A400 question
What wake category is an A400? I heard a Luftwaffe one recently that was using a heavy suffix.
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MTOW 141T. Makes it a “Heavy”. Just.
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Thanks. I heard it on the radio and thought it might be an A340 , so was surprised to see it sitting on the ramp in KEF.
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Not just the weight I'd guess - those turboprops must generate quite some turbulence in their own right
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Originally Posted by Heathrow Harry
(Post 10064486)
Not just the weight I'd guess - those turboprops must generate quite some turbulence in their own right
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Someone on the "Gaining a Pilots Brevet..." thread told me that on the Hastings (1960's) that when dropping supplies, the 2 inner engines were throttled back to make airdrop easier/ more accurate for the crew down the back...
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The inboards on the Hastings were 'throttled back' when dropping paras and then increased again on the 'troops gone' call. This posed problems for the despatchers manually trying to retrieve the bags ! But at least the paras did not cross behind the a/c.
On the Hercules crossover and collisions was always a problem on side door exits which despite some less than clever schemes was never solved. It was accepted by the army as an occupational hazard. Over the ramp jumping and other airdrops were not a problem. It sounds as if the A400 has more severe problems. Perhaps someone could enlighten us. |
A400M is proving a very expensive platform, and seems unfit for purpose, the issue with the deployment of para`s is just a long list of issues blighting this aircraft.
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Originally Posted by ancientaviator62
(Post 10065361)
The inboards on the Hastings were 'throttled back' when dropping paras and then increased again on the 'troops gone' call. This posed problems for the despatchers manually trying to retrieve the bags ! But at least the paras did not cross behind the a/c.
On the Hercules crossover and collisions was always a problem on side door exits which despite some less than clever schemes was never solved. It was accepted by the army as an occupational hazard. Over the ramp jumping and other airdrops were not a problem. It sounds as if the A400 has more severe problems. Perhaps someone could enlighten us. Over the ramp static line parachutists and boxes were “sucked” forward. Fix was to lower the undercarriage. Never saw a problem with Freefall but they made a great play when the head of Airbus made the first jump. Just showed that Sir Issac had been right all along. I always anticipated that the latches for platforms would never be 1x 10^-6 for anything like an MSP or small TypeV platform. Rumour has it that they have been working towards dropping small vehicles. Probably nothing more than was dropped from Halifax around D day! I remember being in town when it was announced the C17 was inbound but could not be used tactically. The SF Colonel said. “Paint them white and park them up at Brize Norton” nearly 20 years later money is being spent developing tactical clearances for C17 |
"A400M is proving a very expensive platform, and seems unfit for purpose, the issue with the deployment of para`s is just a long list of issues blighting this aircraft."
regretfully there has hardly been a modern aircraft that hasn't had serious issues - everyone is pushing the envelope harder and harder........ TBF I don't think dropping paratroops is really very relevant in this day and age - it's pretty much restricted to Special Forces |
Originally Posted by Heathrow Harry
(Post 10068184)
regretfully there has hardly been a modern aircraft that hasn't had serious issues - everyone is pushing the envelope harder and harder........
TBF I don't think dropping paratroops is really very relevant in this day and age And why did Airbus go with a turboprop design? The required powerplant needed tremendous development money. Had they gone with CFM-56s in a C-17 style nacelle the money spent to develop the engine, gearbox, props, etc could have gone to designing in the tactical capabilities from the start. And it would have had equal or likely better tactical capabilities than what the turboprops could provide. This seems like a poorly managed program from the get-go. |
KenV
C-17 had numerous issues in its early days... |
Where to start.....
Sadly, the C-17s that the RAF already own can do all the tactical things the A400 is supposed to do (and more Had they gone with CFM-56s in a C-17 style nacelle the money spent to develop the engine, gearbox, props, etc could have gone to designing in the tactical capabilities from the start. And it would have had equal or likely better tactical capabilities than what the turboprops could provide. This seems like a poorly managed program for the get-go. |
Originally Posted by pr00ne
(Post 10068226)
KenV C-17 had numerous issues in its early days...
In contrast, Airbus has produced 65 A400s over a span of 8+ years. Yet not only is the program not stabilized, but the aircraft delivered do not have the promised tactical capabilities and apparently will never get some of them. |
Yet not only is the program not stabilized, but the aircraft delivered do not have the promised tactical capabilities and apparently will never get some of them. |
Originally Posted by Trumpet_trousers
(Post 10068240)
Where to start.....
.... wrong. ....The customer specified/demanded the choice of powerplant. The A400 started out as FIMA (Future International Military Airlifter) and the FIMA group included Lockheed. It was a slightly enlarged C-130/C-160 and intended as a C-130/C-160 replacement. That program went nowhere. Lockheed pulled out and developed the C-130J on their own. The European consortium did not want to compete with the J, so they proposed a bigger airplane that became known as FLA (Future Large Aircraft.) There were multiple versions of FLA and the first iterations had turbofans. But they did not want to appear to be competing with C-17, so the consortium went with a turboprop and proposed that to the various governments. The government "specification/demand" for a turboprop was the FLA consortium's own doing, as the governments specified what the consortium offered. The point being that the turboprop "requirement" locked out C-17. Eventually Airbus took over the FLA consortium and by that time, the turboprops were well established and Airbus, for whatever reason, did not want to switch to turbofans. Speculation was that SNECMA had the political clout to keep the program sold to the governments since they were developing an engine based on the M88 core. But that core was too heavy and not efficient enough, so they had to go with a clean sheet design, which cost even more to develop. But turboprops over turbofans added nothing to performance (indeed in some areas they degrade performance) but they were perceived as effective in locking out C-17. The thing about the TP400 is that it's the most powerful single-rotation propulsion system ever developed. There are more powerful turboprops, but they all have two contra-rotating prop discs. A400 is in uncharted territory which is proving to be rather problematic and in hindsight may be a bad choice. But that's what happens when politics drive engineering decisions. |
Originally Posted by Trumpet_trousers
(Post 10068269)
Wrong..... again...
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Remind me again how they solved the crossover problem for side door parachuting on the C-17?
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Originally Posted by Trumpet_trousers
(Post 10068351)
Remind me again how they solved the crossover problem for side door parachuting on the C-17?
1. Floor angle. To get the required floor angle required a specific airspeed and AOA, which required experimenting with different flap deployment angles till they found the right one. 2. Air deflector angle and deflector hole size and pattern. There was lots of experimentation with different air deflector angles and hole sizes and patterns 3. Longer static line. Initially a 10 foot static line extension was added for C-17 only. This added to logistics complications (the Army owned the parachutes, but USAF owned the C-17 unique extensions), so all parachutes were equipped with a 10-foot longer static line regardless of the aircraft being jumped from. But C-17 has turbofans so the airflow around the fuselage is very different than A400. C-17 never had the ramp jump problems the A400 is (reportedly) having, and C-17 never had the bundle, CDS, and LVAD airdrop problems the A400 is (reportedly) having. C-17 also has dual-row airdrop, which is unique to C-17 and A400 does not have. Don't know if all the A400 problems are due to the giant props on the A400, but that's the single biggest difference between the two aircraft. |
Any changes at the non-aircraft level, other than your point #3?
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