Talk:1994 Fairchild Air Force Base B-52 crash

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This is an old revision of this page, as edited by 80.4.57.101 (talk) at 16:28, 24 April 2012 (→‎Errant Conclusion: Clarify). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Featured article1994 Fairchild Air Force Base B-52 crash is a featured article; it (or a previous version of it) has been identified as one of the best articles produced by the Wikipedia community. Even so, if you can update or improve it, please do so.
Main Page trophyThis article appeared on Wikipedia's Main Page as Today's featured article on June 24, 2007.
Article milestones
DateProcessResult
May 3, 2007WikiProject A-class reviewApproved
May 4, 2007WikiProject peer reviewReviewed
May 22, 2007Featured article candidatePromoted
Current status: Featured article

Tailwind issue

The text of this article contains the following quote: "The final factor was the 10-knot tailwind that pushed the steeply banked aircraft into the accelerated stall, resulting in the crash." I am not sure where this opinion originated, but it reflects a lack of knowledge in basic aerodynamics. Unless the tailwind manifested itself in the form of windshear, which was not stated in the article, there is no way a tailwind could directly affect the stall of the aircraft. I know from my time spent as a flight instructor that student pilots often get confused on this very point. They some times believe that turning downwind in the landing pattern can cause the aircraft's airspeed to change and bring on a stall. However, this is not the case. Barring windshear, the airspeed of an aircraft in flight is unaffected by the direction that the aircraft is pointing relative to the direction that the wind is blowing across the ground. Only the ground speed is affected. For example, if an aircraft indicates an airspeed of 200 knots and the wind in its area is blowing at 10 knots over the ground, the aircraft will have a ground speed of 210 knots when flying downwind and a ground speed of 190 knots when flying upwind. The important point is that no matter which direction it is flying, it will always have an airspeed of 200 knots. Stall speed is based on airspeed, not ground speed. So changing direction in flight, in and of itself, has no effect on stall speed and will not cause the aircraft to stall. That said, the 10 knot tailwind could have had an indirect effect on this crash. Turning downwind, the aircraft's ground speed would have increased and the pilot may have steepened his turn to avoid overflying a restricted area. The steepened turn could have easily brought on an accelerated stall, stalling at a higher speed than normal, but this is an indirect cause. A tailwind does not cause accelerated stalls!

63.74.232.26 03:07, 19 May 2007 (UTC)[reply]

The exact text from the mishap report is:
If you think the text should read differently, please suggest how it should and I'll add it. I appreciate your input to help the article be more accurate. Cla68 03:31, 19 May 2007 (UTC)[reply]
I think the article is correct, assuming that the aircraft was flying along a particular trajectory with reference to the ground. If a pilot maneuvers the plane so to perform a 360° around a fixed point (e.g. the tower), then the wind is indeed a factor, because at some point along the 360°, that wind will become tailwind, requiring appropriate changes in power/airspeed/bank angle in order to keep both the trajectory and a safe margin from stall. Giuliopp 04:35, 25 June 2007 (UTC)[reply]

As I understand the issue, as the aircraft turns through 180 degrees and a headwind becomes a tailwind, the groundspeed of the airplane increases because it is now being pushed from behind be the wind, however, the actual airspeed should be the same. 71.159.153.171 (talk) 02:43, 24 February 2008 (UTC)[reply]

You are correct - the tailwind was not an issue, regardless what others claim. What may have been an issue is the gust factor. However, it wouldn't matter if it were tailwind or headwind, as gust factors vary both positively as well as negatively, and a momentary lull in a headwind could just as easily induce a stall as a momentary gust in a tailwind.

We have to be careful not to disregard the basic physics in this connection: In principle it is true, when headwind turns into tailwind, then the air speed should ultimately remain the same. But only ultimately. Because changing speed means acceleration. According to Newton's laws: F=am, where F is the force applied, m the mass of the object and a the acceleration. F is here the force applied by the wind, m the mass of the airplane. According to the report, the headwind turned into a tailwind within 15 seconds. When this happens, the airspeed will drop instantly, remain lower temporarily, and then the aircraft will accelerate again to finally return to the previous airspeed. However, for an object as massive as the B 52, this acceleration takes some time, time that was not available. Therefore, in this case, the sudden tailwind could very well have aggravated the stall. —Preceding unsigned comment added by Dram4 (talkcontribs) 08:13, 1 March 2008 (UTC)[reply]

The headwind turned into a tailwind because the aircraft was turning. Further, nothing in dynamics changes "instantaneously." Third, aircraft flying through a moving air mass are unaffected by head/tail winds except for their velocity over the ground (groundspeed, drift). Their velocity through the airmass remains unchanged, and it's the air mass, not the ground, that provides the lift which keeps them flying.

Renaming?

I realize that this is an FA article, so I want to be careful how I proceed on this, but I would like to suggest that this article be renamed to conform to the general naming conventions being promoted by the Wikipedia:WikiProject Aviation/Aviation accident task force. The new name would be 1994 Fairchild Air Force Base B-52 crash. This would put the article in line with other military aviation crash articles, as well. Thoughts? AKRadeckiSpeaketh 17:35, 7 June 2007 (UTC)[reply]

  • No objection from me and I'm the one who started the article. CLA 20:58, 7 June 2007 (UTC)[reply]
  • No obejection from me either. However, since the article is under consideration for being "FA of the Day" in a few weeks, I'd suggest the re-name take place after that. I have already set up a Redirect of the new name to the current article. Check-Six 22:24, 7 June 2007 (UTC)[reply]
Sounds good. I'll keep an eye on the FA of the day...that'll be a big plus for the project! AKRadeckiSpeaketh 01:01, 17 June 2007 (UTC)[reply]
Don't most articles pertaining to aircraft accidents use the specific flight's call sign or flight number? Say, for example, TWA 800 crash is at TWA Flight 800, not "747 crash east of Long Island". So maybe this article should just be renamed "Czar 52"?-albrozdude 06:34, 24 June 2007 (UTC)[reply]
Generally, flight numbers only apply to commercial flights, and then not always. It makes coming up with a uniform naming guideline a bit difficult, but over time this has become the perferred method both in Wikipedia:WikiProject Aviation and Wikipedia:WikiProject Disaster management, and is outlined at the Aviation accident task force page...and input and suggestions are always welcomed there. AKRadeckiSpeaketh 00:48, 25 June 2007 (UTC)[reply]
Actually, the article states that Czar 52 was the pilot's callsign. --Cheezymadman
The article seems to state that because of the way the sentence in question is written. As a former 325th flier, I can state with certainty (and the article's referenced links back me up) that Czar 52 was the flight call sign, not Bud Holland's personal call sign (which I do not recall at the moment). Unless otherwise specified for a specific mission, all the 325th's flight call signs were in the form of "Czar XX" with the "XX" being the crew number; personal call signs were not used as flight call signs. Shawn D. 16:10, 24 June 2007 (UTC)[reply]
  • Another reason to not call it "B-52 aircraft crash at Fairchild Air Force Base" is that it was not the only B-52 crash to occur at or near the base. Two separate incidents occurred in 1959. Shawn D. 16:10, 24 June 2007 (UTC)[reply]
If anyone wants to rename the article as discussed above, I don't have any objection. CLA 20:37, 24 June 2007 (UTC)[reply]

Done. AKRadeckiSpeaketh 00:48, 25 June 2007 (UTC)[reply]

Eyewitness

I watched this aircraft crash and later participated in the clean-up. I was part of the 92ND maintenance squadron and was working in a warehouse (TMO?) near the entrance to the flightline. We were packing B-52 bomb pylons into crates to prepare for shipment to other units because the bomber unit was being decommisioned. We heard the B-52 flying by and had to step outside to watch it. It blasted down the flightline and then banked sharply and turned and came back. It was amazing. I lost sight of it as it moved behind a hangar and then I heard a dull thud. Soon my heart sank as I saw an immense plume of black smoke. Immediately the place went nuts, civilian and military car rushed out to the flightline. I'll never forget this day. BWSK former USAF—The preceding unsigned comment was added by 66.119.205.51 (talkcontribs).

Does this have something to do with the article? ShadowHalo 07:12, 24 June 2007 (UTC)[reply]
I think relating an eyewitness account is definitely interesting enough for the talk page, even if the talk page is normally for comments about the article itself. A2Kafir 18:33, 25 June 2007 (UTC)[reply]
It may be interesting but as you say, not what the talk page is for and should be discouraged. Sure for an article like this it doesn't create a big problem. But for e.g. some big disaster (including terrorist attacks), sports events etc there can be lots and lots of eyewitnesses each with their own account which can quickly get out of hand Nil Einne 21:45, 25 June 2007 (UTC)[reply]
First, there weren't lots of eyewitnesses to this crash. Second, the article is about the crash. Third, one of the eyewitnesses to the crash is reporting what he witnessed. Did you really miss the fact that the eyewitness correctly ID'd the fact that the 325th was in the process of being decommissioned as a bomber squadron? You think, perhaps, that element of information might have been a factor in the crash? The previous questions are rhetorical.

I was also there. I was in the 92nd OMS. I remember the crash. I remember everyone thought the pilot was a hero because he "put it down" in the only open field available. And that stuff about the KC-135 landing was BS. They had been doing those low fly bys for over a week. Someone "up the chain of command" wanted both planes visable after passing low and turning opposite each other. It was practice for a Air Show that was coming up. By tighting up their formation, when the KC banked left it caused a "dead" spot of air. When the B-52 banked hard right, it encountered the dead air. Sitting on the flightline in my bread truck,(call sign red 5) with the other 10 or so guys, we all saw the engines flame out 1,2,3 and then it nosed in to miss the BX where all the families were filming the show. Why do you think there was so many people filming it? Because it was the last day to practice. It was the dress rehersel. If the Air Force needs to blame someone they need to look further up the chain of command. Also how was there time for the AC (aircraft commander)to recieve the "go around" radio back and ask to perform a dangerous manuver right around the tower, recieve permission, realize he was crashing and then attempt to eject? Thats not how it happened, or when for that matter. The dates wrong. —Preceding unsigned comment added by Riolovin (talkcontribs) 05:29, 1 October 2007 (UTC)[reply]

I've been thinking about your comments for some time. If Holland was attempting a 360 degree turn around the tower, then how could he also have been trying to avoid crashing into the BX? The crash occurred on the exact flight path of the 360 degree turn. The 360 turn did not involve any flight over the BX. I don't, however, disagree with you that the AF should have looked further up the chain of command. It's common practice in the Air Force to to blame the mishap pilot when the mishap pilot happens to perish in the accident.{{Fact}} tag added by me. Cla68 (talk) 14:02, 1 March 2008 (UTC)[reply]
I agree, Cla68. Too many errors. As for "blaming" the mishap pilot, I had not one, but three very close calls flying with the mishap pilot, as did a number of my friends, so I don't think it's an issue of pinning it on someone who can't defend himself. I think it's an issue of pinning the accident on the individual who caused the accident.
It might have been a typo -- the filming was done from near Base Ops, not the BX. Shawn D. (talk) 14:39, 1 March 2008 (UTC)[reply]
That makes sense, it would look look like Holland nose dived the aircraft in order to avoid crashing into base ops. However, the investigation indicates that Holland or McGeehan didn't have enough control of the aircraft at that time to avoid a collision with anything, including, obviously, the ground. Cla68 (talk) —Preceding comment was added at 14:43, 1 March 2008 (UTC)[reply]
Since there were seemingly a number of inconsistencies in the statement by Riolovin, I had disregarded the whole comment. I am not implying that he is lying, but just that his recollection doesn't mesh with my observations: 1) The B-52 banked left, not right. 2) I read no report and saw no evidence of an engine failure. In fact, in the video, you can hear the engines spool up as additional thrust is applied about 1/4 the way around. Also at this point the bank angle decreases and the plane appears to be controllable. My guess is that control was lost only after the bank angle increases again nearly half way around the 360. 3) The inconsistency with the location of the BX. 4) I think there were so many people filming because it was Wolff's "fini flight", but he is right, this was the last scheduled practice. 5) What dates are wrong? ... However, I do agree with the statement that there probably wasn't time to radio the tower for clearance to do a 360, and I have read (although I can't find a reference right now) that the 360 was part of the flight plan. Boardhead (talk) 18:17, 4 March 2008 (UTC)[reply]

Chain of command chart

This sentence:

Holland was the chief of the 92nd Bomb Wing's Standardization and Evaluation branch, McGeehan was the commander of the 325th Bomb Squadron, Wolff was the vice commander of the 92nd Bomb Wing, and Huston was the 325th Bomb Squadron's operations officer.

Could confuse readers without a basic understanding of AF unit structure, so i created a basic flow chart to help with any misunderstanding. Anynobody 07:13, 24 June 2007 (UTC)[reply]

wow

wow, the low notability of the topic, surprises me that one would take the time to make it a featured article. --Leladax 11:39, 24 June 2007 (UTC)[reply]

Do you really mean "low notability", or do you mean "uninteresting to you"? --Bongwarrior 12:55, 24 June 2007 (UTC)[reply]

Since when did this page become a smear campaign about Holland? I understand talking about the investigation, but it seems to me that someone is doing everything possible to point fingers, including an itinerary attacking Holland.—The preceding unsigned comment was added by 24.107.125.248 (talkcontribs).

  • Look at the sources and they'll confirm that Holland's behavior and personality are at the core of this tragedy. The sources are very clear on this point. CLA 21:39, 24 June 2007 (UTC)[reply]
  • If you have something to share regarding Holland, please share it here. I would love to see some differing opinions. Check-Six 17:38, 25 June 2007 (UTC)[reply]
Wow. What a good and fascinating article! A tremendous read. Exciting, tragic and full of lessons. Very interesing. Very worthy of a Featured article and the excellence of the contributors. What a joy to read.WHEELER 17:07, 24 June 2007 (UTC)[reply]
I concur. --Haizum μολὼν λαβέ 11:01, 25 June 2007 (UTC)[reply]
Um sorry but opinions of Holland are not what this talk page are for. I suggest you take that to your personal talk page. The talk page is only for ways to improve the article Nil Einne 21:41, 25 June 2007 (UTC)[reply]
I would argue that since the accident investigation board determined Holland's personality was a key factor in the accident, and that the accident IS the article, the principle way to improve the article is by gaining a better understanding of Holland. I flew with him on several occasions, and understand him as well as anyone else in the squadron did. —Preceding unsigned comment added by 87.177.20.134 (talk) 00:35, 13 July 2008 (UTC)[reply]
I agree. This is an extremly fascinating "personality" story. If there is an explanation out there, may it one day surface. Marksmithhfx (talk) 02:46, 11 January 2009 (UTC)[reply]
In my mind, after carefully researching certain aspects of this crash, the explanation is clear: Holland requested a last-minute 360 around the tower, but misjudged the path of the aircraft which would have likely entered the area of restricted airspace had he continued at his original bank angle. When he realized his position, he reacted instinctively by banking harder to avoid the restricted zone, not realizing that this would result in an accelerated stall until it was too late. Boardhead (talk) 15:49, 22 January 2009 (UTC)[reply]
According to what I read on the web while researching for this article, Holland's supporters have a different theory about what happened during the 360 turn. They appear to believe that someone else in the cockpit interfered with Holland's piloting during the turn and therefore helped cause the crash. I believe some of the comments on this talk page are veiled references to this theory. Since there is no evidence, as far as I know, to support this other theory, it will probably always be nothing more than speculation. Cla68 (talk) 21:41, 22 January 2009 (UTC)[reply]
This is a valid point, and I have no way of knowing who was actually at the controls. My explanation was intended to shed light on "why" the crash occurred, and not "who" caused it. So it is fair enough to read "flight crew" instead of "Holland" in my statement above, although isn't Holland ultimately responsible for the actions of the flight crew? Boardhead (talk) 17:06, 23 January 2009 (UTC)[reply]

Dates

In the article it states Bud Holland was killed when the craft crashed in 1993 but later under a picture it states he flew it over a low ridgeline in 1994. Why is this?

One seeming inconsistency

The second paragraph of the 'Other factors' section says "Pellerin, however, was unavailable for the flight on June 24 and Wolff was selected as the replacement aircrewmember. Due to the short notice of his assignment to the mission, Wolff did not participate in the pre-flight briefing and boarded the aircraft after the engines were started. Thus, Wolff was not aware of the planned mission profile and did not have an opportunity to raise any objections before take-off." But the second paragraph of the 'Crash' section says "The flight was also Wolff's "fini flight" — a common tradition in which a retiring USAF aircrew member is met shortly after landing on his or her final flight at the airfield by relatives, friends, and coworkers, and doused with water. Thus, Wolff's wife and many of his close friends were at the airfield to watch the flight and participate in the post-flight ceremony."

How did his friends and family have time to arrive at a special ceremony for his final flight when he didn't know it was to be his final flight until so soon before takeoff that he didn't even have time to review the flight plan?

Otherwise, indeed, an excellent article. 216.77.231.70 19:17, 24 June 2007 (UTC)[reply]

That's what the sources say. It appears that Wolff actually knew that he was flying as early as the day before or at least early the morning of, but for whatever reason didn't join the flight crew until after engine start. Nevertheless, his friends and co-workers had sufficient time to set-up a fini-flight ceremony for him including having an official photographer and videographer present to document the ceremony (this is one reason why there exists video and photographs of the crash). CLA 20:35, 24 June 2007 (UTC)[reply]
Is it possible that Wolff didn't know, but that everyone else did? ie. a "surprise" Fini-flight? I know nothing of this tradition, so I am only speculating here. Boardhead (talk) 20:10, 4 March 2008 (UTC)[reply]
Safety observers aren't a part of the regular crew complement. While they're not required to attend any of the mission planning, they should attend the pre-flight briefing. As for the fini-flight, it may have been scheduled aboard another aircraft. However, the 325th was ramping down at the time of the accident (skeleton squadron only), so flights may have been few and far between, resulting in a last-minute change to marrying Wolff's fini flight with the pre-airshow dry run. Also, you'd be surprised at how quickly the word can spread for any similar event, as the Air Force is a fairly tight community. —Preceding unsigned comment added by 87.177.20.134 (talk) 00:31, 13 July 2008 (UTC)[reply]

excessive precision

I just wanted to explain an edit I made, the edit summary is too short to really justify it. In this edit I changed some of the measurements in meters slightly. For instance, where it said "2,500 feet (762 m)" I changed it to "2,500 feet (760m)".

Now, 762 m is a more exact equivalent to 2,500 feet, so why did I change it to 760 m? The measurement "2,500 feet" is clearly approximate, to about two digits of precision. Whatever source that measurement came from, I doubt they actually meant "2,500 feet, and not a foot more or a foot less." More likely, it was a few feet different from that (and either they rounded it off, or their own source of information was inexact).

Saying "762 m", though, implies a value a lot more precise. One very close to 2,500 feet -- closer even than the original statement "2,500 feet" was supposed to imply. That's why I changed it to the less precise "760 m".

I didn't do this for values in other sections; those values seem to have matching precision in their metric and non-metric forms.

Kudos to Skybunny for adding these translations in the first place. -- Why Not A Duck 22:00, 24 June 2007 (UTC)[reply]

Photo copyrights

Several photographs in this article are labeled "This photo was taken on a U.S. military reservation which makes the photo property of the U.S. government and thereby public domain, even if the photo was taken by a private citizen." This sounds, um, totally made-up to me. Is there any source for this theory?--Pharos 22:01, 24 June 2007 (UTC)[reply]

Perhaps they are a tiny bit edited. This would make them copyrighted. --Ysangkok 22:58, 24 June 2007 (UTC)[reply]
Me too. I'm not aware of any law making photos of U.S. miltary reservations public domain, only works of federal government employees conducted as part of their official duties. Dcoetzee 23:38, 24 June 2007 (UTC)[reply]

Video

Can we see it? Brutannica 02:06, 25 June 2007 (UTC)[reply]

Search YouTube, it's there. - PatrikR 02:15, 25 June 2007 (UTC)[reply]
The Check-six site listed in the references section also has a video of the crash. I would have tried to put a copy of the video in the Commons and linked to the article but the technical issues were beyond my abilities. CLA 02:58, 25 June 2007 (UTC)[reply]


Holland's Picture

Beautiful article! It's odd, though, that there is no picture of Holland's while those of some of the other crew members is. Still, beautiful article! 210.7.132.72 16:29, 25 June 2007 (UTC)[reply]

I'm sure that photos exist of Holland, but I haven't been able to find any. Cla68 14:13, 27 August 2007 (UTC)[reply]

Did Holland ever attempt, or intend to attempt, a roll?

I wonder, did Holland ever attempt to roll a B-52, like the famous roll of the 707 prototype? I had wondered when I first saw the video of this crash years ago whether he was attempting a roll (although it's clear when you think about it that it's just an overly steep banked turn, as described). A2Kafir 18:39, 25 June 2007 (UTC)[reply]

Holland reportedly talked about trying it, but no evidence exists that he ever actually attempted a roll. I don't think he was trying to roll the aircraft when it crashed. CLA 20:47, 25 June 2007 (UTC)[reply]
Holland? No. There was a rumor among the oldheads (Vietnam-era pilots) that someone had rolled a D model while dodging a SAM during 'Nam, but that the roll was inadvertant. The rumor had it that after a gyration or two, the pilot found himself nearly upside down and instead of trying to fight it, just went with it, instead, and recovered a few thousand feet lower. —Preceding unsigned comment added by 87.177.20.134 (talk) 00:22, 13 July 2008 (UTC)[reply]

Ejection Seats?

Did this particular plane have ejection seats? I thought the later models were equipped with ejection seats in at least some of the crew positions. User:jacobst 22:58, 25 June 2007 (UTC)[reply]

To the best of my knowledge, yes - it did. The "about to crash" photo shows one of the cockpit egress hatch was opened in the milliseconds before impact. Check-Six 23:22, 25 June 2007 (UTC)[reply]
The article mentions that McGeehan tried to eject just prior to the crash, but his seat hadn't yet cleared the aircraft when the impact occurred. CLA 23:26, 25 June 2007 (UTC)[reply]
The aircraft does have ejection seats, the pilot and copilot eject up (note the panel just off the aircraft in the crash photo) and the WSO/Navigator eject down. Not a very happy idea at low altitude.
B-52s have six ejection seats: two forward-facing and upward-ejecting (Pilot and Co-Pilot), two rearward-facing and upward-ejecting (Electronic Warfare Officer and Gunner), and two forward-facing and downward-ejecting (Radar Navigator and Navigator). The four other crewmembers that can be carried must bail out manually. Shawn D. 12:32, 16 July 2007 (UTC)[reply]

I assume there's no cockpit voice recorder on B-52s

...because, if there were, the transcript of this crash would probably be public by now. A2Kafir 21:30, 27 June 2007 (UTC)[reply]

I was wondering the same thing myself. In researching for the article I observed indicators that some people believe that there was an altercation occurring in the cockpit between McGeehan and Holland just prior to the crash. If there was a CVR that, of course, would help to confirm or deny whether this was true. CLA 01:26, 28 June 2007 (UTC)[reply]
B-52s did not have CVRs at the time of the crash. By that wording, I am not implying that they have them now. Shawn D. 12:35, 16 July 2007 (UTC)[reply]
Noted. The AF neither confirms nor denies whether there are CVR on their B-52 aircraft. Cla68 14:31, 16 July 2007 (UTC)[reply]
It could be argues that given the mission type of the B-52 and the high likelyhood of craft being downed during strategic bombing campaigns, that a CVR could be considered a mission security risk. That could explain why CVRs weren't (or aren't) considered on the B-52. Frankly, it'd suck if we lost one over wherever and the CVR survives and feeds the opponent with some idle cockpit banter about "We're going to be here again next week too"... --Mfree 14:34, 31 October 2007 (UTC)[reply]
Could perhaps be solved by encrypting a digital recording and making sure the key to decode it remains off-flight. 80.203.20.65 (talk) 14:01, 24 June 2010 (UTC)[reply]

image copyright issue

An image used in the article (File:FairchildB52Crash.jpg) has been proposed for deletion on commons. See Commons:Deletion requests/File:FairchildB52Crash.jpg --rogerd 14:48, 29 June 2007 (UTC)[reply]

Accelerated Stall

The animation of the accelerated stall that has just been added is very nice, but unfortunately it's conceptually wrong. It seems to suggest that the stall speed varies depending on the sideslip angle of the aircraft, whereas the two things are unrelated.
A stall is the reduction of lift caused by the Angle of Attack of the wing exceeding the critical value for that wing, and the AoA depends on the aircraft pitch, not yaw.
Now, if you want to keep flying and you are already at the critical AoA, you'll have to maintain at least a certain speed (the stall speed), otherwise there's no way you can get enough lift to keep you airborne (not considering flaps). If the weight of the aircraft increases, so does the stall speed (since more lift is needed) and the same is true if the aircraft is manoeuvring (e.g. turning), since the effects of acceleration are substantially identical to a change in weight. A 2g coordinated turn is essentially the same as flying straight and level in a world where gravity is double the Earth's one; in both cases the stall speed will be = 1.4 times the normal stall speed achievable while flying straight and level in this world. That's what accelerated stall refers to: a stall that occurs at a speed higher than normal due to the effect of the aircraft's acceleration.
The animation, misleading as it is, is bound to be removed. It would be good to see it re-drawn correctly, because the graphics is nice. I'm happy to give some hints on how it could possibly look like.
Giuliopp 22:39, 5 September 2007 (UTC)[reply]

I drew it, and though I understand your concern it's actually describing one type of stall (there are actually different varieties, some depending on the placement of airfoils on the aircraft itself). Technically a stall is: In aerodynamics, a sudden reduction in the lift forces generated by an airfoil. When an aircraft is moving "forward" but pointing away from the direction of motion, the airflow over the wings is not conducive to the proper generation of lift. (It's essentially the same problem caused by excessive angles of attack, there is air flowing over/under the wing just not properly because of the angle of the wing relative to airflow. Anynobody 04:14, 6 September 2007 (UTC)[reply]

:Essentially it's taking the wing in this illustration and turning it 90 degrees.

File:Anynobodyillustration1.gif
*Note: The diagram was created using one frame to illustrate how the plane is moving, not its exact movements.*

Anynobody 04:19, 6 September 2007 (UTC)[reply]







I think we should be careful not to mix-up stall with sideslip. A sideslip is not a type of stall. Stall is about Angle of Attack, and therefore pitch. Sideslip is about sideslip angle, and thus yaw. In the article about stall, yaw is hardly ever mentioned, and only as an aggravating factor for a stall (potentially resulting in a spin), not as a cause.

It is true that, in a sideslip, the air doesn't flow "properly" around the aircraft, but the main effect of that is the sharp increase in drag (due to the fuselage and fin going sideways), rather than a reduction of lift (which can occur, but not as dramatically as when during a stall). I've never heard of the term 'stall' referred to these sideslip-related effects (if you have, please quote the source), whereas I've always seen it associated with excessive pitch/AoA.

As for the picture above and the wing to be turned 90° to allegedly obtain "essentially the same problem", if I got what rotation you mean, I'm afraid that behind that assertion there is some confusion between Angle of Attack and sweepback angle of a wing. If you take the fully extended wing of an F-14 and pitch it upwards to an AoA of say 50° (i.e. well into the stall region), the resulting airflow and forces are completely different from the same wing at 0° AoA and swept back by 50° (which is a normal setting for a Tomcat).

The current animation shows purely a variation of sideslip angle, which bears some analogy with a wing being gradually swept back, but it has nothing to do with angle of attack nor stall. A meaningful animation could show for example something like this:

Assuming the turn is co-ordinated (that is purple arrow always at right angle to the wings) and the airspeed constant, then the diagram shows what happens when the turn radius decreases (= tightening the turn). More lift is needed to keep the trajectory, which can only be achieved by increasing the AoA (speed is constant and flaps are not considered here). At some point the turn will be so tight that the critical AoA is exceeded and the aircraft stalls. Note that it does so without dropping its speed, which implies that the stall speed Vs has increased while the turn radius was decreasing.

If you can take this sketch and turn it into a nice 3D animation of a B-52, adding the useful speed scale as in the present animation, I think that would definitely be a valuable contribution to the article.
Giuliopp 21:06, 8 September 2007 (UTC)[reply]

I'm sorry to have to disagree with you, given the amount of effort you put into explaining this. In order to avoid a situation where we talk past each other, can we agree that the basic definition as,
Stall
In aerodynamics, a stall is a sudden reduction in lift forces generated by an airfoil? Anynobody 22:45, 8 September 2007 (UTC)[reply]

I agree on that definition, which is a very generic and introductory definition of stall. I also agree on the sentence that, in the WP article about stall, follows the quoted one: "This [reduction in lift] most usually occurs when the critical angle of attack for the airfoil is exceeded", which is what I have been trying to explain and what most likely happened at Fairchild AFB.
Giuliopp 13:18, 9 September 2007 (UTC)[reply]

All right then we're on the same page :) I don't mean to sound like a jerk but that was exactly where I was going next, only with an emphasis on the ...most usually occurs... part. The difference between an aircraft with a sideslip attitude and a stall is how much lift the wings are generating. As the aircraft's sideslip angle increases, less area of the wing's leading edges is meeting the air directly (so instead of airflow going above and below the wing from leading to trailing edges, it is instead going toward or away from the fuselage depending on which wing is going into the wind.) At some point the wings stop producing the amount of lift necessary, no matter how fast the plane is going, and it loses altitude until the pilot can correctly orient the wings toward (instead of perpendicular to) the wind or the plane crashes. Anynobody 05:14, 10 September 2007 (UTC)[reply]

What you say about the sideslip angle increasing etc. makes some sense but, excuse me if I'm blunt, what has it got to do with accelerated stall and the Fairchild crash? From the video you can tell that the fatal 360° turn was for most of it quite coordinated (= no sideslip), then it became too tight (= critical AoA exceeded → accelerated stall), and then the B-52 went down, uncontrollably, with a visible sideslip attitude. I won't go on any further on this thread because I would end up repeating the same things I've already explained.
That animation needs a fix. I suppose I'll have to do it (I can, in 2D, when I have a minute) then you can perfect it with the 3D model, deal? - Giuliopp out.
Giuliopp 00:27, 11 September 2007 (UTC)[reply]

Actually we're there, if you watch the video closely you'll notice that the attitude of the plane is diverging from the direction of motion until it crashes. As it does this it's in an accelerated stall, where the stall speed increases as the divergence grows. Anynobody 02:31, 11 September 2007 (UTC)[reply]

Questions about replacement

  • What does the purple arrow represent?
  • Why does the green arrow representing lift get bigger as the stall speed increases?
  • Why does the caption mention angle of attack but the diagram does not?

As you no doubt are aware, stalls are complicated. The idea of my original diagram was to show that a stall can occur without a large increase in nose up attitude AND at speeds above the aircraft's normal stall speed. Whereas this one appears to be trying to explain every concept related to a stall. Of course weight and angle of attack need to be part of any complete definition, but we're not discussing stalls in general, we're discussing this crash. This crash had less to do with weight distribution than it did interrupted airflow (lift) due to maneuvering. If we were discussing the COD crash at around 00:20 of this video, weight would be a factor to emphasize. Anynobody 03:45, 24 September 2007 (UTC)[reply]

- First of all, "a stall can occur without a large increase in nose up attitude": I don't know where you got this from; to my knowledge, this interpretation of the phenomenon stall is unheard of, in aerospace engineering. It could be true in transonic and supersonic flight (due to shock wave interaction), but this is clearly not the case. In our case, stall is simply caused by excessive Angle of Attack and therefore is primarily, if not exclusively associated with important changes in nose-up attitude.[1] All other factors (like sideslip angle) are secondary; they are not the cause of a stall, at most they can change its evolution (e.g. causing a the aircraft to enter a spin). If you are not convinced, ask any pilot or engineer.
- Second, the new animation: technically speaking, it represents Newton's first law written for a rotating reference frame, which can be expressed as: the sum of all forces,including the apparent ones, acting on a body at rest,[2] must be zero (note that thrust and drag are assumed equal and opposite, and thus omitted from the diagram). The purple arrow, therefore, is the vector sum of weight and centrifugal force and must necessarily equal the only remaining force, i.e. lift. The tighter the turn, the stronger the centrifugal force, the greater the lift required to achieve equilibrium. That's why the lift increases as the turn radius decreases.[3]
- Third, mention of Angle of Attack: the lift is proportional to air density, square of velocity, wing area and lift coefficient. All of the above quantities, except the last one, are assumed constant in our problem. The only variable is the lift coefficient and it varies when either the shape of the airfoil changes (e.g. by extending the flaps, again not considered here) or when the AoA varies. Therefore, in our problem, a change in AoA implies a change in lift, and vice-versa.
- Fourth, the weight distribution: you are right when you say that the Fairchild crash has nothing to do with weight distribution. In fact, in our problem, the distribution of weight is out of the equation, because we have implicitly assumed that the weight is correctly distributed across the aircraft. What we consider is the weight's global effect, i.e. a single force, equal to the aircraft total weight, applied to the airplane's center of gravity (CG). In other words, we reduce the entire aircraft to a so-called material point (its CG), and we study the motion of that point, when subject to forces equivalent to all those that are distributed all over the real aircraft. In this context, weight cannot be ignored if we want to apply Newton's first law meaningfully.[4]
Now, I feel that this thread is becoming almost like a lecture, while this is supposed to be a discussion page (and I don't claim to be a lecturer either), therefore I think I'd better stop (not considering the time it's taking me to put all this together). If I can suggest you a interesting reading, then Introduction to Flight by John D. Anderson covers all the topics we discussed and a lot more, plus it's really a pleasure to read.
Giuliopp 22:53, 27 September 2007 (UTC)[reply]
Notes
  1. ^ The only counter-example I can think of is when an aircraft is flying straight and level (i.e. constant nose-up attitude) and encounters a vertical (ascending) gust of wind; the resulting airflow, relative to the wing, will be tilted upwards, compared to the undisturbed one (i.e. AoA increases); if the gust is strong enough (and the aircraft speed low enough), the AoA will exceed its critical value, causing a stall (and so alleviating the upwards thrust of the gust, self-limiting the load factor; that's why in rough air speed should be kept below the VNO) - but we are straying off topic here; these are not the conditions of the Fairchild crash, nor of the 3D animation.
  2. ^ The aircraft is at rest with respect to the chosen rotating reference frame, which is the one moving with the aircraft itself.
  3. ^ Note that the thickness of the arrow is irrelevant; I only made it wider to emphasize the concept. What represents the intensity of a force is the length of the arrow.
  4. ^ Of course, the approximation used here would be inadequate to study a problem like the COD crash in the YouTube video. In that case there was indeed a problem of weight distribution, and if we want to analyze the dynamics of that flight, we cannot consider the airplane like a point anymore, but we have to consider how the various masses that make up the aircraft are distributed across its length.

WSF and its relation to the flight path?

I would be interested to know the actual flight path of the plane, and its relation to the reported weapon storage facility (WSF). I haven't been able to find this information anywhere, but here is a satellite image from Mapquest [image deleted due to improper copyright] with my notes about locations of landmarks from a video of the crash (runway, control tower, water towers and buildings). Also indicated is my best guess at the location of the WSF (the fenced area south of the runway). Does anyone have a reference which would give some of this information? Boardhead (talk) 17:01, 1 January 2008 (UTC)[reply]

As far as I know, there isn't a reliable source that shows the exact flight path of the aircraft. If you watch the video of the crash sequence, you can more or less guess the flight path from above, and then draw a line on this photo and place it in the article, as long as the copyright status is clear, which right now it isn't. Cla68 (talk) 01:05, 2 January 2008 (UTC)[reply]

Thanks. My main question is the location of the WSF. I can draw the flight path fairly accurately on a map, but I don't know for sure where the WSF is. Also, maybe I'll switch to a Google Earth image because I understand their copyright better. Boardhead (talk) 14:24, 2 January 2008 (UTC)[reply]
250px|thumb|right Here are two screenshots showing the flight path from above, and from the point of view of the camera that took this video [perspective image deleted by bot - 2008-02-17]. The images display a Google Earth KML file where I have calculated the approximate flight path based on landmarks and flying time at the airspeeds specified in the article. (To view the KML file, download and open with Google Earth) Boardhead (talk) 18:01, 2 January 2008 (UTC) -- Edit: Updated to current version of KML file and resolved image licensing issue. Boardhead (talk) 18:43, 7 January 2008 (UTC)[reply]
Is your question really "Where is the WSF?" or "Where did the impact actually occur?" I won't answer the former, but the answer to the latter is: between the leftmost two buildings in your orange-shaded area and S. Arizona Avenue. EDIT -- I was editing while you were posting your flight path estimate. Your pin location doesn't continue the path far enough. Shawn D. (talk) 18:03, 2 January 2008 (UTC)[reply]
Thanks for your comments Shawn. Knowing exactly where the plane crashed would be good. I understand if you don't want to specify the location of the WSF, but if there was an airspace restriction in effect, this certainly could have had an impact on the flight path and be a contributing factor to the crash. I find it hard to reconcile the crash location you gave with the satellite images and the photos/videos from the event. Boardhead (talk) 18:15, 2 January 2008 (UTC)[reply]
You're welcome. Using Google Maps, I estimate the coordinates to be N47.6105 W117.6505. Also note that the description of the crash says the aircraft made it about 3/4 of a turn, whereas your drawing shows about 2/3 of a turn. Sorry if that still seems hard to reconcile, but you don't know the exact filming locations. Shawn D. (talk) 18:33, 2 January 2008 (UTC)[reply]
Shawn, thanks for these coordinates. I had thought you had indicated a location approximately 300m further along to the north east. The coordinates are outside the shaded yellow area, and consistent with my estimates. The "Crash" pin on my map is the estimated location for the first contact of the left wing with a set of hydro lines. The crash debris would of course be further along, with the tip of the right wing contacting almost 2 seconds later (approx 150 meters at 145 knots). The location you gave is 180 meters further along the path, which makes sense if you are talking about the debris field. Boardhead (talk) 18:56, 2 January 2008 (UTC)[reply]
I have updated the KML file with Shawn's indicated crash location. Boardhead (talk) 20:02, 2 January 2008 (UTC) -- Update: Also added altitude estimates to flight path. Boardhead (talk) 03:13, 3 January 2008 (UTC)[reply]
In hindsight, my question about the WSF was not the appropriate thing to ask. Instead, I should have asked about the location of any airspace restrictions. Perhaps this is a question that can be answered. Boardhead (talk) 19:12, 2 January 2008 (UTC)[reply]
The USAF survival school is also in that area somewhere. Was it located in the same compound as the suspected WSF or was it in an adjacent area? Cla68 (talk) 03:24, 3 January 2008 (UTC)[reply]
The school was, and is, in an adjacent area. You wouldn't do unrelated training in a WSF due to the danger to students and due to the need to keep the weapons segregated & secure (the whole point of WSFs). Shawn D. (talk) 13:43, 3 January 2008 (UTC)[reply]
Another question, is that strip of white concrete above the suspected WSF a taxiway? Did the aircraft crash below, on, or above this taxiway as it is shown in the picture? Cla68 (talk) 00:19, 4 January 2008 (UTC)[reply]
That is not a taxiway, but a long-ago-decommissioned runway. Zoom out on a satellite view and you can see it and other decommissioned runways and taxiways. If you take note of the coordinates I provided above, you can see that the aircraft did not crash on, north of, or very near this decommissioned runway. Shawn D. (talk) 13:45, 4 January 2008 (UTC)[reply]
Actually, in the video you can see the aircraft slice through some power lines just before impacting the ground. If the power lines and support poles could be identified from the sattellite photo, that might provide better evidence of the aircraft's flight path. Cla68 (talk) 00:21, 4 January 2008 (UTC)[reply]
I think I have identified the hydro lines from the satellite photo, and they are marked in the KML file I posted. They are very near what appears to be a hydro substation just to the south of the crash site. Boardhead (talk) 19:55, 4 January 2008 (UTC)[reply]
Ah. I just found this reference, and now see the reason for Cla68's questions. The flight path indicated by this reference is not accurate (the turn-around is wrong by about 2km, and the crash location is off by about 800m). I was very careful in drawing my flight path, and it should be accurate to within 100 meters horizontally and 25 meters vertically with 90% confidence. Boardhead (talk) 16:15, 8 January 2008 (UTC)[reply]

If people think an image and/or description of the flight path would be useful, we should find a way to add this to the main article. Boardhead (talk) 18:43, 7 January 2008 (UTC)[reply]

Thank you for the images. I'm going to try to place one or both in the article. Cla68 (talk) 08:07, 22 January 2008 (UTC)[reply]

Article and talk page errors

I am confused by two examples of a similar sentence construction in the article, one stating, "The accident investigation concluded that the chain of events leading to the crash was primarily attributable to Holland's personality and behavior, USAF leaders' delayed reactions to the event, and the sequence of events during the mishap flight of the aircraft," and the other very similarly stating, "The accident investigation concluded that the chain of events leading to the crash was primarily attributable to Holland's personality and behavior, USAF leaders' slow reaction to the accident, and the sequence of events during the final flight of the aircraft." The phrases in bold seem to be attributing the accident itself in part to things that happened after the accident (which would be impossible; an effect cannot precede a cause). The text of the article, though, shows that the USAF leaders' reaction was to repeated violations of flight safety rules as evidenced by both direct observation by those leaders and by reports from crew members who flew with Holland. It would seem that the more accurate phrase to use would be something like, "USAF leaders' slow response to the evidence and reports of that behavior" or something to that effect.

I tend to be cautious when editing a Wikipedia article with such a substantial possible error, so I am posting this here in the talk page in hopes that possibly the original author or an editor with some experience can examine the issue. 170.141.56.4 (talk) 21:26, 2 July 2010 (UTC)[reply]

The mention of a flight plan that included bank angles of 60 degrees contradicts the statement in the section "Holland's Behavior." There the article says he had been cited for bank angles of more than 45 degrees. Those high bank angles exceeded the design limits of the airplane.

I don't see this as an inconsistency in the article. I believe this is an inconsistency in the enforcement of flight profile restrictions. Bank angles were officially restricted to 45 degrees, however Lt. Holland did brief a flight profile exceeding these restrictions for the 1994 air show. [1] The fact that the restrictions weren't enforced is is evidence of the breakdown in the chain of command. Boardhead (talk) 16:30, 25 January 2008 (UTC)[reply]

I didn't find a mention that crews had refused to fly with him. Did I miss that?

L K Tucker69.1.46.40 (talk) 22:48, 24 January 2008 (UTC)[reply]

There is a paragraph that begins "After that mission, the crew decided that they would never again fly with Holland". Boardhead (talk) 16:30, 25 January 2008 (UTC)[reply]
There's that. However, roughly half our squadron refused to fly with him. —Preceding unsigned comment added by 87.177.20.134 (talk) 00:17, 13 July 2008 (UTC)[reply]

View spike

Looking at the view history for this article at Wikipedia article traffic statistics, I noticed that there was a huge spike in views of this article around Feb 3 and 4. Anyone know why so many people came to look at this article that particular day? Cla68 (talk) 08:14, 6 March 2008 (UTC)[reply]

I did a quick forum search and didn't find any active articles around that time, but we can't just assume it was people who caused this spike. I have had some pretty outrageous spikes on my web server due to either errant bots or hacker attacks, although typically they are much larger when this happens (1000's of hits per hour, not per day). Boardhead (talk) 14:24, 7 March 2008 (UTC)[reply]
It must be something like that. Interesting. Cla68 (talk) 14:43, 7 March 2008 (UTC)[reply]

Wrong person in the wrong plane?

The article fails to explain Bud Hollands background. How did a personality like him end up in a mud-mover B-52, rather than a fighter plane? This kind of aerobatic attitude is more commonly found and tolerated in fighter jocks. 91.83.18.103 (talk) 20:09, 20 April 2008 (UTC)[reply]

Unfortunately, I didn't find any sources that gave any better background of Holland's life than the sources used, and they only went into his personality and life in how they related directly to the crash. Was he a frustrated fighter-pilot wannabe? His life might make an interesting story if a journalist were to look into it and write it up. Cla68 (talk) 02:16, 21 April 2008 (UTC)[reply]
The reason could simply be the way slots/billets were awarded to his graduating pilot class, which could be based on class ranking, the USAF's needs at the time of graduation, and graduate choice. One does not get a fighter slot simply due to a "fighter mentality." For example, if there were ten graduates and two fighter, two transport, two tanker, and four bomber slots to be awarded, 80% of the slots would be non-fighter slots. If the top two graduates both selected fighters as their first choice, the #3 graduate would not get a fighter, even if he/she had the "fighter mentality." Shawn D. (talk) 13:17, 21 April 2008 (UTC)[reply]
Yes, that's how it works, from what I've heard. From what I understand, the top graduates usually, but not always, select fighters. Bomber slots are next in demand, followed by airlift aircraft and helicopters. I guess Predator slots are in there somewhere now. Anyway, how Holland ended up with a bomber slot, and if he actually wanted to be a fighter pilot, is not detailed in the sources that I found and used. Cla68 (talk) 00:54, 22 April 2008 (UTC)[reply]

Video about the accident in youtube

http://www.youtube.com/watch?v=YQa4PpIkOZU&NR=1

Just thought you guys should know...

Cernex (talk) 23:39, 7 June 2008 (UTC)[reply]

Errant Conclusion

I'm a former member of the 325th Bomb Squadron, and flew with Holland, McGeehan, and Huston several times, and was there during the accident. While I can't mention specifics, I commend the authors of this article, as it's one of the best, most concise reports on the accident I've yet seen.

The last comment in the Conclusion section, however, is in error. It mentions: "The final factor was the 10-knot (19 km/h) tailwind that pushed the steeply banked aircraft into the accelerated stall, resulting in the crash."

The idea of tailwinds pushing aircraft into stalls disappeared in World War I, and can most commonly be found among top ten lists of "don'ts," which includes not hedgehopping and not turning downwind. Ostensibly, the latter can lead to a stall. This is a myth. Turning underpowered, WWI aircraft at any altitude can lead to a stall, as drag is proportional to wing loading, and wing loading during a turn is significantly higher than in straight and level flight. For the underpowered WWI aircraft, it was often sufficient to overcome the full thrust available from the engine, and at low altitude, with no altitude left to recover, often resulted in a stall. It was the turning that stalled the aircraft in WWI, not turning downwind.

While I admire Diehl's other points, this one just isn't so.

Finally, an airplane in flight moves along with the mass of air through which it's flying. It does not matter if it's a tailwind or headwind, or 10 kts or 50 kts. The effect of an airplane moving through a moving mass of air is the same as if the air mass wasn't moving at all. —Preceding unsigned comment added by 87.177.20.134 (talk) 00:15, 13 July 2008 (UTC)[reply]

Myth removed from article.

I've said this before, the statement that the tailwind helped push the aircraft into the accelerated stall comes directly from the USAF's publicly released accident report, a copy of which I used as a reference when writing this article. It doesn't give me a whole lot of heartburn not to have that statement in the article, but to have the Air Force make special note of it in their investigative conclusions and then ignore it for this article doesn't make complete sense to me. Cla68 (talk) 09:02, 13 July 2008 (UTC)[reply]
The fact that the tailwind issue is discussed in a reputable source, by itself warrants its mention in the article; that's how Wikipedia works. If somebody believes that the source is factually wrong, he should quote an equally reputable and verifiable source that says so.
As for the question itself, the tailwind factor described in the USAF report makes engineering sense to me, although the wording is maybe questionable. User 87.177.20.134 says that "aircraft flying through a moving air mass are unaffected by head/tail winds except for their velocity over the ground", but that is precisely the point: the pilot was attempting a 360° around a fixed object, i.e. he was flying using the ground as reference, not the air mass.
If we consider a pilot who wants to perform a 360° around the tower, with wind calm, he only has to bank the wings, establish a co-ordinated turn and then keep all the parameters constants (bank angle, airspeed, altitude, throttle etc.) The result will be a perfectly circular trajectory, centered on the tower.
Now, let's consider the same pilot flying along the same path as above, but with wind blowing. In this case the maneuver will not be as easy as before, because all the flight parameters will need to be continuously adjusted, to compensate for the changing relative direction of the wind (as seen by the aircraft turning around the tower), while keeping a safe margin from stall. That's how the wind (or tailwind) comes to play.
I agree that "the wind pushing the aircraft into a stall" is not an accurate expression, in order to describe the effect of the wind, but the effect itself is not negligible.
Giuliopp (talk) 10:18, 15 July 2008 (UTC)[reply]
Upon reading the quoted USAF report ("Tailwind issue", above), I see that indeed the explanation of the wind as a factor is rather inaccurate, at best; in particular its comparison with a "decreasing performance windshear". A windshear is totally the opposite to a wind that is "fairly constant in velocity", as the report itself says. The wind "turned" from headwind to tailwind only because the aircraft was turning, as User 87.177.20.134 correctly says, but that would not affect the aircraft performance per se. In conclusion, I would mention the wind as a contributing factor (and I agree that it was), but avoiding the explanation in the terms contained in the report. I've reworded the sentence to something more generic but not less correct.
Giuliopp (talk) 00:32, 16 July 2008 (UTC)[reply]
Thank you for your efforts to sort out this issue. Cla68 (talk) 05:11, 16 July 2008 (UTC)[reply]
If you want to know why not to turn downwind and try and get back to the airfield after engine failure on take-off watch this: [2] — Preceding unsigned comment added by 80.4.57.101 (talk) 18:46, 29 January 2012 (UTC)[reply]
The cause of the Fairchild B-52 accident is fairly apparent when watching the various videos on YouTube - the pilot allowed the airspeed to decay beyond a safe level as he entered the final turn, and in addition he then tightened the turn to the point that as the aircraft entered a downwind direction the aeroplane, already flying very near the stall through the turn, stalled and the nose dropped. One of the difficulties when displaying an aeroplane (the flight was a practice for an air display) at low levels is that because one is so near to the ground one's attention is concentrated outside the cockpit, such that, in the absence of a HUD, it becomes very difficult to make any sort of constant reference to the air speed indicator. This may have lead to the pilot inadvertently allowing the airspeed to decay far more than he had realised when he entered the final turn.
BTW, if you are flying at or very near the stall when heading into the wind, it is almost certain that the aircraft will stall immediately upon turning 180 degrees downwind - that is what happened in the Tiger Moth crash linked above. That is why you don't ever immediately turn back for the airfield when the engine fails on takeoff - you're then turning downwind and, with the aeroplane already at a low airspeed due to being in the climb, the aeroplane stalls because it can't accelerate in relation to the air mass now moving from the opposite relative direction to the aircraft, quickly enough - just like in the Tiger Moth video. Same with a B-52 at or near the stall. Airspeed = Vs + 10kt, equals flying, Airspeed = Vs - 10kt, equals not-flying. A 10kt head- or tail- wind will make that much difference, and it's airspeed that keeps you up, not ground speed. — Preceding unsigned comment added by 80.4.57.101 (talk) 16:18, 24 April 2012 (UTC)[reply]

Proposal to remove date-autoformatting

Dear fellow contributors

MOSNUM no longer encourages date autoformatting, having evolved over the past year or so from the mandatory to the optional after much discussion there and elsewhere of the disadvantages of the system. Related to this, MOSNUM prescribes rules for the raw formatting, irrespective of whether a date is autoformatted or not). MOSLINK and CONTEXT are consistent with this.

There are at least six disadvantages in using date-autoformatting, which I've capped here:

Disadvantages of date-autoformatting


  • (1) In-house only
  • (a) It works only for the WP "elite".
  • (b) To our readers out there, it displays all-too-common inconsistencies in raw formatting in bright-blue underlined text, yet conceals them from WPians who are logged in and have chosen preferences.
  • (c) It causes visitors to query why dates are bright-blue and underlined.
  • (2) Avoids what are merely trivial differences
  • (a) It is trivial whether the order is day–month or month–day. It is more trivial than color/colour and realise/realize, yet our consistency-within-article policy on spelling (WP:ENGVAR) has worked very well. English-speakers readily recognise both date formats; all dates after our signatures are international, and no one objects.
  • (3) Colour-clutter: the bright-blue underlining of all dates
  • (a) It dilutes the impact of high-value links.
  • (b) It makes the text slightly harder to read.
  • (c) It doesn't improve the appearance of the page.
  • (4) Typos and misunderstood coding
  • (a) There's a disappointing error-rate in keying in the auto-function; not bracketing the year, and enclosing the whole date in one set of brackets, are examples.
  • (b) Once autoformatting is removed, mixtures of US and international formats are revealed in display mode, where they are much easier for WPians to pick up than in edit mode; so is the use of the wrong format in country-related articles.
  • (c) Many WPians don't understand date-autoformatting—in particular, how if differs from ordinary linking; often it's applied simply because it's part of the furniture.
  • (5) Edit-mode clutter
  • (a) It's more work to enter an autoformatted date, and it doesn't make the edit-mode text any easier to read for subsequent editors.
  • (6) Limited application
  • (a) It's incompatible with date ranges ("January 3–9, 1998", or "3–9 January 1998", and "February–April 2006") and slashed dates ("the night of May 21/22", or "... 21/22 May").
  • (b) By policy, we avoid date autoformatting in such places as quotations; the removal of autoformatting avoids this inconsistency.

Removal has generally been met with positive responses by editors. Does anyone object if I remove it from the main text in a few days on a trial basis? The original input formatting would be seen by all WPians, not just the huge number of visitors; it would be plain, unobtrusive text, which would give greater prominence to the high-value links. Tony (talk) 08:55, 21 July 2008 (UTC)[reply]

Dead link

During several automated bot runs the following external link was found to be unavailable. Please check if the link is in fact down and fix or remove it in that case!

--JeffGBot (talk) 02:26, 8 June 2011 (UTC)[reply]

Dead link 2

During several automated bot runs the following external link was found to be unavailable. Please check if the link is in fact down and fix or remove it in that case!

--JeffGBot (talk) 02:26, 8 June 2011 (UTC)[reply]