude you have ever encountered rain?" not sure maybe 10,000ft.
Maybe we dont always want to use the wipers simply to remove rain. Maybe we want to use the wipers for a minute when flying through heavy rain to give the windscreen a clean. It works on my car and if there are no limitations on the wiper then why not?
I remember a few years back, flying a brand new Boeing 737-700 (several days old) into Antigua, there was a storm overhead and tried to turn on the wipers during the approach, nothing happened. The windshield coating did not clear enough rain away for us to see safely to complete the approach, so we had to bug out and wait for the storm to pass and landed without incident, come to find out (after the mechanics looked at it)the wipers weren't hooked up at all... Dang quality control...