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AV-8B Harrier II FSD #3 Safety Chase


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McDonnell-Douglas (McAir) and the Naval Aviation Test Center (NATC) deployed to the Edwards AFB to conduct stability and control flight test near Rogers Dry Lake. While a relatively rare occurrence, it was possible that engines might "flameout" due to compressor stall as a result of high angle of attack and/or yaw disturbing the airflow into the intakes. The Edwards airspace had four test areas designated within flameout landing distance of the local dry lake beds (Rogers or Rosamond) should the need arise for an emergency landing. While the "spin areas" might also be within flameout landing distance of the Edwards 'hard' runway (R22/04) The lakebed landing areas allowed greater tolerances for approach and landing.  

 

Images from from four safety chase missions All are fitted with a spin recovery parachute assembly on the tail...

 

7 May 1984 - On this mission, the jet has mounting pads for cameras above the wing roots, just inboard of the flaps.

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8 Jun 1984 - Cameras installed on the mounting plates. Confirmed that the cameras are facing aft to record a planned deployment of the spin chute.

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Note the loads distribution strap running along the aft fuselage from the spin chute assembly to the wing root...

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13 Aug 1984 - Cameras and mounting plates removed. Lower light grey areas repainted white? Previously camouflaged upper wing areas now painted white.

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19 Jan 1985 - 

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The orange-red and white scheme is to aid determining aircraft attitude by ground based optical trackers. Note the stripe on the lower right wing.

 

An image of the AV-8B spin chute assembly taken at the 1884 Edwards Open House:

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Thanks for looking,

Sven

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  • 2 weeks later...

 

 

5 hours ago, Giorgio N said:

 

Do you know if the aricraft ever flew in that scheme but without the spin chute assembly ?

Giorgio - I would not be surprised if it flew at Pax River in this scheme of a short while before or after the High Angle of Attack (AoA) testing, but I really don't know.

 

4 hours ago, Kirk said:

I've often wondered, are spin chutes automatic (seems unlikely) or is there an addition cockpit control. If the latter, any idea where it's located & what it looks like?

Kirk,

 

I can't speak to the Harrier panel.  Here's the F-15 panel...

Spin Chute Control Panel

Since this was a McAir special instrumentation design, I assume the AV-8B panel was similar. A bit over the top compared to the Lockheed design. F-22...

YF-22 spin chute control panel

 

Note that the F-22 is a multi-function panel. Only the top third is for the spin recovery chute (SRC) and very similar to what I remember to the F-16 panel design. The mid-third is for the Flight Control Excitation System (FES). The loser portion looks like other flight test instrumentation controls.

 

On all the high AOA programs I am familiar with (A-10, F-15, F-16), the control panel was high and left on the front panel. The orange outline indicates that the panel is flight test special instrumentation, as in this case, or production equipment with flight test modifications.

 

And NO, they are not automatic. At Edwards, most high AoA testing was initiated above 30,000 ft, usually 35-36 kft. Safety procedures called for mandatory chute activation if the aircraft had not recovered at 15-16 kft AGL and mandatory ejection at 10 kft AGL. High AOA missions always had a ground-based mission control with extensive instrumentation telemetry and a safety chase aircraft. The safety chase would do a spiral descent around the falling test aircraft (trying) to remain co-altitude. Both mission control and the chase aircraft would call for the chute or ejection as necessary if the aircraft had not regained controlled flight. (see my post on the NA-37B Test Pilot School).

 

Interesting that the C-17 also had a departure recovery chute, only it was internally mounted with just the tail cone removed to deploy the chute...

0265 417flts ED spin chute 1991

 

A shot of the airborne chute operation test...

C-17 w departure chute deplayed

 

The aircraft still has the fittings as on display at the US Air Force Museum - sorry National Museum of the USAF (still can't get used to that change!)...

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Note the explosives warning triangle and loads distribution straps. Inside the triangle it says: "SPIN RECOVERY CHUTE".

 

Really want to build my 1/144th C-17 with the spin chute installed.

 

With more than you wanted to know...

Sven

 

 

 

Edited by Old Viper Tester
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24 minutes ago, Old Viper Tester said:

 

 

With more than you wanted to know...

 

 

 

Nah - That almost never happens!

It strikes me that MDD (were they McAir at that point?) would most likely have put a panel like that where the operational aircraft would eventually have weapons panels and the like. Iirc, the early Harrier IIs only had a single MFD so there was a bit of space on the right hand side that also would have been a pretty good location for an SRC panel. The switching on the examples above is quite interesting too. Thinking it through I guess that Toby Test Pilot is going to take off in a conventional sort of way and pootle towards the test area/altitude/height and then arm the system before executing the sorts of test that stand a risk of inducing a spin. Should they be unable to recover, then I reckon you'd want a pretty easy to fire (when potentially subject to silly G and peculiar attitudes) system to bring things back into control after which you'd jettison the chute and head home for tea & crumpets. A few lights to say the system thinks its working and that seems to match up with what your picture show.

 

Now I'm intrigued though and want to find a picture of a Harrier with some test instrument panels...

 

Kirk

 

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1 hour ago, Kirk said:

It strikes me that MDD (were they McAir at that point?) would most likely have put a panel like that where the operational aircraft would eventually have weapons panels and the like. Iirc, the early Harrier IIs only had a single MFD so there was a bit of space on the right hand side that also would have been a pretty good location for an SRC panel.

This panel would not go on the right side  - you don't want to take your hand off the stick for these maneuvers. The "golden arm" test pilot will keep making stick inputs to either break the spin or to rock it nose down (F-16 recovery technique) to get controlling airflow over the wings. The only option is to let go of the throttle and pull the chute handle (McAir) or push the big red button (GD/LMFW) with the left hand.

 

You are right about the run-in. On the way into the spin area, the pilot goes through a checklist for the spin chute and other items with mission control: chute armed, lights, etc. When in the spin area the entry technique is performed. Departure (maybe), recover, then out of the spin area. The chute is then de-armed, instrumentation turned off, and then turn back towards the spin area and the process starts all over again. My favorite for the F-16 was to establish a 45-60 degree climb going into the spin area, rolling inverted, then throttle back and wait for the nose to fall through. Roll-coupling maneuvers were exciting too: get to target AoA then roll 90 degrees converting AoA to sideslip/yaw rate. Mind you, I only got to watch as either the chase observer or in mission control - this guy was a test engineer not a pilot (my wife always reminds me that I only talk like one).

 

Sven

Edited by Old Viper Tester
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Great stuff. Thanks for sharing, and very interesting about the chutes etc.

 

Love Harriers, always nice to see some pictures, and in a nice sunny climate too! 

 

Good luck with the flame out, I believe the Harrier has the glide characteristics of a brick :giles:

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3 hours ago, Smudge said:

 

Good luck with the flame out, I believe the Harrier has the glide characteristics of a brick :giles:

 

... which apparently John Farley spent many hours experiencing whilst solving some development issues with the Mk.107 engine. It's a good book if you get a chance.

 

Thanks Sven for sharing your further thoughts. I get a bit barfy trying to make a 152 stall in a turn so your stories leave me in awe of anyone who can even talk of adding 90 degrees of roll to a precisely held AoA (whilst strapped to an explosive seat). Same sky, completely different league.

 

Kirk

 

 

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On 10/16/2017 at 5:53 PM, Kirk said:

I get a bit barfy trying to make a 152 stall in a turn

I kind of enjoyed the maneuvering, but then I used to be a rollercoaster freak, too.

 

As flight test engineer students in the USAF Test Pilot School, we had to demonstrate the high AoA and departure techniques, first in gliders and then in the A-37B. The gliders were a problem for me and a couple of my pilot classmates. The more forward the center of gravity (CG) the more stable the aircraft. The demonstration objective was to depart the glider, spin for three turns, and then recover. The glider was so docile to begin with that you had to hold pro-spin controls to get three turns in the spin to begin with, if you neutralized the controls the glider just flew out of the spin. But the three of us tipped the scales at just over 200 pounds each, hence we had a well forward CG and it was a challenge to even get the glider into a spin let alone hold it. The most I got out of it was half a turn before the glider began flying on its own again.

 

The A-37 was more exciting, the instructor would demonstrate the technique and we would have to describe all of the airframe motions in detail during and after spin: spin direction, yaw rate, frequency and shape of any nose oscillations, etc. After the instructor demo we, both pilots and engineers had to duplicate the maneuvers and still describe everything that we saw during the event. Again, we went for at least three turns and then effected recovery. I found the inverted spin the most challenging because everything was reversed: were you really spinning to the right or is it to the left? The nose is going up. No wait... that's down! That kind of thing.

 

One of my TPS pilot classmates had a little more excitement when he executed an inverted spin. In the A-37, you are supposed to check that the seat is latched on the support/guide rails in the "Before Cockpit Entry" checklist. You visually peer through the structure on the back of the seat to check this ratchet like engagement. So he enters the spin area, throttles back, brings the nose up and then applies cross controls. Whap! The jet rolls inverted and starts to do its thing. But wait, his seat is starting to ride up the rails and the stick and throttles are getting further away! He ended up scrunched against the canopy with the seat full up. The instructor recovered the aircraft and returned to base with him still pressed against the canopy and his oxygen mask digging into his chest. Couldn't "safe" the seat fast enough once they landed. Whether he missed the latch check or it just somehow came loose from all those spin flights, who's to say?

 

Sven

Edited by Old Viper Tester
grammar
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On 11/22/2017 at 10:36 AM, Maverick231 said:

Thanks for posting this!

I've been toying with schemes to put my AC-8B that I bought at Telford into and with a little scratch building of the device on the tail boom this is what Im gonna go with, the later one with white on the wings.

I was going for the earlier one with just the orange paint on top of the camo scheme, be interesting to have 2 models of the same aircraft in variations of it's colour scheme. We will have to get some close up pics of that spin recovery chute system from somewhere.

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  • 2 years later...

Thanks for sharing these photos. A great little  record of an interesting period in the history of this airframe.

 

Giorgio mentioned the Italeri kit in 1/72 as a candidate to build a model of this ship. Can any Harrier experts confirm that the Italeri kit (in the link) is the one to go for? 

 

https://www.scalemates.com/kits/italeri-137-super-av-8b-harrier--143178

 

Thanks.

 

BM.

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