Landing with Speed Brake open

[Gianlc]

I haven’t found anything on the F-5 flight manual about approach and landing with speed brakes open, but have seen a few photos of real Navy F-5 approaching with them down. Anyone knows if it’s a normal procedure, and when do they do this? Thanks!

Edited March 14, 2023 by Gianlc

[=475FG= Dawger]

When they is too fast and at idle already or need some throttle to keep the engine spooled, they put the speed brake out. Its that simple.

Edited March 14, 2023 by =475FG= Dawger

[Gianlc]

I don’t think that is that simple. First of all, you don’t go idle on final approach with jet engines. Second, the SB will change flight characteristics and will have impact on AOA and scheduled speed. I wanted to know the real procedures, not just plain out guessing. 

[Bummer]

When landing with speedbrakes open, you fly with more throttle.

When you get in a situation where you need more speed quickly, closing the speedbrakes and giving it more throttle get you that speed faster, then waiting for the engines to spool up if you only have the throttle to get you more speed.

Not an expert, so could be wrong.

[=475FG= Dawger]

12 hours ago, Gianlc said:

I don’t think that is that simple. First of all, you don’t go idle on final approach with jet engines. Second, the SB will change flight characteristics and will have impact on AOA and scheduled speed. I wanted to know the real procedures, not just plain out guessing. 

My 6000 hours in jets begs to differ.

When you go to idle is entirely dependent on the engine, but you always get to idle prior to touchdown.

The speed brake is an error correction tool on final, not a "procedure". Quite a bit of flying is not written in some procedure to be slavishly followed. You do have to do some pilot stuff that isn't spelled out for you on paper.

[Cab]

12 hours ago, Gianlc said:

I don’t think that is that simple. First of all, you don’t go idle on final approach with jet engines. Second, the SB will change flight characteristics and will have impact on AOA and scheduled speed. I wanted to know the real procedures, not just plain out guessing. 

It really is that simple. 

Extended speed brakes on final keep the jet engines at a higher, more responsive, RPM range.

[YouBet]

4 minutes ago, Cab said:

12 hours ago, Gianlc said:

I don’t think that is that simple. First of all, you don’t go idle on final approach with jet engines. Second, the SB will change flight characteristics and will have impact on AOA and scheduled speed. I wanted to know the real procedures, not just plain out guessing. 

It really is that simple. 

Extended speed brakes on final keep the jet engines at a higher, more responsive, RPM range.

Agreed.

I don't have 6000 hours... but we always flew aboard with our speed brakes deployed. Kept our engines spooled up and more responsive to the type of small corrections we needed to make in the groove. It was a checklist item spelled out in NATOPS.

I've never flown the F-5 or seen its NATOPS manual, but it wouldn't surprise me if the Navy put that item in the checklist (even for land-based aircraft). Violate NATOPS at your own peril.

[Cab]

5 minutes ago, YouBet said:

Agreed.

I don't have 6000 hours... but we always flew aboard with our speed brakes deployed. Kept our engines spooled up and more responsive to the type of small corrections we needed to make in the groove. It was a checklist item spelled out in NATOPS.

I've never flown the F-5 or seen its NATOPS manual, but it wouldn't surprise me if the Navy put that item in the checklist (even for land-based aircraft). Violate NATOPS at your own peril.

Exactly. It they're extended on final, that's the only reason I know of. 

[fagulha]

The brake opened on final makes the engines RPM go up. it´s done for a quicker response from the engines while landing as already stated.

[Bucic]

Speed brake is usually retracted for landings
https://www.youtube.com/watch?v=Seqwlg95YTs

 

[Gianlc]

I understand that, but The F-5 doesn’t have as much power as the F-18 for example. I know that using SB on final in the T-38 is forbidden, because of the power restriction, I wanted to know if there is some kind of criteria for using SB or not, something like config, temperature, weight. Also if there is some kind of correction on the final approach speed calculation considering when they are deployed. I know that will keep the RPM higher, but the F-5 approaches deep inside the reverse command area, don’t know about other jets. Thanks for the help so far. 

[Cab]

1 minute ago, Bucic said:

Speed brake is usually retracted for landings
https://www.youtube.com/watch?v=Seqwlg95YTs

 

Getting back to the OP, yes, that does seem to be the case for the F-5

The US Navy, however, may very well have different procedures that normally has it extended for approaches. I really don't know.

[Gianlc]

2 minutes ago, Bucic said:

Speed brake is usually retracted for landings
https://www.youtube.com/watch?v=Seqwlg95YTs

 

I know, but I’ve seen them deployed a few times, that’s why I wanted to know the parameters and criteria for using them. 

[VZ_342]

I often use SB during landings, I get bored easily with proper glide slope and airspeed. I tend to turn on final a little hot, drop RPMs to idle, gear out, SB out, watch airspeed drop until 220ish, then retract SB and increase throttle promptly to keep the airspeed at a proper rate. If I've really messed up I'll do a go-around, but most times it's a good landing.

Edited March 15, 2023 by VZ_342

[nairb121]

The -1 notes speed brake on approach variously as "as required" or "as desired", which suggests to me that its use is optional, either based on pilot preference or squadron procedures. Speed brake usage is not elaborated on further other than what is shown in the diagrams.