Ran into a problem. Trying a transcon flight, BOS to SFO. Did the flight plan in Simbrief, as normal, loaded it into the FMC, as normal. The route was there but the SB flight plan had me with 34K lbs of fuel. The jet at the gate had half that amount. I loaded the fuel, pax, cargo into the EFB as normal and nothing changed with the jet’s fuel load. Tried to calculate T/O numbers got an error message “Cannot calculate N1, select a different flap, take off thrust or reduce weight”. I’m well under take off maximums, the wind was favorable and I’m using BOS’s longest runway (4R) for the takeoff. ZFW was 132K but the FMC wouldn’t let me enter it manually. Tried to enter the actual fuel into the FMC, kept showing a sensed fuel load of 15K which didn’t come close to matching the SB amount. What am I doing wrong here?
Yeah that doesn’t sound correct. Are you in SU3? If so, there’s a bug where not all the buttons in the EFB are working correctly.
And if you’re not in SU3, then something is amiss with how you loaded the fuel.
Nope SU2. I don’t get it. Every other flight, the amount of fuel on the jet mirrors what the SB flight plan calls for. I got out of the flight and reloaded everything. This time onboard fuel is higher but still not close to what I need for the flight. This time as soon as powered up, there was a yellow “Fuel Disagree” warning next to the gauges. Still locked out from entering ZFW in the FMC. No idea what is going on. Very annoying, it’s not like a Transcon is outside the capabilities of the MAX-8, right? Is there any way to over-ride the onboard fuel that is present when you initialize the sim?
I think you can define a custom panel state but I’ve never messed with it (or needed it) in the iFly, but the EFB Weight & Balance page is supposed to let you set fuel. Are you sure you don’t have a units (lbs / kgs) issue? That is set in the EFB per livery.
As far as I know, the airplane has no idea what simbrief has calculated for a fuel load. If it’s seemed to have loaded up previously for you with the correct fuel load, that must have been a coincidence.
You have to set the fuel load in the weight and balance section of the EFB, under Fuel tab. After entering it, don’t forget to click Set Fuel or something like that on the right side of the screen.
Also, you don’t use the flight director during rotation, if that’s what you mean. (There is a rotation cue in the HUD though.). You smoothly rotate to an initial pitch attitude of 15 degrees, and then transition to flight guidance as it catches up.
Landing speeds: you add an additive to Vref of half the headwind plus all the gust factor. Minimum approach speed is Vref+5, maximum is Vref+15.
Thanks very much for the tips. Still have no idea why I couldn’t load this flight (doing an Alaska Airlines flight from KBOS to KSFO. Runway 04R is plenty long, winds were favorable, fuel wasn’t close to max (I believe it was around 36K) and I didn’t have a full load of pax. And yet, I kept getting messages that I needed to change thrust settings (I wasn’t doing a derated T/O or reduce weight. I finally ended up dropping 10 pax and 1,000 lbs of cargo and it let me calculate the T/O performance. Very frustrating. Is the real MAX8 that underperforming? Only thing I didn’t tweak was the flap setting. You don’t get any guidance from the EFB calcs so I kept it at a flaps 5 setting.
Anyone have issues with time-acceleration? Did my first transcon in the MAX and decided to try time-acceleration. Only allowed me to go to 2X. Once that was set, I started flipping through some pages in the FMC and got a hard lockup. Entire program froze, had to CTR-ALT-DEL to close down the sim.
Don’t go flipping through PROG pages. PROG page 3 causes a total freeze and game over. It’s a bug they know about.
I’m convinced you’re doing something wrong because I’ve never had such an issue with this arplane. The calculations always worked fine for me even though I wish it gave me optimum flaps and de-rate. Have you checked that you’re set to lbs as @DrVenkman3876 suggested?
Sim Rate and the EFB are my only beefs with this plane.
Unrelated to your freeze, but this plane can’t even follow lateral paths at 2x, let alone 4x. I use this plane mainly on short hops for that reason. (Island hopping in Hawaii is fun.)
Since buying this aircraft I’ve always hand flown the last 3nm to 4nm to land. However a few days ago I was coming down in a pea soup and decided to autoland. By the time I had a visual on the runway I was at around 100ft but the problem was I was also about 100ft from the centreline.
Since then I’ve attempted several more cat3 autolands and with them all I’ve always had to disable the AP and take control.
Am I doing something wrong or is this a feature with this aircraft?
I assume you experience this at different airports/runways? I can see on ILS localizer being incorrect here and there, but if you get this every time, then yeah, that’s odd.
If the PFD shows you centered on the localizer, then it’s an issue with the navdata for the airport. Be sure to check the charts - first off, not every airport and runway have approved CATIII approaches, whether due to terrain, quality/location of navaids, whatever. Second, there are runways in regular use around the world that have offset localizers. Be sure that wasn’t the case in your approach.
Thanks Steve and Doc.
Yes I experience it at different airports and there has never been any offset at any of them I don’t think.
I use navigraph and I’m careful to keep it up to date. You’ve just convinced me It’s me doing something stupid. I’ll have to review my procedures. I’ve never encountered this with any of my other aircraft though.
Thanks guys
How strange, you would think it would be fixed by now. That’s exactly what I did. Thanks for the tip.
Yes and initially that was an issue, the following issue happened after I changed it to lbs. I don’t know what to say. 157 PAX, 8,000 lbs cargo, 35.1K lbs of fuel. Wind was right down RWY 04R at 5 knots, temp was 68F, ZFW was 133.7lbs. Flaps 5, no de-rate. Entered everything and checked that it was in lbs and got the error message that I couldn’t take off with these conditions. Dropped PAX down to around 145 and lost 1,000 lbs of cargo and then provided the T/O calcs.
I had a similar circumstance using the EFB performance calculator several months ago - calm, cool day at Keflavik, 10,000’ runway (maybe longer - don’t recall exactly). Aircraft was about 2/3 full with enough gas for BIKF - BNA, a flight Icelandair does IRL. The EFB wouldn’t calculate that takeoff for me. I used the Simbrief performance calculator and it gave me a perfectly acceptable takeoff - flaps 5, sel temp of around 40C for a moderate derate, pretty much exactly what I would have expected. The plane flew it perfectly. So whenever I get a weird result with the EFB performance calculator, I just use Simbrief instead.
The takeoff calculator most likely wanted a higher flap setting. Flaps 15 would likely have fixed it, and flaps 25 is always an option (Maxs are all SFP aircraft). Would a real Max 8 have required more than flaps 5? I’m not sure, I’m usually leaving BOS in a Max9 or -900ER (which often would). I know it’s a 10,000ft runway, but there’s a large difference between a light airplane and a full one. That’s not “underperforming”, that’s “versatile”. Also though, I’ve seen the team discuss tweaking the takeoff calcs so it might change. When I’m trying to sim a real flight vs zapping around and having fun with FSIPanel, I do what I’d do in reality and just take the takeoff data as it comes - if it wants a 28k flaps 25 bleeds off takeoff, sure, we’ll do that.
Funny, I’ve read the bug about prog page 3. Intentionally tested it the other night and was able to scroll through all progress pages forwards and backwards with no issues. So I guess it’s not an all the time thing and I just didn’t find the right conditions.
Yeah, especially when that’s the PROG page 3 which is the only place where you can read OAT 