All the landing gear doors are open. Is it SOP to gravity extend with a hot gear/brakes/hydraulics indication on the 777? The centre hydraulic system on the 777 powers landing gear actuation including doors. The last item required to complete the gear extension sequence is for the gear doors to clo...
Jump to postVery interesting, yet it seems to run counter to what JetMech posted in #53 (along with links and diagrams) As noted by Kanban, yes the wings are fuel tanks, however there is no fuel in the are where the landing gear struts attach. and with reference to the diagram; https://uspto.report/patent/app/...
Jump to postLooks like the main landing gear pushed through the wing spar. Ouch! Just guessing from the pics, but it looks like the gear took the rear wing spar with it??? That could be a REALLY expensive fix….Not a lot of wing spars just lying around. From the photo on AvHerald; http://avherald.com/img/alaska...
Jump to postAlso the RB211-524G was interchanged between B767 and B744 at BA. In fact they were often to keep good engines on the ETOPS B767. The only work was blanking off a transmitter, and sorting out the thrust reverser deflector vanes. We did the same at QF too, when we acquired ex BA 763's. You also had ...
Jump to postit means it have steel brake wheel(with steel brake version wheel),they brake is carbon,but wheels are not yeah,wheels belong to the steel brake version As others have said, it's unlikely any 744 had steel brakes. In any case, the wheels are different for steel and carbon brakes. Aside from the spo...
Jump to postit means it have steel brake wheel(with steel brake version wheel),they brake is carbon,but wheels are not yeah,wheels belong to the steel brake version As others have said, it's unlikely any 744 had steel brakes. In any case, the wheels are different for steel and carbon brakes. Aside from the spo...
Jump to postSomething that has stuck with me was the incredible performance of the plane on takeoff, as it rocketed down RWY 22 and rotated sooner than practically any airliner I’ve flown on! SQ and CX flew 350's into ASP to drop off pilots and supplies. No doubt they were lightly loaded outbound, but I was no...
Jump to postthe mass of air entering the intake is increased by the fuel burnt, and if all gasses are redirected forwards, I can understand a small amount of deceleration may occur, but I can't picture how it's anything but insignificant since the air has a mass of greater than 10 times per mass of fuel burnt....
Jump to postkalvado wrote:Money is a simple optimisation metric, and in that sense similar may exist outside of human world.
kalvado wrote:Sometimes it's all about money... That is also the most fundamental of basics, though.
Or cancelled the aircraft for dispatch entirely? It certainly happens. We cancelled an A330 flight once due to a nut that was missing on an engine. The Trent 700 has four support vanes in the back of the combined nozzle assembly (green items in photo below), with each vane bolted on by four fastene...
Jump to postYes, it is all still about submicroscopic particles. It all WAS, in fact, F=ma. Just can get really complex. It certainly seems that it's all about the smallest of entities and most fundamental of basics. I don't remember which books we used anymore. 20 years ago now... Nobody forgets the joys of M...
Jump to postWayexTDI wrote:Isn't the center tank forward of the body main gear?
Very deep, but totally non-actionable as well. He was very fond of saying, "it's just F=ma" no matter how complex the equations on the blackboard were. The nature of the universe appears to be a handful of very fundamental forces and particles that combine in an infinite number of ways to...
Jump to postI wonder if the root cause was an undersized oleo strut gland nut à la Iceland Air FI529 .
https://www.rnsa.is/media/4633/interim- ... ikf-r1.pdf
Regards, JetMech
"What you basically need to know is that the faster you go, the harder and harder it gets to go even a lit bit faster." This reminds me of a quote I read in the book, Fundamentals of Aerodynamics , by John D. Anderson Jr.; "the aerodynamic forces and moments on the body are due to on...
Jump to postRight off the top of my head, I'll mention that the horizontal stabilizer on the 1011 was only 2 feet less in span than that of the 747. The tail was huge. So it had very good pitch authority, very stable. I've heard many pilots say that it was the best flying airplane they ever flew. And the DLC m...
Jump to postIf anyone enjoys this type of thing, please let me know. I can post more minutiae. There's interesting stuff all over this airplane. If you have the time and inclination to post more it'd be fantastic. Any details about the flight control system, particularly the DLC and all flying tail plane? Rega...
Jump to postOn most airplanes today, you're in either LP/IP or HP, no mixing That's my understanding too. The IP or LP bleed ducting is often equipped with a check valve specifically to prevent HP discharge air from back flowing into the IP or LP compressor. but on the A350, the "low pressure" bleed ...
Jump to postHappy 40th to the 767! I was fortunate enough to work on 767s powered by all three of the major engine manufacturers (762 P&W, 763 GE, 763 RR). I remember one of the 763 RR's had some experimental engine type fitted. Can't remember what it was specifically, but probably something to do with the ...
Jump to postIt is more than just the brakes and wheels. I cant remember if it was a LRU change or a software update for the anti-skid / autobrake. I'm sure there was a LRU change to the box that controls the anti skid. It make sense as the two types of brakes would most probably have different friction charact...
Jump to postDalmd88 wrote:We converted our 737 NG fleet to carbon.
My dears, I'm nervous and stressed to take a boeing 777-300 for an 11Hours flight ,I have a few questions and your answers will ease my mind. 8-) 1) On boeing 777-300 is there the TCAS device? 2) pilots can quickly switch controls in case of problems (as on A350) during takeoff 3) how many pitot tu...
Jump to postTire is damaged due to FOD (nose gear bolt?) on takeoff roll. Sounds plausible. Apparently, if it was FOD, it was not from the nose gear. A comment in the Avherald article states that the nose gear photo was actually taken in April 2017 at Dusseldorf. I also have it on good authority that there was...
Jump to postTire is damaged due to FOD (nose gear bolt?) on takeoff roll. Sounds plausible. Apparently, if it was FOD, it was not from the nose gear. A comment (now deleted??) in the Avherald article stated that the nose gear photo was actually taken in 2017 at Dusseldorf. I also have it on good authority that...
Jump to postYes, but I would have thought the real mystery would surely be how did the debris from the tyre bursting escape from the wheel well to cause the puncture. Am I incorrect in thinking the wheel well is enclosed? The punctured panel in question is the wall of the wheel well itself. As far as I underst...
Jump to postSurely the MLG and tyre would be fully stowed and enclosed long before the aircraft reached cruise height, would it not? Yep, that's apparently what happened. Landing gear was retracted with the tyre bursting 30-40 minutes after TO according to passengers on board. What the root cause of the tyre f...
Jump to postThe flight crew would not have been able to see any hole at that position so what do you think could have alerted them? I guess they knew they had a tyre let go from the TPIS on ECAM. Probably had no idea about the hole in the fairing though. On that note, the report say that the damage was caused ...
Jump to postThe left side flag has the field of stars in the upper left corner and stripes facing aft on the aircraft. But, you can't use this decal on the right side, it is a different part number and has the field of stars in the upper right corner with the stripes facing aft.. This started a somewhat humoro...
Jump to postToday i had possibility to check system behavoir on real aircraft, cables from mixer definitely move to both direction. Via quadrant they move valves inside actuator but spoiler remains in the same position, it is already at downstop. I think that valve inside actuator is fully open when spoliers a...
Jump to postI think the key to this is understanding which aircraft use a hydraulic to fuel heat exchanger. I only just realised it was the case drain flow by itself that gets cooled. I always thought it was the entire return flow prior to the reservoir. If I am not mistaken, the AMM mentions to not operate th...
Jump to posta) Is this oil cooler (PEOC) used a lot for airlines and MROs (maintenance, repair, and overhaul)? I've never personally seen such a device used. b) Is this oil cooler (PEOC) used only for 737 MAX or all Boeing aircraft? I presume such a device would be needed for all Boeings if you were running el...
Jump to postAs for maintenance manual, this weak signal may be a good diagnostic metric for some reason. For example, weak can become zero if there is any problem with flow or alignment... Definitely makes sense. No doubt it's a complex rigging / adjusting task when you change the mixer and / or ratio changer....
Jump to postJust speculating, but perhaps the changer doesn't care whether the spoilers are stowed by the speed-brake lever. It commands right spoiler drop for left wheel turn, in all cases. If the spoiler is stowed, then no impact. If not stowed, then the changer has the desired effect on the right spoiler. T...
Jump to postHello All, I've been reading up on the 737 spoiler mixer / ratio changer mechanism. It's an amazingly complex and clever device which takes some studying to understand. The following picture is the mixer / ratio changer in the neutral control wheel, speed-brakes down configuration. https://lh3.googl...
Jump to postIf you were to draw a line down the middle of the plane, would both sides be equal in weight? Probably not, but it'd be close to within a very small percentage of the overall OEW. As others have said, any lateral weight imbalance from airline specific cabin fitouts acts upon a very small moment arm...
Jump to post1. Lift means drag, longer takeoff roll etc. Sure, but you're going to have huge amounts of drag on takeoff in any case due to the extended landing gear and in many cases, partially extended trailing edge flaps. If anything, extended leading edge devices reduce the suction peak and thus may slightl...
Jump to postHow much of effect can be achieved with trailing edge devices only? Not sure to be honest. What I can say is the main-plane and trailing edge flaps operate much more effectively when interacting with attached flow. The role of leading edge devices is to promote attached flow by delaying or reducing...
Jump to postTo increase the AoA margin, doesn't the slat have to be fully deployed to open the slot and thus provide increased AoA margin by accelerating the air through the slot, reenergizing the boundary layer? Slats increase the useable AOA in the sealed position. This is due to the increase in leading edge...
Jump to postIs there not also something about the turbine bearing seals not fully pressurizing at low RPM and thus aircraft that tend to have longer than normal taxiing can end up with higher oil consumption? In addition, at low engine RPM, air-oil separators are less effective as they rely on centrifugal forc...
Jump to postGolly, you should see PW engines, if you want to see oil consumption. Or an A35K / Trent XWB after a 15-16 hour sector :shock: ! I guess I'm not understanding how an entry of 0 pints added didn't raise any red flags. Or is it possible to service the oil without adding any. Yes, it is possible for n...
Jump to postHorstroad wrote:spike sticking out of it (whatever it's called. I'm not familiar with the 737)
I am wondering whether Boeing and Airbus horizontal stabilizer jackscrew assemblies are vulnerable to malfunctions that would result in catastrophic losses of the entire aircraft? Modern Boeing and Airbus jack screws use the recirculating ball design with an unthreaded backup shaft mounted concentr...
Jump to postOr do any current models All the Boeing's (747, 767, 777) and Airbus (A330 / 340) I've worked on only have the single jackscrew. Pretty sure the 737, 757, 787, A320, A350 and A380 are similar. These are configured with an unthreaded backup shaft located concentrically inside the threaded shaft, and...
Jump to postDL_Mech wrote:DLC allowed for the aircraft to maintain a constant pitch angle on approach while using spoilers to correct for glide path variations.
seven47 wrote:They take a long time to transit to the selected position!
With no hydraulics, you have no flight controls! Just to add to the topic in general, the 747 flaps are powered by two of the four hydraulic systems only, with #1 powering inboard flaps and #4 powering outboard flaps. Thus, any issues associated with alternate flap extension (i.e. extended transit ...
Jump to postTristarsteve wrote:But then it must be split between the centre and tail tank in the correct ratio.
DartHerald wrote:You must be the leprechaun who maintains the Aer Lingus fleet!
celestar345 wrote:Sliding down the exhaust for the first time to remove panel for changing the ignitor plug... and forgot to keep my head down...