Naked Science Forum

General Science => Question of the Week => Topic started by: katieHaylor on 12/11/2018 15:21:23

Title: QotW - 18.11.11 - Why are propeller-drive planes popular in hurricanes?
Post by: katieHaylor on 12/11/2018 15:21:23
Daniel asks:

Why are propeller planes and not jet engines (with the forward-facing fan blades), used to investigate hurricanes? Are propeller engines safer in high stress situations?

What do you think?
Title: Re: QotW - 18.11.11 - Why are propeller-drive planes popular in hurricanes?
Post by: Kryptid on 12/11/2018 19:03:49
Jet aircraft have been used to fly into hurricanes in the past. The Lockheed U-2 and Boeing WB-47 are two examples. Even today, the Gulfstream IV-SP (G-IV) is used. My best guess for the seeming preference for propeller-driven aircraft is because of their superior fuel efficiency.
Title: Re: QotW - 18.11.11 - Why are propeller-drive planes popular in hurricanes?
Post by: evan_au on 13/11/2018 10:15:06
Could a propeller plane, with its lower speed, be more maneuverable for flying into the eye of a hurricane?

I guess you would want to ensure that the hurricane wind speed does not exceed the maximum speed of the propeller plane/ (...or else you fly downwind instead of upwind!)
Title: Re: QotW - 18.11.11 - Why are propeller-drive planes popular in hurricanes?
Post by: chris on 13/11/2018 13:40:32
I guess you would want to ensure that the hurricane wind speed does not exceed the maximum speed of the propeller plane/ (...or else you fly downwind instead of upwind!)
Interesting point - I'd never considered that; it's certainly possible with a small plane I would think to fly "backwards" in a hurricane.
Title: Re: QotW - 18.11.11 - Why are propeller-drive planes popular in hurricanes?
Post by: alancalverd on 13/11/2018 15:44:18
Wind speed is unimportant once you are airborne - a plane flies relative to its ambient air, not the ground.

Choice of plane depends on the precise mission. If you want to explore a small part of the sky, a low stall speed (and a fairly benign stall characteristic) will give you a tighter turn radius: most small prop planes stall at 60 kt or less, but bizjets tend to drop out of the sky at 80 or more, and can be a handful to recover from a spin. If you are interested in turbulence, you'll want a ship with good aerobatic capability (+10 -5 g at least)  which is not what bizjets do best. At low levels, you won't expect much icing in a hurricane, and props are more economical than jets below 10,000 ft.  Some prop aircraft are known to be good ice carriers at higher altitude but for routine exploration above 15,000 ft a turboprop or pure jet comes into its own.

Piston engines are generally more tolerant of short flights with widely varying power demand from loiter via "75% cruise" to "120% combat" and in the event of an encounter with hail or flying debris, a propeller is a lot cheaper to repair than a jet fan. Jets really don't like starting, stopping, or loitering: think retrievers and greyhounds!.
Title: Re: QotW - 18.11.11 - Why are propeller-drive planes popular in hurricanes?
Post by: Bored chemist on 14/11/2018 20:43:16
I guess you would want to ensure that the hurricane wind speed does not exceed the maximum speed of the propeller plane/ (...or else you fly downwind instead of upwind!)
Interesting point - I'd never considered that; it's certainly possible with a small plane I would think to fly "backwards" in a hurricane.
I suspect that from at least some points of view it is almost inevitable to fly backwards in a hurricane.
Title: Re: QotW - 18.11.11 - Why are propeller-drive planes popular in hurricanes?
Post by: alancalverd on 15/11/2018 17:55:44
But not a Hurricane. Though more tolerant of bullet damage than a Spitfire, it doesn't take well to tailsliding or any reverse flow over the control surfaces.
Title: Re: QotW - 18.11.11 - Why are propeller-drive planes popular in hurricanes?
Post by: evan_au on 15/11/2018 19:58:06
I once exceeded the speed of sound in a commercial airliner (as measured by ground speed).

They took a longer path around an intense low-pressure system, but got to the destination ahead of schedule (without ripping off the wings :)  ) by "going with the flow".
Title: Re: QotW - 18.11.11 - Why are propeller-drive planes popular in hurricanes?
Post by: jimbobghost on 15/11/2018 23:18:42
I landed a Beechcraft Musketeer (stall speed about 60 MPH) at a small airport in FL with a headwind straight down the runway at a constant speed of about 60 MPH.

no problem landing, but then proceeding to the taxi way was interesting...she insisted on wanting to fly again as I crept forward with an additional 5-10 MPH just to get there.
Title: Re: QotW - 18.11.11 - Why are propeller-drive planes popular in hurricanes?
Post by: guest45734 on 16/11/2018 14:02:15
I asked the captain and he said https://eu.usatoday.com/story/travel/columnist/cox/2016/05/29/turboprop-propeller-plane/85045552/ "Answer: The turboprops are more tolerant of hail than the jets. Airplanes that penetrate thunderstorms have an increased chance of encountering hail. Additionally, the two types of airplanes used, the P-3 and the C-130, are especially rugged."

I guess the same applies in a Hurricane, A prop driven plane is slower than a jet engine, and if a plane is flying slower then it will also suffer less strain, in adverse weather conditions :)  flying through hail, fishes, buses, trees, cows etc, that one might find in a hurricane after being sucked up. :)