Flight characteristics of full size Douglas Skyray ?

[dvint]

This plane seems to have been phased out quickly by the Navy.Any problems?

[vintage1]

wasn't that good I think.

Did hold the world speed record briefly...

IIRC

Lots of things make a plane less than totally successful.

[BMatthews]

It was also a wild and crazy time for designs of airframes, engines and weapon systems and the expectations of all of those systems. Any one of those four factors can account for a shorter operational life.

Do a search for material on it?

[Sparky Paul]

The F8 Crusader shortened the service life of the Ford.
420 were produced, which is a good number for that time.
I recall seeing a dogfight between F-86s and F4Ds over northeast Wash DC in 1956.. only time I can think when I saw any of the F4Ds.

[Thomas B]

Phil Oestricher, YF-16 flight "0" test pilot, local modeler and all around nice guy speaks fondly of the old Skyray,which he flew as a Marine pilot before coming to work for General Dynamics.

It did hold the world speed record for 5 years...no small feat.

Technology left the Skyray behind, much as BMatthews mentions.

The text below, from
http://www.vectorsite.net/avskyray.html
does a good job of summing up the Skyray issues that lead to it's fairly short service life:

[3] SKYRAY IN SERVICE
* In service, the F4D-1 was nicknamed the "Ford" due to its "eff-four-dee" designation. Although the delays in development ensured that the Skyray had a short operational history, pilots really admired its capabilities. It had a terrific rate of climb; following some informal climb trials by Bob Rahn in a production Skyray in 1955, Marine Major Edward N. LeFaivre used the Ford to establish a set of world climb records in May 1958.

It was also very maneuverable, featuring an incredible rate of roll, and one Navy test pilot who flew the Skyray said that Air Force chase-plane pilots were desperate to find a USAF machine that could out-turn it. Air Force pilots flew the F4D, no doubt with an eye to assessing its strengths and weaknesses. It did have weaknesses, significant ones. Along with its agility came a degree of instability, particularly in the critical transonic speed range. This does not seem too surprising given the aircraft's aspect in the top view, which suggests some of the aerodynamic features of a pancake; it also had a steep glide ratio, being described as a "lead sled".

One pilot said the Ford's handling "bordered on the bizarre." In fact, there were some test pilots who despised the F4D and felt it should have never been accepted into operational service. This appears to have been a minority opinion, but even its admirers admitted the Ford's instability made it a handful for a relatively inexperienced pilot. Skilled pilots who liked the machine also found it tiring to fly for long distances: keeping it on the level was a continuous balancing act. Of course, modern digital fly-by-wire flight control systems would have tamed the Skyray, even exploited its instability to optimize maneuverability, but such things were almost unimaginable in its day.

Stability is regarded as a good feature for carrier landings, and getting a Skyray on deck could be tricky, one pilot saying that was where "the Ford really got your attention." It tended to "skid out" when the landing gear was lowered, because one main gear would drop before the other. Another Skyray pilot commented on watching one of his colleagues make "seven unsuccessful passes at the deck. We thought we might have to shoot him down, but on the eighth attempt he landed." The F4D-1 had a high AOA on its critical carrier approach, but pilots claimed the forward visibility was excellent and that was not such a problem.

Takeoffs could be tricky -- the main gear didn't go up together, either, causing the aircraft to skid out again -- though once pilots got used to the Ford, they didn't have a problem with it. However, it was regarded as something of an amusement to watch green pilots try to get it off the deck. In general, it seems that the Ford's eccentricities were not regarded by most pilots as anything all that threatening, and those who enjoyed flying the machine said its idiosyncracies helped make it fun to fly.

The F4D also had a number of difficulties common among jet fighters of its generation. The cockpit was an ergonomic slum; this was not unusual in those days, the term "ergonomics" having hardly been invented, but pilots complained that the stick blocked the view of the radar display, evidence of the fact (obvious to anyone who's ever worked in a development environment) that engineers can be clueless at times. To add to the embarrassment, the simple solution to the problem was provided, not by Douglas engineers, but by a Navy ground crewman who was clever with his hands. He lifted two small mirrors from his wife and fitted them into a cardboard frame to build a periscope so the pilot could actually see the radar screen over the top of the stick. This scheme worked so well that the Navy ordered construction of a formal periscope with a plastic housing, and installed them in Fords in service as standard gear.

The F4D's range left something to be desired -- it was always flown with external tanks -- and the reliability of its subsystems was poor. For example, although pilots praised the radar, it tended to be broken a good part of the time. One pilot observed: "It had a good many things in the cockpit that never worked and indeed could not be maintained ... this was typical of the analog era. Now when you step into an F-18, everything works nearly all the time." In addition, although the landing gear was very solid, the airframe itself was a fairly high-maintenance item.

Pilots had no confidence in unguided rocket packs for interception. The folding-fin rockets jinked around like crazy until the fins deployed, and the usual comment was "it was a wonder anybody could hit anything with them." Attacks on target drones apparently bore this out. The Sidewinder AAM was a big step in the right direction, but as Vietnam would prove, the Sidewinder needed some work to be turned into the "wonder weapon" it was promoted as being.

A total of 420 Fords were built by the time production ended in December 1958. It never saw any real combat service and there were no export users, though Douglas did demonstrate the type to potential buyers, including the government of India. The type was redesignated "F-6A" when the US military consolidated aircraft designations in September 1962, but by this time the Skyray was increasingly being shunted off to the reserves. In 1962, a few were fitted out as target drone controllers and redesignated "DF-6A".

The Skyray was completely phased out by the end of the 1960s. One of its last duty posts was at the Navy Test Pilots School, where it was used to give students familiarity with how an unstable aircraft flew. One cynic also said that the school held on to its Skyrays for so long simply to hammer in the lesson: "Don't ever buy another one like this airplane." However, the Ford appears to be remembered with some affection, tempered by an awareness of its peculiarities and the realization that it probably wasn't the best combat aircraft the Navy and Marines ever flew.

[JRuggiero]

There was also an F5D Skylancer version, with uprated engine thrust, reinforced skin, and 8-foot longer, area-ruled fuselage. But the improvements were too little, too late. It was canceled after four were built, being replaced by Vought's F8U crusader.

Jim R

[dvint]

Thanks for the abundant info.
Dvint

[supercorgi]

Roll rate was astounding with the Skyray, I saw a quoted 800+ degrees per second, building up a fearsome inertia. Climb rate was also stellar, a high AoA limit giving some upperhands over more conventional types if you progressed into a scissors type of fight, perhaps not ideal though as you would end up rather slow in a hurry.

It really would've been interesting to see how it would've done against Mig 15s and 17s, say over the Straights of Taiwan.

[vintage1]

I've always been astounded by the slight difference that makes a basically reasonable product into a dud.

The history of aircraft and indeed cars shows that what happens is that either some niggling faulty makes a plane basically unuseable, or a happy coincidence of factors makes one great.

A lot depends on what else is around. In the UK teh 'rep car wars' - the battle for the company fleet market - swung between Ford and GM for years. One year the car to have was the GM offering: it was slightly better, slightly more reliable and slightly cheaper..then Ford came out with an ugly thing..but it was slightly better,slightly more reliable and slightly cheaper - and the pendulum swung..form about an 80/20 split in favour of GM to an 80/20 split in favour of Ford.


In all cae teh opposition wasn't at all bad, it was just not quite as GOOD.

I WWII the real success story was the hurricane. Slightly slower, slightly less manouverable than the spitfire, but sturdy, easy to build in great numbers, stable and capable of carrying good loads and so on.

Then post war I remember the Supermarine Swift, and the Hawker Hunter. Both looked very similar, but the Swift had flaws..and was consigned to low level duties and phased out,. whilst the Hunter went on for many years and was sold all round the world.

Likewise the Mirage, - an adaptation of the Fairy Delta concept - became a top seller everywhere as well.

Why is it that the Douglas DC3 an to an extent the DC2 still soldier on, but the DC4,5, 6 and so on languish?

The devil is usually in the detail. In that case I suspect that the DC4 and onwards were just too big and too complicated,: The DC3 works because it is easily run off short airstrips and is simple to fix in third world countries.

If you have space for a DC4 and that kind of traffic level, its probably cheaper to run a jet or turboprop..

[macboffin]

Have seen a duct-fan Skyray flying, no problems, could get crazy slow at high angle of attack for landing.It was light ; suspect that was why it flew so nicely.

[Geoffinpdx]

If you had actually seen a Skyray in flight, as I have, you would initially wonder whether it was an airplane or some sea creature out of its element, it's so startlingly organic looking.

Smithsonian Air and Space Magazine had a feature story on it some while ago.
http://www.airspacemag.com/issues/2006/june-july/skyray.php

If you're a west-coaster, stop by the Pima Air & Space Museum in Arizona. They've got one - and a whole lot of other neat birds!

[vintage1]

Excellent article. Thx

[flieslikeabeagle]

A little over a year ago I made a simple RC "Sorta Skyray" with a flat-plate wing and the foam fuselage from a $5 chuck glider to fly at the park. It flew well, and those beautiful moth-like wings attracted plenty of attention. Even though I made little attempt to put in any sort of scale details, people who knew of the Skyray / F4D had no trouble recognizing it - that wing planform is pretty unique.

I had a rudder in my Sorta Skyray, and during low speed turns it worked very well, allowing the pilot to make nice smooth coordinated turns. At high speeds it was better not to use the rudder or to barely nudge it: if you pushed the rudder over at speed, the model would do a quick roll! With the drastic wing sweepback angle, there was quite a strong coupling between yaw and roll.

If anyone wants to make their own, here's the thread:
http://www.rcgroups.com/forums/showthread.php?t=562053

Around the same time another RCG user (Corsair Nut) designed and built a Depron or FFF Skyray, and did a thread in the Pusher Jets forum. His version is much prettier and much closer to scale than mine, but also a much more complex build.

-Flieslikeabeagle