Restricted takeoffs, VRS, and ground effect
Avoid imitations
Joined: Nov 2000
Aviation Qualifications: ATPL
Posts: 15,110
Likes: 1,083
From: Wandering the FIR and cyberspace often at highly unsociable times
This discussion is sounding like one of those pointless arguments in a pub about whose footaball team is best.
Irrespective of the reliability of modern turbine engines, the point about twin engined aircraft is that they have other duplicated systems, such as those which are required for flight in IFR e.g. generators, SAS/autopilot systems, hydraulics etc.
This rules out singles where continued flight is a safety and legal requirement. There is certainly no compelling evidence that a single engine is more reliable and therefore safer than two.
Having flown both singles and twins, I've always said that I'd rather have a well equipped, powerful single than an underpowered twin, some of which I've also flown.
But the latter came from "the dark ages" and modern twins do not generally fit into that category.
I'd say that both singles and twins each have their own "niche" and both will always exist. It's totally pointless trying to argue that singles should be exclusively manufactured and used because of a personal preference.
Irrespective of the reliability of modern turbine engines, the point about twin engined aircraft is that they have other duplicated systems, such as those which are required for flight in IFR e.g. generators, SAS/autopilot systems, hydraulics etc.
This rules out singles where continued flight is a safety and legal requirement. There is certainly no compelling evidence that a single engine is more reliable and therefore safer than two.
Having flown both singles and twins, I've always said that I'd rather have a well equipped, powerful single than an underpowered twin, some of which I've also flown.
But the latter came from "the dark ages" and modern twins do not generally fit into that category.
I'd say that both singles and twins each have their own "niche" and both will always exist. It's totally pointless trying to argue that singles should be exclusively manufactured and used because of a personal preference.
Joined: Dec 2008
Posts: 843
Likes: 0
From: N/A
Crab
Your assumption that I haven't had my share of dark and stormy nights in inhospitable places is a little harsh. Been more than 500nm from land just for starters.
Yes Shy is right to some extent and Crab's examples are the emotional ones that make people kneejerk to believing that the twin is obvious. BUT the point I am trying to make is deeper than that. Extending to the 'lazy' redundancy concept. The most unreliable part of some helicopters are the duplicated parts and I would prefer to spend the weight/cost/complexity on making a very reliable SIMPLEX system with minimal to zero need for backup.
Safety systems in general really ought to be evaluated with the cost to payload etc taken into account. Otherwise you get the daft situation where 3 flights need to be made in an 'engine failure immune' helicopter against 1 flight in an engine 'exposed' helicopter. [not a complete arguement]. AND duplication can be the answer sometimes, just nothing like as often as people's emotion leads them to believe.
3000shp? do you need 3000hp? 3000x 10 lbs/hp = 30000lbs that's heavy.
How many hp was the Huey (did pretty well, payload and performance wise)
As with the chinook if you need both engines to obtain enough hp then it's not the same thing as redundancy.
Your assumption that I haven't had my share of dark and stormy nights in inhospitable places is a little harsh. Been more than 500nm from land just for starters.
Yes Shy is right to some extent and Crab's examples are the emotional ones that make people kneejerk to believing that the twin is obvious. BUT the point I am trying to make is deeper than that. Extending to the 'lazy' redundancy concept. The most unreliable part of some helicopters are the duplicated parts and I would prefer to spend the weight/cost/complexity on making a very reliable SIMPLEX system with minimal to zero need for backup.
Safety systems in general really ought to be evaluated with the cost to payload etc taken into account. Otherwise you get the daft situation where 3 flights need to be made in an 'engine failure immune' helicopter against 1 flight in an engine 'exposed' helicopter. [not a complete arguement]. AND duplication can be the answer sometimes, just nothing like as often as people's emotion leads them to believe.
3000shp? do you need 3000hp? 3000x 10 lbs/hp = 30000lbs that's heavy.
How many hp was the Huey (did pretty well, payload and performance wise)
As with the chinook if you need both engines to obtain enough hp then it's not the same thing as redundancy.
Joined: Apr 2000
Aviation Qualifications: ATP+Mil
Posts: 10,959
Likes: 1,814
From: EGDC
As with the chinook if you need both engines to obtain enough hp then it's not the same thing as redundancy.
Otherwise you get the daft situation where 3 flights need to be made in an 'engine failure immune' helicopter against 1 flight in an engine 'exposed' helicopter.
Pie = sky...
Care to elaborate on your 500nm from land in a helicopter? Love to know what has that range.
3000shp? do you need 3000hp? 3000x 10 lbs/hp = 30000lbs that's heavy
Any one got any Skycrane figures?
Joined: Mar 2012
Posts: 386
Likes: 4
From: steady
This discussion is sounding like one of those pointless arguments in a pub about whose footaball team is best.
Joined: Aug 2001
Posts: 1,308
Likes: 0
From: Cornwall
Second class citizens???
We must all remember that whatever regulatory principles are handed down to us chopper pukes it will be the philosophies that apply in the fixed wing world that will dominate.
The old joke about the difficult journey - you know, the one that begins "well if I were you I wouldn't have started from here......"
Gentlemen, we are where we are, sad though that may be.
G.
The old joke about the difficult journey - you know, the one that begins "well if I were you I wouldn't have started from here......"
Gentlemen, we are where we are, sad though that may be.
G.
