Scary story about landing on a Lake Tahoe golf course

re https://youtu.be/BBpqvPujZgM


In my opinion, this video shows the difference in training between a power pilot and a glider pilot. A glider pilot in a similar situation (eg being low and not finding lift) would have remained close to one of the excellent large grass fields immediately visible in the video. A glider pilot would not have attempted to continue further without keeping another good field within reach. Once close to a airport, a glider pilot would not have attempted to fly a normal pattern, once a runway could be reached with an early turn in. A glider pilot would not have chosen to extend his downwind, for no obvious purpose, to place a highway between him and the runway. To summarize: a glider pilot would have calmly landed in a large grass field, and would not have made a panicky gear-up landing in a crop field.

On Monday, August 3, 2020 at 12:02:38 AM UTC-4, wrote:
re https://youtu.be/BBpqvPujZgM


In my opinion, this video shows the difference in training between a power pilot and a glider pilot. A glider pilot in a similar situation (eg being low and not finding lift) would have remained close to one of the excellent large grass fields immediately visible in the video. A glider pilot would not have attempted to continue further without keeping another good field within reach. Once close to a airport, a glider pilot would not have attempted to fly a normal pattern, once a runway could be reached with an early turn in. A glider pilot would not have chosen to extend his downwind, for no obvious purpose, to place a highway between him and the runway. To summarize: a glider pilot would have calmly landed in a large grass field, and would not have made a panicky gear-up landing in a crop field.

With the engine only partly running, how long will it take the P-51 to lower the landing gear? How long to lower the landing gear manually?

On Sun, 2 Aug 2020 13:40:28 -0700, Eric Greenwell
wrote:

The tighter turn works for gliders after a rope break, so I'm thinking (as did
Paul B), it would work for the P51 pilot.

There is an optimum bank for minimizing the loss of altitude (and he did have some
altitude). Had he turned tighter (about 40 degrees typically), he would have made
it further around the turn than making a wide turn. Yes, initially he would be a
bit lower, but his greater turn rate would more than compensates for that, and he
can get back some of the that altitude when he stops turning and slows down.

Hi Eric,

From the video one can clearly see that his energy is barely enough to
cross the extended center line, including the flare. Definitely not
enough energy to make a turn, not to mention to drop the gear.


Let's do some maths:
When he started the turn to base leg he was between 250 and 350 ft AGL
(depending on his altimeter settings) and 150 mph.

P-51D stall speed clean: 100 mph, hence stall speed at 40 degreed
bank: 114 mph .

So, if he had flown a perfect approach at 120 MPH and 40 degrees of
bank, he would have had a turn diameter of 2305 ft, resulting in a
flight path distance of 3620 ft.

Having an altitude of 350 ft AGL, this would have needed an L/D of
10.3, with 250 ft he would have needed 14.5.

At 175 mph the L/D of the P-51D is 15:1, prop in high pitch. Close to
the stall speed L/D is an estimated 30 percent less, hence 10:1.
Propellor in low pitch will further reduce this number. I found no
numbers on the influence of open cooling flaps.
Let's assume an L/D of 10:1 for now (from the video probably a lot
lower).


Hence, the pilot might have had the chance to complete his turn if all
his factors had been in his favour, but even under these circulstances
he would not have had the energy to extend the gear. He didn't have
the altitude to extend it over the runway after the turn, and
extending it during the turn would have affected his L/D so much that
a crash was unavoidable.


If he had run out of energy (altitude and/or speed) in the last phase
of the turn, he would have definitely crashed, directly in front of
him the M-11 motorway, his flightpath still pointing at the thousands
of spectators. Hardly survivable.



Conclusion:
This landing is a perfect example of getting one's priorities right:

Fly the plane to a safe controlled landing instead of trying to get
back to the airfield, risking a probably deadly crash if only the
slightest thing goes wrong.


Cheers
Andreas

On Sun, 2 Aug 2020 21:02:36 -0700 (PDT), wrote:


re https://youtu.be/BBpqvPujZgM


In my opinion, this video shows the difference in training between a power pilot and a glider pilot. A glider pilot in a similar situation (eg being low and not finding lift) would have remained close to one of the excellent large grass fields immediately visible in the video. A glider pilot would not have attempted to continue further without keeping another good field within reach. Once close to a airport, a glider pilot would not have attempted to fly a normal pattern, once a runway could be reached with an early turn in. A glider pilot would not have chosen to extend his downwind, for no obvious purpose, to place a highway between him and the runway. To summarize: a glider pilot would have calmly landed in a large grass field, and would not have made a panicky gear-up landing in a crop field.

Jut out of interest:
How many hours in the P-51D do you have that you are able to transfer
glider tactice to a fighter aircraft?


I have none, but I am extremely sure that you don't simply land a
P-51D on a field with extended gear without damage...

Cheers
Andreas

On Sun, 02 Aug 2020 03:39:34 -0700, Paul B wrote:

Great video, there are couple of questions I would ask though.

1) Why did he not turn much tighter to return to the airfield, one
looses much less height in a tight turn that a shallow one? From a tight
turn he might have been able to land downwind. Of course I do not know
what the winds were, or how feasible is to land P-51 downwind.

2) Why did he cross the highway, surely he could have turned base
halfway down the strip and have enough runway to stop.

I thought I'd posted this a day ago, but it evidently didn't make it to
the newsgroup somehow.

I've been to airshows at Duxford, flown gliders past it, flown from there
in a Tiger Moth, and driven past it on the M.11 many times, so I have
some small knowledge of the area. Here's my take:

The formation was joining up on the far side of the motorway when the
P-51s engine had its tizzy. Look at a map or a satpic of the airfield -
the M.11 is almost glued to the east (departure) end of the runway. When
that part of the M.11 was built they chopped 1200ft off the Eastern end
of the runway to keep the road straight.

From the vid it looks as though the formation was joining up a bit North
of the centre line, possibly somewhere near Wittlesford, so when the
engine hiccuped the second time, setting up a left-hand circuit on the
north of the airfield must have looked good. The south side has no
obstacles but (a) it makes the circuit quite a bit longer and (b) it
would have meant crossing the departure end of an active runway.

Turning in early: that would have meant crossing a row of large hangars
and the airshow spectators, which were all along the northern side of the
airfield. In the UK at least, the rules are clear: you DO NOT overfly a
crowd of people below 1000ft AGL under any circumstances - and the P-51
was below that with a dead engine by the time he was past the M.11.

As I said: bring up Duxford Airfield on Google Earth or Google Maps,
compare that with the video shot from the P-51 and draw your own
conclusions.


--
Martin | martin at
Gregorie | gregorie dot org

On Monday, August 3, 2020 at 6:38:25 PM UTC-7, Martin Gregorie wrote:
On Sun, 02 Aug 2020 03:39:34 -0700, Paul B wrote:

Great video, there are couple of questions I would ask though.

1) Why did he not turn much tighter to return to the airfield, one
looses much less height in a tight turn that a shallow one? From a tight
turn he might have been able to land downwind. Of course I do not know
what the winds were, or how feasible is to land P-51 downwind.

2) Why did he cross the highway, surely he could have turned base
halfway down the strip and have enough runway to stop.

I thought I'd posted this a day ago, but it evidently didn't make it to
the newsgroup somehow.

I've been to airshows at Duxford, flown gliders past it, flown from there
in a Tiger Moth, and driven past it on the M.11 many times, so I have
some small knowledge of the area. Here's my take:

The formation was joining up on the far side of the motorway when the
P-51s engine had its tizzy. Look at a map or a satpic of the airfield -
the M.11 is almost glued to the east (departure) end of the runway. When
that part of the M.11 was built they chopped 1200ft off the Eastern end
of the runway to keep the road straight.

From the vid it looks as though the formation was joining up a bit North
of the centre line, possibly somewhere near Wittlesford, so when the
engine hiccuped the second time, setting up a left-hand circuit on the
north of the airfield must have looked good. The south side has no
obstacles but (a) it makes the circuit quite a bit longer and (b) it
would have meant crossing the departure end of an active runway.

Turning in early: that would have meant crossing a row of large hangars
and the airshow spectators, which were all along the northern side of the
airfield. In the UK at least, the rules are clear: you DO NOT overfly a
crowd of people below 1000ft AGL under any circumstances - and the P-51
was below that with a dead engine by the time he was past the M.11.

As I said: bring up Duxford Airfield on Google Earth or Google Maps,
compare that with the video shot from the P-51 and draw your own
conclusions.


--
Martin | martin at
Gregorie | gregorie dot org

What does a P51 have to do with soaring? There are other newsgroups that deal with warbirds.

On Monday, August 3, 2020 at 8:54:22 PM UTC-5, 2G wrote:
On Monday, August 3, 2020 at 6:38:25 PM UTC-7, Martin Gregorie wrote:
On Sun, 02 Aug 2020 03:39:34 -0700, Paul B wrote:

Great video, there are couple of questions I would ask though.

1) Why did he not turn much tighter to return to the airfield, one
looses much less height in a tight turn that a shallow one? From a tight
turn he might have been able to land downwind. Of course I do not know
what the winds were, or how feasible is to land P-51 downwind.

2) Why did he cross the highway, surely he could have turned base
halfway down the strip and have enough runway to stop.

I thought I'd posted this a day ago, but it evidently didn't make it to
the newsgroup somehow.

I've been to airshows at Duxford, flown gliders past it, flown from there
in a Tiger Moth, and driven past it on the M.11 many times, so I have
some small knowledge of the area. Here's my take:

The formation was joining up on the far side of the motorway when the
P-51s engine had its tizzy. Look at a map or a satpic of the airfield -
the M.11 is almost glued to the east (departure) end of the runway. When
that part of the M.11 was built they chopped 1200ft off the Eastern end
of the runway to keep the road straight.

From the vid it looks as though the formation was joining up a bit North
of the centre line, possibly somewhere near Wittlesford, so when the
engine hiccuped the second time, setting up a left-hand circuit on the
north of the airfield must have looked good. The south side has no
obstacles but (a) it makes the circuit quite a bit longer and (b) it
would have meant crossing the departure end of an active runway.

Turning in early: that would have meant crossing a row of large hangars
and the airshow spectators, which were all along the northern side of the
airfield. In the UK at least, the rules are clear: you DO NOT overfly a
crowd of people below 1000ft AGL under any circumstances - and the P-51
was below that with a dead engine by the time he was past the M.11.

As I said: bring up Duxford Airfield on Google Earth or Google Maps,
compare that with the video shot from the P-51 and draw your own
conclusions.


--
Martin | martin at
Gregorie | gregorie dot org

What does a P51 have to do with soaring? There are other newsgroups that deal with warbirds.

O.P. of the P51 video clearly stated this might be useful to Tow Pilots "power loss in a tug" Also, I understand sometimes gliders are equipped with engines, which sometimes fail. I found the video useful as a cautionary tale of procedures and pilot responses to a rapidly deteriorating flight event.
I know that I will not live or fly long enough to learn these lessons on my own.
I'm happy to learn from pilots regardless of what they may have been flying..
Thanks to all the Tow Pilots and their contribution to Soaring.
Respect,
Scott

"Conclusion:
This landing is a perfect example of getting one's priorities right"

Yes, but only in the last 5 seconds of the flight. Right before he aborted the left hand turn, he was going to land on the strip. That was his plan.

My point is that he should have turned before he reached the freeway. Not necessarily when it was all happening, I am aware of the pressure that he was under.

However he clearly was desperate to make the runway and that mistake, to me, was a teaching moment. He did allude to the fact that a disabled aircraft is simply a tool dissipate energy, but did not discussed the fact that he was trying to reach the runway when he should not have.

Also, Martin G, from the video and the topology, his downwind was to the south of the airfield, flying West to East (approx), otherwise a left hand turn could not take him across the freeway. And as you have noted there are no obstacles or crowds on that side. So he had choices.

To reiterate, I am NOT discussing his performance during the event. I know nothing about flying P-51 etc.

I am only discussing the debrief.

Cheers

Paul







On Tuesday, 4 August 2020 10:34:35 UTC+10, Andreas Maurer wrote:
On Sun, 2 Aug 2020 13:40:28 -0700, Eric Greenwell
wrote:

The tighter turn works for gliders after a rope break, so I'm thinking (as did
Paul B), it would work for the P51 pilot.

There is an optimum bank for minimizing the loss of altitude (and he did have some
altitude). Had he turned tighter (about 40 degrees typically), he would have made
it further around the turn than making a wide turn. Yes, initially he would be a
bit lower, but his greater turn rate would more than compensates for that, and he
can get back some of the that altitude when he stops turning and slows down.

Hi Eric,

From the video one can clearly see that his energy is barely enough to
cross the extended center line, including the flare. Definitely not
enough energy to make a turn, not to mention to drop the gear.


Let's do some maths:
When he started the turn to base leg he was between 250 and 350 ft AGL
(depending on his altimeter settings) and 150 mph.

P-51D stall speed clean: 100 mph, hence stall speed at 40 degreed
bank: 114 mph .

So, if he had flown a perfect approach at 120 MPH and 40 degrees of
bank, he would have had a turn diameter of 2305 ft, resulting in a
flight path distance of 3620 ft.

Having an altitude of 350 ft AGL, this would have needed an L/D of
10.3, with 250 ft he would have needed 14.5.

At 175 mph the L/D of the P-51D is 15:1, prop in high pitch. Close to
the stall speed L/D is an estimated 30 percent less, hence 10:1.
Propellor in low pitch will further reduce this number. I found no
numbers on the influence of open cooling flaps.
Let's assume an L/D of 10:1 for now (from the video probably a lot
lower).


Hence, the pilot might have had the chance to complete his turn if all
his factors had been in his favour, but even under these circulstances
he would not have had the energy to extend the gear. He didn't have
the altitude to extend it over the runway after the turn, and
extending it during the turn would have affected his L/D so much that
a crash was unavoidable.


If he had run out of energy (altitude and/or speed) in the last phase
of the turn, he would have definitely crashed, directly in front of
him the M-11 motorway, his flightpath still pointing at the thousands
of spectators. Hardly survivable.



Conclusion:
This landing is a perfect example of getting one's priorities right:

Fly the plane to a safe controlled landing instead of trying to get
back to the airfield, risking a probably deadly crash if only the
slightest thing goes wrong.


Cheers
Andreas

On Sunday, August 2, 2020 at 9:02:38 PM UTC-7, wrote:
re https://youtu.be/BBpqvPujZgM


In my opinion, this video shows the difference in training between a power pilot and a glider pilot. A glider pilot in a similar situation (eg being low and not finding lift) would have remained close to one of the excellent large grass fields immediately visible in the video. A glider pilot would not have attempted to continue further without keeping another good field within reach. Once close to a airport, a glider pilot would not have attempted to fly a normal pattern, once a runway could be reached with an early turn in. A glider pilot would not have chosen to extend his downwind, for no obvious purpose, to place a highway between him and the runway. To summarize: a glider pilot would have calmly landed in a large grass field, and would not have made a panicky gear-up landing in a crop field.


This discussion is useful, and should not be regarded as a criticism of the pilot. Such discussions remind me of the description of an accident enquiry, as "six people taking six months to decide what the pilot should have done in six seconds".

On Mon, 03 Aug 2020 22:01:17 -0700, Paul B wrote:

Also, Martin G, from the video and the topology, his downwind was to the
south of the airfield, flying West to East (approx), otherwise a left
hand turn could not take him across the freeway. And as you have noted
there are no obstacles or crowds on that side. So he had choices.

Yes, you're right - after reviewing the start of the video a few times I
now see that I was 180 out of sync. He was turning to base when he
crossed the M.11, and then realised that he wasn't going to make the
runway, which would have required crossing the road a second time and put
it down parallel to road.


--
Martin | martin at
Gregorie | gregorie dot org