KSNA max landing weight?

[vonmar 122]

>I got curious, so I asked a knowledgeable retired ATP FS'er.>The weight limits are per wheel assembly. The 757 has two DT>(dual tandems), which means it would have a load limit of 304k># (152x2). It's MTOW is under this limit.>>Thanks again for the information.I just got this off the internet:For KPDK:1987--from DeKalb County

[vonmar 122]

>I got curious, so I asked a knowledgeable retired ATP FS'er.>The weight limits are per wheel assembly. The 757 has two DT>(dual tandems), which means it would have a load limit of 304k># (152x2). It's MTOW is under this limit.>>Thanks again for the information.Meshman,I know ATP but I am not familiar with ATP FS'er?I did not understand what you meant by "load limit" for the 757?Also, we were not talking about MTOW for the 757.Would it be possible for you to contact your ATP contact again and askfor his FAA reference document ... the one that explains the multiplicationfactors (in your example 2x) to use for each aircraft type based onthe reference information on the airport diagrams?We only need resource documentation for the "airport" Maximum LandingWeights, by aircraft type and main landing gear configuration. We donot need any landing specifications for the nosewheel.

[jvile 1]

Do not put a lot of faith into the published Weight Bearing Capacity found in the AF/D. You must know what the Airport owner sent the FAA and for Airliners the Dispatch has on record what system was used to calculate what is published.The standard in use today is the PCN (google PCN) and based on MTOW that a Apron, taxiway and runway can support for takoff with a tire air pressure factor. The landing is not what tears up a runway as per study's done by EHAM flight engineering but it is the takeoff side forces of tires. The MD11 tears up asphalt on takeoff more then other type plane so it carry's a very high PCN number of 70.California uses a Weight Bearing Capacity system that they developed in the 1940's. The published Weight Bearing Capacity that you see for a lot of Calif. airports is much lower then the actual PCN standard in use. The FAA has ask Airport Owners to send them bearing loads that reflect the standard that many airports around the world use. Some have and some have not.Many airports send the FAA Weight Bearing Capacity that differes such as KPDK uses D75 because of the GII/GIII. There is a foot note for KPDK that says the Owner of that airport specifies to FAA the MTOW of any plane cannot exceed Weight Bearing Capacity Single-46,000 lbs. Dual-75,000 lbs. **Prior Authorization Required for aircraft with a Max Gross Certificated Takeoff Weight over 75,000 lbs. So the Weight Bearing Capacity for KPDK is the MTOW of a GIII and not some landing weight or PCN calculated tire weight. For KPDK it is all about noise DB's and not what the actual runway can support.Look at KLAX AF/D and it only saysWeight bearing capacity: PCN 70 /R/A/W/T so Dispatch fiqures the proper weight for the company plane.Look at the AF/D for KOKC and compare it to KSNA. KOKC takes the PCN and converts it to Double wheel: 200.0 lbs Double tandem: 400.0 lbs which is the MTOWLook at airnav KJFK which saysDouble wheel: 185.0 Double tandem: 550.0 Dual double tandem: 823.0 KJFK uses the PCN of 80/R/B/W/T so dispatch must fiqure the Apron, Taxiway, runway departure and arrival weight even though JFK sends the FAA a weight value for the AF/D. KJFK is more concerned with what the MTOW is when the airplane loaded and sitting at their GATE which at many airports is portland cement and not asphalt. When KSNA was built the Airport Owner sent the FAA a standard used from the 1940's but what is published is not what the Airliner Dispatch uses and you will see larger then expected airplanes landing there as per the TCN standard that is in use at KLAX north of KSNA. The TCN standard says a fully loaded B752 can takeoff from KSNA given all the other varibles are calculated correctly such as runway length, density altitude, weather, safty margins, etc.If a PIC ask Dispatch what has been calculated as a landing weight, in the past Dispatch would give the weight as a single main landing weight (multiplied by 2, 3, 4, etc.) based on what Maint was using as a tire pressure per individual wheel. That is not a FAA rule but what a Company will tell a pilot in years past.Only when all Airport Owners get on the same page when sending the FAA the published AF/D will we be able to say everything is consistant. Dispatch works with the Airport Owners and not the Pilot when Takeoff/Landing weights are calculated. Google Airline Dispatch for what their role is in respect to the Pilots role. It will surprize you why they are FAA certified and considered the silent on ground Pilot of any plane.

[vonmar 122]

Jim,Thanks for the additional information.Looking at KSNA "airport diagram" and its runway weightbearing capacity information.Max landing weight rwy 19R for (DT152) is 150,000 lbs.Based on that information alone.Can a 757 land there?Is a 757 supposed to use the airport?

[jvile 1]

A better question is why can a B737-800 land there based on what the Airport Owner (Owner: ORANGE COUNTY) is sending the FAA as the weightbearing capacity information.This thread keeps using the following"Max landing weight rwy 19R for (DT152) is 150,000 lbs".Where does it say Max Landing weight on the AF/D and is that an assumption. The published values the FAA have on record from Orange County owners areWeight bearing capacity: Single wheel: 70.0 Double wheel: 95.0 Double tandem: 152.0We know Noise Abatement takes precedence over what a runway can support (see KPDK above) Are those numbers MTOW, Landing Weight, type plane vs Noise Sensitive Area of the 65 dB in use, PCN calculated weight or are they the numbers used when the airport opened with a new commerical terminal in 1967 (based on the calif 1940 measurment rule of weight bearing load). I can only speculate same as everyone else. What we do know is larger airplanes use higher bypass engines that produce less noise and KSNA is very strict on noise. So does KSNA wavier higher aircraft weight over lower noise to get the airline business or does KSNA charge extra for a heavier plane over quieter engines. I do not think the Owners are releasing that as public information and if the surrounding neighborhoods are not complaining and the 10 monitoring dB stations are still showing 65 dB's then the plane has become larger in size and the weight bearing tables need updating. Airport Owners around the KLAX airport want the business and allow higher weight airplanes as long as they are not too noisy in my way of thinking. Airline Company's and Dispatch know the answer but for competition purposes are not talking on what arrangements have been made with the owner of KSNA. Many runways in the USA and Europe need additional payment thickness along with updated weight bearing tables because airplanes have become larger and quieter. In answer to your questionIf we use the standard that Weight bearing capacity is the MTOW value for a airport (ramp, taxiway, runway) then no B757 or B737-800 should be using KSNA as a airport. However, if Dispatch says to KSNA the single main weight of a B737-800/B752 is less then the published Weight bearing capacity then a fully loaded B757 (220,000 lbs) can calculate 152,000 x 2 = 304,000 lbs and can use KSNA for takeoff if it meets 65dB. Dispatch and Engineering uses a 3/4 rule that says a Double Tandem airplane does not load a runway that much more (factor of 1 using the 3/4 rule) then a Double Wheel airplane since the weight of a single main gear double tandem is distributed across a larger foot print. Also the TCN standard measures the surface with lasers to see how much the payment deflects downward based on a single main gear and not the weight of the aircraft across the entire main gear. However it is like Reggie says, we do not have all the facts that the Airliner/Dispatch is using based on what has been worked out with the airport owner. Forget about what the airplane weighs landing at KSNA and think about what it weighs departing KSNA vs what KSNA published as the weight bearing capacity.My speculation is, as long as the heavier airplane is meeting the 65dB at all those monitoring stations, then KSNA is repairing any asphalt on the runway if that departing plane is tearing it up. Ramp and one taxiway to 19R is portland cement. The amount of Airline Business offsets the Maintenance repair of the 01L/19R runway in revenue.These are my opinions and not the facts as per what the Owners of KSNA are doing for the Airlines to get their business rather then KLAX getting all the revenue.

[vonmar 122]

Jim,This thread keeps using the following"Max landing weight rwy 19R for (DT152) is 150,000 lbs".** my error .. it should be (DT152) is 152,000 lbs.Any way, I got the information off the internet just now as one example of the codes that appear on the airport diagram."Where does it say Max Landing weight on the AF/D and is that an assumption."Weight Bearing Capacity & Fred v3.0Updated 20 June 2008 IFR Supplement Extract RUNWAY BEARING STRENGTH - may be shown as follows: 1. The runway weight bearing capacity in thousands of pounds will be shown expressed in terms of gross weight which can be accepted for continuing operations. It is determined by adding 000 to the figure following S, T, ST, SBTT, TT, TDT, DDT, TRT, TTT and AUW. A blank space following the letter designator is used to indicate the runway can sustain aircraft with this type landing gear, although definite runway weight bearing capacity figures are not available, e.g., T. Aircraft weights higher than given require prior permission from the airport controlling authority.

[jvile 1]

VonmarI was using the MAX weight as an example for KSNA. That is because we do not know what their weight table actually means. I am familiar with what the IFR supplement says but getting the Airport Owner to list it that way is another issue.The FAA has ask Owners to do just that but in some cases it is still not accurate. Some AF/D's are correct and some need updating or a NOTAM on why the listing is lower then the allowable type plane.The last line in the No.1 is probably what KSNA is using for all those Airliners landing there.

[vonmar 122]

Jim,As always, I appreciate your accurate comments and thoughts.I agree with you .. the last line in my previous post has been mentioned several times in this thread.So, last Thursday I flew into KSNA from KSFO (VATSIM) and I told the controller I had prior permission to land (just kidd'in) ... as my FEDEx763 was right at 301,000 lbs at touchdown.