McDonnell Douglas F-4 Phantom II

KJ_Lesnick

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From numerous sources, it would seem the F-4 Phantom had a somewhat heavily-loaded wing (medium, medium-heavy).

I'm not saying I dispute this as the F-4's performance obviously reflects it, but I am wondering how an aircraft with such large wings, which appear to be substantially cambered, fairly thick for a supersonic design, and not exactly razor sharp at the leading edge (all things that generally reflect a high L/D ratio) would yield a somewhat heavily-loaded wing?


KJ Lesnick
 
KJ_Lesnick said:
From numerous sources, it would seem the F-4 Phantom had a somewhat heavily-loaded wing (medium, medium-heavy).

I'm not saying I dispute this as the F-4's performance obviously reflects it, but I am wondering how an aircraft with such large wings, which appear to be substantially cambered, fairly thick for a supersonic design, and not exactly razor sharp at the leading edge (all things that generally reflect a high L/D ratio) would yield a somewhat heavily-loaded wing?


KJ Lesnick

Wing loading is simply the weight divided by wing area. Things like camber, leading edge design etc. to enter into it.
 
Well I meant L/D ratio vs speed and such, not necessarily just wing-area vs weight.
 
F-4 had a reasonable wing loading for its era and mission. It had a relatively high wing loading compared to a MiG-17 perhaps, but that's rather irrelevant, they are planes from different eras, and it didn't seem to help the MiG-17's poor kill ratio.
 
KJ_Lesnick said:
From numerous sources, it would seem the F-4 Phantom had a somewhat heavily-loaded wing (medium, medium-heavy).

I'm not saying I dispute this as the F-4's performance obviously reflects it, but I am wondering how an aircraft with such large wings, which appear to be substantially cambered, fairly thick for a supersonic design, and not exactly razor sharp at the leading edge (all things that generally reflect a high L/D ratio) would yield a somewhat heavily-loaded wing?


KJ Lesnick

Among other things, a well-designed fighter aircraft should have moderate wing loading (between sixty and seventy-five pounds per square foot,
and a high thrust-to-weight ratio.
Aircraft engines from the Vietnam era produced combat thrust-to-weight ratios ranging from 0.75:1 for the F-105 Thunderchief ( with a W/S=91) to
0.87:1 for the F-4 Phantom II.
F-4B/C had a wing loading of 86,
The F-4E had a wing loading of 101,
The wind tunnel models (5%scale) tested at NACA/NASA had a wing loading of 65.
Advances in material technologies and turbojet engine design allow modern fighter aircraft, such as the F-15 Eagle and the F-16 Falcon, to have
thrust-to-weight ratios of equal to or greater than 1:1.Thrust-to-weight ratio governs an aircraft's acceleration and climbing performance.
An aircraft with a 1:1 thrust-to-weight ratio can maintain vertical flight. If the thrust-to weight ratio exceeds 1:1, the aircraft can accelerate in vertical flight.
 
Cat-Shot,

Among other things, a well-designed fighter aircraft should have moderate wing loading (between sixty and seventy-five pounds per square foot,
and a high thrust-to-weight ratio.

What is considered to be a light wing-loading then if 60-75 lbs/ft^2 is moderate?

Aircraft engines from the Vietnam era produced combat thrust-to-weight ratios ranging from 0.75:1 for the F-105 Thunderchief ( with a W/S=91) to
0.87:1 for the F-4 Phantom II.
F-4B/C had a wing loading of 86,

I assume W/S means something to the effect of wing-loading?

Are you talking about the wing-loading that you'd see on the F-4 in an air-to-air configuration? Or are you talking about a fully loaded Air-to-Ground set-up? I wouldn't have thought, even fully loaded that the F-4B/C had a wing-loading so close to the F-105 who's wings were absolutely tiny...

The F-4E had a wing loading of 101,

I thought the F-4E weighed the same as the F-4C? 101 lbs/ft^2 is higher than even the F-105...

The wind tunnel models (5%scale) tested at NACA/NASA had a wing loading of 65.

Why such a huge difference? Was this based on the weights encountered in air-to-air missions, or did they make some kind of a mistake?

Thrust-to-weight ratio governs an aircraft's acceleration and climbing performance.
An aircraft with a 1:1 thrust-to-weight ratio can maintain vertical flight. If the thrust-to weight ratio exceeds 1:1, the aircraft can accelerate in vertical flight.

This I am aware of
 
overscan said:
F-4 had a reasonable wing loading for its era and mission.

Indeed, the F-4 had to manage a minimally acceptable approach speed for carrier landings, while accomplishing supersonic performance that was the equal of any land based type. I really can't imagine how a lower wing loading could have been accomplished at the time, as the F-4 design appears to have been a near optimal compromise, given the technology of the time. A larger conventional wing would have reduced performance, while a smaller wing would have increased an already marginal 150 knot approach speed. Obviously, it was too soon for variable geometry, and a delta wing would have been unworkable for a number of reasons.
 
I don't know why, but it just boggles my mind that a wing of that size, with some camber, apparently reasonable thickness, and the fact that it doesn't have the sharpest leading edge (which generally is favorable for low-speed handling) would behave like it did, and especially the fact that it needed not just trailing edge flaps with blown air, but leading-edge devices with blown air.

Maybe I'm missing something, but...


KJ Lesnick
 
wing loading is just a basic parameter to get an impression , to make quick calculations . Bf-109 in early models could nearly match contemporary Spits and Hurricanes with its De Havilland patented leading edge devices , ı forgot what they were called . And similarly a P-47 wing would give the same wing loading on the F-16 since it has the same area but times change .
 
R-16,

Yeah, but I'm not talking about comparing a 1940's plane to a 1950's plane. I'm comparing two 1950's era planes (The F-105 and F-4). One has a wing-area of 565 square-feet and the other has a wing-area of 385 square feet, and yet they have wing-loadings that are surprisingly close...

KJ Lesnick
 
The F-105 and F-4

But the F-4 is rather heavier than the F-105 so the lifting force produced by the wing must be bigger to support it, which generally means a bigger wing.
 
Wing loading is weight divided by wing area. I fail to see how this can be difficult to understand. If one plane has smaller wings but weighs less its wing loading can be identical to a plane with larger wings but heavier.
 
not that anybody asked for it , but let me offer what ı think . It is probably a mental exercise that forms the basis of this discussion ,which might be about whether it was possible to make a better Phantom or to improve it later ,say like at the F-4E/J period etc etc . ı don't know , am just speculating .

aircraft design is a confusing mess of various disciplines and as one might have to live with the results for decades , utmost care is needed to make sure that what you decide to produce ends up good , which calls for long and careful analysis . But of course you have to start somewhere , from a fixed point so that you can examine the alternatives . ı will speculate , without any evidence but by just a personal belief that the fix in the case of F-16 was the wing . Aspect ratio of 3 , thickness ratio of 4 , area of 300 square feet ; they probably took a wing that was throughly researched and known ( maybe as an academic endeavour ) and built the Falcon around it . ı can visualise a couple of people looking at a chart that said at this speed , the wing produces that much lift and the projected weight means lots of performance is lost so they decide to build a 9G airframe instead of the 7.33 costumary and required . Because the wing can be useful up to a higher AoA than the standarts of the day , they decide to use the underbelly inlet instead of a more costumary side bifurcated or a F-8 like nose inlet solution .( The most common and - ı hasten to add - realistic explanation is Harry Hillaker pruned the nose and the tail area to save weight and drag but ı am r16 ; ı have a reputation to maintain .) The result cuts down the space for the underbelly pylon or threatens more FOD risk and forms a flat underbelly that makes the cockpit bulge , which causes the seat to be angled to nearly twice of usual to cut down the increased drag but in the end the engine can cope with anything so it is left raised for visibility concerns . And so on .

on the other hand the fix for the Phantom of 1958 is without doubt the preceding Voodoo / Demon series . Now , ı have this Casio FX-3600P pocket calculator which ı think first came to know in about '88 and bought one of my own in 1990 , when ı thought ı might hack being an industrial engineer . Having failed , ı use the thing for calculating household bills . If there was a way of moving that calculator back to '58 , ı would be very rich or very dead . Another way of saying that the engineers of that were limited in the way of tools they could use . Basing their new designs on the experience they had was necessary to avoid surprises and Russians were masters of the evolutionary approach .ı think it is possible to say that Su-15 is a descendant of the Mig one . One of the most revolutionary western companies , Lockheed started U-2 from the F-104 .

returning to F-4 the wing might also be compromised for the need to have the fuel volume to feed the J-79s . According to a cutaway ı have the integral tanks in the wings form nearly 34% of the internal fuel load of an F-4E . In the previous models assuming everything was similar apart from the 318 lt # 7 tank put on the Es the ratio would climb up to 35.5. And as USAF versions needed bulges to house thicker wheels the wing was probably not "thick enough" . So , checking wing profiles from the period and discussing why this profile was chosen instead of that might not be exactly fair .

it might already been pointed through PMs but the ( W / S =91 ) value given for the F-105 means Weight divided by Surface area of the wing gives 91 pounds per square feet . 101 pounds per square feet of the Phantom works out to 24280 kg which ı would believe to be an air to air take off weight probably with external tanks . ı remember the air combat weight for a Phantom as 19400 kgs ( with 4 sparrows and half internal fuel ) and that would be about 81 pounds per square feet . The 86 given for B/C variants might be calculated through other assumptions . Boyd et all preferred using 100% internal fuel . Regarding 65 pounds on the 5% windtunnel models , the reason is probably the models are hollow inside and are not fully representative of an aircraft . But ı can't guarantee of being right on that either .ı have seen it in a Bill Gunston book that objects grow in weight much faster than in dimensions .Growing everything exactly same a twice longer plane should have 4 times the wing area but be 8 times heavier . 530 sqfeet wing area on the real plane should be 1.325 on a 5 percent model which then would give 86 pounds of weight for the test article , multiplied by 20 x 20 x 20 , the end result would by be 689 000 pounds .All calculations through my beloved Casio . Well , it seems the windtunnel models were solid instead of hollow . In any case the models could not be fully equal to a full size aircraft .

and rereading my previous post ı think the leading edge devices on the Messerschmitt were patented by Handley Page .
 
Was the F-4's wing reasonably efficient at supersonic speeds? (It's hard to tell because of the camber and the sweep angles...) I'm just wondering if it could hold a supersonic speed (even if a fairly low one) without it's afterburners, because the F-106A, which was considered similar in performance could do this from what I've been told.

KJ Lesnick
 
I only have about 1,000 hours in the F-4 and even clean (double underlined) I doubt if it would stay super without burner. Hang anything on it and NO WAY! As to the Cadilac (106), maybe if you got it super in burner it would stay that way in mil, but it wasn't going super without help from the burner or trading off altitude.
 
John Hay, Civil Lord of the Admiralty in 1963-1964, said on 2 March 1964 that "Our present information and advice is that the aircraft should be able to operate from "Hermes" after she has undergone her refit."

http://hansard.millbanksystems.com/commons/1964/mar/02/vote-a-numbers#S5CV0690P0_19640302_HOC_423

Mr. Hay

(snip)

I was asked how many Phantoms we intended to buy and how much the aircraft would cost. I shall not give either the cost or the total numbers. I cannot divulge this information, because it would not be in the public interest and it would be contrary to precedents. I can say a little about the phasing out of the Sea Vixen which the Phantom, if we get it, will replace. We expect the Sea Vixens to be phasing out between the end of the 1960s and the early 1970s. The last carrier to operate Sea Vixens will be "Ark Royal". Phantoms will be operated from "Hermes", "Eagle" and the new carrier when it is built. I say "Hermes", because I made a slip of the tongue when I was interrupted earlier, in my first speech.

The Committee will recollect that I said that we were proposing to embark on a programme of technical evaluation, and one of the things about which we shall have to be completely satisfied is that the Phantom II will be able to operate from these three carriers. Our present information and advice is that the aircraft should be able to operate from "Hermes" after she has undergone her refit.

The hon. Member for Dudley and the hon. Member for Islington, North talked about the engine of the Phantom. The purpose of fitting the Spey engine is to get not a lower, but a better performance. That is why we want the Spey engine, not because we have some special national pride which we wish to satisfy but because we believe and are advised that with the Spey engine the Phantom II will have a better performance than it has now. This is the whole object of the operation and I ask the Committee to accept that.

Mr. Reynolds

According to the hon. Gentleman, it is safe to operate the aircraft with a more powerful engine from a 23,000-ton aircraft carrier, and yet Mr. McNamara has said that it cannot be operated safely with its present engine from a 31,000-ton aircraft carrier. The hon. Gentleman must have seen that speech.

Mr. Hay

I have a great respect and admiration for Mr. McNamara—as I believe every hon. Member must have—but I find it a little galling, whenever I say something at this Box, constantly to have Mr. McNamara's speech to Congress thrown in my face. I have told the Committee that the advice and information we have from those experts upon whom we are entitled to rely is that this aircraft could operate from "Hermes" and the other two carriers that I have mentioned. I must ask the Committee to accept that from me. I cannot be drawn into arguments about what Mr. McNamara has told Congress.

==========

Attached picture shows a USN F-4B Phantom doing touch-and-go on the Hermes.

Found at http://www.axfordsabode.org.uk/pdf-docs/hermes14.pdf
 

Attachments

  • hermes_F4_touch_and_go.JPG
    hermes_F4_touch_and_go.JPG
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I always find this one a bit suspect, though of course nothing is impossible, just difficult.
In this instance since we know the F4K could take off using the mk4 151ft stroke catapult, the critical issue is landing safetly and here the short length of Hermes recovery strip strikes me as the chief problem.
Do-able, but.........but at what weight. Key question that one.
Still even if they do, Hermes is rather marginal for a machine of such needs, there where a number of limitations in 'ready to use' weapons storage and I suspect other such 'shaft of the spear' issues would lurk in Hermes.
How many F4K's would they consider for her?
Touch and go excercises are not the same as actual recovery. As was, USN F4s did do some such excercises but I imagine they reserved the idea of actualy landing on Hermes to emergency only.
 
Look at the date 1963/64 Zen, at the time the Phantom was being flogged as the super new generation naval interceptor, specs were still based on the manufacturers data so whould have replaced the USN Crusaders & other fighters on both the Supercarriers and the Essex class, the RN still saw it as an ideal replacement for the Sea Vixen and don't forget the RAN were looking at it for use on Essex to replace the Melbourne.

Sometime in 1964 the USN let the truth be known that its wasn't quite as good as was made out and as reality kicked in expectations dropped. :(
 
True, they did overhype it if my memory of reading goes.

Might have been ok if they'd kept a lot of kit off the beast, but the tendancy of the times is to pile on the weight.

Still this one is now going to crop up elsewhere and all sorts of hyperbole will be forthcomming.
 
Hermes was too small for Phantoms, as this picture of the only one to ever land on it shows:
https://lh4.googleusercontent.com/_8XAc95JQygs/TcIJ9stDu9I/AAAAAAAABIo/PeGozocwxSs/2.jpg

;D

But seriously, I recall seeing at Kew a fair bit of discussion justifying the use of Speys on the basis that without them Phantoms could not launch from Hermes. There was also a discussion around how Hawker were 'having their feet held to the fire' regarding the folded width of the P.1154RN (22ft max), while the Phantom was 27ft. The difference reduced hangar capacity by a third, assuming the same length, which on Hermes meant hardly any could be carried.
 
Now concentrate Michael,

That Phantom is very big. That Hermes is far away.

Ted

Apologies to Graham Linehan
 
Its not the take off thats really the problem here, but the recovery.
Hermes made less speed than Ark Royal, or Victorious and had a shorter length of recovery from 'undershoot' (ramp in US parlance) to the end of the angled deck. Let alone the matter of pull out distances from wire 1. You'd have to accept a harder decceleration which would tell on the airframe's life, wires, and on the arrestor machinary.
22ft was pushing things as it was, if memory serves Centaur class hangers where 62ft wide rather than 67ft. Once you factor in the spacing they really ought to be demanding 18ft folded width.
 
I guess they could make an updated version of this short film to promote the F-35. Perhaps make it feel a bit more loved in certain quarters. Just a thought...!

"This is a weapon system...it is the property of..."
 
I am researching the many models of the F-4 Phantom II (both made and proposed) and trying to document and make drawings of many of them. I have a problem that I can't find any information on a feature that was proposed, and must not have been implemented.
On the Israeli Kurnass 2000 it had first been proposed that they would have canards on the intakes, but later that was changed to fixed strakes rather than full canards. But for the life of me I can't find a picture or drawing showing the strakes. This feature was also to be included on the Terminator 2020 upgrade, but there again I find no picture showing strakes on the upper intake. Does anyone have any information on this? I would appreciate the help. I am amazed at what this group comes up with.
 
Have you had a look at these books?

photo_zps83674372.jpg

photo_zps053bc68e.jpg



They have a lot of detailed drawings.
 
GTX said:
Have you had a look at these books?

They have a lot of detailed drawings.

I have not, they look great. Any idea where I can get them in the USA? I have searched for them and all I get are hobby shops elsewhere.
Thanks for the information though.
 
Has anyone found any information on this, as I don't have anything on it in my information on the F-4. Then again, I don't have a POH of it either.
 
Does anybody know anything about a version of the F-4 titled the "Strike Phantom"? I discovered it being mentioned on the Hush Kit blog:

McDonnell Douglas responded with a ground attack optimised F-4 Phantom II in the early 1970s. Primarily aimed at the European market, this impressive aircraft was fitted with TFR, FLIR and a laser target designator. A fuselage ‘plug’ and uprated engines gave the new Phantom impressive range/payload performance. The aircraft was dubbed ‘Strike Phantom’.
[Source]

Ideally a three view drawing would be nice but something describing where the stretch was and what it consisted of will do. Anybody with any information?
 
It happened to a French Crusader pilot, from a land base... he lifted off, found that the aircraft "behaved a little bizarre" landed only to be told the entire flight had been done with the wing tips folded. No kidding.


 
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The addition of LERX for vortex lift probably would've made the wing much more effective as alpha rose, but would require a revised intake structure to handle the loads involved (and with it more weight). Not sure if the Phantom's wings were of high enough sweep to create a substantial enough vortex as with "proper" higher sweep deltas a la the Mirages, MiG-21 and F-106. The flat fuselage bottom of the F-4 I suspect created quite a bit of body lift, like on the F-5 and the teens series, so true wing loading becomes a bit dubious to actually calculate. Of course deltas and LERX reliant semi-deltas like the Viper need lots and lots of thrust to maintain energy in high alpha maneuvers because of all the induced drag. Kill the thrust, kill the energy-maneuverability.

And in the end, the F-4's performance could be "fixed" with more thrust as with the PW1120 equipped Kurnass 2000, benefiting all regimes of flight.
 
plus it was extremely sleek and beautiful one of the cutest interceptors to ever grace the skies...
 
It happened to a French Crusader pilot, from a land base... he lifted off, found that the aircraft "behaved a little bizarre" landed only to be told the entire flight had been done with the wing tips folded. No kidding.

Taking off with the wings folded has been done a fair few times, even more than the events detailed in the links. Given that folding wing outer panels are now seeing application beyond carrier aviation, I wonder when the first commercial aircraft will add to the list?
 

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