727 Flight Planning

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727 Flight Planning

Postby David Reed » Mon Oct 15, 2018 11:24 am

Recently I flew the Trip of the Week using the First Air 727-44C. These flights in the frozen north need careful planning. Alternates are distant, runways are short and weather is unpredictable.
Our first leg is from Iqaluit to Arctic Bay, 662 nm over frozen tundra. Flight plan says it will take us 1+36 block time. Arctic Bay's gravel runway is only 3935' long, so for jet service I upgraded it to pavement and lengthened it to 5500'.
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Flight planning the 727 is all about weight. The limiting number isn't maximum takeoff weight, it's actually landing weight. First, let's calculate our zero fuel weight.
Empty weight: 91,100 lbs
Passengers: 52 @ 180 lbs each = 9360 lbs
Cargo: 4x pallets, 22,500 lbs
ZFW: 122,960 lbs. (max = 132,000 lbs)

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Next, let's compute fuel requirements. We will use our departure airport as our alternate. It's a little more predictable. 1.6 hrs enroute, 1.6 hrs to the alternate, .75 reserve, .50 for flying the approach and giving us some extra. Total is 4.45 hrs of fuel needed. I normally figure on 6600 pph, so that is 29,370. Being the conservative type, I'm going to round this up to an even 30,000 lbs.
ZFW 122,960 + 30,000 = 152,960 lbs takeoff weight (max 169,000 lbs).

So far we are under the zero fuel limit, and well under our maximum takeoff weight limit. Let's see if this works. Subtract enroute burn and this will be our landing weight. 152,960 - 10,560 = 142,460 lbs (max 142,500 lbs). We should be landing a mere 40 lbs under maximum landing weight. This will be a fairly fast Vref, so we must consider runway conditions (clear, snow or ice covered) and wind (pray for a good headwind). On landing we will definitely be using all of the flaps and lots of brakes. No messing around, plant it in the touchdown zone! And that's how you flight plan a 727 :)

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David Reed
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