Devil505x
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Runway Length Question

Sat Feb 24, 2007 2:56 am

When checking airport diagram information I have noticed there are quite a few military bases past and present (mostly naval) with runways of 8002 feet (NXX, ARA, Warminster Nas, etc) It seems to be a popular length for civilian airports as well. Why is this such a popular length for the military?
In my opinion 6000ft was good for smaller aircraft but when larger planes had to land a longer runway was needed and 8002 was some sort of standard to follow.
 
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kc135topboom
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RE: Runway Length Question

Sat Feb 24, 2007 12:53 pm

While an 8002' long runway will work well for the USN, it doesn't work for the USAF as well. Since runway design and construction takes so long, you want to plan the correct lenght. To short and you will not see the types of airplanes you want. To long and you waste money as runways are very expensive to build.

You plan the lenght based on the noraml climotoligy for the area, and the most restrictive airplane you expect. The USN who did not have many airplanes bigger than a C-130 (until the E-6 came along), did not need more than 8000'.

The USAF, who had lots of B-52s and KC-135As, needed at least 11,000', depending on where the base was. Some bases needed 13,000'.

So it is a combination of weather, airport altitude, and airplane type that determines how long your runway needs to be.

That is over simplified, but it does hit the high points.
 
f4wso
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RE: Runway Length Question

Sat Feb 24, 2007 1:22 pm

I was wondering why 8002 vs 8000. Perhaps there is a lip on either end that is included in the total for a certain style of construction.

Gary
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PADSpot
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RE: Runway Length Question

Sat Feb 24, 2007 5:42 pm

Quoting F4wso (Reply 2):
I was wondering why 8002 vs 8000. Perhaps there is a lip on either end that is included in the total for a certain style of construction.

Maybe some sort of NATO or metric system standardization? 8002ft is almost exactly 2439 meter, while 8000ft is 2438,4 meter. I know it's basically hair splitting, but i'll be hard to explain someone in Europe to build his runway 2438,4 meter long instead of rounding up to 2439 meter ... some (maybe even most?) German ABs do follow this standard ...
 
zanl188
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RE: Runway Length Question

Sat Feb 24, 2007 8:51 pm

Quoting KC135TopBoom (Reply 1):
The USAF, who had lots of B-52s and KC-135As, needed at least 11,000', depending on where the base was. Some bases needed 13,000'.

Just a nit... it was the B-36 & B-47 that drove USAFs runway requirements. The B-52s & KC-135s came along after many of SACs runways had been designed and built.
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kc135topboom
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RE: Runway Length Question

Sun Feb 25, 2007 2:34 am

Quoting ZANL188 (Reply 4):
Just a nit... it was the B-36 & B-47 that drove USAFs runway requirements. The B-52s & KC-135s came along after many of SACs runways had been designed and built.

That is true for some SAC bases. But those designed and built in the 1950s were designed for the then new B-52 and the soon to be operstional KC-135. These include Plattsburgh AFB, NY, Pease AFB, NH, Dow AFB, ME, Loring AFB, ME, Westover AFB, MA, Robbins AFB, GA, KI Sawyer AFB, MI, Minot AFB, ND, Offutt AFB, NE, Castle AFB, CA, Fairchild AFB, WA, and a few others.
 
zanl188
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RE: Runway Length Question

Sun Feb 25, 2007 3:32 am

Quoting KC135TopBoom (Reply 5):
But those designed and built in the 1950s were designed for the then new B-52 and the soon to be operstional KC-135. These include Plattsburgh AFB, NY, Pease AFB, NH, Dow AFB, ME, Loring AFB, ME, Westover AFB, MA, Robbins AFB, GA, KI Sawyer AFB, MI, Minot AFB, ND, Offutt AFB, NE, Castle AFB, CA, Fairchild AFB, WA, and a few others.

Of these bases only PBG & LIZ were purpose built for SAC.... In fact several served as WWII training bases and Offutt was the location of Martins B-29 manufacturing operation.
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f4wso
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RE: Runway Length Question

Sun Feb 25, 2007 12:02 pm

I hadn't thought of the metric conversion. That is the most plausible of any that I have heard.

Gary
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ptrjong
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RE: Runway Length Question

Mon Feb 26, 2007 5:04 am

Quoting PADSpot (Reply 3):

You're probably on the right track, but if standard runway length in Germany is exactly 2,439 metres, then I bet this is a conversion of 8,000 feet (rounded up by a dutiful civil servant, to be on the safe side Wink), and not the other way around.

The 8,002 figure probably comes from recycled data, 8,000 feet having been converted to 2,439 metres and reconverted to 8,002 feet.

Peter Smile
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kc135topboom
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RE: Runway Length Question

Mon Feb 26, 2007 7:03 am

Quoting ZANL188 (Reply 6):
Of these bases only PBG & LIZ were purpose built for SAC

PSM opened in 1956, too.
 
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RE: Runway Length Question

Tue Feb 27, 2007 5:37 am

Quoting Ptrjong (Reply 8):
The 8,002 figure probably comes from recycled data, 8,000 feet having been converted to 2,439 metres and reconverted to 8,002 feet.

 checkmark . That is want I wanted to say. There is certainly no standard saying that standard runway lenght for a fighter base is 2439meter, but I do think there are NATO standard for runway length. At the time of construction lengths were rounded up (rounding down would violate the standard). 8002ft probably came up when 2439 were transferred back to feet.

Off topic though, but is there any chance that the remaining "imperial" countries will accept metric standards?? Apart from tradition the old system has not a single advantage ... beside keeping people practiced in mental arithmetic.
 
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RE: Runway Length Question

Tue Feb 27, 2007 7:39 am

Quoting KC135TopBoom (Reply 9):
PSM opened in 1956, too.

Pease was a Naval Air Station during WWII
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ptrjong
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RE: Runway Length Question

Tue Feb 27, 2007 10:10 am

Quoting PADSpot (Reply 10):
is there any chance that the remaining "imperial" countries will accept metric standards??

There are not many left. I'm currently translating a British book on World War I, and to my surprise the British editor changed units into metric (leading to awkward figures such as 'More than 703,000 kilometres of cable'). Australia and Canada also have gone metric.

However, the USA is just too important to adopt anyone else's standards I'm afraid.
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kc135topboom
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RE: Runway Length Question

Wed Feb 28, 2007 12:54 am

Quoting ZANL188 (Reply 11):
Pease was a Naval Air Station during WWII

No, it was not. The Portsmouth NAS during WWII was south of Portsmouth at the old Portsmouth Airport. It closed in 1955. Pease, then Portsmouth AFB, was built west of Portsmouth, in Newington, NH. PSM opened in 1956 as a SAC base, it was built with an 11,300' X 300' runway. IIRC, the runway at Portsmouth NAS (part of it is still along US Route 1) was about 4500' X 100'.
 
Devil505x
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RE: Runway Length Question

Thu Mar 01, 2007 11:25 am

Thanks to all of your replies
 
TeamAmerica
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RE: Runway Length Question

Thu Mar 01, 2007 2:06 pm

Quoting PADSpot (Reply 10):
Off topic though, but is there any chance that the remaining "imperial" countries will accept metric standards?? Apart from tradition the old system has not a single advantage ...

Off topic, but it's a pet peeve of mine...the "old system" actually did have some advantages in commerce, specifically in ease of physical (vs. mathematical) division. More to the point though, is that the length of a runway doesn't change depending on the system of measurement. There is no actual benefit to converting one way or the other, and there are great disadvantages if mixed systems of measurement were attempted.

Quoting Ptrjong (Reply 12):
However, the USA is just too important to adopt anyone else's standards I'm afraid.

 talktothehand Please spare me your politics. The USA was one of the original 17 nations that signed the treaty formalizing the metric system in 1875, and the US government officially converted via the Metric Conversion Act of 1975 (see: http://www.pueblo.gsa.gov/cic_text/misc/usmetric/metric.htm ). The fact is that there is little or no legal recourse under American law to compel people to use the metric system, but most American manufactured goods are in fact produced in metric even though specifications may be listed in "old" units.

For example, American cars and trucks use metric fasteners and specify torque in Nm. The speedometer has kph tickmarks along with the mph. Engine displacements are listed in liters. Even Coca Cola is sold in one, two or three liter bottles. The US military is metric, believe it or not, but the conversion is ongoing. NASA has only recently committed to going fully metric. In short: the USA has been converting to metric for a full generation, and given another generation may be slightly further along. biggrin 

I've noted that food labels in the EU list energy content in calories...so don't be so quick to declare America entirely backwards. Seems that the EU is flexible enough to adopt units that people find convenient. smile 
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RE: Runway Length Question

Thu Mar 01, 2007 5:33 pm

Quoting TeamAmerica (Reply 15):
actually did have some advantages in commerce, specifically in ease of physical (vs. mathematical) division

Well, I think you will admit, that we have overcome the ages where life was predominantly based on physical division? Of course a lumber man in Canada probably gives a shit on meters, grams and justifiably so.

Quoting TeamAmerica (Reply 15):
There is no actual benefit to converting one way or the other, and there are great disadvantages if mixed systems of measurement were attempted.

While you're right saying that much of hassle comes from the need of converting, I think that a common multiplier (10) and a foundation on physics (Speed and wave length of light, gravitation etc.) brings many advantages and simplifications in itself. Some domains simply cannot use imperial metrics because they are internationally interweaved to a great extent and it would make communication difficult to impossible. Others need very high precision - for them talking in nanometers is certainly easier than in billionth fractions of an inch. A friend of mine works in the machining industry and once complained that they had to reproduce each product that is exported to the States with nuts and bolts based on the imperial system, had to rewrite tons of documentation, and had to stock extra spare parts etc ... economically not having a totally unified system is a disaster. I am sure you can express the annual financial benefits of having a REALLY unified system in a two to three digit number of billion dollars ...easily.

A word on former "imperial" countries: The extent of conversion varies. All Canadian people I met so far were talking in inches, feet and pounds. I guess the Canadians speaking french prefer the metric system? (just a guess). In Australia though it really seems to be on the way out. I met quite a few and all were naturally using meters, grams and so on ...

Quoting TeamAmerica (Reply 15):
More to the point though, is that the length of a runway doesn't change depending on the system of measurement.

As I said above ... 8000ft vs 8002ft is hairsplitting.
 
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RE: Runway Length Question

Fri Mar 02, 2007 12:19 am

Quoting PADSpot (Reply 16):
Well, I think you will admit, that we have overcome the ages where life was predominantly based on physical division?

Yes. of course. I use metric in all my engineering work and wouldn't consider doing otherwise. I was only responding to the statement that there was no advantage at all to the old system. That's not really true. Anybody can look at a clock and ask why we use 60 minutes and 24 hours...it's for much the same reason that we had inches and feet. For some reason nobody objects to the archaic timekeeping system we all share, yet they look down their noses at the old English measurements. I'm not in favor of the old system, I just don't share in unduly criticizing it.

Quoting PADSpot (Reply 16):
A friend of mine works in the machining industry and once complained that they had to reproduce each product that is exported to the States with nuts and bolts based on the imperial system, had to rewrite tons of documentation, and had to stock extra spare parts etc ... economically not having a totally unified system is a disaster.

This is becoming less common. Most US industries either have converted or at least made provision to accept machinery with metric fasteners and so on. Those that don't are doomed to fail. Even so, you won't likely see a change in the standard lengths of lumber, just as you said. It would be an economic disaster to try to change things like that.

Quoting PADSpot (Reply 16):
8000ft vs 8002ft is hairsplitting

So is 8000ft vs. 2439m. It's the same runway regardless of the system of measurement. smile 
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ptrjong
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RE: Runway Length Question

Fri Mar 02, 2007 5:11 am

Quoting TeamAmerica (Reply 15):
Please spare me your politics.

I wasn't making a political statement, I was just observing that America is a very big and important country, not influenced by the outside world as much as most other countries, and thus, I reasoned, not under pressure to adopt the metric system.

Thanks for correcting me about this. I can imagine conversion will takes a while. (I'm not sure it is succeeding though.)

So, if and when America converts, will aviation ever follow, or will it remain the last outpost of pounds and feet?

Peter Smile
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TeamAmerica
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RE: Runway Length Question

Sat Mar 03, 2007 1:44 am

Quoting Ptrjong (Reply 18):
not influenced by the outside world as much as most other countries, and thus, I reasoned, not under pressure to adopt the metric system.

That era is coming to an end. I think US industry has felt the pressure to convert, and the resistance is ebbing away. The majority of US-educated engineers are taught in metric, so if nothing else the lack of new engineers available to do work in the old system will drive things forward.

Quoting Ptrjong (Reply 18):
will aviation ever follow, or will it remain the last outpost of pounds and feet?

I don't see a reason to change. It would cause immense disruption and raise safety concerns.

Standardization is of great value, but we should note that aviation is standardized. Changing those standards to another system of measurement simply because that would be more familiar to people outside of aviation really makes no sense. No doubt it will seem quaint in the future, but if the system is safer if left as it is - then we should leave it.
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ptrjong
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RE: Runway Length Question

Sat Mar 03, 2007 8:29 am

Quoting TeamAmerica (Reply 19):

Good and interesting post, thanks.
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