Courious Crash

[john smith]

Sunday evening, 17 December, a small plane crashed two miles south of
the Bucyrus Ohio airport (17G). A family of four (father, mother, two
children) died in the crash. There was minor damage to an apartment
building from flying debris, and no injuries to those on the ground.
The husband and wife are reported to have been pilot rated and
preliminary reports describe the aircraft as a 60's/70's Comanche.
Witnesses on the ground reported the engine sputtering and seeing sparks
coming from the airplane prior to the crash.
The aircraft had departed Oklahoma earlier in the afternoon.

Q: what are the possible ranges of various models of Comanche's?

My speculation...
Oklahoma to Bucyrus Ohio is a long haul. If the engine is sputtering, I
am guessing fuel exhaustion.
That it was within two miles of the airport makes me strongly think they
were stretching it.
Tulsa OK to Bucyrus OH is 665 nm. Fuel burn on a Comanche 260 is what?
14 per hour?
Cruise speed is 160 kts?
That gives about five hours and 700 nm.
How close am I?

[Dan[_1_]]

14 per hour is what I use for planning in a Comanche 260. With aux
tanks, we're talking about 84 gallons usable. 84/14 = 6 hours of
cruise at 155 kts. = 930nm to dry tanks.

If there were no aux tanks, that's 56 gallons usable/14 = 4 hrs x 155
kts = 620nm.. with a tailwind, you just might run dry slightly short of
the airport in that scenario.

I've also noticed that line folks often leave the tanks less than
completely topped due to the nature of the tanks looking full when they
still have room. A few weeks back, I called the lineman back to the
plane and he added 5 gallons after "topping it off" earlier. Maybe
that's a bit "anal" but on a night/IFR flight from Oakland, CA to
Phoenix I want all the fuel I can get... that's an extra 22 minutes of
cruise.

--Dan


john smith wrote:
> Sunday evening, 17 December, a small plane crashed two miles south of
> the Bucyrus Ohio airport (17G). A family of four (father, mother, two
> children) died in the crash. There was minor damage to an apartment
> building from flying debris, and no injuries to those on the ground.
> The husband and wife are reported to have been pilot rated and
> preliminary reports describe the aircraft as a 60's/70's Comanche.
> Witnesses on the ground reported the engine sputtering and seeing sparks
> coming from the airplane prior to the crash.
> The aircraft had departed Oklahoma earlier in the afternoon.
>
> Q: what are the possible ranges of various models of Comanche's?
>
> My speculation...
> Oklahoma to Bucyrus Ohio is a long haul. If the engine is sputtering, I
> am guessing fuel exhaustion.
> That it was within two miles of the airport makes me strongly think they
> were stretching it.
> Tulsa OK to Bucyrus OH is 665 nm. Fuel burn on a Comanche 260 is what?
> 14 per hour?
> Cruise speed is 160 kts?
> That gives about five hours and 700 nm.
> How close am I?

[Jose[_1_]]

> I've also noticed that line folks often leave the tanks less than
> completely topped due to the nature of the tanks looking full when they
> still have room.

If a tank is completely topped off in the cool evening air, how much gas
will pour overboard when the wing heats up in the noonday sun?

I know - "it depends". Let's take as an example a cherokee 24 gallon
wing, 45 degrees at night, 80 degrees under hot spring sun. Or
something similar. Could one lose more than a gallon per tank?

Jose
--
"There are 3 secrets to the perfect landing. Unfortunately, nobody knows
what they are." - (mike).
for Email, make the obvious change in the address.

[Orval Fairbairn]

In article >,
john smith > wrote:

> Sunday evening, 17 December, a small plane crashed two miles south of
> the Bucyrus Ohio airport (17G). A family of four (father, mother, two
> children) died in the crash. There was minor damage to an apartment
> building from flying debris, and no injuries to those on the ground.
> The husband and wife are reported to have been pilot rated and
> preliminary reports describe the aircraft as a 60's/70's Comanche.
> Witnesses on the ground reported the engine sputtering and seeing sparks
> coming from the airplane prior to the crash.
> The aircraft had departed Oklahoma earlier in the afternoon.
>
> Q: what are the possible ranges of various models of Comanche's?
>
> My speculation...
> Oklahoma to Bucyrus Ohio is a long haul. If the engine is sputtering, I
> am guessing fuel exhaustion.
> That it was within two miles of the airport makes me strongly think they
> were stretching it.
> Tulsa OK to Bucyrus OH is 665 nm. Fuel burn on a Comanche 260 is what?
> 14 per hour?
> Cruise speed is 160 kts?
> That gives about five hours and 700 nm.
> How close am I?

I have never had an engine "sputter" when a tank goes dry! They just
quit until you switch tanks.

[Montblack]

("Orval Fairbairn" wrote)
> I have never had an engine "sputter" when a tank goes dry! They just quit
> until you switch tanks.


....plus the "sparks" before the crash. ???


Montblack

[Jim Macklin]

§ 23.969 Fuel tank expansion space.
Each fuel tank must have an expansion space of not less than
two percent of the tank capacity, unless the tank vent
discharges clear of the airplane (in which case no expansion
space is required). It must be impossible to fill the
expansion space inadvertently with the airplane in the
normal ground attitude.

"Nomen Nescio" > wrote in message
...
| -----BEGIN PGP SIGNED MESSAGE-----
|
| From: Jose >
|
| >If a tank is completely topped off in the cool evening
air, how much gas
| >will pour overboard when the wing heats up in the noonday
sun?
| >
| >I know - "it depends". Let's take as an example a
cherokee 24 gallon
| >wing, 45 degrees at night, 80 degrees under hot spring
sun. Or
| >something similar. Could one lose more than a gallon per
tank?
|
| A quick look at the Marks' Mechanical Engineers Handbook
puts
| the coefficient of expansion at about .0007.
| So I'd tend to say no.
| You're probably looking at a little over a half gallon.
|
|
| -----BEGIN PGP SIGNATURE-----
| Version: N/A
|
|
iQCVAwUBRYem+JMoscYxZNI5AQF09QQAmrNzWVb46u3Kp+PszB zVMBUUbnoXuRgi
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|
V5MS8hMA0e0EO7XamlvaK77Rx2lp3mos/Viot31mWwNtnzLnAxot/9imkyOctIfC
| TxaJ3pMZdBw=
| =/h7e
| -----END PGP SIGNATURE-----
|
|

[Paul Tomblin]

In a previous article, "Montblack" > said:
>("Orval Fairbairn" wrote)
>> I have never had an engine "sputter" when a tank goes dry! They just quit
>> until you switch tanks.
>
>
>...plus the "sparks" before the crash. ???

One truth of NTSB reports is that non-pilot witnesses are *never*
reliable.

--
Paul Tomblin > http://blog.xcski.com/
But seriously, I've got root, so it's his problem.
-- Nick Manka

[Jose[_1_]]

> § 23.969 Fuel tank expansion space.
> Each fuel tank must have an expansion space of not less than
> two percent of the tank capacity, unless the tank vent
> discharges clear of the airplane (in which case no expansion
> space is required). It must be impossible to fill the
> expansion space inadvertently with the airplane in the
> normal ground attitude.

I don't know whether cherokees have expansion space, but they do have a
fuel vent that vents fuel "clear of the airplane" (as far as I can tell).

However, I would infer from the reg that 2% would be typical of expected
expansion. So, half a gallon loss out of a 24 gallon tank would not be
outrageous.

Am I missing something?

Jose
--
"There are 3 secrets to the perfect landing. Unfortunately, nobody knows
what they are." - (mike).
for Email, make the obvious change in the address.

[John Clonts]

Paul Tomblin wrote:
> In a previous article, "Montblack" > said:
> >("Orval Fairbairn" wrote)
> >> I have never had an engine "sputter" when a tank goes dry! They just quit
> >> until you switch tanks.
> >
> >
> >...plus the "sparks" before the crash. ???
>
> One truth of NTSB reports is that non-pilot witnesses are *never*
> reliable.
>

Statements asserting "always" or "never" are always wrong!

[Christopher Campbell[_1_]]

On Mon, 18 Dec 2006 19:51:14 -0800, john smith wrote
(in article >):

> Sunday evening, 17 December, a small plane crashed two miles south of
> the Bucyrus Ohio airport (17G). A family of four (father, mother, two
> children) died in the crash. There was minor damage to an apartment
> building from flying debris, and no injuries to those on the ground.
> The husband and wife are reported to have been pilot rated and
> preliminary reports describe the aircraft as a 60's/70's Comanche.
> Witnesses on the ground reported the engine sputtering and seeing sparks
> coming from the airplane prior to the crash.
> The aircraft had departed Oklahoma earlier in the afternoon.
>
> Q: what are the possible ranges of various models of Comanche's?
>
> My speculation...
> Oklahoma to Bucyrus Ohio is a long haul. If the engine is sputtering, I
> am guessing fuel exhaustion.
> That it was within two miles of the airport makes me strongly think they
> were stretching it.
> Tulsa OK to Bucyrus OH is 665 nm. Fuel burn on a Comanche 260 is what?
> 14 per hour?
> Cruise speed is 160 kts?
> That gives about five hours and 700 nm.
> How close am I?
>

Who knows? No one here knows any more about it than anyone else. We do not
even know if they stopped to refuel along the way. You don't know when the
oil was last changed, what kind of weather briefing he got, when the last
annual was, the condition of the electrical system, or anything else. So it
seems to be going out on a limb to be immediately suspecting fuel exhaustion.

Pilots in general have a pretty good idea of how far they can fly on a full
tank and they do not intentionally stretch it. Most of the guys who get in
trouble with fuel exhaustion seem to be people who encounter unexpected
headwinds, had to divert to another airport for some reason, or who did not
find fuel where they expected it.

So, I would not assume fuel exhaustion right off the bat. In fact, from the
facts given, I would not assume anything.

One thing I do know -- these people had family and friends, some of whom
might read these news groups.

[Gig 601XL Builder]

"John Clonts" > wrote in message
ups.com...
>
> Paul Tomblin wrote:
>> In a previous article, "Montblack"
>> > said:
>> >("Orval Fairbairn" wrote)
>> >> I have never had an engine "sputter" when a tank goes dry! They just
>> >> quit
>> >> until you switch tanks.
>> >
>> >
>> >...plus the "sparks" before the crash. ???
>>
>> One truth of NTSB reports is that non-pilot witnesses are *never*
>> reliable.
>>
>
> Statements asserting "always" or "never" are always wrong!
>

And never right.

[Peter Dohm]

> > § 23.969 Fuel tank expansion space.
> > Each fuel tank must have an expansion space of not less than
> > two percent of the tank capacity, unless the tank vent
> > discharges clear of the airplane (in which case no expansion
> > space is required). It must be impossible to fill the
> > expansion space inadvertently with the airplane in the
> > normal ground attitude.
>
> I don't know whether cherokees have expansion space, but they do have a
> fuel vent that vents fuel "clear of the airplane" (as far as I can tell).
>
> However, I would infer from the reg that 2% would be typical of expected
> expansion. So, half a gallon loss out of a 24 gallon tank would not be
> outrageous.
>
> Am I missing something?
>
> Jose
> --
I suspect that it means that the expected loss is much less. They probably
wanted to ensure that no fuel is leaked inside the aircraft over the widest
expected range of temperature and a reasonable range of attidudes--such as a
flat tire and/or a sloping ramp.

Peter

[Greg Farris]

In article >,
says...

>>
>
>Who knows? No one here knows any more about it than anyone else. We do not
>even know if they stopped to refuel along the way. You don't know when the
>oil was last changed, what kind of weather briefing he got, when the last
>annual was, the condition of the electrical system, or anything else. So it
>seems to be going out on a limb to be immediately suspecting fuel exhaustion.
>
>Pilots in general have a pretty good idea of how far they can fly on a full
>tank and they do not intentionally stretch it. Most of the guys who get in
>trouble with fuel exhaustion seem to be people who encounter unexpected
>headwinds, had to divert to another airport for some reason, or who did not
>find fuel where they expected it.
>
>So, I would not assume fuel exhaustion right off the bat. In fact, from the
>facts given, I would not assume anything.
>
>One thing I do know -- these people had family and friends, some of whom
>might read these news groups.
>

I agree with your post.
I do not agree with those who regularly post that it is unacceptable to
speculate or even to discuss possible causes until all the factual information
has been processed. I think it is useful, interesting and natural - but I
agree with you that early speculation must be respectful of what is a tragedy
for a circle of individuals.

The information given here is indeed very sparse. My initial question was the
same - did they stop to refuel? We don't know anything about their fuel
management scenario. Perhaps they started "nearly full" with the intention to
refuel somewhere, and that didn't work out. Perhaps there's no fuel management
question at all. Won't take much on the factual side to confirm or reject this
possible cause. The initial post is a compelling theory until the factual
information does that.

As for witness accounts - how many KingAir accidents have witness accounts of
the engine "missing"? Impressive events are something like dreams - we
remember sketchy things and "fill-in" the details.

GF