|Quoting PolymerPlane (Reply 68):|
Come on. You know it's true that required runway length is not used only for take off.
Far from it, the shortest runway performance on the A330 is obtained from using high flap settings and an engine derate to reduce the V1/Vr speeds, this is exactly what we use when we takeoff from 16L/35R with the A330 at Narita (RJAA/NRT
) which is only 7,153 ft long.
The min V speeds for the 330 are around V1=113 kt, Vr=113 kt, V2
=116 kt, for full thrust takeoffs speeds are up more around 140 kt plus, the engines can be derated up to 40% which reduces the V speeds for takeoff. We also normally do packs off takeoffs for better performance as well.
Also my reading of the RFP did not seem to indicate that the 7,000 ft was a balanced field length requirement, I read it to mean 7,000' take off run available (TORA), for heavy jet performance charts when they have the limit code 3, it is for runway length limit, referring to TORA, this would assume that the runway would have an infinite clearway as post liftoff we have not was of knowing what the fist, second, third, and final segment obstacle requirements are.
"The offeror shall document the ability of the proposed KC
-X aircraft to operate, including takeoff gross weight, from a 7000 ft runway for standard day conditions and using FAA ground rules."
So according to FAR
25.113 Subpart B 126.96.36.199. Runway with Clearway
a) The takeoff run on a dry runway is the greater of the following values :
TORN-1 dry = Distance covered from brake release to a point equidistant between the point at which VLOF is reached and the point at which the aircraft is 35 feet above the takeoff surface, assuming failure of the critical engine at VEF and recognized at V1,
1.15 TORN dry = 115 % of the distance covered from brake release to a point equidistant between the point at which VLOF is reached and the point at which the aircraft is 35 feet above the takeoff surface, assuming all engines operating.
From memory the 767 also had an exemption to the current FAR
25.109 regs for accelerate stop distance calculations, so the 767 and 330 numbers may not be comparing apples with apples as the 330 was certified post FAR
25 amendment 42.
|Quoting BlackKnight (Reply 69):|
A comment like this clearly shows that you do not understand military aircraft and the additional equipment they carry.
It actually shows that I have read the USAF
fleet maintainability report, and the majority of the KC
-135 that are in deport level maintenance are there for serious problems, some spending upwards of 400 days in maintenance according to the USAF
Retiring the aircraft with the most serious problems could then automatically free up to 400 days of maintenance for a single aircraft, with the USAF
planning on retiring 48 KC
-135s this year, the additional availability of hanger space could be significant.
|Quoting RedFlyer (Reply 70):|
So after 10 days of asking this question in this thread and another one, and countless replies, no one has yet to step forward and say definitively that the KC-30 can take off in 7,000 feet.
Considering we operate from Narita runway 16L/35R with the A330 I don't think it would be a problem (I guess other A330 operators do as well). But as I said before I don't have a chart to show you, our takeoff performance data is calculated by our mainframe for the actual runway conditions for each takeoff via ACARS, we don't have charts. Also our numbers are padded by 10% to give us some more buffer.
Also MTOW is a moving target with the A330, it has more than one depending on what is was built as, full fuel on some A330s would actually put the aircraft over MTOW, e.g. the latest weight variation has a MTOW of 192,000 kg, 35,000 kg below the KC
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