Flaps 60 ?

[scottb613 1,186]

Hi Folks,

 

What are "Flaps 60" for - as it states for "ground use only" ???  Do pilots actually increase the flaps setting after touchdown (new one on me) ??? I found some reference that stated the speed brakes should deploy with the flaps 60 setting as well - does this happen on the model and are the flaps/brakes effective ??? Is there a way to "arm" this to deploy automatically ???

 

Thanks...

 

Regards,

Scott

[KenG 492]

Yeah this is a Cessna Citation thing and I cannot think of any other aircraft that has this lift dump feature using flaps. As opposed to maximum effort landings on the King Airs one of our customers teaches to raise the flaps to dump lift. (I was skeptical at first but it works well on contaminated runways.)

 

From AOPA's review of the CJ3:

 

 

... One landing was a maximum performance effort, with the goal of stopping smartly. After I planted the airplane this time, Martin ran the flap control all the way down to the 55-degree "lift-dump" position while I did my best to lock up the brakes. Lift-dump not only extends the flaps to their greatest deflection — it also simultaneously deploys the spoilers. Try as I did, the brakes grabbed without sliding the tires and we stopped in a breathtakingly short distance. We figured it was about 2,200 feet...

 

I can not speak if Carenado got this right.

[flyuthere 1]

That setting is used for maintenance access.

[KenG 492]

AOPA which is a fairly reliable source calls them ground flaps http://www.aopa.org/News-and-Video/All-News/2011/December/1/The-deal-on-CJs

 

 

 

The CJ series are the first Citations that incorporate a “ground flaps” flap position for use after touchdown. Ground flaps give you a new, 60-degree flaps position that provides additional drag and lift-dumping, and automatically extends the speedbrakes. To help control the high idle thrust of the Williams International FJ44 engines and further improve landing distance, Cessna also developed a thrust attenuator system that incorporates a small hydraulic-actuated “paddle” aft of each engine; the attenuators deploy to deflect each engine’s exhaust stream sideways when weight is on the wheels and the throttles are at the idle stop.

 

Not sure why a "maintenance access" position would be accessible in the cockpit and labeled ground use. Do you happen to have the maintenance manual for the CJ2 stating this?

[scottb613 1,186]

Hi Folks,

 

Thanks for the responses...

 

I searched a bit more and I found this:

 

===========================================================================

 

FLAPS

 

General

 

The flap selector lever can be selected to the following positions:

 

UP .................................................. 0°

TAKEOFF AND APPROACH .......... 15°

LAND ............................................ 35°

GROUND FLAPS ............................ 60°

 

A slight downward pressure is required to move the handle out of the TAKEOFF AND APPROACH detent to the LAND position. The handle must be lifted at the landing stop before it can be moved aft to the GROUND FLAPS (60°) position.

 

The GROUND FLAPS (60°) flap position pro-vides increased aerodynamic drag for landing rollout. Landing performance data is based on touchdown, nose down, brakes on, then se-lecting the GROUND FLAPS position. Se-lecting the GROUND FLAPS position closes the 60° flap position switch in the quadrant, extending the speedbrakes, and directs the flaps from 35° to 60°. Selecting the FLAPS handle from 60° to 35° opens the 60° flap po-sition switch, retracting the speedbrakes, and moving the flaps from 60° to 35°. Avoid cy-cling the throttles above and below 85% N2 while in the ground flap position.

 

The ground flap position is not locked out in flight. Selection of GROUND FLAPS will significantly increase drag and sink rate. Intentional selection of GROUND FLAPS in flight is prohibited.

 

If an inflight malfunction results in 60° flaps and can not be corrected, consider carrying power to touchdown. Reducing power to idle at 50 feet could result in high sink rate.

 

Even though the ground flap position is pro-hibited in flight, it has been demonstrated that the airplane can be safely flown at the 60° position whether caused by malfunction or in-advertent selection. Do not exceed 140 KIAS.

 

The FLAPS >35° annunciator and MASTER CAUTION lights illuminate immediately on the ground if the flaps are beyond 35° and both throttles are above 85% N2. On the ground with throttles below 85% N2, no annunciator lights come on.

 

In flight, with the throttles below 85% N2, the MASTER CAUTION and FLAPS >35° lights illuminate after an 8-second delay any-time flaps are beyond 35°. The lights illumi-nate immediately if the throttles are above 85% N2.

 

Go-around should not be attempted once GROUND FLAPS have been selected.

 

===========================================================================

 

I won't be in front of my FS computer to test any of this until next weekend... I hope Carenado interlocked the flap setting with the speed brakes... Somehow I'm skeptical that all these features have been included... I think many people will probably use 60 degrees in the air for normal landings not realizing their purpose... LOL - I've already done that... It sounds like 60 degree flaps are routinely used for ground braking - on landings though...

 

Regards,

Scott

[raymar 969]

Ground flaps should never ever be selected in flight. But, the approved Steep Approach landing require the speed brakes deployed all the way down to landing.

 

Ray

[JRBarrett 3,034]

Yeah this is a Cessna Citation thing and I cannot think of any other aircraft that has this lift dump feature using flaps.

Hawkers have this feature as well. The lift dump on a Hawker is linked to the airbrake lever. After landing (with full flaps at 45 degrees), the airbrake lever is pulled back to the normal stop, then pulled out to unlock the detent, and pulled all the way back, which rapidly drives the flaps to almost 90 degrees.

[raymar 969]

Yep, the Hawker had ground flaps to assist in lift dumping way before Cessna came up with it. The basic Citation design criteria requires a short landing distance and most of the previous Citations had Thrust Reversers but they went Cheap and Simple with the CJs. The mechanical step of lifting the flap lever to get it back in the 60 Deg position is to avoid accidental deployment when on short final.

 

Regards,

Ray

[KenG 492]

Hawkers have this feature as well. The lift dump on a Hawker is linked to the airbrake lever. After landing (with full flaps at 45 degrees), the airbrake lever is pulled back to the normal stop, then pulled out to unlock the detent, and pulled all the way back, which rapidly drives the flaps to almost 90 degrees.

 

Jim,

 

 Thank you, you are right. I was thinking of lift dumping using just the flap lever to actuate and forgot about the Hawker using the speed brake lever. 

[scottb613 1,186]

Hi Folks,

 

As mentioned - traveling this week - can anyone confirm if the speed brakes deploy when setting Flaps 60 after landing ???

 

Thanks...

 

Regards,

Scott

[raymar 969]

Yes they do. Part of the short landing procedure.

 

Ray

[scottb613 1,186]

Thanks Ray !!!

:smile:

[scottb613 1,186]

Hi Ray,

 

Sorry for being vague - but you are confirming it works that way on the Carenado model as well - correct ???

 

Thanks...

 

Regards,
Scott

[toddc 0]

Yes they do. Part of the short landing procedure.

 

Ray

 

In the checklist provided by Carenado, there is a ground check for flaps, specifically Item 7 under BEFORE TAXI.  I have been unable to see this work and I am guessing it is not modeled.  Has anyone else tried?

 

The checklist item is as follows:

 

7. Flaps - CHECK and SET.

    a. Set flaps to GROUND FLAPS and verify both speed brakes deploy.

    b. Advance the throttles to above 85% N2; verify speed brakes retract and the FLAPS >35° annunciator illuminates.

    c. Retard throttles to idle; verify lights extinguish and speed brakes redeploy.

    d. Set flaps to TAKEOFF AND APPROACH; verify speed brakes retract.

 

Regards

[scottb613 1,186]

Hi...

 

I'll try and test tonight - all I can suggest is submit tickets - I've been reporting all the issues I've found even though they seem to just get a canned response from Carenado beore they close them...

 

Regards,

Scott