The SAAF Forum

Discussion on the SAAF and other southern African air forces.
It is currently 19 Oct 2018, 06:15

All times are UTC + 2 hours




Post new topic Reply to topic  [ 104 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7
Author Message
PostPosted: 15 Dec 2017, 08:57 
Offline
User avatar

Joined: 08 Apr 2013, 19:28
Posts: 314
rynopot wrote:
I was corrected a few years ago, so let me help you.

It's not a fuel dump. [-X

It's a fuel VENT. A dump is a purposeful act by the pilot, in Gripen's case it is an automated part of design.


Pardon hijacking the tread a bit here, but I was explained by one of the ground crew why we saw this fuel vent but I still have two questions. Why do I never see a vent like that in other Gripen display videos (or am I going blind?). And the other one is that at the top part of the inverted loop where Goosen lights the burner to ignite the fuel and air mixture, is that not a dump as I remember two "batches" of vented or dumped fuel before the desired effect (flames) was achieved?

Again sorry for going off topic! :roll:

MAMBA

_________________
MAMBA

Keep your feet on the ground, and reach for the skies!


Top
 Profile  
Reply with quote  
PostPosted: 15 Dec 2017, 12:36 
Offline
User avatar

Joined: 16 Nov 2007, 14:19
Posts: 1399
Location: Bellville, CPT
mamba wrote:
rynopot wrote:
I was corrected a few years ago, so let me help you.

It's not a fuel dump. [-X

It's a fuel VENT. A dump is a purposeful act by the pilot, in Gripen's case it is an automated part of design.


1. Why do I never see a vent like that in other Gripen display videos (or am I going blind?).
2. And the other one is that at the top part of the inverted loop where Goosen [Geoffrey Cooper] lights the burner to ignite the fuel and air mixture, is that not a dump as I remember two "batches" of vented or dumped fuel before the desired effect (flames) was achieved?
MAMBA


1. I have a two fold answer for you - not many people shooting Gripen displays will show that top part of the loop to you, for various reasons: e.g. damn difficult to get your neck all the way behind the camera. Secondly: The older the Jets get, the more they vent.
2. Let me see if I can find out.


Top
 Profile  
Reply with quote  
PostPosted: 15 Dec 2017, 13:08 
Offline
Site Admin
User avatar

Joined: 29 Jun 2004, 17:19
Posts: 7177
As rynopot said, the Gripen pilot is just lighting up vented fuel.

Reason you don't normally see so much vented fuel streaming from the aircraft is that, in this case, the pilot forces a maneuver to allow maximum venting. The afterburner then ignites the vented fuel.

_________________
How come every time my ship comes in, I'm at the airport?


Top
 Profile  
Reply with quote  
PostPosted: 15 Dec 2017, 14:33 
Offline
User avatar

Joined: 08 Apr 2013, 19:28
Posts: 314
Thanks Dean and Rynopot. Just a correction, I was mainly refering to the vent after the inverted pass in front of the crowd - I have never seen that vent before. I know why it is caused but not why this is the first time I am seeing it hence my blindness question :lol: .

And big apologies for getting the pilot's name wrong! Not sure where Goosen replaced Cooper in my mind... #-o

MAMBA

_________________
MAMBA

Keep your feet on the ground, and reach for the skies!


Top
 Profile  
Reply with quote  
PostPosted: 15 Dec 2017, 15:39 
Offline

Joined: 20 Aug 2010, 14:40
Posts: 1716
mamba wrote:
rynopot wrote:
I was corrected a few years ago, so let me help you.

It's not a fuel dump. [-X

It's a fuel VENT. A dump is a purposeful act by the pilot, in Gripen's case it is an automated part of design.


Pardon hijacking the tread a bit here, but I was explained by one of the ground crew why we saw this fuel vent but I still have two questions. Why do I never see a vent like that in other Gripen display videos (or am I going blind?). And the other one is that at the top part of the inverted loop where Goosen lights the burner to ignite the fuel and air mixture, is that not a dump as I remember two "batches" of vented or dumped fuel before the desired effect (flames) was achieved?

Again sorry for going off topic! :roll:

MAMBA


Hi MAMBA

here is a neat explanation on this youtube video..

https://www.youtube.com/watch?v=3YXkzGM58XM

Quote:
Each tank is vented (or pressurised) to allow air into the tank to take the place of burned fuel, otherwise, the tank would be in negative pressure, resulting in engine fuel starvation. A vent also allows for changes in atmospheric pressure and temperature.


It is fairly common to see jets venting fuel at airshows, but it only happens for a split second or so.


Top
 Profile  
Reply with quote  
PostPosted: 15 Dec 2017, 21:01 
Offline

Joined: 31 Aug 2010, 15:01
Posts: 4286
Location: Centurion, Pretoria, SA
Have witnessed Gripens at RIAT vent. :D


Top
 Profile  
Reply with quote  
PostPosted: 16 Dec 2017, 07:54 
Offline
Site Admin
User avatar

Joined: 29 Jun 2004, 17:19
Posts: 7177
The Hercules gave a nice but muted display by Dakota standards!

The afternoon display saw her take-off and land without performing her routine. Not sure if there was a problem.

Image

Image

Image

Image

Image

_________________
How come every time my ship comes in, I'm at the airport?


Top
 Profile  
Reply with quote  
PostPosted: 18 Dec 2017, 07:14 
Offline
Site Admin
User avatar

Joined: 29 Jun 2004, 17:19
Posts: 7177
Mango and Silver Falcons

Image

Image

Image

Image

Image

Image

Image

_________________
How come every time my ship comes in, I'm at the airport?


Top
 Profile  
Reply with quote  
PostPosted: 04 Jan 2018, 08:03 
Offline
User avatar

Joined: 16 Nov 2007, 14:19
Posts: 1399
Location: Bellville, CPT
My videos of the Airshow.

FIGHTERS:










PROPS:









SILVER FALCONS:





Top
 Profile  
Reply with quote  
PostPosted: 04 Jan 2018, 08:58 
Offline
Site Admin
User avatar

Joined: 29 Jun 2004, 17:19
Posts: 7177
:smt023

_________________
How come every time my ship comes in, I'm at the airport?


Top
 Profile  
Reply with quote  
PostPosted: 23 Mar 2018, 16:12 
Offline

Joined: 23 Mar 2018, 16:08
Posts: 2
Location: Chile
Is Maj Venter son of Cmdt Steyn Venter, OC 85 ACS Pietersburg 1982?

If so, eternal respects to your father, from Chile


Top
 Profile  
Reply with quote  
PostPosted: 23 Mar 2018, 17:04 
Offline
Site Admin
User avatar

Joined: 29 Jun 2004, 17:19
Posts: 7177
He is the son of 'Jeronkie' Venter, one time Mirage F1 pilot and Silver Falcon member.

_________________
How come every time my ship comes in, I'm at the airport?


Top
 Profile  
Reply with quote  
PostPosted: 01 Apr 2018, 04:52 
Offline

Joined: 23 Mar 2018, 16:08
Posts: 2
Location: Chile
Dean wrote:
He is the son of 'Jeronkie' Venter, one time Mirage F1 pilot and Silver Falcon member.


:smt023


Top
 Profile  
Reply with quote  
PostPosted: 04 Apr 2018, 14:19 
Offline
User avatar

Joined: 16 Nov 2007, 14:19
Posts: 1399
Location: Bellville, CPT
Mirage F1 (Venter) - Which a technical problem in a Durban air show, but due to excellent training and experience, managed to save the jet in a high angle dive. The video is on YouTube.



COPIED FROM AVCOM:
Quote:
Correct, it was not an Impala, it was a Mirage F1 CZ no 203 from 3 SQN flown by the then display pilot Maj J VENTER "Scorpio",

During that specific show sequence, he had just completed a full horizontal eight manoeuvre and executed a standard fighter repositioning manoeuvre called a 90 to 270.

Whilst pulling out of the dive, the combat flap/leading edge slats failed to deploy below the designated speed.

This resulted in a noticeable loss of lift at low speed with very poor control response.

His years of experience immediately told him that it could be the combat flap/leading edge slats that had failed and the warning light subsequently caught his eye and confirmed his suspicion. He immediately elected to light the burner and pulled full aft stick deflection.

The R.O.D was very high which placed him well outside the ejection envelope, so he elected to stay with the aircraft, pulling out at approximately 40ft.

From the low pullout, he immediately went into a straight roll and continued the show without further incident. He said the shock had only set in after he had landed, and he subsequently slept it off before giving the afternoon show.

That specific show was suppose to be flown by Capt Leon Meech Noyes (RIP), a young fighter pilot, who at the time was not very experienced. If this had happened to him,the result might have been much worse.

I have the video if anyone is interested to see it.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 104 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7

All times are UTC + 2 hours


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group