flashlight?

[fitness88]

>I was wondering what this command is supposed to do as it doesn't work?

"LAlt - L" -flashlight

Also, I don't see the radar altimeter showing on the HUD when in ILSN under 1000'.

Does it work?

 

Instrument Landing System Navigation (ILSN)

"At an altitude of less than 1,000 feet, along the right side of the HUD, there appears a radar altimeter scale, graduated in hundreds of feet. The current radar altimeter bar moves along the left side of this scale."

P.40

 

I understand once you're comfortable with your plane pilots calculate rate of decent visually at touchdown. The F-15 unlike many other planes doesn't have a VVI on the HUD only at the bottom of the instrumentation panel so I'm finding it a bit of guesswork on my initial touchdowns...with a few bent landing gears.

Any suggestions?

 

Thank you.

[Svend_Dellepude]

Instrument Landing System Navigation (ILSN)

"At an altitude of less than 1,000 feet, along the right side of the HUD, there appears a radar altimeter scale, graduated in hundreds of feet. The current radar altimeter bar moves along the left side of this scale."

P.40

 

AFAIK F-15C doesn't have one.

[fitness88]

AFAIK F-15C doesn't have one.

 

Page 40 of the F-15 manual is where I quoted from.

[Svend_Dellepude]

I thought that.

Probably a leftover from old times.

The F-15 manual is not completely up to date.

 

There is a post from GG here:

http://forums.eagle.ru/showpost.php?p=2241311&postcount=2

[MikeMikeJuliet]

From what I've found, a good plan is to keep the flight path marker over threshold at 3 degrees decent, and keep a good speed crossreferencing the AOA-indicator on the hud. About 18-20 degrees of alpha seems to be good, and flare for landing for a touchdown at 22 degrees alpha.

 

As the AOA takes weight into consideration, you only need to keep the proper alpha and your speed is good regardless of loadout... as long as you are with full flaps.

[fitness88]

I thought that.

Probably a leftover from old times.

The F-15 manual is not completely up to date.

 

There is a post from GG here:

http://forums.eagle.ru/showpost.php?p=2241311&postcount=2

 

Yes I had read that, GG was referring to radar altimeter during regular flight, I was referring to landing only.

Thanks for the reply

[fitness88]

From what I've found, a good plan is to keep the flight path marker over threshold at 3 degrees decent, and keep a good speed crossreferencing the AOA-indicator on the hud. About 18-20 degrees of alpha seems to be good, and flare for landing for a touchdown at 22 degrees alpha.

 

As the AOA takes weight into consideration, you only need to keep the proper alpha and your speed is good regardless of loadout... as long as you are with full flaps.

 

Getting that flare right and holding it is really important, done correctly will slow you right down very quickly.

I've found speed and AOA cross reference each other when one is correct the other is too so long as you have the correct angle of decent...as you stated 3 degrees.

Thanks.

[GGTharos]

There is no radar altimeter in any flight phase for the F-15.

Be aware of your airfield's elevation.

 

Regarding the landing, 20-22AoA for approach (21 ideal) with a 2.5-3deg glideslope. Flare when the runway fills the HuD.

[fitness88]

There is no radar altimeter in any flight phase for the F-15.

Be aware of your airfield's elevation.

 

Regarding the landing, 20-22AoA for approach (21 ideal) with a 2.5-3deg glideslope. Flare when the runway fills the HuD.

 

I see, so it was mis-information in the manual that had me confused.

I will practice your approach and hopefully soft landing technique.

Thanks.

[fitness88]

I've read that discrete braking can occur when you use pedals with each mapped separately. However with no pedals 'W' is used as only on/off. Is there a way to use discrete braking without pedals?

[GGTharos]

I don't believe so.

[fitness88]

There is no radar altimeter in any flight phase for the F-15.

Be aware of your airfield's elevation.

 

Regarding the landing, 20-22AoA for approach (21 ideal) with a 2.5-3deg glideslope. Flare when the runway fills the HuD.

 

For the 2.5-3deg glideslope to be achieved am I using the datum or the velocity vector on the HUD at -2.5-3deg on the pitch ladder?

[Svend_Dellepude]

You will use the FPM for that.

The datum doesn't tell where you are going but only where your nose is pointing.

[MikeMikeJuliet]

There is no radar altimeter in any flight phase for the F-15.

Be aware of your airfield's elevation.

 

Regarding the landing, 20-22AoA for approach (21 ideal) with a 2.5-3deg glideslope. Flare when the runway fills the HuD.

 

I stand corrected. Anyway, I felt it easier to fly final with a little less alpha, otherwise my flare seems to give me too slow speeds at touchdown. Perhaps I flare just a little bit too much.

 

Does the manual say anything about max alpha at landing, btw?

[GGTharos]

No problem, I know flying 21 uAoA is a little less comfortable, but it will help you avoid floating in the flare or bouncing.

Your touchdown AoA should be less than 25; higher AoA will result in a tail-strike.

Aerobraking on the roll out is not very effective if less than 23 units.

 

This is for the normal/standard landing approach in the eagle.

[fitness88]

You will use the FPM for that.

The datum doesn't tell where you are going but only where your nose is pointing.

 

Thanks...sorry about that MikeMikeJuliet mentioned it earlier and I missed it.

[fitness88]

There is no radar altimeter in any flight phase for the F-15.

Be aware of your airfield's elevation.

 

Regarding the landing, 20-22AoA for approach (21 ideal) with a 2.5-3deg glideslope. Flare when the runway fills the HuD.

 

I wonder why it was not thought important enough to have radar altitude capabilities?

I know radar altimeter has alerted me several times to the ground coming up at me when flying through mountains in poor visibility. I know I should be aware of my geographic surroundings and be flying higher than the mountains but occasionally I get lost.

An advanced plane in its time like the F-15, I thought it would have been a standard feature like in the Russian planes.

[GGTharos]

But you need a TFR for this, not a radar altimeter.

 

I don't believe real pilots will do this, or, if they do, they understand the risks and they pre-plan very well.

Edited April 3, 2016 by GGTharos

[fitness88]

But you need a TFR for this, not a radar altimeter.

 

I don't believe real pilots will do this, or, if they do, they understand the risks and they pre-plan very well.

 

 

I'm not sure I understand what you mean when you say: "But you need a TFR for this, not a radar altimeter."

 

Is a TFR some sort of terrain avoidance radar? If so doesn't it use a forward looking ground scanning radar?

 

I want to make sure I understand the terminology... I use the Mig-29s as an example; there is a barometric altimeter which is giving altitude based on barometric pressure, and also there is a radar altimeter giving the altitude not based on barometric pressure, but instead I believe based on a radar signal emanating from the plane and bouncing off the ground.

[mj3437]

Any ideas on the OP question about "Fashlight"?

MJ

[GGTharos]

Yes you are correct. A radar altimeter is not a good tool for terrain avoidance because it only tells you what's under you, not what's in front of you.

 

I'm not sure I understand what you mean when you say: "But you need a TFR for this, not a radar altimeter."

 

Is a TFR some sort of terrain avoidance radar? If so doesn't it use a forward looking ground scanning radar?

 

I want to make sure I understand the terminology... I use the Mig-29s as an example; there is a barometric altimeter which is giving altitude based on barometric pressure, and also there is a radar altimeter giving the altitude not based on barometric pressure, but instead I believe based on a radar signal emanating from the plane and bouncing off the ground.

[MikeMikeJuliet]

No problem, I know flying 21 uAoA is a little less comfortable, but it will help you avoid floating in the flare or bouncing.

Your touchdown AoA should be less than 25; higher AoA will result in a tail-strike.

Aerobraking on the roll out is not very effective if less than 23 units.

 

This is for the normal/standard landing approach in the eagle.

 

That's good to know.

 

I wonder why it was not thought important enough to have radar altitude capabilities?

I know radar altimeter has alerted me several times to the ground coming up at me when flying through mountains in poor visibility. I know I should be aware of my geographic surroundings and be flying higher than the mountains but occasionally I get lost.

An advanced plane in its time like the F-15, I thought it would have been a standard feature like in the Russian planes.

 

I believe the radar-altimeter was left out because there is no critical need for it when it comes to the design of the F-15. As we all know, the F-15 is an air superiority fighter and thus designed to fight high, not in mountain passes.

 

If compared to the russian counterparts, that might be a difference in design philosophy. The russian planes seem to be designed more as jacks-of-all-trades in this regard.

 

Any ideas on the OP question about "Fashlight"?

MJ

 

I'd like to know an answer to this too :D

[fitness88]

Thanks all for the info.