Take Off roll takes to much time

[cmbaviator]

Hello.

 

With the F14A, when I set the TO thrust to 90% N2, the plane take ages to reach 150kt and almost all the runway, is this normal ?

 

4xAIM54C-47

2xAIM7P

2xAIM9M

2 ET

[Spurts]

You're trying a non-AB take-off in a heavily loaded F-14A?  I would expect a long take-off run then, yeah.

[cmbaviator]

Just now, Spurts said:

You're trying a non-AB take-off in a heavily loaded F-14A?  I would expect a long take-off run then, yeah.

In chuck's guide, it is mentionned to put the Engines at 90% N2 for take off, thats what I did as you are only allowed to engage AB after the wheels are off the ground

[razo+r]

What runway are you using? It makes a big difference if you were to use for example Gelendzhik as your airfield, or Al Dafra.

[Spurts]

In Chuck's F-14B Guide... Read the Note.  AB is not allowed because of the higher thrust of the F110 motors causing controllability issues at low speed if an engine fails.  None of that applies to the F-14A with its much less powerful TF30 motors.

[sLYFa]

Its always at least MIL power and whatever rpm that gives for takeoff on both variants. There are no derated TO procedures for the Tomcat. 

[AH_Solid_Snake]

Its worth bearing in mind where the expectation comes from - for the majority of us who are just enthusiasts theres 2 broad categories of takeoff we've witnessed (IRL or videos)

• Airshow / training from a land based runway -  this is very light weight, for training maybe an ACMI sidewinder and bags, for airshows slick with the bare minimum fuel to complete the routine safely
• Operationally from a carrier - heavy but usually actually still less weight than your average players DCS sortie and most of the work being done by a 100 yard catapult stroke

The example only really found in DCS or maybe by Iran is taking operational warloads off from a land based runway, which is going to look much less impressive than either of the two aforementioned cases we're used to thinking of.

[Callsign JoNay]

Long take off roll is probably being affected by the same sticky tires that make the landing roll too short, and prevent the plane from sliding around on the deck.

[IronMike]

1 hour ago, Callsign JoNay said:

Long take off roll is probably being affected by the same sticky tires that make the landing roll too short, and prevent the plane from sliding around on the deck.

unlikely, in this case my bet is on fully laden + 90% RPM in an F14A with TF30s. Else the take off roll is fine.

(You can even recreate the taxi take off from Top Gun 2, fwiw, lol, not that that would account for any realism, but yeah. I think someone made a youtube video about it.)

Edited October 12, 2022 by IronMike

[lunaticfringe]

<3000' takeoff roll on described loadout using maneuver flaps.

With a barrier at the 3000' mark.

It does what it's supposed to do. 

 

[cmbaviator]

3 hours ago, lunaticfringe said:

<3000' takeoff roll on described loadout using maneuver flaps.

With a barrier at the 3000' mark.

It does what it's supposed to do. 

 

But you were at 100% N2 not 90% N2. I used 90%N2 with the same loadout and 14000LBS fuel lol

[lunaticfringe]

15 minutes ago, cmbaviator said:

But you were at 100% N2 not 90% N2. I used 90%N2 with the same loadout and 14000LBS fuel lol

 

And?  I took off in the correct profile for a Tomcat with TF30s with the same stores configuration and 20,000 lbs of gas.  As others have described above, F-14As use AB for land based takeoff.  

Observe.  You can even see actuation of the nozzles as they back out of burner post-rotation in those instances the burner plume isn't captured. 

 

[Callsign JoNay]

6 hours ago, IronMike said:

unlikely, in this case my bet is on fully laden + 90% RPM in an F14A with TF30s. Else the take off roll is fine.

Yeah, you're right. I did a tacview and the acceleration is pretty linear all the way. No acceleration spikes when the wheels lift up at around 200kts. My bad.

 

[Jayhawk1971]

vor 1 Stunde schrieb lunaticfringe:

 

And?  I took off in the correct profile for a Tomcat with TF30s with the same stores configuration and 20,000 lbs of gas.  As others have described above, F-14As use AB for land based takeoff.  

Observe.  You can even see actuation of the nozzles as they back out of burner post-rotation in those instances the burner plume isn't captured. 

 

Thanks for posting this video. Also interesting to see them taking off with flaps, despite being "light".

Incidentally, the video shows what I would love to be able to do in DCS one day: 

Being able to walk to the jet, do the walkaround (with the ground crew), get into the jet....all in VR. Bonus: do all that on the Carrier as well (Ready Room to flight deck).

[draconus]

On 10/12/2022 at 11:53 AM, cmbaviator said:

In chuck's guide, it is mentionned to put the Engines at 90% N2 for take off, thats what I did as you are only allowed to engage AB after the wheels are off the ground

That's simply BS.

90% rpm is only the moment you should release the pedal brakes at while engines spool up further. You take off with either MIL or AB (zone 2 preferred) - and that includes the rollout. So say NATOPS.

[cmbaviator]

1 minute ago, draconus said:

That's simply BS.

90% rpm is only the moment you should release the pedal brakes at while engines spool up further. You take off with either MIL or AB (zone 2 preferred) - and that includes the rollout. So say NATOPS.

Is AB allowed in the F14B during the take off roll ? i thought it was prohibited in case of an engine failure?

[draconus]

1 minute ago, cmbaviator said:

Is AB allowed in the F14B during the take off roll ? i thought it was prohibited in case of an engine failure?

In the OP you said about F-14A.

Correct, F-14B double engine AB take offs are prohibited.

[cmbaviator]

8 minutes ago, draconus said:

In the OP you said about F-14A.

Correct, F-14B double engine AB take offs are prohibited.

i see so the F14B only allows 90% N2 for take off roll?

 

[draconus]

1 minute ago, cmbaviator said:

i see so the F14B only allows 90% N2 for take off roll?

No, please stop using rpms. The throttle has a clear mark at MIL. You can hear the AB when you cross it and also the nozzle indicators will jump.

[Q3ark]

On 10/13/2022 at 11:56 AM, cmbaviator said:

i see so the F14B only allows 90% N2 for take off roll?

 

Use full dry power in the F14B, that 90% thing is not right, you’ll take forever to get up to speed. 

Edited October 21, 2022 by Q3ark

[Schlomo1933]

You give 100% (mil power) for take off. But when the rpm’s will reach  90% u release the brakes .