What is the purpose of the storm window?

[Fred Gassit]

I have wondered for many years about the purpose of the storm window on some smaller planes having personally used it for ventilation occasionally on hot days.
Funny thing is nobody has ever been able to tell me why they are there.
I'm sure someone here will know.
Regards

[barit1]

If you ever had to land with an obscured windshield, it would be pretty obvious why it's there. Every plane I've ever seen has some cockpit window that can be opened - for visibility, ventilation, smoke removal, shouting to ground crew, etc.

[downsouth]

Yea, no wonder its usefull... The question is: Why is it call STORM WINDOW?? That's something I asked myself many times...

DS

[TyroPicard]

barit1..
Have you ever seen a 747?
TP

[411A]

Or...a TriStar?
No FD windows needed, nor desired, thank you very much.

Now, as to the term 'storm window'...it was coined by a small airplane pilot long ago, who needed to land in a severe rain storm, where visibility was totally obscrued out the front.
On larger transport aircraft (pistons, turbopropellor types) they are referred to as DV (direct vision) windows.

Next question?...

[Fred Gassit]

Thanks, thats what I suspected, most planes I fly with window wipers dont have'em , they have a whisky hatch instead, how about the origins of that name?

[airsupport]

On some Aircraft types also called a CV (clear view) Window.

[barit1]

TP & 411A -

Sorry - my 1011 & 747 background is rather limited & a long time ago.

How are the aforementioned contingencies handled?

[Clarence Oveur]

I suspect the ability to open windows on large commercial aircraft, has more to do with jumping out of them than anything else.

[barit1]

I distinctly remember the 747-200 has a cockpit roof hatch with escape ropes - that must be quite a ride sliding down from that height!

[IGh]

Cockpit Sliding Windows -- visibility, ventilation

This may not be obvious: the biggest risk of inflight fire is eventual Loss of Control.

Fatal fire and crash, TWA Lockheed Constellation NC86513 Star of Lisbon, ... near Reading, PA 11Jul46. Sixteen minutes after T/O (during practice engine-out ops) an F/E smelled odor of burning insulation; when he opened cockpit-bulkhead Door to cabin blast of heat and dense black smoke poured into cockpit. Smoke in cockpit inhibited pilots Nilsen and Brown from seeing panel. Cockpit crew-hatch was opened to clear air, but this only drew more smoke into cockpit. IP Brown opened right sliding window; Brown put head out window and flew aircraft to emergency landing (smoke created danger of losing control). Landed 2 miles NE of airport, skidded 1000' across hay field. Tanks ruptured, fuel fire. Only IP-PIC RF Brown survived (burned, amputee) ...


Varig 820 / 11Jul73,
Clipper 160 / 3Nov73,
Air Canada 797 / 2Jun83

In the Varig, Pan Am, and Air Canada cases, and in others, the smoke accumulation in the cockpit became so thick (and physically irritating) as to motivate pilots to open their cockpit Sliding Window. In the case of UA 823 / 9Jul64 the smoke/fire in the cabin motivated a passenger to open the Over-wing Exit while still in flight.

[Basil]

On light a/c, e.g. Aztec, if main door opens in flight, opening panel on LHS equalises pressure and assists with closing door.
May also be used as urinal - by chaps and, possibly, by highly skilled chapesses

[AirRabbit]

Originally Posted by barit1

I distinctly remember the 747-200 has a cockpit roof hatch with escape ropes - that must be quite a ride sliding down from that height!

Well, they aren’t “ropes” … they’re inertia reels, unwinding ribbon tape – and, at one time (perhaps still?) that ribbon was actually metal. It was always A LOT more preferred to be first out, because later users had to contend with the already dispensed “ribbon” from the previous users, and getting sliced on the way down was not a particularly attractive prospect, particularly noting what part of your anatomy was most vulnerable!

But you are right about it being “quite a ride.” Those of you old enough to remember, may be familiar with the old Disney Land Park ticket structure … using that reference we affectionately referred to the “B747 escape system” as “an E-Ticket ride!”

[barit1]

Yeah - I knew they were inertia reels - I was oversimplifying.

[safetypee]

The background relating to the question and some of the answers are in CS25 (FAR25); also see part 23 for the smaller aircraft.

CS 25.773 Pilot compartment view.
(b) (2) No single failure of the systems used to provide the view required … must cause the loss of that view by both pilots in the specified conditions.
(3) The first pilot must have –
(i) A window that is openable under the conditions … when the cabin is not pressurised, … or
(ii) An alternative means to maintain a clear view under the conditions.
(4) The openable window specified in sub-paragraph (b)(3) of this paragraph need not be provided if it is shown that an area of the transparent surface will remain clear sufficient for at least one pilot to land the aeroplane safely in the event of - … …

CS 25.775 Windshields and windows
(e) The windshield panels in front of the pilots must be arranged so that, assuming the loss of vision through any one panel, one or more panels remain available for use by a pilot seated at a pilot station to permit continued safe flight and landing.

I suspect that many years ago the conditions which caused a loss of view were associated with storms, ice etc; thus the term ‘storm window’. The regulations in those days might have even used the term.
More recently the window was known as a 'direct view' or 'clear vision' window, and even more recently, particularly when 773 (4) is used, then the term 'escape' window may be used.

[old,not bold]

I've always called it the DV Panel...DV for Direct Vision, I was told, but I haven't a clue why "Panel".

There to use for landing if the main windshield becomes opaque for any reason, I was also told, although it always seemed to me unlikely that one could see much ahead through it on most aircraft I've flown.

Mostly used, on light aircraft, for squeaking "Clear Prop", isn't it?

[108.9]

Im confused here.

Are we refering to the little window on the RHS and/or RHS of light aircraft doors that are about the size of an envelope and fip down or slide across?!

How can one use this to see ahead if the windscreen is obscured?

[airsupport]

Talking about a window in the cockpit that can be opened to see out of.

Not sure about light aircraft, but most airliners have them.

On DC9s for example, there is a CV window on each side that opens inwards and then slides back out of the way, this can be used to see forward if you cannot see through windscreen, also on the DC9 it is big enough to escape through, or as I have done many times open to clean the windscreen. (on the ground).

[Centaurus]

Now, as to the term 'storm window'...it was coined by a small airplane pilot long ago, who needed to land in a severe rain storm, where visibility was totally obscrued out the front

I don't know about a small aeroplane pilot inventing the term but I do know we called them storm windows on the Dakota and Lincolns I flew in the early Fifties. They were mainly there if ice obscured the main windows and in fact it was a normal design feature of old British aircraft and some American types as well. Circling in blinding rain when the wipers simply could not cope, it was SOP to open the storm window to improve forward vision and it was very effective although a trifle noisy with four RR Merlins on the wings.

The sliding cockpit windows installed on the 737 can also be used in the open position for not only smoke egress but if you have to land and vis is severely restricted through the forward screens. The wipers on the 737 are inefficient in blinding rain and if the chips are really down it may be the only way to get the aircraft on the ground by peering through the open window. The FCTM covers this.

[ManaAdaSystem]

I've landed the 737 in heavy raiin on many occations, and the thought of opening the cockpit window never occured to me. Neither is it suggested to do so in my FCTM.

Visibility in the 737 is mainly determined by the state of the rain repellant coating. The window vipers are a joke.