Perhaps a funny question, and I am only wondering, without any practical issue:
What aircraft have windshield wipers? ISTR the larger i.e. faster craft generally have them. But wouldn’t they be more wanted in slower planes? I should think that, the faster one goes, the more effective the airflow will be in removing rain?
I guess it’s more a function of the shape of the glass. Small aircraft have spheric cockpit windows where the water flows around the aircraft. Larger aircraft have flatter surfaces like cars where water tends to stay.
Yes. Also: the more spheric the windshield, the harder it will be to make a wiper that fits it.
But are there wipers on, say, a Cessna 404 or a Beech Baron? On a Twin Otter? On a LearJet?
But are there wipers on, say, a Cessna 404
Some do have them, some don’t. They were sold as an option.
or a Beech Baron?
No
On a Twin Otter?
Yes
On a LearJet?
No
It depends very much on the shape of the nose, the shape of the windscreens and whether or not there is bleed air available for rain repulsion.
Most small jets don’t have wipers, most large jets and turboprops of all sizes do.
You are right, it seems to be some of the bigger twins have wipers. I also never really understood why they dont have them on small GA planes. Rain on the windshield is an issue on the final stages of landing, when slowed right down, and the prop is not blowing the windshield clear. On occasions I have given a quick boost of power to clear the windshield. If you have a large tarmac runway, with lightting and/or an ILS, forward visibility isnt such a big issue, but on a small grass strip, a set of wipers would be quite nice.
I suspect that scratching the perspex on small GA a/c might be one reason they aren’t installed. Bigger airplanes have glass windshields.
… and mine has Makrolon aka polycarbonate, too feeble to support wipers (and too curvy, too).
King Airs do, Citations don’t.
On the King Air the wipers make more noise than the engines and are fairly useless except for frightening the passengers.
On the Citation there is a deflector you can open supposedly to clear the screen. Nobody uses it as it usually fails to shut properly and from that day on makes an annoying noise.
There are regulatory requirements for windshield clearing, but they don’t specifically mandate wipers.
EU-OPS:
CAT.IDE.A.120 Equipment to clear windshield
Aeroplanes with an MCTOM of more than 5 700 kg shall be equipped at each pilot station with a means to maintain a clear portion of the windshield during precipitation.
CS-25:
CS 25.773 Pilot compartment view (See AMC 25.773)
…
(b) Precipitation conditions. For precipitation conditions, the following apply:
(1) The aeroplane must have a means to maintain a clear portion of the windshield during precipitation conditions, sufficient for both pilots to have a sufficiently extensive view along the flight path in normal flight attitudes of the aeroplane. This means must be designed to function, without continuous attention on the part of the crew, in –
(i) Heavy rain at speeds up to 1?5 VSR1, with lift and drag devices retracted, and
(ii) The icing conditions specified in CS 25.1419 if certification for flight in icing conditions is requested.
(2) No single failure of the systems used to provide the view required by subparagraph (b)(1) of this paragraph must
cause the loss of that view by both pilots in the specified precipitation conditions.
…
