How Much Ballast Are You Carrying Around?

[Milt]

Ballast in Aircraft

Most aircraft, if not all, are ballasted with lead or tungsten weights to retain stability in pitch over approved cg ranges within their performance and manoeuvre envelopes.
What with down loads on the tails and ballast weights for pre fly-by wire (FBW) aircraft there should be considerable efficiencies available to the future designs using FBW.

Some crafty designers move heavy items such as batteries instead of having to use excessive ballast weights. Then some spoil it all by placing APUs in the tails. Often the positioning of batteries in helicopters becomes critical.

How much ballast is there in the aircraft with which you are familiar and if not in the nose where else will you find it?

[411A]

Well......
Take the FH227B for example.
When Fokker stretched the F.27, it was by three feet forward of the wing, and three feet aft.
Fairchild, on the other hand, stretched the F-27 by six feet ahead of the wing, so...batteries and all sorts of other items went to the tail.
There was a benefit however...the cargo door was further from the LH propellor....dicing and slicing reduced.

[Tarnished]

Milt,

I'm not sure if the benefits of reduced stability made possible in fighter-size aircraft through the introduction of FBW will actually be allowed to be realised in commercial airliners.

The trouble being that an unstable aircraft is very difficult to fly manually, and whereas it is "acceptable" to loose a fighter because there is no "realistic" manual reversionary system when the FBW system fails, I can't see the loss of a future unstable FBW passenger aircraft with however many souls onboard being palatable (no matter how low the reliability numbers work out to be).

Not sure how the Airbus family of aircraft work in this respect, do they still have a SSLP (suitable system of levers and pulleys) to connect the pilot to the control surfaces ??

T

[Old Smokey]

UNWANTED BALLAST

Back in my youth when I was just a boy pilot, we flew enormous quantities of freight into the New Guinea Highlands on DC3s, there was no other way, no roads, so everything went by air.

One particular DC3, known as being 'gutless', had, over the years carried literally thousands of tons of cement into the highlands. Slowly, oh so slowly, the cement dust was sifting down through the floor cracks and settling on the keel, and in the tropical humidity became hard.

At the next major overhaul, 2000 Lb of hardened cement was removed from the keel. After that, the aircraft performed just as well as any other.

A bit off topic sorry, but there's ballast you want, and ballast you definately don't want.

[Paladini]

Just found an infrequently used HP computer charger lodged in the bottom of my Nav Bag... under some Company Memoranda.. the charger has been removed to a more suitable location.... memoranda still in place.

Hadn't seen this particular chunk of electronic gizmo for over 4 months......

How much ballast is being schlepped around the world tucked neatly beside your seat...... that's pretty far fwd of the CG!

Next time you go through "security" (heh heh) in DXB, ask Mohamad if you can take a peek at his screen to see what's actually underneath your CD's, Leathermen, and Nav compasses! Maybe you can identify them by shape, he certainly can't!!!!

A "lost" high-tech steak knife which also showed up in my "carry-on" had been there since September and had remained thoroughly undetected on 3 separate trips through LAX.....
:uhoh:

Guys, sometimes we MUST police ourselves.

[Milt]

Old Smokey

2000 pnds of cement on the keel would have been a BIG handicap for a Gooney. Probably meant that your AUW fully loaded was always 2000 pnds over.

Must have been a hell of a job getting the cement out. Any Pictures?

I think it was 26,000 pnds AUW for civil and 28,500 for Mil.

Do you know whether a Gooney had any lead in the nose?

And was Leon Murtagh with you in PNG ?

[etrang]

"Most aircraft, if not all, are ballasted with lead or tungsten weights "

Isn't DU the preferred ballast these days?

[Milt]

etrang

Used to be DU but it became a bit of a potential PR problem.

Pure Tungsten has about the same density and doesn't need the regular attention required of DU so tungsten is taking over from DU.

[Old Smokey]

Milt,

The overhauls were done in Australia whilst we were in New Guinea, so sorry, no pictures.

Yes quite right, 26,200 was Max AUW for the Civil DC3, so, using your figures we had artificially militarised it, well, almost.

Do I know whether a Gooney had any lead in the nose? - No, only a dead weight in the right hand cockpit seat, ME.

I'm sorry that the name Leon Murtagh doesn't ring a bell, we were a pilot population in transit, so whilst many names are indelibly remembered, some are complete strangers.

Regards,

Smokey

[john_tullamarine]

(a) haven't seen Leon in years .. he ended up in Ansett mainline

(b) don't think DU has been used in civil aircraft .. although a post accident problem from time to time with military

(c) DC3 middle age spread is much the same problem as we all have .. although a good major can go a long way to fixing it up .. best I can recall for a Gooney was around a 400 lb gain by cleaning up the bilges

[gas path]

don't think DU has been used in civil aircraft .. although a post accident problem from time to time with military
The B747-100 series aircraft had DU mass balance weights on the rudders/elevators and outbd ailerons, (I'm not entirely sure but it may have been replaced by Tungsten in the latter years on some fleets) also the JT9d engines had DU in the nose cowl on the outbd engines (can't remember why but I think it was to damp out 'pod nod') this was later replaced with a big lump of tungsten in the end of the exhaust cone on all engine positions that had the same effect and also 'detuned' the natural resonance.
The DU used to be inspected for corrosion and paint damage.
It did become something of an issue after the loss of PanAM 103 when the NRPB got all excited and there was a problem in finding out how many weights were fitted and where.

[john_tullamarine]

... learn something new every day ....

[Flightwatch]

In the 60's and 70's BEA aircraft procurement department had a great reputation for specifying requirements on new aircraft which subsequently made them very poor sellers compared with their American cousins. The Trident was a good case in point - it would have been a worthy competitor to the 727 if Hawker Siddley had been left to their own devices.
The BAC 1-11 was similarly "modified", happily only in the 18 examples specifically ordered by BEA. The theory was that since the aircraft was to be used mostly with the then new Jetways the forward integral airstair was deemed to be surplus to requirements and removed, leaving only a small step which was mechanically operated by a lever adjacent to the door once opened. The neccessary mods were ordered and doubtlessly handsomely paid for by BA but the c of g was found to be unacceptable. The answer was to mould around 300lbs of lead to fit in the airstair well which was carried about until the scrap man called (gloating?) and cost significantly more than leaving the airstair as it was intended to be.
The irony was that for the first 7 years of service most of the fleet was based either in Manchester or Tempelhof neither of which had jetways in those days, neccessitating the purchase of many more sets of steps than would otherwise have been the case! In the 14 years I flew these aircraft we had forward steps provided on a vast majority of occasions and where a jetway was available they had to be modified with a special cut out in the leading edge of the platform to fit around the door thus allowing it to marry up to the aircraft floor or a movable "plank" which fitted onto attachment points in the aircraft step so the pax didn't fall down the 6 inch gap to said step.

[cirrus01]

DU also used on the DC-10s...... certainly on the balance weights on the Outboard Ailerons and Elevators :ok:

[unowho]

Usually only the navigator, waste of space where extra fuel should have been. Civil equivalent I suppose is the passengers (Hee Hee)

[airborne_artist]

The BAC 1-11 was similarly "modified", happily only in the 18 examples specifically ordered by BEA. The theory was that since the aircraft was to be used mostly with the then new Jetways the forward integral airstair was deemed to be surplus to requirements and removed

This story has been repeated - on the Typhoon - the UK didn't want a gun, but that affected the CoG, so they've put the gun back in, but won't use it!