FAA Accident Report discrepancy.

I have just read the FAA final report for a glider accident with which I am familiar. The original narrative and the report itself contradict each other to some degree. One says the pilot was trying to land on a perpendicular runway, the other on the reciprocal of the original runway on which he was trying to land. While this might not be the most earth shaking event ever investigated by an arm of the Federal Government, it indicates a lack of accuracy in something which should have been easy. Does anyone care about accuracy in reporting anymore?

We can learn from these things, but only if the reporting officials get it right. I will be interested in seeing the report of the 2-32 that crashed in Montana with a DPE and a CFI-G on board.

Walt

On Jul 15, 7:14*am, Walt Connelly Walt.Connelly.
wrote:
I have just read the FAA final report for a glider accident with which I
am familiar. *

What does the NTSB final report say?

Andy

Originally Posted by Andy[_1_]

On Jul 15, 7:14*am, Walt Connelly Walt.Connelly.
wrote:
I have just read the FAA final report for a glider accident with which I
am familiar. *

What does the NTSB final report say?

Andy

Andy, I don't know. Haven't seen it as yet but I would assume that the NTSB report would have to be written from the results of the FAA investigator's report. If the FAA investigator contradicts himself between the original narrative and the final report, what chance does the NTSB have of getting it right? They, the NTSB did not come out and investigate the accident.

Walt

On Jul 15, 3:42*pm, Andy wrote:
On Jul 15, 7:14*am, Walt Connelly Walt.Connelly.

wrote:
I have just read the FAA final report for a glider accident with which I
am familiar. *

What does the NTSB final report say?

Andy



Is this still the case...NTSB investigators have widly varying
backgrounds, one of the nice'st NTSB folks I met had a degree in
physics and had never set foot in the front seat of any aircraft
ever...But most of the FAA folks I have met have at a minimum an: A &
P certificate and at a minimum: air crew time or at least a private
rating...is this the difference? I was at the Fitchburg airport,
being invited to take a look and when the FAA inspector arrived,
without so much as 5 min passed and he prononced "Pilot Error," it was
a horrific crash of a single engine light plane. How could he make
such a snap decision I wondered... Untill He explained..."four
adults...golf clubs...fulll tanks." you don't always have to get
eyewitness reports and measure distances and etc., because there
isn't a light single, (172, Cherokee class) that can leave the
ground...ever...that heavy!!! The NTSB people were all running around
trying to preserve the engine and being a real pain trying to justify
their own exsistance...At that moment I shared the seasoned FAA's
inspectors attitude of disgust with the beurocrats and then each
department had their own version of what happened. excuse my
spelling

On Jul 17, 6:19*am, Chris Donovan wrote:
the FAA inspector arrived,
without so much as 5 min passed and he prononced "Pilot Error," it was
a horrific crash of a single engine light plane. *How could he make
such a snap decision I wondered... Untill He explained..."four
adults...golf clubs...fulll tanks." *you don't always have to get
eyewitness reports and measure distances and etc., *because there
isn't a light single, (172, Cherokee class) that can leave the
ground...ever...that heavy!!! *

Hmm.

http://en.wikipedia.org/wiki/Cessna_172

Empty: 1691 lb
Gross: 2450 lb
Rate of climb: 721 fpm (at gross as these things are)

Useful load: 759 lb.
Fuel: 56 USgal, 212 litres ~= 170 kg, 374 lb

Four adults and golf clubs? Maybe 800 lb?

So It'll be overloaded by about 415 lb, weighing a total of about 2865
instead of 2450, or about 17% overload.

I find it very hard to believe that an aircraft that can climb at 721
fpm at gross weight can not fly at all with a 17% overload!

Use more runway, sure. Climb slower, sure. But not fly? Inconceivable.

On Jul 17, 3:09*am, Bruce Hoult wrote:
On Jul 17, 6:19*am, Chris Donovan wrote:

*the FAA inspector arrived,
without so much as 5 min passed and he prononced "Pilot Error," it was
a horrific crash of a single engine light plane. *How could he make
such a snap decision I wondered... Untill He explained..."four
adults...golf clubs...fulll tanks." *you don't always have to get
eyewitness reports and measure distances and etc., *because there
isn't a light single, (172, Cherokee class) that can leave the
ground...ever...that heavy!!! *

Hmm.

http://en.wikipedia.org/wiki/Cessna_172

Empty: 1691 lb
Gross: 2450 lb
Rate of climb: 721 fpm (at gross as these things are)

Useful load: 759 lb.
Fuel: 56 USgal, 212 litres ~= 170 kg, 374 lb

Four adults and golf clubs? Maybe 800 lb?

So It'll be overloaded by about 415 lb, weighing a total of about 2865
instead of 2450, or about 17% overload.

I find it very hard to believe that an aircraft that can climb at 721
fpm at gross weight can not fly at all with a 17% overload!

Use more runway, sure. Climb slower, sure. But not fly? Inconceivable.

It's not that simple. Using your estimated 415 Lb overload and an
estimated C172 L/D of 7 works out to need 60 pounds-force more thrust
at the airframes best L/D airspeed of roughly 65 knots. (Extra weight
divided by L/D = extra thrust required) Since the stock fixed
propeller is optimized for cruise flight, it will be operating well
off its best efficiency so that 60Lb-f of extra thrust needed to fly
will be hard to get.

Depending on the density altitude, it's entirely possible the
overloaded airplane wouldn't fly out of ground effect. It's a classic
C-172 accident scenario seen in hundreds of accidents across the
western US. This FAA inspector had probably seen way too many of them
and was feeling understandable frustration and anger.

Gross weight limits must be respected.

Bill Daniels

On Jul 17, 2:09*am, Bruce Hoult wrote:
On Jul 17, 6:19*am, Chris Donovan wrote:

*the FAA inspector arrived,
without so much as 5 min passed and he prononced "Pilot Error," it was
a horrific crash of a single engine light plane. *How could he make
such a snap decision I wondered... Untill He explained..."four
adults...golf clubs...fulll tanks." *you don't always have to get
eyewitness reports and measure distances and etc., *because there
isn't a light single, (172, Cherokee class) that can leave the
ground...ever...that heavy!!! *

Hmm.

http://en.wikipedia.org/wiki/Cessna_172

Empty: 1691 lb
Gross: 2450 lb
Rate of climb: 721 fpm (at gross as these things are)

Useful load: 759 lb.
Fuel: 56 USgal, 212 litres ~= 170 kg, 374 lb

Four adults and golf clubs? Maybe 800 lb?

So It'll be overloaded by about 415 lb, weighing a total of about 2865
instead of 2450, or about 17% overload.

I find it very hard to believe that an aircraft that can climb at 721
fpm at gross weight can not fly at all with a 17% overload!

Use more runway, sure. Climb slower, sure. But not fly? Inconceivable.

721 fpm climb rate at sea level on a standard temperature and pressure
day.
What was the Density Altitude and resulant effect on engine
performance, propellor performance and aerodynamic performance on the
wings.

Did the pilot lean on take off for high density altitude?
4 adults alone can easily top 800# additional weight, and I'd like to
see how 4 adults and 4 golf bags can fit in a C172 or PA28-180.

The effects of exceeding GW and effects of high DA can be logrithmec,
not linear in requireing more HP to climb out of ground effect.

T

On 17/07/2011 19:09, Bruce Hoult wrote:

http://en.wikipedia.org/wiki/Cessna_172

Empty: 1691 lb
Gross: 2450 lb
Rate of climb: 721 fpm (at gross as these things are)

Useful load: 759 lb.
Fuel: 56 USgal, 212 litres ~= 170 kg, 374 lb

Four adults and golf clubs? Maybe 800 lb?

Come on! Each man AND his golf clubs (up to 14 clubs, bag, balls, etc)
weighs only 200lbs total??

And nobody took a change of underpants? Deodorant? Shaving cream?
The aeroplane didn't have a fuel drain test set? A litre of oil? A
tiedown kit? Control locks? Chocks? Maps, Jeppesen, GPS? No
instruments installed? No u/c spats full of mud?

Here's what's realistic:
The 4 men and their overnight bags weighed about 400kg (880lbs)
The four bags of golf clubs (and balls, shoes, etc) weighed 40kg (88lbs)
minimum.
The fuel SG was .75 max so the fuel weighed only 160kg (say 350lbs)
The 172 was one of the vast majority with max wts of 22-2300lbs.

So It'll be overloaded by about 415 lb, weighing a total of about 2865
instead of 2450, or about 17% overload.

I do the maths differently. It was probably overloaded by between 25 -
40% and the density altitude was probably significantly above the MSL
from which it will climb at 721fpm (I love that "1").

I find it very hard to believe that an aircraft that can climb at 721
fpm at gross weight can not fly at all with a 17% overload!

Use more runway, sure. Climb slower, sure. But not fly? Inconceivable.

You're quite right, Bruce. Of course it will fly - eventually. But I
have a reasonable amount of tired 172 time behind me and I'm with the
guy from the FAA. For all practical purposes - it won't fly.

GC

On Jul 18, 6:30*am, GC wrote:
On 17/07/2011 19:09, Bruce Hoult wrote:

http://en.wikipedia.org/wiki/Cessna_172

Empty: 1691 lb
Gross: 2450 lb
Rate of climb: 721 fpm (at gross as these things are)

Useful load: 759 lb.
Fuel: 56 USgal, 212 litres ~= 170 kg, 374 lb

Four adults and golf clubs? Maybe 800 lb?

Come on! *Each man AND his golf clubs (up to 14 clubs, bag, balls, etc)
weighs only 200lbs total??

Four sets of gold clubs? OK, sure, that's a big difference. I read it
as four people and one set of clubs.

I do the maths differently. *It was probably overloaded by between 25 -
40% and the density altitude was probably significantly above the MSL
from which it will climb at 721fpm (I love that "1").

Yup, that's getting to be extremely dodgy unless you've got a runway
suitable for a 747, at sea level. I sure wouldn't try it.

I absolutely agree that you've got to take the limitations seriously,
but I do get annoyed at people who say "we'd be 10 lbs over gross
weight so we can't fly". Which I've been told multiple times, at
different places.

A lot of pilots don't seem to realize that published specifications
are huge compromises. Sure, manufacturers like to be able to advertise
high payloads, but they like to be able to quote short takeoff
distance and high rates of climb even more –*far above what is
actually necessary for many flights. Those things can be traded off
against each other, over some limited range of values.

(and of course cruise speed, service ceiling, allowed maneuvers all
come into it too)

On Jul 15, 7:14*am, Walt Connelly Walt.Connelly.
wrote:
I have just read the FAA final report for a glider accident with which I
am familiar. *The original narrative and the report itself contradict
each other to some degree. *One says the pilot was trying to land on a
perpendicular runway, the other on the reciprocal of the original runway
on which he was trying to land. *While this might not be the most earth
shaking event ever investigated by an arm of the Federal Government, it
indicates a lack of accuracy in something which should have been easy.
Does anyone care about accuracy in reporting anymore? *

We can learn from these things, but only if the reporting officials get
it right. *I will be interested in seeing the report of the 2-32 that
crashed in Montana with a DPE and a CFI-G on board. *

Walt

--
Walt Connelly

I've found that NTSB final reports leave a lot to be desired.
Locations wrong, local landmarks named wrong, just for a couple of
examples.
T