Twin take off on one engine?

On Sun, 30 Aug 2009 19:40:51 -0400, Peter Dohm wrote:

then the questions would center on the preflight calculations
regaerding density altitude, gradient, distance to obstacles,


If you Google Earth CYFD you'll see it's 98% farmland, except off RWY 11
about 3,000 feet, there's looks to be a small stand of pine trees.

This is still a weird crash... Why couldn't he continue his take off with
one engine and 3,000 feet?... Why couldn't he bank a little to the left
and avoid the trees in favor of some pretty nice uncultivated farmland?

--
Dallas

Aztec crash.
Vr is 70mph. Vmc is 80mph. Vy is 120mph.

The latest article said he knew he had an engine out and was taking
off single engine. Prop wouldn't be feathered because you can't
feather Piper twins on the ground after the engine is dead; you need
800rpm.

Best effort takeoff with 25 degrees flaps, 2 engines, he'd need around
1200' to clear 50' obstacle. No flaps for him because it's too much
drag, so add 50%. Half the engine power is gone, so assuming no loss
to lift, you'd still take twice as long to accelerate. That's 3600'.

What sort of climb should he expect? Best climb at 120mph at sea level
will be about 250fpm. Sub out 50fpm for being 815' MSL Plus 50'
obstacle. Assume he was at 4000lbs and add 150fpm. So, call it 350fpm
at 120mph clean (gear up, prop feathered).

At Vr, he's not going to climb out of ground effect. With gear down,
he's not going to get out of ground effect. With an unfeathered prop
he's not going to get out of ground effect. He's have to hug ground
effect for best acceleration, as pulling up too much would induce too
much drag.

Assuming he had all of that resolved, you'd still have to factor in
the distance to get to a climbing airspeed. Vyse of 120 means he
probably could expect climb performance at about 100 or 105mph. Based
on a whole lot of best case assumptions, you've still chewed up the
entire 5000' runway just to get to some minimum climb speed.

Add in best practices of abort if not climbing by 2/3 down the runway,
and another 25% distance because it's obviously not in new condition,
he shouldn't have attempted such a takeoff, even on a ferry flight,
unless he had 9000' to go with.

Even so, the POH says that if you haven't gotten to within 5mph of
Vyse before the engine fails, that you should abort the takeoff, even
if you're in the air. "Power to idle, land straight ahead."


747 single engine takeoff
Can it fly on 1 engine? Yes. Can it maintain altitude? Maybe. Can
it take off? If it were stripped, light on fuel, maybe.

The Boeing 747 has four turbofans. 4-engine transport category
aircraft are required to demonstrate a 3% positive gradient with an
engine out and gear up.

BEW is about half of MGW on a 747. Parasite drag is 2.2%, and you're
looking at around 150% engine power for climb. But there would be
more induced drag from the rudder pressures, so you might have to
strip the plane and unload 2 of the engine pods. Boeing might also go
past the mins, or use derated engines, so you this might all be
doable. Even so, you'd probably need 5 miles to accelerate to V2.

With passengers, landing fuel, cargo, luggage, SEATS, single engine,
max power, you're still descending.

That's all hypothetical though. A decent flight sim could probably
test this with some model tweaks. AA's sim center could probably test
this. Boeing might have some calculations for this on file somewhere.

On Tue, 15 Sep 2009 19:02:38 -0700 (PDT), JDS Davis wrote in
:

Aztec crash.

... The latest article said he knew he had an engine out and was taking
off single engine. ...

Do you have a link to the latest article?

A reference?

Marty
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On Tue, 15 Sep 2009 19:02:38 -0700 (PDT), JDS Davis wrote in
:

... The latest article said he knew he had an engine out and was taking
off single engine. ...

OK. I went looking for the latest article myself:

http://www.brantford.com/news.cfm?pa...articleId=4997

Published: Thu, 27 Aug 2009 by Tom Kennedy

The Transport Safety Board of Canada yesterday concluded its
investigation into a plane crash which occurred at Brantford
Municipal Airport on Monday afternoon [24 Aug 2009].

The investigation finished yesterday as TSB officials determined the
reason for the crash was not an unavoidable malfunction.

On the contrary, TSB’s senior regional investigator Peter Rowntree
said the pilot, Peter VanBerlo of Simcoe, had attempted to take off
from the Brantford airport with the knowledge that one of his
engines was not working.

VanBerlo’s twin engine Aztec Piper was down one engine when he
attempted to take off and, Rowntree said, he subsequently clipped a
line of evergreen trees on the edge of the runway and caused
irreparable damage to the plane causing him to crash in a cornfield
bordering the western side of the airport.

Rowntree said while it isn’t uncommon for pilots to fly with one
engine, it is very dangerous to attempt a takeoff.

“It’s not wise to take off in a two-engine aircraft when only one is
working,” he said.

The crash happened at around 5 p.m. Monday and Brant County OPP,
Brantford police and fire and ambulance crews were on scene but
VanBerlo only suffered minor injuries to his head and was released
from hospital the following day.

==== end quote ====

http://www.avcanada.ca/forums2/viewtopic.php?f=54&t=57597&sid=9217e1945ec9b5c6483 3597ab6e50812&start=25

A09O0179: The privately owned Piper PA23-250, registration C-FGAZ,
arriving from the United States stopped in Brantford to clear
customs before continuing to his private strip. When the pilot was
preparing to depart Brantford, he was unable to get to the right
engine to start. The pilot elected to attempt a single engine
takeoff from runway 23. During the take off roll the pilot was
unable to maintain direction control and the aircraft departed the
right side of the runway just prior to the intersection of taxiway
echo and runway 23. The aircraft struck a taxiway light and
continued across the taxiway becoming airborne. The aircraft began a
slow climb, but was unable to clear trees at the edge of the airport
property. The aircraft's right wing struck a tree approximately 20
feet from the ground severing the outboard portion of the right
wing. The aircraft crashed into a cornfield approximately 300 feet
beyond the tree and was substantially damaged. The pilot was the
only occupant on board and received minor injuries.

==== end quote ====

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Dallas wrote:
I'm wondering if it's legal? I'm referring to a recent crash where the
pilot decided to take off on one engine and clipped a tree.

Looking over 91.205, you can't take off with out a magnetic compass.. but
it doesn't say anything about one engine out of two.


He violated 91.13a, careless and reckless operation endangering the life
or property of another, unless he owned the aircraft, the crash site,
and the tree.

Curt

You could probably do it in a skymaster. We had a 58 barron loose one
engine and was almost impossible to taxi. No was you could take off. Legal
or not

Clark wrote

Considering a 747 has been fairied on one engine

I doubt that very seriously. You probably meant to say "with one
engine inop". BTW, it's called "ferried", past tense of "ferry".

I imagine that under the right circumstances a twin might legally
depart on one engine.

If the FAA would issue a "Ferry Permit", also doubtful.

Bob Moore
ATP B-707, B-727
CFI ASEL-IA

Robert Moore wrote:
Clark wrote

Considering a 747 has been fairied on one engine

I doubt that very seriously. You probably meant to say "with one
engine inop". BTW, it's called "ferried", past tense of "ferry".

I imagine that under the right circumstances a twin might legally
depart on one engine.

If the FAA would issue a "Ferry Permit", also doubtful.

Bob Moore
ATP B-707, B-727
CFI ASEL-IA

In the early days of the 747, one arrived at London Heathrow with one
engine silent. Not only silent, but missing....

Brian W

"Clark" wrote in message
...
Robert Moore wrote in
.247:

Clark wrote

Considering a 747 has been fairied on one engine

I doubt that very seriously. You probably meant to say "with one
engine inop". BTW, it's called "ferried", past tense of "ferry".

Doubt it all you like. Your doubt won't change the fact that it occurred.
The
aircraft was grounded at some eastern Europe airport with three dead
engines
and it turned out to be feasible and cheaper to fly the plane to
maintenance
rather than bring the maintenance to the plane. I believe it was written
up
in Flying magazine.



Seems unlikely that a 747 could even take off on one engine. Maybe if the
runway was 10 miles long.

On Aug 31, 11:35*am, Clark wrote:
Robert Moore wrote 85.247:

Clark wrote

Considering a 747 has been fairied on one engine

I doubt that very seriously. You probably meant to say "with one
engine inop". BTW, it's called "ferried", past tense of "ferry".

Doubt it all you like. Your doubt won't change the fact that it occurred. The
aircraft was grounded at some eastern Europe airport with three dead engines
and it turned out to be feasible and cheaper to fly the plane to maintenance
rather than bring the maintenance to the plane. I believe it was written up
in Flying magazine.

Sorry you don't get the joke of a single engine operative 747 imitating a
fairy.



I imagine that under the right circumstances a twin might legally
depart on one engine.

If the FAA would issue a "Ferry Permit", also doubtful.

Let's see here now. It's happened in the past and somehow it's doubtful that
it'll happen again. Hmmm, can't agree with you there.



Bob Moore
ATP B-707, B-727
CFI ASEL-IA

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According to the data I can find, the 747 can't climb on one engine so
how can it take off?
Cheers