Suggestions for IF

I have had overspeed issues regarding the A350 and B772. These aircraft even on a light load, refuse to slow down at light downward pitch even with the correct airspeed given to the autopilot. I am aware of the airbrake function in the game however with VNAV I have no knowledge of when the moment the aircraft begins to descend hence I cannot activate the spoilers accordingly even after setting the airspeed. This has lead to two airspeed violations within the last year, for which I claim no fault of my own. I strongly suggest either adding an automatic speed brake, or allowing waypoints to have speeds input alongside or remodeling the aforementioned aircraft to slow down on light descents as I presume they do in real life. The circumstances regarding the overspeed are 14,000ft at 240KIAS descending to 9,000ft. The B772ER accelerated to nearly 290KIAS during a -1,800 fpm descent on idle power. I heard the warning from Approach and activated the spoilers. However even the spoilers are lethargic hence my inability to slow down before I was given the violation. I am unware if these characteristics are correctly modeled.
Also even after the minor annoyance the app crashes as I check my grade 3 info after hours of flight panning, enroute and excitement for this update; overall i’ve had a bad day. I seek clarifications on if these traits are realistically modeled or a way to avoid this issue in the future and I suggest to IF dev team to think of a possible prevent this issue as I’m sure it’ll become more common due to the user not being always immediately present due to VNAV doing a lot of the work automatically.
Thank you for reading this far!

so
that should not happen
make sure that you are not descending to fast, also make sure you are using the VNAV
it helps alot

Howdy! You should always be at your device during descent. VNAV has not been implemented to allow you to have more time to brush your teeth in the morning. :D Stay attentive to your aircraft and monitor you v-speeds. Try descending earlier with a lesser vs. As to you not knowing when your aircraft will descend, you should keep your aircraft cruising until you are ready to descend and are at your device. About one minute before the TOD (top of descent), turn on VNAV and monitor your speed. Here’s a link to Infinite Flight’s new user guide where it explains how to properly use VNAV:

1 Like

These aircraft were tested by real world pilots who have flown these aircraft in the real world and have made mention that it flies like the real thing. In terms of drag coefficients and other forces acting on the aircraft, its fairly accurate in terms of physics.

4 Likes

Btw I was using VNAV that’s the issue. It overspeed basically by itself. VNAV starts an automatic descent, somehow in 5,000 ft at 1,800 fpm the aircraft gained 50+ knots of airspeed with idle power. Which I am certain isn’t right.

Good to hear. Did you test the crjs :)

Heyy, btw I saw you controlling at MMMEX center.

What altitude was your TOD at and what speed was your autopilot set to while descending?

I was flying MMMEX to KLAX via SNSTT2. I was flying FL360, TOD was about 174nm out. My autopilot during the descent was set to hold 240KIAS to maintain the distance from the aircraft in front and behind me.

The issue starts to happen when even at a shallow descent of 1,800 fpm and idle it gains 50 knots in 5,000ft.

@Frequentfliyer I did get to test the CRJ but this was before I flew it IRL.

@SeekingSunsets229 Yes. I controlled Mexico and Albuquerque Centers for just under 2hrs this evening. 🙂


Going back, was your question/concern addressed regarding how detailed the physics are. I will say, taking the 777 into KLAX on one of the arrivals, it was near impossible to slow down due to how the arrival and its waypoints were set up. When the waypoints are close, the aircraft groundspeed is high, and the altitude change between waypoints are of a decent change, we run into an issue of excessive descent rates. VNAV will max out at -3000fpm

For VNAV, the bottom altitude meaning the lowest altitude for a waypoint, is used. IRL we have an altitude range that we can cross certain fixes at. For example if the waypoint name was FLIGT and we had to cross it below 17,000 and above 15,000, Infinite Flight will say ok, we’ll take 15,000 and use that for VNAV. When in the real world we aim for an altitude between the altitude constraints listed on the chart. Its much more challenging to try and code something when we have constraints where an aircraft needs to cross waypoints at. So instead, giving it one altitude to cross at was determined to be favored.

Hope I explained that in a way that makes the slightest amount of sense.

2 Likes

Load at T/O was 58,000 lbs of fuel, 16,000 pounds of cargo and 299 passengers.
At that point, I remember 24,000 lbs of FOB.

Since you weren’t monitoring your flight during descent, perhaps take a look at the replay and see if you can figure out what caused this overspeed.

I did, that’s how I got VNAVs rate of descent.

1 Like

Was this speed increase rapid or gradual?

Thanks for the input, what really gets my me, is that I had 240KIAS input but it still went awry. :(
In terms of the question, it was answered, thank you!

2 Likes

It was gradual.

Btw if you’re lost, I mean overspeed as in the 260KIAS limit below 10,000ft. Not the aircrafts performance limit.

Happens to me too. Nothing that can be done other than trying to hand fly it. VNAV is just too accurate. So accurate it will try to overspeed the aircraft because we as pilots programmed it. Sometimes we may need to disengage and show 'em who’s boss!

2 Likes

I can definitely recommend watch a tutorial about VNAV!