Hubble to be abandoned

Peter Stickney wrote:

The airplane was also rather dangerous to fly, as well, and losses
were high. - by 1960, when it had been in service for 5 years, more
than 500 had been totally destroyed in flying accidents.


I knew about the roll coupling problem due to the undersized vertical
fin, but didn't know the attrition rate was quite that appalling.

Pat

In article ,
OM om@our_blessed_lady_mary_of_the_holy_NASA_researc h_facility.org wrote:
And the one with the conspicuously biggest production run -- the F-100 --
was also the simplest of the lot. (Partly because its design solidified
shortly before it became clear that fighters needed their own radar, and
the shape it solidified to was severely unsuited to adding radar.)

...Which begs the question as to what shape mods would have had to
been made to the F-100 to accomodate mounting an onboard radar?

Basically, you'd have had to completely rethink the nose layout. (And as
others have already noted, when you do that, and make some other changes
which might seem like good ideas at the same time, you get the F-107.)

The F-100 nose was absolutely, completely full of air intake. Even adding
a tiny range-only gunsight radar, with an antenna only a few inches
across, required a noticeable blister. You couldn't bulge the nose upward
to get more room because the pilot view forward for landing was none too
good in the first place, you couldn't bulge it downward without messing up
the flow over the belly (I think), and you couldn't bulge it sideways
because it was *already* bulged sideways as far as reasonably possible.
Trying to put a nose intake in a long, slim supersonic shape just left no
room to maneuver.

The only answer was to move the intake somewhere else -- above like the
F-107, below like the F-103 (or F-16), or the sides like most of the other
Century series fighters and many others since.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

From Pat Flannery:
I wonder how
many Canadians know that their country once possessed nuclear weapons?

I wonder how many know about a nuclear device being *dropped* on
Canada!

( The story was posted a couple of years ago:
http://tinyurl.com/2sjut )

I first learned of it in reading the Bulletin of Atomic Scientists.
The amazing article "Where They Were" is also available online:

http://www.bullatomsci.org/issues/19...d99norris.html


~ CT

Henry Spencer wrote:

The only answer was to move the intake somewhere else -- above like the
F-107, below like the F-103 (or F-16), or the sides like most of the other
Century series fighters and many others since.

Or go the MiG/Sukhoi route and put it in the middle of an enlarged
intake; in which case you can use it as a shock cone to slow the
supersonic airflow. North American tried something truly strange with
the intakes on the YF-93; NACA style intakes on the _sides_ of the
aircraft body: http://www.aerofiles.com/noram-yf93a.jpg these didn't
work at all well, although they may have had some proto-stealth
characteristics. The F-107's top mounted one would have solved the
problem of foreign object ingestion from debris on the runway, but they
found out that the top mounted intake on the horrible looking Tacit Blue
stealth aircraft* (is it just me, or does it look like a styrofoam
submarine sandwich box with wings?):
http://www.vic.karoo.net/images/tacit_blue.jpg became a natural place to
accidentally store tools and work gloves during maintenance operations.

* Remark of pilot who upon seeing "Shamu" for the first time:
"Well...it's _got_ to fly better than it looks..."
Reply from its pilot: "You haven't flown it yet..."

Pat

Peter Stickney wrote:


http://www.wpafb.af.mil/museum/resea...hter/f107a.htm


Is that a big air inlet on top? Sorta like an upsidedown F-16?



--
Hop David
http://clowder.net/hop/index.html

In article ,
Hop David writes:


Peter Stickney wrote:


http://www.wpafb.af.mil/museum/resea...hter/f107a.htm


Is that a big air inlet on top? Sorta like an upsidedown F-16?

Yes, It looks a bit, well, different, but it was in a good position
wrt clean, controllable airflow, and for good pressure recovery.
It would have been a bit of a problem in terms of rearward visibility,
but, for some reaon, nobody thought that the Bisonic fighters would
ever have to look behind themselves.

North American wasn't wedded to any particular inlet configuration,
The F-107 had it on top. The B-70 had its inlets below the fuselage,
and the F-108 Mach 3+ interceptor, and the A3J/A-5 Vigilante for teh
Navy hat their inlets on the sides.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

Edward Wright wrote:

Have either of you done an Environmental
Impact Statement on the effect of dumping 17 tons of extremely toxic
chemicals in the South Pacific?

Have you looked at the MSDS's and other reference material to determine how
much of your "17 tons of extremely toxic chemicals" will survive entry?
Have you examined entry plans to determine how much of your "17 tons" will
even remain aboard when entry starts?

I thought not . . .

--
Herb Schaltegger, B.S., J.D.
Reformed Aerospace Engineer
Remove invalid nonsense for email.

In article ,
Pat Flannery writes:


Peter Stickney wrote:

The airplane was also rather dangerous to fly, as well, and losses
were high. - by 1960, when it had been in service for 5 years, more
than 500 had been totally destroyed in flying accidents.


I knew about the roll coupling problem due to the undersized vertical
fin, but didn't know the attrition rate was quite that appalling.

Loss rates for early jet fighters were very high, Generally at levels
that would give Bob Haller an aneurysm.

The Air Force Safety Center has many (but not all) of their statistics
on-line. The numbers only cover from 1950 onward, though, and may
include combat losses in korea (but not from Viet Nam)

http://afsafety.af.mil/AFSC/RDBMS/Fl...aft_stats.html

is a good place to start.

But, if you take a look at, say, the numbers for the F-86, you;ll see
that in in 54 (The first year with no possible confusion about combat
losses, they totalled 261 aircraft, and had class A (Totalled
aircraft or damage significant enough to require an entire reduild, or
somebody got injured or killed) Damage to the tune of 487 aircraft,
for a rate of roughly 61 per 100,000 Flying Hours. So, if you put in
about 1500 hours of Sabre time over your career (About 3 years of
flying, at that time, you had a near certain probability of being
involved in a Class A. Not at all acceptable, by our standards.
Note that earlier rloss rates, which may include combat losses, and
therefore be skewed, show loss rates of over 100 per 100,000 hours.

And the Sabre was one of the safer ones. It's a little hard to tell,
but it appears that by 1950, between 1/3 and 1/2 of all the F-84
Thunderjets that had been built up to that time had been written off.

I don't have the Navy stats at hand, but when you consider that they
were flying things like the F7U Cutlass, and throwing themselves at
ships in the Ocean Sea, their numbers are even worse.

It's useful to look at this context. You may remember when stuf4
first appeared, he was being rather noisy about Eeevil T-38 killing
off Poor Defenceless Astronauts. It turns out that if you look at the
Air Force's T-38 stats for the same time, NASA lost fewer '38s, and
their pilots, than the statistics would indicate.

The fact is, if you fly anything long enough, whether it be an Otto
Lilienthal Hang Glider, or even a perfectly functioning, Super Safe
Hyper-XYZ New Shuttle Orbiter, you will, at some point, lose it.
The perfect safety that some have demanded, nay, _required_ is only
achievable if you don't even make the attempt. The only perfect
safety is if you never get out of bed. (And even that's not perfect -
a meteor might crash through the roof and wipe you out anyway.

I'm not saying that we shouldn't be striving to be as safe as
possible, but it should be realized that no matter how much we work to
ameleorate the risks, there will be losses. Orbiters _will_ be lost,
adn people will die. This won't matter if it's STS Orbiters, Brand
New Capsules, or Zeta Reticulan Flying Disks.

(SOrry for the rant - strong coffee this morning)
--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

Hop David wrote:


Is that a big air inlet on top? Sorta like an upsidedown F-16?


Yup, that's what it is. One of the stranger places to put an air intake.
And of course the source of many jokes about the ejection seat's safety:
http://f-100.org/images/pima_f-107_19.jpg the design is similar to the
one on the bottom of North American's B-70 bomber.

Pat

Peter Stickney wrote:

Yes, It looks a bit, well, different, but it was in a good position
wrt clean, controllable airflow, and for good pressure recovery.


And you get some stealth out of it as the jet's turbine face isn't
directly visible.

It would have been a bit of a problem in terms of rearward visibility,
but, for some reaon, nobody thought that the Bisonic fighters would
ever have to look behind themselves.


A very Russian concept, that.


North American wasn't wedded to any particular inlet configuration,
The F-107 had it on top. The B-70 had its inlets below the fuselage,
and the F-108 Mach 3+ interceptor, and the A3J/A-5 Vigilante for teh
Navy hat their inlets on the sides.


But basically rectangular intakes with a wedge shape in all these cases;
the F-108 Rapier was going to use it also:
http://perso.wanadoo.fr/prototypes.c...s/xf108_13.jpg
....and MiG liked it well enough to use on the Foxbat and Foxhound.

Pat