Bonanza crash caught on video

[Newps]

wrote:

>>And several Mountain Flying books mention that specifically. The
>>official temperature anywhere is always in the shade. Ever seen a
>>runway in the shade?
>
>
> The runway will no doubt have a higher temperature and the air above
> will be warmer than reported but how high would you need to fly to
> reach the reported air temperature as measured in the shade?



An irrelevant question if you can't get there in the first place. But
if you want an answer just look at the standard lapse rate as a start.

[Matt Barrow[_4_]]

"Newps" > wrote in message
. ..
>
>
> wrote:
>
>>>And several Mountain Flying books mention that specifically. The
>>>official temperature anywhere is always in the shade. Ever seen a runway
>>>in the shade?
>>
>>
>> The runway will no doubt have a higher temperature and the air above
>> will be warmer than reported but how high would you need to fly to
>> reach the reported air temperature as measured in the shade?
>
>
>
> An irrelevant question if you can't get there in the first place. But if
> you want an answer just look at the standard lapse rate as a start.

Remember, too, that a thermometer held in the sun is going to read higher
than a thermometer in the shade. What it's reading is the sunlight on skin
or a thermometer, not the air temp. That's why they takes temps in the
shade -- the heat transfer is much different.

[Morgans[_2_]]

"Dudley Henriques" > wrote in message
...
> john smith wrote:
>> Following the Palm 90 crash in Washington DC, I heard someone in aviation
>> say something to the effect that if you are not airborne within
>> 30-seconds of brake release following throttle up, abort and determine
>> why you had not reached flying speed.
>
> I wouldn't be a fan for such a rule.

Yep, way too general.

You need to have specific standards for the plane and the airport, and
follow those considerations when faced with a need to abort a takeoff.
--
Jim in NC

[Dudley Henriques[_2_]]

Morgans wrote:
> "Dudley Henriques" > wrote in message
> ...
>> john smith wrote:
>>> Following the Palm 90 crash in Washington DC, I heard someone in aviation
>>> say something to the effect that if you are not airborne within
>>> 30-seconds of brake release following throttle up, abort and determine
>>> why you had not reached flying speed.
>> I wouldn't be a fan for such a rule.
>
> Yep, way too general.
>
> You need to have specific standards for the plane and the airport, and
> follow those considerations when faced with a need to abort a takeoff.

For a T38, going into max AB from a standing start, at 30 seconds I'm
busting 10 thou at .9 mach :-))
30 seconds is a LOT of time in high performance airplanes. Time
generally is a bad data point for an abort...WAY too many variables as
you have correctly noted.


--
Dudley Henriques

[Robert M. Gary]

On Sep 13, 8:39 pm, "Morgans" > wrote:

> > I wouldn't be a fan for such a rule.
>
> Yep, way too general.
>
> You need to have specific standards for the plane and the airport, and
> follow those considerations when faced with a need to abort a takeoff.

I can just imagine the pilot sitting there on the take off roll "one
thousand one, one thousand two....".

-Robert

[Dudley Henriques[_2_]]

Robert M. Gary wrote:
> On Sep 13, 8:39 pm, "Morgans" > wrote:
>
>>> I wouldn't be a fan for such a rule.
>> Yep, way too general.
>>
>> You need to have specific standards for the plane and the airport, and
>> follow those considerations when faced with a need to abort a takeoff.
>
> I can just imagine the pilot sitting there on the take off roll "one
> thousand one, one thousand two....".
>
> -Robert
>
......and put this guy in a Lear at 30 seconds and see if he can still
see the runway behind and under him :-)))

--
Dudley Henriques

[[email protected]]

On Thu, 13 Sep 2007 19:45:44 -0700, "Matt Barrow"
> wrote:

>
>"Newps" > wrote in message
. ..
>>
>>
>> wrote:
>>
>>>>And several Mountain Flying books mention that specifically. The
>>>>official temperature anywhere is always in the shade. Ever seen a runway
>>>>in the shade?
>>>
>>>
>>> The runway will no doubt have a higher temperature and the air above
>>> will be warmer than reported but how high would you need to fly to
>>> reach the reported air temperature as measured in the shade?
>>
>>
>>
>> An irrelevant question if you can't get there in the first place. But if
>> you want an answer just look at the standard lapse rate as a start.
>
>Remember, too, that a thermometer held in the sun is going to read higher
>than a thermometer in the shade. What it's reading is the sunlight on skin
>or a thermometer, not the air temp. That's why they takes temps in the
>shade -- the heat transfer is much different.
>

That is the reason for my question.

Surely standard lapse rate does not apply?

I'm wondering if the ground temperature will reduce quickly as you
climb. In other words will the air temperature drop quickly as you
leave ground effect or will it continue for many tens of feet?
I presume if there's any cross wind the hotter air above the runway
will drift sideways so maybe the effect will be less..

[Peter Dohm]

> wrote in message
...
> On Thu, 13 Sep 2007 19:45:44 -0700, "Matt Barrow"
> > wrote:
>
> >
> >"Newps" > wrote in message
> . ..
> >>
> >>
> >> wrote:
> >>
> >>>>And several Mountain Flying books mention that specifically. The
> >>>>official temperature anywhere is always in the shade. Ever seen a
runway
> >>>>in the shade?
> >>>
> >>>
> >>> The runway will no doubt have a higher temperature and the air above
> >>> will be warmer than reported but how high would you need to fly to
> >>> reach the reported air temperature as measured in the shade?
> >>
> >>
> >>
> >> An irrelevant question if you can't get there in the first place. But
if
> >> you want an answer just look at the standard lapse rate as a start.
> >
> >Remember, too, that a thermometer held in the sun is going to read higher
> >than a thermometer in the shade. What it's reading is the sunlight on
skin
> >or a thermometer, not the air temp. That's why they takes temps in the
> >shade -- the heat transfer is much different.
> >
>
> That is the reason for my question.
>
> Surely standard lapse rate does not apply?
>
> I'm wondering if the ground temperature will reduce quickly as you
> climb. In other words will the air temperature drop quickly as you
> leave ground effect or will it continue for many tens of feet?
> I presume if there's any cross wind the hotter air above the runway
> will drift sideways so maybe the effect will be less..

IIRC, there is a large difference within the first few feet, and the first
few tens of feet; but I don't recall what stardard there might be, nor the
effects of wind and ground clutter. Logically, everything would have some
influence...

Peter

[Matt Barrow[_4_]]

> wrote in message
...
> On Thu, 13 Sep 2007 19:45:44 -0700, "Matt Barrow"
> > wrote:
>>> An irrelevant question if you can't get there in the first place. But
>>> if
>>> you want an answer just look at the standard lapse rate as a start.
>>
>>Remember, too, that a thermometer held in the sun is going to read higher
>>than a thermometer in the shade. What it's reading is the sunlight on skin
>>or a thermometer, not the air temp. That's why they takes temps in the
>>shade -- the heat transfer is much different.
>>
>
> That is the reason for my question.
>
> Surely standard lapse rate does not apply?

SLR is only a _standard_ rate. It can be effected by pressure, inversions,
wind, even the terrain. In this latter point, it's probably nullified in
the first hundred or so feet.

>
> I'm wondering if the ground temperature will reduce quickly as you
> climb.
That would depend on several factors including those mentioned above. A wind
shear would probably have a great effect.

> In other words will the air temperature drop quickly as you
> leave ground effect or will it continue for many tens of feet?

Ground effect can be ten feet, or a few hundred. It would be different if
the runway surface was asphalt as opposed to concrete (different albedo).

> I presume if there's any cross wind the hotter air above the runway
> will drift sideways so maybe the effect will be less..

Possibly, but it would depend on the wind SPEED.


--
Matt Barrow
Performance Homes, LLC.
Cheyenne, WY

[[email protected]]

>
> My guess, from watching the video and hearing about the number of people
> aboard, was that the aircraft was overloaded. And the only reason anyone died
> was probably that the plane flipped over, otherwise they might have all walked
> away from it.

Why guess when you can fire up your simulator and tell us exactly what
happens at 107 F and 230 lbs overweight at Cameron park with a
tailwind? ;)

[[email protected]]

On Fri, 14 Sep 2007 10:51:07 -0700, "Matt Barrow"
> wrote:

>
> wrote in message
...
>> On Thu, 13 Sep 2007 19:45:44 -0700, "Matt Barrow"
>> > wrote:
>>>> An irrelevant question if you can't get there in the first place. But
>>>> if
>>>> you want an answer just look at the standard lapse rate as a start.
>>>
>>>Remember, too, that a thermometer held in the sun is going to read higher
>>>than a thermometer in the shade. What it's reading is the sunlight on skin
>>>or a thermometer, not the air temp. That's why they takes temps in the
>>>shade -- the heat transfer is much different.
>>>
>>
>> That is the reason for my question.
>>
>> Surely standard lapse rate does not apply?
>
>SLR is only a _standard_ rate. It can be effected by pressure, inversions,
>wind, even the terrain. In this latter point, it's probably nullified in
>the first hundred or so feet.
>
>>
>> I'm wondering if the ground temperature will reduce quickly as you
>> climb.
>That would depend on several factors including those mentioned above. A wind
>shear would probably have a great effect.
>
>> In other words will the air temperature drop quickly as you
>> leave ground effect or will it continue for many tens of feet?
>
>Ground effect can be ten feet, or a few hundred. It would be different if
>the runway surface was asphalt as opposed to concrete (different albedo).
>
>> I presume if there's any cross wind the hotter air above the runway
>> will drift sideways so maybe the effect will be less..
>
>Possibly, but it would depend on the wind SPEED.

I am not pre-judging the cause of the accident but there has been
mention of high temperature above the runway causing a higher density
altitued than perhaps calculated. Since I usaully fly in a low level
and colder climate (UK) where density altitude is mostly of little
importance I was interested in the effects. My only experience is from
a long runways in Palm Springs (100°F) and Minden (near Tahoe) with
runway around 5000ft and maybe 80°F.

From comments it would appear that at take-off density altitude may be
higher than expected but soon after take-off your density altitude
would reduce quite quickly.

Re. Ground Effect, I thought that was normally within about one
wingspan?

Thanks for the input.

[Matt Barrow[_4_]]

> wrote in message
...
> On Fri, 14 Sep 2007 10:51:07 -0700, "Matt Barrow"
> > wrote:

>>
>>Possibly, but it would depend on the wind SPEED.
>
> I am not pre-judging the cause of the accident but there has been
> mention of high temperature above the runway causing a higher density
> altitued than perhaps calculated. Since I usaully fly in a low level
> and colder climate (UK) where density altitude is mostly of little
> importance I was interested in the effects. My only experience is from
> a long runways in Palm Springs (100°F) and Minden (near Tahoe) with
> runway around 5000ft and maybe 80°F.
>
> From comments it would appear that at take-off density altitude may be
> higher than expected but soon after take-off your density altitude
> would reduce quite quickly.
>
> Re. Ground Effect, I thought that was normally within about one
> wingspan?
>
> Thanks for the input.

Correct - one wingspan; my brain did a fart and I was thinking of the
thermals you can start picking up within a couple hundred feet when the sun
shines onto the ground at higher altitudes. It's not ground effect, and it
dissipates quickly at altitude.

[Roger (K8RI)]

On Thu, 13 Sep 2007 20:24:39 -0600, Newps > wrote:

>
>
wrote:
>
>>>And several Mountain Flying books mention that specifically. The
>>>official temperature anywhere is always in the shade. Ever seen a
>>>runway in the shade?
>>
>>
>> The runway will no doubt have a higher temperature and the air above
>> will be warmer than reported but how high would you need to fly to
>> reach the reported air temperature as measured in the shade?
>
>
>
>An irrelevant question if you can't get there in the first place. But
>if you want an answer just look at the standard lapse rate as a start.

Even with a light breeze you should be out of the rising, high
temperature air in 30 to 50 feet unless the breeze is right down the
runway. (or if it's calm)

Roger (K8RI)

[Roger (K8RI)]

On Thu, 13 Sep 2007 21:23:08 -0400, john smith >
wrote:

>Following the Palm 90 crash in Washington DC, I heard someone in
>aviation say something to the effect that if you are not airborne within
>30-seconds of brake release following throttle up, abort and determine
>why you had not reached flying speed.

30 Seconds? I'd be in the shopping center IF I could make it through
the brush and airport fence...and jump the ditch...and through traffic
on a 5-lane road. Even in my 48 year old plane it would have become
blatantly obvious well before 30 seconds.

Roger (K8RI)

[[email protected]]

On Fri, 14 Sep 2007 23:58:42 -0400, "Roger (K8RI)"
> wrote:

>On Thu, 13 Sep 2007 20:24:39 -0600, Newps > wrote:
>
>>
>>
wrote:
>>
>>>>And several Mountain Flying books mention that specifically. The
>>>>official temperature anywhere is always in the shade. Ever seen a
>>>>runway in the shade?
>>>
>>>
>>> The runway will no doubt have a higher temperature and the air above
>>> will be warmer than reported but how high would you need to fly to
>>> reach the reported air temperature as measured in the shade?
>>
>>
>>
>>An irrelevant question if you can't get there in the first place. But
>>if you want an answer just look at the standard lapse rate as a start.
>
>Even with a light breeze you should be out of the rising, high
>temperature air in 30 to 50 feet unless the breeze is right down the
>runway. (or if it's calm)
>
>Roger (K8RI)

That's the direction of my thinking so this incident it may not be a
simple density altitude problem. I hope I never have a problem like
this guy. The worst experience I had was a 500m grass runway in a
Warrior with 3 people (not too heavy) and half fuel. I was used to
grass but this was about 8" and the fence looked quite close on
take-off :-( After that I was over water. Made me think more about
soft-field take-off which I now practice frequently even with a 6000ft
runway!

[Newps]

wrote:


>
> That's the direction of my thinking so this incident it may not be a
> simple density altitude problem. I hope I never have a problem like
> this guy. The worst experience I had was a 500m grass runway in a
> Warrior with 3 people (not too heavy) and half fuel. I was used to
> grass but this was about 8" and the fence looked quite close on
> take-off :-( After that I was over water. Made me think more about
> soft-field take-off which I now practice frequently even with a 6000ft
> runway!

A soft field may not be the best takeoff strategy there. Was it soft or
was it short or both? Also it's very common that when launching over
water you better have a healthy margin above the stall as downdrafts are
common.

[[email protected]]

On Sat, 15 Sep 2007 11:39:27 -0600, Newps > wrote:

>
>
wrote:
>
>
>>
>> That's the direction of my thinking so this incident it may not be a
>> simple density altitude problem. I hope I never have a problem like
>> this guy. The worst experience I had was a 500m grass runway in a
>> Warrior with 3 people (not too heavy) and half fuel. I was used to
>> grass but this was about 8" and the fence looked quite close on
>> take-off :-( After that I was over water. Made me think more about
>> soft-field take-off which I now practice frequently even with a 6000ft
>> runway!
>
>A soft field may not be the best takeoff strategy there. Was it soft or
>was it short or both? Also it's very common that when launching over
>water you better have a healthy margin above the stall as downdrafts are
>common.

Short and long grass (500m = 1640ft).
I realised on the take-off run I was not gaining speed as fast as I
expected, due to the long grass. At that time I hadn't initially
appreciated the drag with very long grass and should have pulled the
nose up much more agressively sooner. Training on hard runways is
quite different to real life situations! It was over ten years ago but
a lesson remembered :-)