21
$\begingroup$

Im looking at purchasing disused 747-400:

  • The aircraft will be stripped of all seats and other non essential items.
  • The aircraft will be then flown to my property in Victoria, Australia and perform a one off landing.
  • The landing distance would be between 1500-2300 feet.

Can this be done?

$\endgroup$
  • 9
    $\begingroup$ Are you willing to land gear up? :-) $\endgroup$ – Dan Pichelman Oct 4 '14 at 19:24
  • 5
    $\begingroup$ "Sure. Once." -- Flying into a local airport that can handle a 747 and then dismantling and trucking the aircraft would be substantially safer though... $\endgroup$ – voretaq7 Oct 5 '14 at 16:29
  • $\begingroup$ A 747 was landed in Longreach which has a 6500 ft runway. I seem to recall that this was considered a major endeavour. youtube.com/watch?v=tDJOtwGUAcI $\endgroup$ – Hugh Oct 6 '14 at 23:49
  • $\begingroup$ Boeing has flown 747s into Renton Airport during the late 60s, which has a 5000 ft runway. $\endgroup$ – Steve Kuo Oct 7 '14 at 1:54
  • $\begingroup$ If they can land a C-130 on an aircraft carrier without a tailhook, you can land a 747 wherever the hell you want as far as I'm concerned. youtube.com/watch?v=ar-poc38C84 $\endgroup$ – Bassinator Oct 10 '14 at 23:45
27
$\begingroup$

Interesting question. I think it could be done in the right conditions if you are willing to accept some damage and depending on the runway.

Is the runway level or uphill/downhill? If you could land uphill in a high wind that was almost all headwind, I believe you could either do it or would overrun the runway at a low speed. Airplanes slow down really quickly going uphill.

A stripped 747-400 probably weighs about the same as a 747-400 freighter, maybe a little less because the freighter has the equipment for loading and securing pallets. If you're using Firefox or Chrome (IE won't work), click on any aircraft at 747.terryliittschwager.com and you'll see the empty weight is around 362,000 lbs (you can change the weight unit to kilos there if you wish).

I used to land at Tel Aviv with only 15,000 lbs of fuel in 747-200s. The -400 burn rate may be a little higher, but let's use that. You would have to be comfortable with being totally committed to landing, with the possibility of only one quick go-around. Maybe you could even cut the 15,000 down to 10,000 with no go-around possibility?

Let's use 375,000. Vref for a -200 at 400,000 (lowest figure in the table I have) is 118 kts. In that area Vref decreases 3 kts for every 20,000 drop in weight, so we can take that 118 down to 115. I forget whether Vref is 1.2 or 1.3 times stall. Let's use 1.2, which would put the stall at 96. I would imagine a -400 is comparable insofar as these speeds are concerned, but I don't know.

How about one-time-use arresting gear of some sort on the last 400 meters of runway?

You could drop some more weight by taking out one engine. 747s regularly do 3-engine ferries. It's no big deal. However, I'm not sure if the weight loss would be worth losing the reverse thrust of the engine being taken out. There is a lateral imbalance consideration there, but 747s used to carry a spare engine in a pylon under the wing, so if you removed an inboard engine, I'm guessing you could live with the imbalance.

Speaking of reverse thrust, it used to be for the 747-200 that the published figures for minimum landing distance were brakes only, no use of reverse thrust. If that's the case for the chart shown in the previous answer, the figures there can be reduced, and you would want to use FULL reverse immediately. Don't worry about compressor stalls, after all, I'm guessing you're not going to use the engines again.

Also, I'm sure there are performance figures for the effect of runway slope and headwind.

It would be a challenging situation, one of those things some crazy Aussie might try! lol

$\endgroup$
  • 7
    $\begingroup$ This post is a great example how experience beats theory. I didn't know that the landing distance in manuals is brakes-only, and that changes the picture. However, in a strong headwind I would be careful to approach with only $1.2 \cdot v_{min}$. Think of the wind gradient close to the ground! And leave all engines in - the reverse thrust is worth it. $\endgroup$ – Peter Kämpf Oct 4 '14 at 7:38
  • 2
    $\begingroup$ In addition to arresting equipment near the end of the runway, you might be able to add parachutes to the rear of the craft that could deploy just prior to landing. Also, since you're modifying the craft anyway, you could add additional landing gear, which would increase braking power. It's a lot of extra cost and modification, but you're buying a 747 and trying to put it in a difficult location - it might still be cheaper than disassembling it and shipping it from the nearest airport or water port that can deal with it. $\endgroup$ – Adam Davis Oct 4 '14 at 12:58
  • 3
    $\begingroup$ @raptortech97 One would probably want to include in the estimated cost of the effort whatever fines were to be expected. It might also be best to use a pilot who was not concerned with loss of license, maybe a retired guy who would do it primarily for the challenge, or bring in a foreign pilot who would conveniently disappear afterwards. $\endgroup$ – Terry Oct 5 '14 at 17:17
  • 8
    $\begingroup$ "...maybe a retired guy who would do it primarily for the challenge" -- Terry, are you volunteering? 8vD $\endgroup$ – Fred Larson Oct 6 '14 at 16:36
  • 2
    $\begingroup$ @FredLarson You know, if it was a -200 instead of a -400, and I had recently retired and thus still had real currency in the airplane, I would seriously consider it Unfortunately, though, I've never flown a -400 or a glass cockpit. I did consider getting a -400 type rating right after I retired just for the hell of it, but I couldn't justify the $20,000 price tag at the time. $\endgroup$ – Terry Oct 6 '14 at 17:58
21
$\begingroup$

No, it can't be done.

There has been a similar situation in the Netherlands. KLM donated an old B747-200SUD to the Aviodrome Aviation Themepark at Lelystad airport. Lelystad airport is a general aviation field located about 60 kilometers from Amsterdam airport and has a 4100 feet runway.

Even a stripped down B 747 would require more runway. In addition, the weight would damage the runway and taxiways at the destination since these are designed for a lighter category of aircraft.

They ended up taking the plane apart and shipping it over the canals and a lake to its final home.
enter image description here enter image description hereenter image description here

$\endgroup$
  • 30
    $\begingroup$ Does this convert the barge to an aircraft carrier? $\endgroup$ – DJohnM Oct 4 '14 at 23:36
10
$\begingroup$

The charts say no, and I agree. 3000 feet is standard at a small GA airport and that's tight even for a Gulfstream. If your runway is that short have you considered the width? A 747 has 11 meters between the tires - although you might stop a lot faster with the outboard wheels in the grass it will be really difficult to move it after it stops. Only one wheel in the grass could be quite exciting.

Without running the numbers ('cause your case is well off the charts) in self-contradiction I will say that it's conceivable that if you land with NO fuel remaining, full flaps, set the mains down right on the beginning of the pavement, apply full reverse and full braking, AND do this on a day with a cooking headwind you might pull it off. Heavy rain will actually help here as a few inches of standing water on the runway will slow you down pretty fast. Of course, you have no option for a go-around. Such a landing would be illegal in almost any developed country.

Who's going to fly it? 747 drivers are used to things like 12,000 foot paved surfaces and ILS, not bush-grade airstrips in the outback. Bush pilots who think 1500 feet of pavement is a luxury typically don't know how to fly a 747. Just in case you don't know, large aircraft licenses are NOT interchangeable. You need a commercial license, ATP and a type rating. For an older 747 it's a fairly small club.

If you do go ahead with the project, call the Discovery Channel, producers of Dangerous Flights. they'll probably be interested.

Oh, and forget the parachute. I'm a master parachute rigger - anything capable of slowing a 747 will take 1500 feet just to deploy (you have to stage it). And the plane is not equipped with the necessary attachments.

Maybe a dozen JATO bottles hooked up backwards?

$\endgroup$
  • 2
    $\begingroup$ Re: your last point: youtube.com/watch?v=WKCl3lfAx1Q (idea scrapped because it's so dangerous) $\endgroup$ – SSumner Oct 4 '14 at 15:10
  • 1
    $\begingroup$ Also, I don't think standing waste will slow you down faster...you will end up hydroplaning. In the military, we use standing waste as 'icy' when running TOLD charts, which significantly decreases braking effectiveness $\endgroup$ – SSumner Oct 5 '14 at 16:34
8
$\begingroup$

You can find detailed technical specifications for the 747-400 in this document. On page 97, a landing chart appears:

enter image description here

The operating empty weight (OEW) of a 747-400 (from the same document) is 394,088 lbs (178,756 kg).

Though the chart does not go all the way down to 394,088 pounds, towards the lower end of the chart, the change is almost linear, so we can get a rough estimate of the landing runway length requirement at OEW. With Flaps 30, at Sea Level, on a Dry Runway, you're looking at about a 1,390 meter requirement (about 4,560 feet).

The approximate slope of the graph is for every 100,000 pounds lost, landing distance decreases by 300 meters (~984 feet). Obviously this is not completely accurate, but for this purpose, it'll do. To land on a 2300-foot runway, you would need to lose another 230,000 pounds or so, putting the weight around 165,000 pounds. I'm fairly sure that stripping all nonessential equipment would not be enough here, and this ballpark estimate would require you to touch down brick one, with no gas, and no extra runway. Even if you could fly a 165,000 747, I wouldn't try to land it on that short of a runway.

So in answer to your question: No, I'm certain this cannot be done

$\endgroup$
2
$\begingroup$

For a truly one-shot deal, you don't even need "enough" runway, as long as you put enough EMAS at the end to handle the size, weight, and speed you expect to be dealing with. Sure, the EMAS itself gets destroyed in the process, but even an old 747 is probably a lot more expensive, and it is pretty well done flying at the end of this adventure, right?

$\endgroup$
  • $\begingroup$ I'm sorry Ralph, but you should expand this with at least some numbers, or I cannot see how you would be answering the question. $\endgroup$ – Federico Mar 18 '16 at 8:08
1
$\begingroup$

5000 feet would be the minimum runway size under normal conditions and even this would be dangerous.

To land on a 2500 is possible but would require arresting equipment and a pilot with balls of steel.

If it were me, I would flood the runway with some kind of heavy mud, like drilling fluid or a non-flammable oil. That would probably do it. I would obviously do some physical calculations to make sure it would work before trying it.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.