h a l f b a k e r yCall Ambulance,
Rebuild Kitchen.
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
browse anonymously,
or get an account
and write.
register,
|
|
|
Please log in.
Before you can vote, you need to register.
Please log in or create an account.
|
I recently took a short haul jet flight, a mere 44 minutes of low
cost intercity travel that would have been a pleasant rail
journey
were it not for the inconvenient but necessary Irish sea. The
flight
profile seemed faintly ridiculous. A quick investigation on FR24
reveals that after the
initial climb, a phase that varies little
between routes, the flight had three distinct phases. Phase 1: 7
mins of climbing from 4000ft to 18,000ft averaging 265kn.
Phase
2: a 7 minutes gentle descent from 18,000ft to 15,600ft at
308.5kn. Phase 3: an 8 minute 15,600 to 3500ft descent at
258kn.
Before the proper and unavoidable approach.
Now, that plane was either climbing or descending, the poor
cabin
crew had to push the drinks uphill from the back, then uphill
from
the front on the way back. It was silly. I have done some
calculations and just because of the ascent and descent angles
that plane flew 0.17 nautical miles further than it had to*. I'm
not sure why they bothered going all the way to 18,000ft when
they had to immediately had to start descending. It costs fuel
and
or speed to gain altitude, you put the aircraft through more
pressurization cycles and make the poor cabin crew work uphill.
I assume this is because the aircraft is designed to be efficient
at
>30,000ft and has a fancy wing to go with it. How about an
aircraft designed for a quick low altitude dash across the sea? A
flight profile after take off would consist largely of
acceleration
and climb to say, 3000ft. There it stays, maintaining a
respectable oooh, 420kn, until it"s time for final approach.
You'll need a new airframe for this kind of flying, the wings of a
traditional airliner are all wrong. Instead our model will be
TSR2.
Low wing area/weight giving a relatively large wing loading and
minimal drag in low altitude thick air. The civilian passenger
aircraft wont have the power surplus for high altitude flight,
but
that doesn't matter, it'll never need to. These restrictions mean
we can simplify the aircraft considerably. If it can't get above
10,000ft we can start throwing stuff out. Pressurization
associated airframe design, pressure management equipment,
fancy heating systems and so on. Small wings are lighter and
tougher, they take up less space at the airport meaning you can
park close and the jet way** will be much shorter. Now you flew
faster, landed faster***, parked closer and as such you're in
front
of those morons on the 737 in the immigration line... has to be
15
mins right there.
*I admit, that was quite small.. the number for a 30min cruise-
climb is not insignificant, however.
** 1 min extra walking here was 8 miles in the air.
*** landing speed could be a bit scary, aircraft should also be
optimized for quick taxiing... maybe a folding fin so it can
sneak under a 777 wing and steal a better baggage carousel.
Antonov AN-72
https://en.wikipedi.../wiki/Antonov_An-72
A good starting point ? [8th of 7, Nov 03 2016]
TSR-2
http://www.gknapman...xr219-in-flight.jpg
[bs0u0155, Nov 04 2016]
Hunting H.126
https://en.wikipedi.../wiki/Hunting_H.126
"... built by Hunting Aircraft in order to test the concept of blown flaps ..." [8th of 7, Nov 16 2016]
[link]
|
| |
[+] How about an ekranoplan? |
|
| |
// I'm not sure why they bothered going all the way to 18,000ft when they had to immediately had to start descending. // |
|
| |
Could just be fickle ATC ... |
|
| |
3000' AMSL means you're in uncontrolled airspace; there could be anything hiding behind (or in) that cumulus ... |
|
| |
What about the AN-72 as a starting point ? A high-loaded wing doesn't go well with STOL so the short-field cability would need to be sacrificed, but would give higher cruising speeds. |
|
| |
Also beneficial to Chinese short distance between cities flights. |
|
| |
High speed trains would be more cost effective in the long term in that application- once the huge capital cost of the track has been paid. |
|
| |
Given that the Chinese are so small, why don't they
just build their cities closer together? |
|
| |
My TSR2 inspired anhedral wingtips will harness extra
ground effect for take off. However, the Soviet naval
yard construction techniques may be prohibitively
expensive to recreate. I will, instead, have to rely on
the disappointingly reliable and lightweight methods so
prevalent in the current aviation industry. Perhaps as a
tribute, I could ignore conspicuous productivity/laziness
and instead reward those who agree with me, special
privileges for those who come up with creative new
ways in which I was right. |
|
| |
I think a high wing and high engine mounting may also
be carried over. These allow shorter undercarriages,
possibly short enough that a full length platform, rather
than stairs/jet way, would be sufficient. In further
tribute to British transport ingenuity, each row could
have its own door opened by the passengers
themselves. As a result parallel, rather than serial,
entry and exit may be achieved. |
|
| |
//there could be anything hiding behind (or in) that
cumulus ...// |
|
| |
A brief mention of this fact during the pilot's PA would perk
up the most jaded of passengers. Adrenaline is lighter,
more effective and freer than coffee. Throw out the coffee
and all associated gubbins at the back. |
|
| |
For short journeys, how about having a very long
arm (half as long as the distance between starting
and ending points) mounted on a pivot at the
midway point? |
|
| |
An aircraft bolted to the end of this arm would
have to provide enough power to lift the arm (and
itself) to the vertical position; but this energy
could be recovered by a suitable generator at the
base of the pivot, as the plane descended on the
other side. |
|
| |
As a bonus, if a plane ever went missing, the
search could be confined to a circle of arms-length
radius around the pivot point. |
|
| |
That's sheer insanity, [Ian]. You'll have wingless
planes that float next. |
|
| |
It seems to me that with a bit of fore planning, it would be
simpler to store the drinks forward so they are pushing the
trolleys downhill both ways. |
|
| |
Better yet, simply plumb drinks to each seat, and
equip said seat with a tap. |
|
| |
// reward those who agree with me, special privileges for those who come up with creative new ways in which I was right // |
|
| |
In terms of management science, that's just sheer undiluted genius. We have no doubt that your meteoric* rise to fame and fortune is even now beginning. |
|
| |
In ages to come, there will be statues of you in every town, images of you in every home and workplace, your name will be spoken only in hushed whispers by the anointed priesthood, and the bulk of the population will worship you as a God. |
|
| |
// You'll have wingless planes that float next. // |
|
| |
Hahaha ... for an extra laugh, why not make them of thick steel plates, welded together ? |
|
| |
*Spectacular, fascinating, and ending in a huge explosion on the edge of the atmosphere, after which little charred fragments rain down over a wide area. |
|
| |
ahem, continuing to think the idea has merit, I will casually include Chinese searchbait so the Chinese will discover this idea as well as the halfbakery. Short range improved passenger airplane with minimal defense applications is 最小 的国 防应 用短 范围 提 高 铁路 客运 飞机, or so Bing tells me. |
|
| |
// High speed trains / cost of the track // |
|
| |
Bah, track?? Get them fast enough and skip them across the water like pebbles. This alleged Irish Sea can't be that wide, shirley? |
|
| |
// Get them fast enough and skip them across the water like pebbles. // |
|
| |
That would be a great way of getting pedestrians across rivers, certainly. A casing similar to Barnes Wallis's "Upkeep" bouncing mine could contain several passengers, if they were forced in. And they would undoubtably have to be forced in ... |
|
| |
It's actually not the wings, it's the engines. Going up to
18,000ft only briefly does save fuel and the planned
cruising altitude is calculated to take air density,
temperature, and winds aloft into account for the most
efficient cruise. If you do want a more efficient plane for
short, low altitude hops that does exist. It's called a Q400.
Passengers don't like propellers for some reason though. |
|
| |
Could the high altitude route also be a risk mitigation
strategy? In case of engine failure, higher altitude results
in a higher probability of gliding to land. I know these
things are supposed to fly on one engine, but every now
and again you can loose both. It seems like pilots and
regulators like to add safety margin wherever they can if it
doesn't add too much to the cost. |
|
| |
"Height is money in the bank" |
|
| |
The five most useless things for a pilot are: |
|
| |
Sky above you
Fuel in the bowser
Runway behind you
Maps in your car
Airspeed you don't have
|
|
| |
// Passengers don't like propellers for some reason though. // |
|
| |
An underground tunnel to the Irish? You British really are
suicidal, aren't you? One would think the Chunnel to France
would have been bad enough. |
|
| |
Ah, but there's a Secret Plan to link the two English ends without telling the french (the Irish won't notice). |
|
| |
//Q400. Passengers don't like propellers for some
reason though.// |
|
| |
350knt cruising speed? Pfft. Massive ungainly wobbly
wings, they just add unnecessary stuff, engineers get
carried away! Someone suggests longer heavier wing,
then the ailerons are further away, you need longer
hydraulics with more fluid, more weight. Then you need
more lift. So you add flaps and slats and all the
associated jackscrews and hydraulics, more weight!
Now you need even more wing. That gives you more
drag, so you need bigger engines which weigh more and
use more fuel, which weighs more. Look at what
happened to the B2! That was supposed to be an
airliner until the engineers got carried away and had to
ditch the whole fuselage and empennage to save
weight. |
|
| |
No no. Short stubby lightweight wings, make the
ailerons fully independent flaperons doing double duty,
save weight again. The real genius is the speed. You can
have Q400 style 700sq ft of wing and fly at 300kn or
300sq ft of wing at 600kn. You get there quicker, you
even take off faster, the pilot has less distance to cover
on the pre-flight walkaround. While it might not be
true, it is a fact that 32% of B52 flights have to be
cancelled due to pilot navigation errors during the
walkaround, resulting in confused aviators walking on
compass bearings babbling incoherently about fabled
engine nacelles just beyond the horizon. |
|
| |
// You get there quicker, you even take off faster // |
|
| |
... and presumably land faster, too ? |
|
| |
You aren't advocating the likes of the MD-82, are you ? Little thin wings, long narrow fuselage - basically a passenger version of the Starfighter (It didn't get the nickname "flying coffin" by chance). |
|
| |
Even with flaperons along the whole trailing edge, and slats or droops, what's the margin between stall speed and landing speed ? If it isn't generous, thou shalt be Banished to the Outer Darkness, or Basingstoke (whichever is more bleak, desolate and soul-destroying, so probably Basingstoke). |
|
| |
// due to pilot navigation errors during the walkaround // |
|
| |
They give them those electric golf buggy things now, with a GPS strapped to the dash. |
|
| |
// So you add flaps and slats and all the associated jackscrews and hydraulics, more weight! // |
|
| |
Say hello to this little chap, on display at RAF Cosford ... |
|
| |