Max. Ramp Weight

[Blueridge]

I'm studying for recurrent and this question came up. I hope someone can help...

Suppose an airplane is parked on the ramp and it gets loaded such that the max ramp weight is exceeded. The aircraft is never moved until weight is removed. Has a limitation been broken?

I have heard arguments both yes and no. Those who say "no" argue that this is a dynamic limitation and therefore only applies to taxiing the aircraft. Those who say "yes" argue that this is a structural limit on the airplane.

I personally feel that no limitaion would be broken in this case, but would appreciate comments from others.

BR

 

[TurboS7]

The only time that any limitation has been broken is when the airplane is being taxied out for the intention of taking off. Other then that it is all hoggypuck, the aircraft is stress to withstand a minmum of 1.5 over the certified G-load of the aircraft. If an aircraft is sitting there static and its ramp weight is 2000lbs, you would have to put 2000x3.8x1.5 before you would have any structural failure of any kind.

 

[avbug]

While certainly exceeding max ramp weight will likely not adversely affect the aircraft structurally (unless it has been grossly exceeded, as opposed to exceeding gross), it is nevetheless a violation of the aircraft limitations.

Maximum ramp weight isn't designed as a function of a strength limit on the ramp, but is designed as a utility limitation which allows enough fuel to be carried to taxi, to enable the aircraft to takeoff with it's full takeoff weight. In other words, it's established to prevent penalizing the aircraft's takeoff fuel capacity by the amount required to taxi.

That said, ramp weight is a limitation, and a function of the aircraft type certification (or ammendments to type certification). Exceeding ramp weight means exceeding the type certification limits to the aircraft, which by definition means a violation of the airworthiness limits of the aircraft, which violates the terms of the airworthiness certificate, and renders the aircraft legally unairworthy. Accordingly, the pilot may be violated under 14 CFR 91.7(a).

Under 14 CFR Part 25, maximum ramp weight is used to define maximum handling weight in terms of structural strength, use and movement of systems (such as braking, steering, etc), and performance. It is also used to define tire requirements, or is limited by tire or gear requirements, in a static condition.

 

[stingray]

avbug

you are thinking of (Zero Fuel Weight)


Max ramp is simply the max total weight allowed while on the ramp or while taxing.

Now wheither you are busting any limitations if you overload it with out the intention of flight(how much). Probably, at a certain point things will start to break and yes i know it will take a lot to do that. How many times the alllowed weight who knows except the engineers. and yes with the proper paper work you can even fly planes over the certified T.O. weight for such thing as ferry flight over long distance over water, and while doing this you are usally well over the max ramp weight at the beginning of the flight.

 

[Andy Neill]

I have to take exception to TurboS7's response. While the 3.8 and 1.5 factors are good for the strength of the wings and wing roots, they would not NECESSARILY be good for where the ramp weight forces are felt - at the three gear attaching points. I would imagine that if you loaded 11,700 lbs on an aircraft with a 2000 lb ramp weight limit, there is a very real possibility that there would be structural damage at one or more gear attaching points while if you were to lift the aircraft evenly by its wings, it would be just fine. The point is, you wouldn't KNOW. At our company, if we have overloaded a static aircraft, we have exceeded a limitation and maintenance is called in to inspect.

 

[Blueridge]

Thanks for the responses so far. At the risk of being anal about this, let me propose this scenario:

You are sitting at the ramp and your plane is loaded at exactly its max ramp weight. A ramper walks up the stairs and hands you the baggage slip. Now you're overweight. What do you do?

 

[ILLINI]

Blueridge:

The definition for Maximum Ramp Weight in the C208 B Caravan I defines Max Ramp Wt. as "the maximum weight approved for ground maneuver. (It includes the weight of start, taxi, and runup fuel.)"

It is my understanding that the reason there is a max weight for ground maneuvering is because when you are maneuvering the a/c on the ground, you are imposing additional forces on the gear and tires that isn't felt when the a/c is standing still. Maneuvering on the ground at a weight at or below Max Ramp Wt. will prevent you from exceeding the design limitations of the gear and tires. It's kinda like Va while you're on the ground.

Using your example with the ramper boarding the plane when you are right at max ramp weight, I would have to say that you have not exceeded the max ramp wt. limitations based on the definition mentioned above as long as you do not perform any ground manervers. I know this doesn't mean that you could safely load a plane with a max ramp wt. of 8785 lbs up to 25,000 pounds without causing some structural damage, but if you go by the definition - it is within limits. I'm sure the engineers have a maximum weight limit that the plane can weigh on the ramp without structural damage to the aircraft, specifically the gear and tires, that is greater than the max ramp weight.

Interesting question.... What does everyone else think?

 

[ifly4food]

Thanks for the responses so far. At the risk of being anal about this, let me propose this scenario:

You are sitting at the ramp and your plane is loaded at exactly its max ramp weight. A ramper walks up the stairs and hands you the baggage slip. Now you're overweight. What do you do?

We had exactly this scenario occur the other day on an E120. We gave a max of 25pax and 48bags. The gate sent us 28 pax, promising that they had made up for it in bags. Well, once everything is on, we get the manifest and it shows 41bags and 5 "carryons". We exceeded the ramp weight of 25529# by about 400#. We called and got the pax removed to get back under MRW. We considered writing it up as a limititations excursion and having maintenance inspect, but since our company doesn't have a procedure for this, we dismissed it the same as the original post here; basically the a/c wasn't in motion.
Though in a legal and literal sense "a limitation had been exceeded" does anyone really think we jeapordized safety by not writing it up? Personally, I think maintenance would have laughed us off the plane if we delayed a flight and called them out for something like that. The CPs might have something to say about it too, but they wouldn't be laughing.

 

[TurboS7]

Point well taken about the "3.8G x1.5" that is what the aircraft can handle in flight with the wings supporting all the weight. On the ground all that weight would be taken only by two or three structural points. Sound like we need an engineer, any DER's out there that would like to comment?????I go to an IA class tomorrow night and I will ask a couple of DER's that I know what the deal is and let you know.

 

[avbug]

Stingray,

I said nothing of zero fuel weight, which is a wing bending moment issue. Maximum ramp weight is intended as a limitation over takeoff weight which allows extra fuel to be carried for the taxi, but not for the takeoff. It allows takeoff with maximum fuel, without penalty for the fuel burned during the taxi. Hence, being slightly higher than takeoff weight. In this manner, the aircraft may still take off with all the fuel it can possibly carry, rather than taking off with maximum fuel, minus what was burned during taxi. Max ramp weight simply adds the extra weight of the fuel burned during taxi, to accomplish this. It has NOTHING to do with zero fuel weight.

Respectfully, a DER is not qualified to determine, and may not determine, that max ramp weight is or is not exceeded based on structural limitations. If one were attempting to obtain certification for a higher maximum ramp weight, the input of a DER would be crucial. However it would not be the final word, and it does not address the topic of legality.

Further, there are other limitations aside from gear attach points, wing attach points, nosegear turning limitations, etc, to max ramp weight. The tires are among them, as are a host of other limitations.

All of that is superfluous, as maximum ramp weight is a function of certification, and is a legal issue. It is an aircraft limitation. It may also affect airport operations limitations. For example, when I operated the PB4Y-2, we operated at 79,990 lbs. We did this because it allowed us to use many airports that restricted our operation at 80,000 lbs. 10 lbs made the difference, and we got checked on it a number of times. We could easily have loaded another 3,600 lbs of retardant and much more in tools; the aircraft would hold it on the ground. But that wasn't the issue. it was a legal issue (and in the air a performance issue, of course).

Again, exceeding an aircraft limitation invalidates the airworthiness of the aircraft, as airworthiness means compliance with approved data. Until that limitation is no longer exceeded, and in many cases even after it's been exceeded, the aircraft is not airworthy. It does not meet it's type certification limits, and any additiona limits placed on the aircraft via approved data, to include the aircraft flight manua, required placards, etc.

Again, when an aircraft is loaded to this condition, it does become eligible as evidence under 91.7, for enforcement action. Will loading it a few pounds over that limitation likely affect the physical condition of the airplane or make it unsafe? Most likely not, as yes, there are wide margins built and designed into the aircraft structurally. However, that is not relevant. One is then arguing legal vs. safe, and we know that as professionals, the operation must be both legal and safe, right?

 

[stingray]

Avbug
I understand zero fuel weight versus takeoff weight i've been dealy with them for over 15 years. Anyways after re-reading your 1st post on this subject. I realize i misread what you said in your as normal lengthy post.

flysafe stingray
I

 

[TurboS7]

Airworthiness is a condition predicated on TCDS and other data including Part 25or23,Part 21 and 43 and the Part 39, and I am dong this from memory so I could have left anything out. Ramp weight applies to airworthiness and compliance with the TCDS I agree with that. Just for argument I decide to store my life's saving of 4000 pounds of gold ingots in the airplane. One day I decide to go fly, I take my gold ingots out, fuel up and load up my airplane well within the limits set by the TCDS. Has there been a violation???Is the aircraft unairworthy???Your opinion guys, and we are in weird legal ground I have no pet answer.

 

[avbug]

Just tell me where you put the ingots while you are out flying...I'll keep them safe for you.

 

[enigma]

I don't really know the conditions on which ramp weight is determined/predicated. But, let's look at the question in the context of the world in which work. If the weight was exceeded, was it exceeded in such a way that the paperwork will reflect that condition? If so, you probably should at least contact m/x control and allow them to make the decision. If not, and the weight was only exceeded by a few pounds before you made them stop loading the comat, then I would ignore it. This sort of falls into the same catagory as overspeed. If you get the clacker for one second on descent in smooth air, do you write it up? No. If you get the clacker for one minute in heavy turbulence, do you write it up? Yes. If you are asked the question on a PC, with a Fed in attendence, did you exceed a limitation? Dang right you did.

regards,
8N

 

[TurboS7]

It's our retirement fund, I split them with you as long as you don't tell where I got them.....LOL(I better put the lol in there or I'll have the FBI on my doorstep)

 

[avbug]

Tell who where you got what? It's a deal.