F-35 Down in Albuquerque

[ORAC]

https://x.com/clashreport/status/1795554760042446908?s=61&t=rmEeUn68HhlFHGKbTPQr_A
A F-35 fighter jet just crashed during takeoff at Albuquerque International, New Mexico.

Pilot reportedly ejected.

https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/828x453/image_2f52f0b1bf0ada4746020f3005d634afe4cdb102.jpeg
​​​​​​​

[RAFEngO74to09]

https://pbs.twimg.com/media/GOsQMW7bcAITCjL?format=jpg&name=4096x4096

[RAFEngO74to09]

https://pbs.twimg.com/media/GOsWqEebcAIvyBp?format=jpg&name=large

[RAFEngO74to09]

Pilot conscious - being transported

[RAFEngO74to09]

Lucky it didn't take out anyone on the road - short video

https://x.com/i/status/1795561121312608381 (https://x.com/i/status/1795555291339092231)

[RAFEngO74to09]

Includes first report from local Fire PIO

https://www.youtube.com/watch?v=2qI6RYiZHws

[RAFEngO74to09]

Aircraft belonged to USMC - so was a F-35B or F-35C - and was a new aircraft being flown by a Defense Contract Management Agency pilot on delivery [source: Pentagon > ABC News]

[RAFEngO74to09]

CBS News told by 2 Pentagon officials that it was a development model being delivered to Edwards, AFB.

[RAFEngO74to09]

Lockheed Martin just confirmed to The War Zone that it was a F-35B en route to Edwards AFB

https://www.twz.com/air/f-35-crashes-in-new-mexico

[Lonewolf_50]

Look like flight test will be delayed a bit.
Glad the ejection was a success.

[LowObservable]

Looks as if something went pear-shaped during takeoff roll but too late to abort, from the location of aircraft and parachute.

[EXDAC]

Appears to have gone off the departure end of 21 then down the embankment above University Boulevard.

[RAFEngO74to09]

Moments before the crash

https://pbs.twimg.com/media/GOuXK3EWAAAy04o?format=jpg&name=large

[RAFEngO74to09]

Crash point - from same viewpoint

https://pbs.twimg.com/media/GOuXKz4XUAAhcUD?format=jpg&name=large

[LowObservable]

Couple of new photos and some audio are circulating, things that investigators will be looking at.

[CAEBr]

Interesting from the take off shot that the toilet lid was up implying front fan activation, but in the wreckage aerial shot the rear nozzle appears fully aft. Not a combination for a STOL take off as I understand it ? Cancelling the STOL configuration at low speed isn't going to suddenly increase speed to to go fully wing borne is it, or is that the emergency FRC action ?

[EXDAC]

The airborne shot and the crash shot appear to have been taken from the SW end of the cargo ramp close to the departure end of RW21. RW21 was active so the aircraft seems to have used up all its length before crashing just off airport.

The GE shot shows my interpretation of the photo evidence. Just one person's speculation and happy to be corrected.

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/829x589/photo_interpretation_df79ac030124ab9e84dfc02eb31c282121f4254 1.png

[EXDAC]

This ABC News image seems to show that the aircraft wreckage is on the South side of University Boulevard not on the North side.
https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/727x438/abc_news_pic_of_crash_site_da0e352cb5bb55bdb6524bef8fe82696b b88a6a4.png

If true it impacted rising terrain rather than the downslope of the airport mesa.

[Lookleft]

Should he have turned left then?

[SpazSinbad]

CBS News told by 2 Pentagon officials that it was a development model being delivered to Edwards, AFB.
29 May 2024 "...“The aircraft was a test jet equipped with Technology Refresh 2 (TR-2) and was transferring to Edwards AFB for additional test equipment modification...." F-35B test jet crashes in New Mexico, pilot ejects safely but sustains injuries - Breaking Defense (https://breakingdefense.com/2024/05/f-35b-test-jet-crashes-in-new-mexico-pilot-ejects-safely-but-sustains-injuries/)
__________

https://www.airandspaceforces.com/air-force-pilot-f-35b-crash-kirtland/ 29 May 2024
"The F-35B that crashed May 28 in New Mexico was flown by an Air Force pilot, the F-35 Joint Program Office and the Air Force said. The pilot ejected at low altitude and suffered serious injuries, but is in stable condition, according to the Air Force.... Due to the investigation now underway, the JPO could not provide details on the pilot’s identity or experience other than to say the person was checked out on the F-35B and qualified to fly the short takeoff/vertical landing (STOVL) variant, which is flown operationally by Marine Corps pilots. The Air Force pilot was flying the jet on behalf of the Defense Contract Management Agency....
&
...A former F-35 test pilot told Air & Space Forces Magazine that both combined test force pilots and DCMA pilots are typically qualified to fly all three F-35 variants, which include the conventional takeoff F-35A model, the STOVL F-35B, and the carrier-capable F-35C.

The three airplanes “are similar in the way [they] fly,” the test pilot said. “With the B [version], you simply move a lever, and then you’re in STOVL mode, and the controls then do their STOVL moves.” He said it was not possible to tell from an image taken just before the crash what was happening with the main exhaust, which rotates from downward to rearward in the transition from vertical to horizontal flight. But he said the jet should have been at a higher altitude by that point in a STOVL takeoff and the jet’s attitude seemed high for the configuration."..."

[Ascend Charlie]

Lookleft, isn't it more like "I shoulda toined left at Albakoiky"

[Lookleft]

I was trying to be more subtle to flush out those whose mind thinks the same way mine does so you and vne165 can share first prize which is a laurel and hardy handshake.

[57mm]

Lift fan intake door, aka the Toilet Seat; gotta love it.....

[EXDAC]

But he said the jet should have been at a higher altitude by that point in a STOVL takeoff........"

If we assume he parked at the ANG base then there was 10,000 ft of RW21 available. Even if he just made a quick fuel stop at Atlantic there is at least 5,500 ft available.

Could he have been attempting to abort a normal mode takeoff using STOVL. Could the high pitch attitude be explained by attempting to decelerate?

What is the normal range of pitch attitude in the deceleration from normal flight to vertical landing?

[RAFEngO74to09]

Aircraft back on the ground then the pilot ejected when it went off the end of the runway

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/760x419/f_35b_crash_8000dacd0a064067f1e322e4db02e1afbd496768.jpg

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/1235x340/f_35b_crash_2_efad05264e3a24108ab5e46a55a2d4ed90544c1e.jpg

[LowObservable]

The plot thickens.
Other things relevant to sustained flight, not so much.

[XZ439]

A hot and high airfield with an unfamiliar and slow accel/climb from a STO may have been a factor?

[Redbud]

A hot and high airfield with an unfamiliar and slow accel/climb from a STO may have been a factor?

Would be on my list of possibilities.

[LowObservable]

A hot and high airfield with an unfamiliar and slow accel/climb from a STO may have been a factor?

5300 feet and 90F. That's one Mile High Club you don't want to join.

[jolihokistix]

The firefighters mentioned people in a car (pickup?) hit by flying debris.

[SpazSinbad]

I did not realise the airfield was in the mile high club: upload.wikimedia.org/wikipedia/commons/d/df/KABQ_Airport_Diagram.svg (https://upload.wikimedia.org/wikipedia/commons/d/df/KABQ_Airport_Diagram.svg)

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1591x1050/kabq_airport_diagram_8295f915192102b4d8ad121dfbd842501be4549 f.gif

[EXDAC]

Why the concern about KABQ altitude? Is anyone really suggesting that a normally operating F-35 with no stores can't safely takeoff from a 10,000 ft runway in the prevailing conditions?

(I've been flying in AZ for over 35 years and I do have some understanding of DA)

[Redbud]

Why the concern about KABQ altitude? Is anyone really suggesting that a normally operating F-35 with no stores can't safely takeoff from a 10,000 ft runway in the prevailing conditions?

(I've been flying in AZ for over 35 years and I do have some understanding of DA)

Assuming everything is in working order, of course not. However, if one plans to use this jet’s powered lift system and that system does not generate the expected power/lift, you will have a problem — the successful resolution of which will be highly reliant upon pilot technique and finesse.

[LowObservable]

Why the concern about KABQ altitude?

Q is what effect it has on the speed at which you can hit the convert button.

[Redbud]

Q is what effect it has on the speed at which you can hit the convert button.

Mode 4 conversion (depression of the ‘Hook/STOVL’ button on the upper right of the instrument panel) happens before you start your engine run up; the environmentals (OAT etc etc) and the predicted lift system performance determine the KCAS at which one initiates rotation, whether it be auto, manual or hotas.

[SpazSinbad]

One day there will be a public version of Flight Manuals / NATOPS for answers to a lot of F-35 questions. Meanwhile some nice 'from the front' STO JPGs: https://www.twz.com/uploads/2024/03/14/1S9A2381-1-scaled.jpg & https://www.twz.com/uploads/2024/03/14/3Z7A1408-scaled.jpg

https://www.twz.com/uploads/2024/03/14/1S9A2381-1-scaled.jpg

https://www.twz.com/uploads/2024/03/14/3Z7A1408-scaled.jpg

[SpazSinbad]

THREAD: http://www.pprune.org/military-aircrew/221116-future-carrier-including-costs-152.html

FOR: https://www.pprune.org/military-aviation/221116-future-carrier-including-costs-152.html#post6590554

LO: "...Once the jet is above stall speed, the pilot presses the conversion button. The reverse conversion takes about 10 seconds...."

http://www.codeonemagazine.com/images/media/2011_01_100th_STO_11P00140_28_1267828237_6628.JPG

http://www.codeonemagazine.com/images/media/2011_01_100th_STO_11P00140_28_1267828237_6628.JPG

[ORAC]

Video of crash and ejection.

https://x.com/theaviationist/status/1796270564253774243?s=61&t=rmEeUn68HhlFHGKbTPQr_A
​​​​​​​

[LowObservable]

"...Once the jet is above stall speed, the pilot presses the conversion button

I still have the source document on file. One way or another it looks as if the conversion was started at a speed that was too low for the prevailing conditions - the video closes the loop and shows the aircraft sinking relative to the altitude in the earliest photo.

[Redbud]

"...Once the jet is above stall speed, the pilot presses the conversion button

I still have the source document on file. One way or another it looks as if the conversion was started at a speed that was too low for the prevailing conditions - the video closes the loop and shows the aircraft sinking relative to the altitude in the earliest photo.

‘Conversion’ describes the transition of the propulsion system from Mode 1 to Mode 4 (conventional to STOVL flight). I think the term you’re looking for is ’rotation.’ You might recall that it was/is very simply NRAS — nozzle rotation airspeed — in Harrier.

[fitliker]

What was the trailing plume ? Engine intake plugs not removed ?
I thought you did it , no you thought I did it events ?
What kind of plume could you expect with wrong fuel or algae bloom in the fuel ?

[ORAC]

What was the trailing plume ?
Dust driven up by the lift fan and jet exhaust.

[DogTailRed2]

Why the fascination with VTOL at the moment? Is the intention to deploy these in rough, restricted areas similar to the Harrier?

[ORAC]

I believe the F-35B can do a conventional take-off with a standard runway available, so not sure why this mode was used anyway - unless the pilot doesn’t get to do many and was using the take-off to tick a box for currency on type.

[SpazSinbad]

Mode 4 conversion (depression of the ‘Hook/STOVL’ button on the upper right of the instrument panel)....
JPG of the F-35 Cockpit which I assume is more or less how it is laid out these days? Hook/STOVL conversion UPPER LEFT as annotated.


https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1627x1050/f_35_hook_stovl_button_cockpit_70280cb2038dc75d24c853e6b673d 72c8ab63103.jpg
https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/846x1050/f_35_hook_stovl_button_brake_chute_zoom_705b804504c755675dc6 1f936c19ed9f45f057b0.jpg
https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/1680x943/hookstovlbuttonannotated_94dbee07f1b45a5e4fb812369c38e2a8568 692fa.jpg
BELOW: http://www.codeonemagazine.com/images/media/Front_Office_05_1267828237_9967.JPG

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/1621x909/hookstovlbuttonzoom_e3453fe0897e7a9a83c48eb9fb2a337b3bfb0dba .jpg

[SpazSinbad]

F-35 Begins Year With Test Objectives Unmet [STOVL IAS Change]
Jan 4, 2011 By Graham Warwick [URL no longer workee]
"...McFarlan says... The lift-fan door was programmed to open to 65 deg. below 120 kt., and to 35 deg. above that airspeed. But with the large door fully open, loads on the auxiliary-inlet doors behind it are reduced, so the schedule has been changed to keep the lift-fan door open 65 deg. up to 165 kt. during a short takeoff, he says...."

Video show Mike Skaff demonstrating the F-35B on a flat deck take off and landing in the F-35 Travel Simulator. At 2 minutes 45 seconds we see him transition with the HOOK/STOVL button.

F-35 flight simulator [Skaff STOVL HOOK button 2m 45s]

https://www.youtube.com/watch?v=OkWuB9wA_18

[RAFEngO74to09]

Comment from a retired RC-135W Crew Chief who lives locally for what it's worth.

"Supposedly he was cleared for an unrestricted climb to 20k, but denied it because he promised a short field takeoff for some guys on the ramp."

https://x.com/Heywood01/status/1796376177734455366

[Mogwi]

Comment from a retired RC-135W Crew Chief who lives locally for what it's worth.

"Supposedly he was cleared for an unrestricted climb to 20k, but denied it because he promised a short field takeoff for some guys on the ramp."

https://x.com/Heywood01/status/1796376177734455366

OUCH! If true.

Mog

[ORAC]

Just have to wonder if the figures/software are only calibrated for STOL take-offs at sea level……

[SpazSinbad]

Just have to wonder if the figures/software are only calibrated for STOL take-offs at sea level……
“STOVL only applies below 10 thousand feet and below 250 knots,” Tomlinson notes….”
_________

VX-23 Strike Test News 2014 [02 Sep]
"...STO testing included crosswind expansion out to 20 knots, completed primarily at Edwards Air Force Base [2,300 feet] and NAWS China Lake [2,300 feet] during a wet runway and crosswind detachment...."
_________

VX-23 2015 STRIKE TEST NEWS Maj M. Andrew “Tac” Tacquard
F-35[B] Short Takeoff & Vertical Landing (STOVL) Mode http://issuu.com/nawcad_pao/docs/striketest2015_single
“...Flying qualities during asymmetric testing were nearly identical to symmetric testing from the pilot’s perspective. The team performed Rolling Vertical Landings (RVL), Creeping Vertical Landings (CVL), Vertical Landings (VL), Slow Landings (SL), and Short Take Offs (STO) tests with nominal winds at Patuxent River. They continued landing and takeoff testing during a detachment to Edwards AFB, Air Force Plant 42 in Palmdale, California, and at NAWS China Lake. Testers focused on expanding the crosswind envelope with crosswinds of up to 25 knots. We also performed the 1st high altitude CVL & VL during the detachment...."

[Redbud]

Like the XZ439 and ORAC posts above suggest, one has to wonder how accurate the performance predictions might be for the airfield conditions at takeoff time, and how much exposure the pilot might have had to aircraft handling during STOs with marginal aircraft performance.

[Dominator2]

ORAC Just have to wonder if the figures/software are only calibrated for STOL take-offs at sea level……

Good point. I recall the Sea Harriers joining us for a Trial at an airfield in Northern Nevada with an Elevation of 7000ft. When the aircraft arrived they seemed a bit "squirly" from the break and around final.
Once they shutdown I spoke to the lead pilot. He admitted that they had not appreciated the effect of flying circuits at 8500ft. He had over sped the gear and flap and nearly departed on final whilst trying to fly a "punchy " pattern.
He later admitted that the Seajet ODM performance figures for takeoff and landing were only for sea level!!

I had to stage through Albuquerque (Elevation 5500ft) in a Heavy Tornado F3. At 14.00 in the afternoon we were offered a Take off Runway with a 7kt tailwind. We declined the offer and waited for the into wind runway. Once ATC saw our take off and climb performance they understood our decision.

[typerated]

Q is what effect it has on the speed at which you can hit the convert button.

Indicated - nothing.

But you need to be going much fast to get there!

[SpazSinbad]

https://www.afmc.af.mil/News/Article-Display/Article/804079/stovl-f-35-conducts-flight-testing/
“STOVL F-35 conducts flight testing 15 May 2014 EDWARDS AIR FORCE BASE, [2,311 feet] Calif. -- A Short Takeoff and Vertical Landing variant of the F-35 Lightning II is shown performing Crosswind and Wet Runway testing here May 6. Pilot Dan Levin and a team from the F-35 Integrated Test Facility at Patuxent River, Md., accompanied aircraft BF-4 for the deployment to Edwards April 11. Testing is expected to continue until June 14....” JPG: https://media.defense.gov/2014/May/15/2000850186/-1/-1/0/140507-F-TW412-035.JPG

https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/1733x1120/stovl_test_140507_f_tw412_035_pdf_0e5ffdfb122dcc07a80025a0f5 49510d8614b724.jpg

[EXDAC]

Nice pictures but what testing was done for short takeoff transition at 8,000 ft DA or higher? Was this simply a case of operating outside the tested envelope? Even if that was the case why couldn't the takeoff have been aborted?

[Redbud]

Nice pictures but what testing was done for short takeoff transition at 8,000 ft DA or higher? Was this simply a case of operating outside the tested envelope? Even if that was the case why couldn't the takeoff have been aborted?

All fair questions. However, the operative question is what caused unsustainable flight after getting airborne? The jet got airborne; why didn’t it remain so (safely)? There are a host of mechanical matters that might be in-play. There is also the potential that the jet didn’t just leap off the ground, but wallowed (airborne) down the runway struggling to climb. I can tell you from experience w powered lift that is an attention-getting experience. Pull the nose up too much (and it doesn’t take much) and you get a drag increment greater than aero lift with less acceleration resulting in a settle. Did that happen? Dunno, but it’s a possibility.

[XZ439]

Agreed, could be a mechanical issue but it may also be a case of marginal performance and being out of gound effect.

[LowObservable]

OUCH! If true.

Mog
I believe there is a recording from someone monitoring the public traffic. Not sure of the USAF translation of "Axminster shuffle" let alone "no tea and biscuits".

[sycamore]

The wx at KABQ at the time of the crash appx 1352pm was T*85 F/29*C,ALTIM.PRESS 24.74",Wind 5mph..
To me that looks like a `pressure altitude of 8430ft.,and a density altitude of (temp correction) 11500 ft......Others may disagree with the calcs,but in hindsight,a14000 FT runway`may` just have been a `better` option.....

[EXDAC]

I found the tower takeoff clearance on the LiveATC.net archive.

I can't provide a direct link to the archived recording but it can be found at https://www.liveatc.net/archive.php
It should be possible to navigate to May 28, KABQ tower 1, and select the recording starting at 1930Z.
File name is KABQ1-Twr-May-28-2024-1930Z.mp3 and the takeoff clearance is at 13:45 play time.

[EXDAC]

The wx at KABQ at the time of the crash appx 1352pm was T*85 F/29*C,ALTIM.PRESS 24.74",Wind 5mph..
To me that looks like a `pressure altitude of 8430ft.,and a density altitude of (temp correction) 11500 ft......Others may disagree with the calcs,but in hindsight,a14000 FT runway`may` just have been a `better` option.....

I estimated DA at about 8,300 ft for 90 deg F. I don't think 11,500 is correct. (24.74 inHg is the station pressure not the altimeter setting)

[EXDAC]

I found the tower takeoff clearance on the LiveATC.net archive.

Hustler 91 is audible in the ground frequency recording and is heard refusing the unrestricted climb for a short takeoff demo. File - KABQ1-Del-Gnd-May-28-2024-1930Z.mp3

Taxi clearance was from B5 (military ramp) for RW21 full length. Starts at 8:15 play time.

"I told some of the guys down here I'd do a short takeoff"

[sycamore]

EXDAC,You are more correct,PA is about 5300,and DA about 8300`.
Been there a few times,parked on the `Hot Spot`,for a couple of days,then early morning decisions,
East or West departure in a `heavily` loaded C130..usually W,even with a `light` tailwind...

[fdr]

JPG of the F-35 Cockpit which I assume is more or less how it is laid out these days? Hook/STOVL conversion UPPER LEFT as annotated.


https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1627x1050/f_35_hook_stovl_button_cockpit_70280cb2038dc75d24c853e6b673d 72c8ab63103.jpg
https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/846x1050/f_35_hook_stovl_button_brake_chute_zoom_705b804504c755675dc6 1f936c19ed9f45f057b0.jpg
https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/1680x943/hookstovlbuttonannotated_94dbee07f1b45a5e4fb812369c38e2a8568 692fa.jpg
BELOW: http://www.codeonemagazine.com/images/media/Front_Office_05_1267828237_9967.JPG

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/1621x909/hookstovlbuttonzoom_e3453fe0897e7a9a83c48eb9fb2a337b3bfb0dba .jpg

So, for the RAF and those used to the art of British ergonomics, where do you blast off the 12 guage shot to install the requisite gyros, vertical P4 or P8 compasses, and ganged triple and quadruple switches for the requisite 'lecky stuffs? Seems to be incompatible to the ethos of 120 years of heritage. It takes nimble minds to dream up radio masters in the back o' plane, hand swung ADF antenna's and Rebecca, a nice biblical girls name but a curious means of determining ppos. The F-35 is cool, notwithstanding 1 engine. (A-4, A-7, F-8... A-1... ).

The F-35 and its HMD is a heck of a move forward in SA for the driver. Flying apparently still needs some awareness of speeds etc such as the bingle at Eglin, FL highlighted.

[fdr]

Hustler 91 is audible in the ground frequency recording and is heard refusing the unrestricted climb for a short takeoff demo. File - KABQ1-Del-Gnd-May-28-2024-1930Z.mp3

Taxi clearance was from B5 (military ramp) for RW21 full length. Starts at 8:15 play time.

"I told some of the guys down here I'd do a short takeoff"

Mission accomplished, it was a short takeoff, and an even shorter flight.

[SpazSinbad]

Shotgun instrument placing was a jolt when facing the two variations of dual Vampires in the RAN FAA at Nowra. When two AHs fitted they were directly in front of 'hand on the stick in the left seat'. When on instruments that pilot would lean left usually to see the AH. (Leaing right meant you were snuggling up to the right seat occupant). :}

An F-35 test pilot complained about the lack of an indication in the vHUD when the aircraft was NOT in some kind of computer controlled engine approach. When in MANUAL fuel there is no light dot in the vHUD. So the F-35C pilot approaching at 'idle' power after a Sh!tHot Break did not register that the aircraft engine was NOT being controlled for 'on speed'. Too late the LSO realised a wave off was required with full A/B but... The accident report mentions that such a 'manual power' indication should be placed in the vHUD. <sigh>

The night approach crash at Eglin AFB had the pilot having the aircraft on speed hold at some 250KIAS IIRC. Pilot did not look at the speed during the approach so speared in on the nosewheel and then the aircraft went nuts so he ejected. Two pilots not aware of what the aircraft was doing during a landing approach. Perhaps there is some kind of computer/pilot glitch in this latest accident but I do not know.

[RAFEngO74to09]

Video of the attitude just before the bondhu bashing portion of the sortie

https://www.youtube.com/watch?v=0RaN3KYOgIY

[SpazSinbad]

This JPG has bin burnin' a hole in me screen so here 'tis for the STO attitude innit: “Marine Fighter Attack Training Squadron (VMFAT) 501, Marine Aircraft Group (MAG) 31, 2nd Marine Aircraft Wing (MAW), takes off during an airshow demonstration practice at Marine Corps Air Station Beaufort, South Carolina, Aug. 21, 2023. US Marine Corps Photo” https://news.usni.org/wp-content/uploads/2023/09/7987977-scaled.jpeg

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/2000x1290/f_35b_sto_side_7987977_scaled_ed_b2d23b6f01262845bab73c48512 1be19767e4521.jpg

[SpazSinbad]

“STOVL only applies below 10 thousand feet and below 250 knots,” Tomlinson notes….”
_________

VX-23 Strike Test News 2014 [02 Sep]
"...STO testing included crosswind expansion out to 20 knots, completed primarily at Edwards Air Force Base [2,300 feet] and NAWS China Lake [2,300 feet] during a wet runway and crosswind detachment...."
_________

VX-23 2015 STRIKE TEST NEWS Maj M. Andrew “Tac” Tacquard
F-35 Short Takeoff & Vertical Landing (STOVL) Mode http://issuu.com/nawcad_pao/docs/striketest2015_single
“...Flying qualities during asymmetric testing were nearly identical to symmetric testing from the pilot’s perspective. The team performed Rolling Vertical Landings (RVL), Creeping Vertical Landings (CVL), Vertical Landings (VL), Slow Landings (SL), and Short Take Offs (STO) tests with nominal winds at Patuxent River. They continued landing and takeoff testing during a detachment to Edwards AFB, Air Force Plant 42 in Palmdale, California, and at NAWS China Lake. Testers focused on expanding the crosswind envelope with crosswinds of up to 25 knots. We also performed the 1st high altitude CVL & VL during the detachment...."

This video is on one of my SPAZZINbad channels (of two). I make nothing from them however GOOGLE/youtube insert advertisements at their whim over which I have no control because I make no profit from them. Earlier a video about another topic was from another channel entirely. Yes advertisements on YOUboob are wearysome but dems de breaks. IF one does not like the music that can always be MUTED, the original video had no soundtrack whatsoever.

MEANWHILE: F-35B ITF VL & STO Crosswind & USMC Expeditionary Field Tests [at 2,300 feet altitude at above locations]

https://www.youtube.com/watch?v=wqipBujzaA4

[EXDAC]

What was the basis for “STOVL only applies below 10 thousand feet and below 250 knots,” Tomlinson notes….”

At what maximum density altitude was it actually demonstrated? I'm interested in the short takeoff to normal flight transition that seems to have gone horribly wrong at ABQ. Demonstrating at 2,300 ft and extrapolating to 10,000 ft seems a bit of a stretch to me. (The 8,300 ft point didn't go well.)

[SpazSinbad]

What was the basis for “STOVL only applies below 10 thousand feet and below 250 knots,” Tomlinson notes….”
At what maximum density altitude was it actually demonstrated? I'm interested in the short takeoff to normal flight transition that seems to have gone horribly wrong at ABQ. Demonstrating at 2,300 ft and extrapolating to 10,000 ft seems a bit of a stretch to me. (The 8,300 ft point didn't go well.)
You would have to ask early UK test pilot TOMLINSON for that information. He gave an interview when early testing was underway. What other problems would cause the accident we see? I have no idea at this stage. This link to the original article does not work now: http://www.examiner.com/article/ride-the-lightning-testing-the-marine-corps-latest-fighter
Ride the Lightning: Testing the Marine Corps’ latest fighter 27 Mar 2009 Dave Majumdar
“…Other than the reduced G-limit, in conventional flight the F-35B handles almost exactly like the F-35A, Tomlinson explained [Lead Test Pilot for the F-35B. Tomlinson, a former Royal Air Force (RAF) Harrier pilot and a graduate of the prestigious Empire Test Pilot School, has over thirty years of flight test experience with STOVL aircraft. (now retired)]. The F-35B retains the same outstanding low-speed, high angle of attack handling qualities as well as the same incredible acceleration as the F-35A. “You struggle to tell the difference between the CTOL and the STOVL in the cockpit,” Tomlinson said, adding that test pilots are trained to notice even minute differences in aircraft handling qualities. Tomlinson noted that while the F-35B’s lift-fan causes a visible bump in the aircraft’s outer mold line, the only cue in the cockpit is a slightly different wind noise. “STOVL only applies below 10 thousand feet and below 250 knots,” Tomlinson notes….”
Probably the entire article is in my humungous archive if required.

[SpazSinbad]

Lockheed Martin rebuts F-35 critics on cost, progress by Chris Pocock July 15, 2010
http://www.ainonline.com/taxonomy/term/506881?q=node/25359
“...When asked how the F-35B compared to the Harrier in terms of ease of takeoff/landing, Tomlinson replied: “It’s chalk and cheese–and so it should be! This is a single-button operation with no special controls–much easier than the Harrier. For short takeoffs you just power up; the system takes care of everything else. On the ski-jump, for instance, the system detects the change in deck angle & doesn’t apply any rotation as it would on a flat deck.”...”
&
Test Flying The Joint Strike Fighter by Graham Tomlinson 17 Jun 2011
[url]http://myweb.tiscali.co.uk/hawkerassociation/hanewsletters/hanewsletter030nvu/testflyingjointstrikefighter.html
"...The Short take-off (STO) mode was checked at altitude followed by 100kn STO and then 80 kn STO, circuit and VL from 150 ft on 18 March 2010. Post touchdown the procedure was all automatic. There were no problems in STO...."
&
1,000 and Counting – The F-35B’s Journey to the 1000th Vertical Landing NAS Patuxent River, July 25, 2016
[url]https://www.f35.com/in-depth/detail/1000-and-counting-the-f-35bs-journey-to-the-1000th-vertical-landing [guesswot? URL not werk]
"...On January 7, 2010, BAE Systems test pilot Graham “GT” Tomlinson, the lead STOVL pilot at the time, engaged the aircraft’s STOVL propulsion system in flight for the first time. During this flight, Tomlinson, a former Harrier pilot in the Royal Air Force, climbed to 5,000 feet and engaged the propulsion system – lift system engaged, lift fan spinning, propulsion effectors active – at 210 knots, then slowed to 180 knots with the system engaged before converting back to conventional flight mode...."

[SpazSinbad]

Video of the attitude just before the bondhu bashing portion of the sortie
https://www.youtube.com/watch?v=0RaN3KYOgIY
I hope this video is available and IF it has ads I have no control over them nor kickback cash. ONLY 10 seconds duration and no sound. OTHERWISE video above has this msg below:

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/627x252/video_unavailable_msg_68305e3df8a67d11adfd0b7b5a8b29724026d8 ad.gif

F-35B STO Crash Ejection OK New Mexico 28 May 2024

https://www.youtube.com/watch?v=QmnwU-e5r-U

[gums]

Salute!

Gotta join others' opinions here about the density alt plus a plane problem involving the motor.

Those who have not flown up there at 5k or 6k or higher, or at 40C deg with 90% humidity understand. I never appreciated doing the takeoff calcs until it hapened to me. BFD. So after a scary takeoff at Colorado Springs I had religion. Rolled about 10,000ft, on an 11,000 ft rwy in my heavy Sluf, but was smooth enuf to gradually gain speed, and having terrain sloping down made me feel better.

I have seen videos of the Bee on short takeoffs but here at Eglin have only seen conventional launches and a rare "roll on" in the Bees.

Hate to lose one of those jets, but this one seems a system problem and the experienced pilot got out.

I checked out the Tacos when they converted to A-7D's, and those fellows appreciate DA. Also checked out the Colorado guard unit and they fully honored takeoff calculations.

Gums opines...

[LateArmLive]

Salute!

Gotta join others' opinions here about the density alt plus a plane problem involving the motor.

Those who have not flown up there at 5k or 6k or higher, or at 40C deg with 90% humidity understand. I never appreciated doing the takeoff calcs until it hapened to me. BFD. So after a scary takeoff at Colorado Springs I had religion. Rolled about 10,000ft, on an 11,000 ft rwy in my heavy Sluf, but was smooth enuf to gradually gain speed, and having terrain sloping down made me feel better.

I have seen videos of the Bee on short takeoffs but here at Eglin have only seen conventional launches and a rare "roll on" in the Bees.

Hate to lose one of those jets, but this one seems a system problem and the experienced pilot got out.

I checked out the Tacos when they converted to A-7D's, and those fellows appreciate DA. Also checked out the Colorado guard unit and they fully honored takeoff calculations.

Gums opines...

What makes you think it was a system problem?

[gums]

Salute!

What makes you think it was a system problem?

The very shallow climb angle is not what I have seen here at Eglin when the bee was doing go arounds from a brief touch or even after a hover, and had all the doors open.

So a contributing factor could have been engine related. The visible profile looks exactly like our F-16 crashes due to the FBW maintaining wings level and increasing AoA or on the AoA limiter. So I would not bet on the FBW system being a major factor.

Gums opines...

[Redbud]

Salute!



The very shallow climb angle is not what I have seen here at Eglin when the bee was doing go arounds from a brief touch or even after a hover, and had all the doors open.

So a contributing factor could have been engine related. The visible profile looks exactly like our F-16 crashes due to the FBW maintaining wings level and increasing AoA or on the AoA limiter. So I would not bet on the FBW system being a major factor.

Gums opines...

And, some propulsion systems have temperature-limiting systems that will reduce thrust upon reaching prescribed limits (eg Pegasus). Thus, an engine, functionally performing as designed, can limit one’s ability to fly out of this kind of corner in the envelope. Do we know this happened? No. Is it in the realm of possibility? Perhaps.

[SpazSinbad]

And, some propulsion systems have temperature-limiting systems that will reduce thrust upon reaching prescribed limits (eg Pegasus). Thus, an engine, functionally performing as designed, can limit one’s ability to fly out of this kind of corner in the envelope. Do we know this happened? No. Is it in the realm of possibility? Perhaps.
I do not know what exactly is meant in the highlighted part of this quote (for context). Perhaps the pilot did a 'spur of the moment' decision to STO not having accessed the computer for performance details at the current altitude (just my wild guess)? Anyhoo...

Test Flying The Joint Strike Fighter 17 Jun 2011 Graham Tomlinson
[url]http://myweb.tiscali.co.uk/hawkerassociation/hanewsletters/hanewsletter030nvu/testflyingjointstrikefighter.html
”The STOVL mode control system is derived from ‘Unified’ developed by the ‘RAE’ on the VAAC Harrier. The throttle commands acceleration and deceleration (or thrust on the ground and in the STO mode, and in all conventional modes); in the hover the stick moved backwards / forwards commands upwards / downwards vertical velocity (or pitch rate elsewhere); in the hover the stick moved from side to side commands bank angle (or roll rate elsewhere) and if released returns the aircraft to wings level; in the hover the pedals command yaw rate (or sideslip elsewhere).

Future development will clear full envelope autopilot/auto throttle, automatic deceleration to a spot, and TRC (translational rate command) which in the hover allows the pilot to make small positional corrections easily, and will then bring the aircraft to a standstill if the pilot releases the controls.…

...In the Harrier the pilot must obey the rules. The F-35B flyby-wire system gives angle-of-attack and sideslip control, and departure protection. Further pilot workload reduction is given by performance deficit protection, conversion speed window protection and FOD protection warning; and flight test has a watching brief on the requirement for possible tail strike protection during slow landings (currently not considered necessary [2011]). Pilot cognitive errors (of trying to control thrust with the throttle) have been mitigated in the design.…”

THOUGHT it might be useful to show the full monte from no longer HTML url above.

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1566x1050/test_flying_the_joint_strike_fighter_tomlinson_2859334223f67 60229fca79bff7eab4d5172d695.gif

[tdracer]

And, some propulsion systems have temperature-limiting systems that will reduce thrust upon reaching prescribed limits (eg Pegasus). Thus, an engine, functionally performing as designed, can limit one’s ability to fly out of this kind of corner in the envelope. Do we know this happened? No. Is it in the realm of possibility? Perhaps.
We got rid of automatic EGT thrust limiting very early on with commercial engines (with the notable exception of auto-start) for two reasons - first off, EGT isn't the most reliable signal in the world, and we didn't want to cut back thrust during a critical flight phase due to a bad EGT reading.
Second, if EGT exceeds redline, the pilot(s) are immediately alerted (at least if they are pay attention) and can take corrective action if circumstances allow. If circumstances don't allow (e.g. close to the ground during takeoff with a single engine aircraft), it's cheaper to replace an engine after an EGT exceedance than to replace the aircraft (and perhaps the pilot) after it crashed when power was cutback due to EGT.
I'd be very, very surprised if Pratt and Lock-Mart have forgotten that lesson...