View Full Version : 2 simple Q's
Squiddley
3rd Jul 2001, 08:07
Two unrelated questions that I've been wondering about for too long: hope someone can help.
1) Why does the B737 have little "skylight" windows in the cockpit & what are they for? Unique to this type.
2) Nitrogen-filled A/C tyres : why?
Must be good reasons for these, I'd be grateful for enlightenment :)
Thanks.
the_fat_maintroller
3rd Jul 2001, 08:37
1) no idea
2) Nitrogen is an inert gas, which is meant to be easily obtainable, (not at some of the line stations I've asked to change wheels.) It also has a low moisture content, so little chance of it freezing.
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Yeap, yor right Captain, it is broken..I'll get you an engineer
Chirpy Pilot
3rd Jul 2001, 12:47
Why shen taxiing behind a 737 do they appear to be bent. ie altough they are taxiing straight the fuselage apaers to be pointing in the 11 O'clock position. Tell me it is not time to quit.!!!!
DownIn3Green
3rd Jul 2001, 14:50
Squiddly,
1.) Not only the 737, but the 707, 727, and DC-9 series as well. This stems from a certification requirement for pilot visibility during turns. I don't know the exact parameters, but in a 45 degree bank, there is a requirement to have certain areas visible, and these "skylight" windows are the result. They're actually called "eyebrow" windows and on the 727 are even heated.
2.) Nitrogen doesn't get as hot as air when the tires spin up. The Mexicana 727 that crashed because of an inflight fire due to tires exploding in the wells had air in the tires. In fact, even now tire servicing in many places in Mexico is still done with air instead of nitrogen.
CP, I've noticed that also, but thought it was just me. Don't have an answer to that illusion.
Squiddley
3rd Jul 2001, 15:08
Thank you one and all! I was beginning to think the "eyebrows" were just to allow a better view when on the ground such as for docking etc.
Live and learn !
Have been told that the sideways 737 thing is caused by crosswind landings.
The landing gear can twist a certain amount on a crosswind landing (they're designed to do this) and dont properly straighten out until next time its roaring down the runway.
DownIn3Green
3rd Jul 2001, 19:31
Up,
Makes as much sense as anything I suppose...
3 putt
3rd Jul 2001, 20:45
RE: 737 taxiing slightly sideways-this was well covered in recent tech log thread.
Thought the eyebrow windows were to cook the pilots. Still is a great place to put the aerad charts!
CCccccc.ooooough
DeltaTango
4th Jul 2001, 22:32
There was a thread about crabbing taxiing a while ago.
It was explained there that after a side wind landing the weels turn a bit resulting from the slightly sideways touchdown, and align the next time you land straight.
don't kill me!
Just relaying information.
DT
wysiwyg
6th Jul 2001, 16:23
I thought the eyebrow windows were there to tan the bald patch.
mad_jock
8th Jul 2001, 03:25
As a wannabie but a mech eng.
Nitrogan would also have the benift that if you manage to get the tyre hot enough to blow there may also be a problem with brake fire. And as n2 dosn't support combustion i can't think of anything better to be blowing all over the brake units if the tyre goes.
Not sure but seems logical. Havent a clue about the windows.
MJ.
dallas dude
8th Jul 2001, 20:04
The B737 nosegear isn't aligned with the aeroplane's centreline, it's very slightly to the left of centre (not quite as pronounced as an A10's though!).
This gives the impression , when taxying behind a FLUF, that the aeroplane's crabbing.
dd
Mister Proach
11th Jul 2001, 04:06
Nothing to do with the nosegear offset.
The main gear on a 737 caster, like a shopping trolley. If you land with some side force they will displace but can do so when taxying too.
Unfortunately the 737 flies like a shopping trolley too.