Max Weight of Non Lift Producing Components

Le jeudi 30 novembre 2017 05:39:23 UTC+1, a écritÂ*:
From the BGA:

5. Non-Lifting Parts. For sailplanes where the Leading Particulars specify a maximum weight
of non-lifting parts, it will additionally be necessary to weigh the wings to enable the weight of the
fuselage and tailplane to be calculated; this is the empty weight of non-lifting parts.


I can't say what the significance of exceeding the max would be, but from general life experience exceeding the max of anything is usually a bad idea.

RC

Exeeding max weight of non-lifting parts makes you exceeding the structural limits of the plane (i.e. you start eating up the safety factor of 1.5), which is generally acknowledged as being a fairly stupid idea.

MTOW is not really connected to max weight of non-lifting parts.

While studying for my Flight Engineer license back in the 70s (do they
have Flight Engineers any more?), it was explained that the max weight
of non lifting components had to do with the strength (bending moments)
of the wing spar.Â* Help us out here, Steve L.

MTOW has, I believe, to do with landing gear, brakes, tires, etc. Think
MV**2 during an aborted takeoff.Â* Higher weight - higher takeoff speed
- WAY higher energy to dissipate, that V squared component.

On 11/30/2017 2:40 AM, Tango Whisky wrote:
Le jeudi 30 novembre 2017 05:39:23 UTC+1, a écritÂ*:
From the BGA:

5. Non-Lifting Parts. For sailplanes where the Leading Particulars specify a maximum weight
of non-lifting parts, it will additionally be necessary to weigh the wings to enable the weight of the
fuselage and tailplane to be calculated; this is the empty weight of non-lifting parts.


I can't say what the significance of exceeding the max would be, but from general life experience exceeding the max of anything is usually a bad idea.

RC
Exeeding max weight of non-lifting parts makes you exceeding the structural limits of the plane (i.e. you start eating up the safety factor of 1.5), which is generally acknowledged as being a fairly stupid idea.

MTOW is not really connected to max weight of non-lifting parts.

--
Dan, 5J

I believe you are correct, you don't want to overload the spar with fuselage weight, thus, spread it out through the wings.
I know some ships had water in the wings but also additional in a tank in the fuselage to get the wing loading up due to low volume wings. You would load the wings, then finish off with the fuselage. Dumping ballast is fuselage first, then wings.

As to MTOW, some larger aircraft also have a MLW, max landing weight which I believe is mostly due to loads when the mains hit the runway.
So, some aircraft can take off at a higher weight than they can land! So, if they run into an issue, they may have to fly around to burn fuel off to get within landing weight, or even dump fuel (don't tell the EPA!).

Screw the EPA!Â* When I was doing engine out maintenance recovery
flights, it was standard practice to open all the tank dump valves
before take off leaving only the wing tip nozzle valves to start fuel
dumping.Â* That might save a second or two should the situation become
critical.

On 11/30/2017 8:56 AM, Charlie M. (UH & 002 owner/pilot) wrote:
I believe you are correct, you don't want to overload the spar with fuselage weight, thus, spread it out through the wings.
I know some ships had water in the wings but also additional in a tank in the fuselage to get the wing loading up due to low volume wings. You would load the wings, then finish off with the fuselage. Dumping ballast is fuselage first, then wings.

As to MTOW, some larger aircraft also have a MLW, max landing weight which I believe is mostly due to loads when the mains hit the runway.
So, some aircraft can take off at a higher weight than they can land! So, if they run into an issue, they may have to fly around to burn fuel off to get within landing weight, or even dump fuel (don't tell the EPA!).

--
Dan, 5J

Well.....all I can say is, the EPA is a major US government agency, thus, likely quite large.
So, either eat a huge amount of oysters or renew your prescription for your "little blue pill of choice" as it may be borderline on screwing the whole agency......
YMMV.......
;-)

Whatever.....the basics of what I posted is correct (minus stupid side comments on my part). I'm really concerned on the physics. I believe I am correct.

I'm not an engineer.
I know a few.
I can spell it.
I have not stayed at a certain hotel chain in a couple years.

:-)
LOL......

On Thursday, November 30, 2017 at 8:44:24 AM UTC-7, Dan Marotta wrote:
While studying for my Flight Engineer license back in the 70s (do they
have Flight Engineers any more?), it was explained that the max weight
of non lifting components had to do with the strength (bending moments)
of the wing spar.Â* Help us out here, Steve L.

MTOW has, I believe, to do with landing gear, brakes, tires, etc. Think
MV**2 during an aborted takeoff.Â* Higher weight - higher takeoff speed
- WAY higher energy to dissipate, that V squared component.
Dan,
No more flight engineers. You have to go back to 727s or early 747s to find a Flight engineer panel and all of those have been retired in this country years ago. MTOW is based on 5 different Performance charts (4 of which are based on engine out performance). MLW is based on Landing Gear and brake energy. Zero Fuel Weight is based on bending moment just like you said. I checked with the factory on my glider and yes, Non Lifting is just like Max Zero Fuel WT is on a jet. Everything beyond this must be wing ballast.

The weight of the wings should not change much from the factory weight
until
repairs or refinishing.

In the fuselage, instruments, batteries, O2 system, pilot, chute,
documents,, tie
down kit, lunch and drinks need to be included.

It all adds up.

Northwest Airlines hated it when they got ride of the flight engineer, less people to play drinking games with all night before flight.

On Thursday, November 30, 2017 at 11:55:47 AM UTC-8, K m wrote:
On Thursday, November 30, 2017 at 8:44:24 AM UTC-7, Dan Marotta wrote:
While studying for my Flight Engineer license back in the 70s (do they
have Flight Engineers any more?), it was explained that the max weight
of non lifting components had to do with the strength (bending moments)
of the wing spar.Â* Help us out here, Steve L.

MTOW has, I believe, to do with landing gear, brakes, tires, etc. Think
MV**2 during an aborted takeoff.Â* Higher weight - higher takeoff speed
- WAY higher energy to dissipate, that V squared component.
Dan,
No more flight engineers. You have to go back to 727s or early 747s to find a Flight engineer panel and all of those have been retired in this country years ago. MTOW is based on 5 different Performance charts (4 of which are based on engine out performance). MLW is based on Landing Gear and brake energy. Zero Fuel Weight is based on bending moment just like you said. I checked with the factory on my glider and yes, Non Lifting is just like Max Zero Fuel WT is on a jet. Everything beyond this must be wing ballast.