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Which are the aircraft models that need their tail to be supported by a jack when empty?

Wikipedia says this:

Aircraft Tripod Jack

They are used to support a parked aircraft to prevent their tail from drooping or even falling to the ground. When the passengers in the front get off an aircraft, the aircraft becomes tail heavy and the tail will droop..... When needed, they are tugged to the tail and setup by manpower. Once setup, no supervision to the jack is needed until the aircraft is ready to leave.

Are there even commercial airliners that need to be supported this way every time they load / unload? Sounded like a lot of work for ground staff. Was this a legacy equipment thing or still in use today?

https://en.wikipedia.org/wiki/Ground_support_equipment

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  • $\begingroup$ Related $\endgroup$ – fooot Jan 24 '16 at 6:24
  • $\begingroup$ Anecdotally, Dad and some colleagues on a business trip got a chance to look round Concorde in Paris : the guard counted them; six; and asked them not all to go to the rear of the cabin at the same time... $\endgroup$ – Brian Drummond Jan 24 '16 at 10:39
  • $\begingroup$ The Quest Kodiak uses these. $\endgroup$ – J Walters Jan 24 '16 at 13:55
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Tripods are mostly found in cargo aircraft (and combis) as the cg shift is severe there (particularly for front loading). A good example is the Boeing 747s. Also used in DC10/MD11s used as freighters.

747F

Image from reddit.com

Some 747-400 combis also use these, though it is mainly for cargo loading.

747-400M

Photo: Je89 W. / Source: PlanePictures.Net

Some passenger airliners are prone to tipping (737-900 comes to mind) and are usually supported by a pole rather than by a tail stand (same procedure is used in a KC-135 tanker too). For example, a Boeing 737-932ER with tail support.

B737-900

Image from airliners.net

The tail supports are not strictly necessary and the loading can be carried out sequentially (from front to back) for safe operation, but are used as a precaution. In some aircraft (like ATR-72 and Saab 340, called pogo sticks) small tubings are attached to the rear fuselage to prevent tipping over when loading/unloading.

ATR 72

Image from theflyingengineer.com

The nose can be tethered to prevent tipping during loading/unloading as done in this Korean Air 747F

747F

Image from koreanair.com

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  • 1
    $\begingroup$ Also in some older aircraft such as 727 the airstairs performed this function. $\endgroup$ – TomMcW Jan 24 '16 at 17:39
  • $\begingroup$ Are you sure that EVA 747-400 is a combi? The passenger cabin seems to extend awfully far back for a combi aircraft... $\endgroup$ – Sean May 24 '18 at 22:47
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    $\begingroup$ @Sean how do you see to where the passenger cabin extends? Afaik all 747 combi's have windows that extend all the way to the back with a (moveable) bulkhead in between to separate the cargo and passenger space. The aft cargo bay door is on the other side and not visible in the picture. $\endgroup$ – MadMarky May 25 '18 at 11:17
  • $\begingroup$ Your 737 link is dead. Looks like someone didn't pay the bill. $\endgroup$ – Pheric Apr 25 '19 at 6:19
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DC-8 freighters used tail supports as a safety precaution. As I remember, if you loaded them properly the support wasn't needed, but people didn't always do that. The cargo door was forward of the wing. I've long since thrown out my DC-8 weight & balance manuals, but as best I remember, the proper protocol was to put the desired most forward ULDs in first and slide them to their positions forward of the door. Next you would put in the rearmost ULD, but then move it just far enough aft to get the next ULD on, then move it and the previous one just enough aft to get the next one on, and so on. At some point you had enough weight forward of the main gear to start moving pallets all the way to the rear. If you miscalculated, the airplane would sit on the installed tail support. This reportedly happened at Newark, as I remember, in the early 1990s, but they had neglected to put up the tail support. The airplane sat on it's tail.

The same attention to balance was also needed when unloading. Read this link for an unloading accident when the tail stand collapsed, causing one of the cargo pallets to roll down to the tail of the cargo compartment. Three loaders were able to get out of the way of the runaway pallet, but the fourth got his foot caught, sustaining serious injury.

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  • $\begingroup$ Edited to clarify what, precisely, injured the fourth loader; the way it was worded previously made me originally think that he was injured when the DC-8's tail sat on his foot. $\endgroup$ – Sean May 24 '18 at 22:46
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Back in the day I was weight and balance / loading qualified for all B747 types. The tail-stand is promarily used for freighters. If I'm doing a full load change (eg all off and reload) with a crew familiar with the aircraft .. , then I wouldn't be too worried about tipping a freighter. BUT for a 747 Combi I would say that a tail-stand is indispensable! Especially for a transit flight where everything is happening all at once.

A fully loaded 747 combi and you have to have your wits about you when working around this aircraft.

The MD11 freighter was another aircraft you had to watch out for. An empty plane will have its CG (centre of gravity) right up the back but once fully loaded the CG will be at the forward limits! To get it in trim you have to load all the heavy stuff back in the rear of the aircraft but this will require a careful loading sequence as the maindeck cargo door is in front.

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